WorldWideScience

Sample records for jupiter neptune uranus

  1. Uranus and Neptune: The distant giants

    International Nuclear Information System (INIS)

    Burgess, E.

    1988-01-01

    The history of observations and probe missions to the outer planets is reviewed, and major results are summarized, in an overview for general readers. Consideration is given to Voyager images of the Uranian satellite Miranda; the ring system of Uranus; zonal bands on Jupiter, Saturn, and Uranus; the Voyager instruments, mission profile, and ground support system; Saturn and its satellites; the discovery of Uranus by Herschel; the surface and atmosphere of Uranus; and theoretical models of the Uranian interior structure. Also discussed are the discovery of Neptune by Galle and d'Arrest, ground-based knowledge of Neptune and its satellites, the discovery of Pluto, and the possible existence of additional planets. Extensive diagrams, drawings, and photographs are provided

  2. Scientific rationale for Uranus and Neptune in situ explorations

    Science.gov (United States)

    Mousis, O.; Atkinson, D. H.; Cavalié, T.; Fletcher, L. N.; Amato, M. J.; Aslam, S.; Ferri, F.; Renard, J.-B.; Spilker, T.; Venkatapathy, E.; Wurz, P.; Aplin, K.; Coustenis, A.; Deleuil, M.; Dobrijevic, M.; Fouchet, T.; Guillot, T.; Hartogh, P.; Hewagama, T.; Hofstadter, M. D.; Hue, V.; Hueso, R.; Lebreton, J.-P.; Lellouch, E.; Moses, J.; Orton, G. S.; Pearl, J. C.; Sánchez-Lavega, A.; Simon, A.; Venot, O.; Waite, J. H.; Achterberg, R. K.; Atreya, S.; Billebaud, F.; Blanc, M.; Borget, F.; Brugger, B.; Charnoz, S.; Chiavassa, T.; Cottini, V.; d'Hendecourt, L.; Danger, G.; Encrenaz, T.; Gorius, N. J. P.; Jorda, L.; Marty, B.; Moreno, R.; Morse, A.; Nixon, C.; Reh, K.; Ronnet, T.; Schmider, F.-X.; Sheridan, S.; Sotin, C.; Vernazza, P.; Villanueva, G. L.

    2018-06-01

    The ice giants Uranus and Neptune are the least understood class of planets in our solar system but the most frequently observed type of exoplanets. Presumed to have a small rocky core, a deep interior comprising ∼70% heavy elements surrounded by a more dilute outer envelope of H2 and He, Uranus and Neptune are fundamentally different from the better-explored gas giants Jupiter and Saturn. Because of the lack of dedicated exploration missions, our knowledge of the composition and atmospheric processes of these distant worlds is primarily derived from remote sensing from Earth-based observatories and space telescopes. As a result, Uranus's and Neptune's physical and atmospheric properties remain poorly constrained and their roles in the evolution of the Solar System not well understood. Exploration of an ice giant system is therefore a high-priority science objective as these systems (including the magnetosphere, satellites, rings, atmosphere, and interior) challenge our understanding of planetary formation and evolution. Here we describe the main scientific goals to be addressed by a future in situ exploration of an ice giant. An atmospheric entry probe targeting the 10-bar level, about 5 scale heights beneath the tropopause, would yield insight into two broad themes: i) the formation history of the ice giants and, in a broader extent, that of the Solar System, and ii) the processes at play in planetary atmospheres. The probe would descend under parachute to measure composition, structure, and dynamics, with data returned to Earth using a Carrier Relay Spacecraft as a relay station. In addition, possible mission concepts and partnerships are presented, and a strawman ice-giant probe payload is described. An ice-giant atmospheric probe could represent a significant ESA contribution to a future NASA ice-giant flagship mission.

  3. On the detection of magnetospheric radio bursts from Uranus and Neptune

    International Nuclear Information System (INIS)

    Kennel, C.F.; Maggs, J.E.

    1975-11-01

    Earth, Jupiter, and Saturn are sources of intense but sporadic bursts of electromagnetic radiation or magnetospheric radio bursts (MRB). The similarity of the differential power flux spectra of the MRB from all three planets is examined. The intensity of the MRB is scaled for the solar wind power input into a planetary magnetosphere. The possibility of detecting MRB from Uranus and Neptune is considered

  4. Possibility of detecting magnetospheric radio bursts from Uranus and Neptune

    International Nuclear Information System (INIS)

    Kennel, C.F.; Maggs, J.E.

    1976-01-01

    It is known that Earth, Jupiter and Saturn are sources of intense sporadic bursts of electromagnetic radiation, known as magnetospheric radio bursts. These bursts are here described. It is thought that the similarities in the power flux spectra, together with the burst occurrence patterns, suggest a common physical origin for these bursts in all three planets. The common mechanism may be noise amplification by field aligned currents, since it has been shown that the Earth's MRBs are associated with bright auroral arcs that involve intense field aligned currents. Such currents result from the interaction of the solar wind with the magnetosphere and should be a general feature of the interaction between the solar wind and planetary magnetospheres. If MRBs are produced by solar wind-magnetosphere interaction their total radiated power might scale with the solar wind input into the magnetosphere, and it has been suggested that the frequency of emission scales with the polar magnetic field strength of a planet. The intensity of MRBs is here scaled to the solar wind input and the frequency of emission to the polar field strength with a view to estimating the possibility of detecting MRBs from Uranus and Neptune. It is found that scaling of MRB power to the solar wind-magnetosphere dissipation power is probably a reasonable hypothesis. It is suggested that detection of MRB bursts from Uranus and Neptune might be a reasonable radioastronomy objective on future missions to the outer Solar System. (U.K.)

  5. Uranus, Neptune, Pluto, and the outer solar system

    CERN Document Server

    Elkins-Tanton, Linda T

    2010-01-01

    Unlike all the planets closer to the Sun, known since antiquity, the farthest reaches are the discoveries of the modern world. Uranus was discovered in 1781, Neptune in 1846, Pluto in 1930, the Kuiper belt group of objects in 1992, and though the Oort cloud has been theorized since 1950, its first member was found in 2004. The discovery of the outer planets made such an impression on the minds of mankind that they were immortalized in the names of the newly discovered elements: uranium, neptunium, and plutonium, an astonishingly deadly constituent of atomic bombs. Uranus, Neptune, Pluto, and t

  6. Absolute spectrophotometry of Titan, Uranus, and Neptune 3500-10,500 A

    Science.gov (United States)

    Neff, J. S.; Humm, D. C.; Bergstralh, J. T.; Cochran, A. L.; Cochran, W. D.; Barker, E. S.; Tull, R. G.

    1984-01-01

    The present absolute measurements of Titan, Uranus and Neptune geometric albedo spectra in the 3500-10,500 A range have a resolution of about 7 A, together with high SNR, in virtue of the exceptional effeciency of the spectrograph and Reticon detector employed. The high precision and spectral resolution of the data, which are in excellent agreement with the Uranus albedo measurements of Lockwood et al. (1983), make possible quantitative measurements of the effects of Raman scattering by H2 in the Uranus and Neptune atmospheres.

  7. An Assessment of Aerocapture and Applications to Future Missions to Uranus and Neptune

    Science.gov (United States)

    Beauchamp, P. M.; Spilker, T. R.

    2017-12-01

    Our investigation examined the current state of readiness of aerocapture at several destinations of interest, including Uranus and Neptune, to identify what technologies are needed, and to determine if a technology demonstration mission is required, prior to the first use of aerocapture for a science mission. The study team concluded that the current state of readiness is destination dependent, with aerocaptured missions feasible at Venus, Mars, and Titan with current technologies. The use of aerocapture for orbit insertion at the ice giant planets Uranus and Neptune requires at least additional study to assess the expected performance of new guidance, navigation, and control algorithms, and possible development of new hardware, such as a mid-L/D entry vehicle shape or new thermal protection system materials. A variety of near-term activities could contribute to risk reduction for missions proposing use of aerocapture, but a system-level technology demonstration mission is not deemed necessary before the use of aerocapture for a NASA science mission.

  8. Dynamo Scaling Laws for Uranus and Neptune: The Role of Convective Shell Thickness on Dipolarity

    Science.gov (United States)

    Stanley, Sabine; Yunsheng Tian, Bob

    2017-10-01

    Previous dynamo scaling law studies (Christensen and Aubert, 2006) have demonstrated that the morphology of a planet’s magnetic field is determined by the local Rossby number (Ro_l): a non-dimensional diagnostic variable that quantifies the ratio of inertial forces to Coriolis forces on the average length scale of the flow. Dynamos with Ro_l ~ 0.1 produce multipolar magnetic fields. Scaling studies have also determined the dependence of the local Rossby number on non-dimensional parameters governing the system - specifically the Ekman, Prandtl, magnetic Prandtl and flux-based Rayleigh numbers (Olson and Christensen, 2006). When these scaling laws are applied to the planets, it appears that Uranus and Neptune should have dipole-dominated fields, contrary to observations. However, those scaling laws were derived using the specific convective shell thickness of the Earth’s core. Here we investigate the role of convective shell thickness on dynamo scaling laws. We find that the local Rossby number depends exponentially on the convective shell thickness. Including this new dependence on convective shell thickness, we find that the dynamo scaling laws now predict that Uranus and Neptune reside deeply in the multipolar regime, thereby resolving the previous contradiction with observations.

  9. Small Nuclear-powered Hot Air Balloons for the Exploration of the Deep Atmosphere of Uranus and Neptune

    Science.gov (United States)

    Van Cleve, J. E.; Grillmair, C. J.

    2001-01-01

    The Galileo probe gathered data in the Jovian atmosphere for about one hour before its destruction. For a wider perceptive on the atmospheres of the outer planets, multiple, long-lived observations platforms would be useful. In this paper we examine the basic physics of hot-air ballooning in a hydrogen atmosphere, using plutonium RTGs as a heat source. We find that such balloons are buoyant at a sufficiently great depth in these atmospheres, and derive equations for the balloon radius and mass of plutonium required as a function of atmospheric mass density and balloon material parameters. We solve for the buoyancy depth given the constraint that each probe may contain 1.0 kg of Pu, and find that the temperature at that depth is too great for conventional electronics (>70 C) for Jupiter and Saturn. However, the Pu mass constraint and the operating temperature constraint are consistent for Uranus and Neptune, and this concept may be applicable to those planets. Additional information is contained in the original extended abstract.

  10. 143 GHz BRIGHTNESS MEASUREMENTS OF URANUS, NEPTUNE, AND OTHER SECONDARY CALIBRATORS WITH BOLOCAM BETWEEN 2003 AND 2010

    International Nuclear Information System (INIS)

    Sayers, J.; Czakon, N. G.; Golwala, S. R.

    2012-01-01

    Bolocam began collecting science data in 2003 as the long-wavelength imaging camera at the Caltech Submillimeter Observatory. The planets, along with a handful of secondary calibrators, have been used to determine the flux calibration for all of the data collected with Bolocam. Uranus and Neptune stand out as the only two planets that are bright enough to be seen with high signal-to-noise in short integrations without saturating the standard Bolocam readout electronics. By analyzing all of the 143 GHz observations made with Bolocam between 2003 and 2010, we find that the brightness ratio of Uranus to Neptune is 1.027 ± 0.006, with no evidence for any variations over that period. Including previously published results at ≅ 150 GHz, we find a brightness ratio of 1.029 ± 0.006 with no evidence for time variability over the period 1983-2010. Additionally, we find no evidence for time variability in the brightness ratio of either Uranus or Neptune to the ultracompact H II region G34.3 or the protostellar source NGC 2071IR. Using recently published Wilkinson Microwave Anisotropy Probe results we constrain the absolute 143 GHz brightness of both Uranus and Neptune to ≅ 3%. Finally, we present ≅ 3% absolute 143 GHz peak flux density values for the ultracompact H II regions G34.3 and K3-50A and the protostellar source NGC 2071IR.

  11. Detection of HD in the atmospheres of Uranus and Neptune : a new determination of the D/H ratio

    NARCIS (Netherlands)

    Feuchtgruber, H; Lellouch, E; Bezard, B; Encrenaz, T; de Graauw, T.; Davis, GR

    Observations with the Short Wavelength Spectrometer (SWS) onboard the Infrared Space Observatory (ISO) have led to the first unambiguous detection of HD in the atmospheres of Uranus and Neptune, from its R(2) rotational line at 37.7 mu m Using S(0) and S(1) quadrupolar lines of H(2) at 28.2 and 17.0

  12. Tilting Uranus without a Collision

    Science.gov (United States)

    Rogoszinski, Zeeve; Hamilton, Douglas P.

    2016-10-01

    The most accepted hypothesis for the origin of Uranus' 98° obliquity is a giant collision during the late stages of planetary accretion. This model requires a single Earth mass object striking Uranus at high latitudes; such events occur with a probability of about 10%. Alternatively, Uranus' obliquity may have arisen from a sequence of smaller impactors which lead to a uniform distribution of obliquities. Here we explore a third model for tilting Uranus using secular spin-orbit resonance theory. We investigate early Solar System configurations in which a secular resonance between Uranus' axial precession frequency and another planet's orbital node precession frequency might occur.Thommes et al. (1999) hypothesized that Uranus and Neptune initially formed between Jupiter and Saturn, and were then kicked outward. In our scenario, Neptune leaves first while Uranus remains behind. As an exterior Neptune slowly migrates outward, it picks up both Uranus and Saturn in spin-orbit resonances (Ward and Hamilton 2004; Hamilton and Ward 2004). Only a distant Neptune has a nodal frequency slow enough to resonate with Uranus' axial precession.This scenario, with diverging orbits, results in resonance capture. As Neptune migrates outward its nodal precession slows. While in resonance, Uranus and Saturn each tilt a bit further, slowing their axial precession rates to continually match Neptune's nodal precession rate. Tilting Uranus to high obliquities takes a few 100 Myrs. This timescale may be too long to hold Uranus captive between Jupiter and Saturn, and we are investigating how to reduce it. We also find that resonance capture is rare if Uranus' initial obliquity is greater than about 10°, as the probability of capture decreases as the planet's initial obliquity increases. We will refine this estimate by quantifying capture statistics, and running accretion simulations to test the likelihood of a low early obliquity. Our preliminary findings show that most assumptions about

  13. Chaos in Kepler's Multiple Planet Systems and K2s Observations of the Atmospheres of Uranus Neptune

    Science.gov (United States)

    Lissauer, Jack J.

    2016-01-01

    More than one-third of the 4700 planet candidates found by NASA's Kepler spacecraft during its prime mission are associated with target stars that have more than one planet candidate, and such "multis" account for the vast majority of candidates that have been verified as true planets. The large number of multis tells us that flat multiplanet systems like our Solar System are common. Virtually all of the candidate planetary systems are stable, as tested by numerical integrations that assume a physically motivated mass-radius relationship, but some of the systems lie in chaotic regions close to instability. The characteristics of some of the most interesting confirmed Kepler multi-planet systems will be discussed. The Kepler spacecraft's 'second life' in theK2 mission has allowed it to obtain long time-series observations of Solar System targets, including the giant planets Uranus & Neptune. These observations show variability caused by the chaotic weather patterns on Uranus & Neptune.

  14. Uranus

    CERN Document Server

    Rajczak Nelson, Kristen

    2017-01-01

    The seventh planet from the sun, Uranus is known for its blue-green color and tilted axis, which makes it look like it's spinning on its side. But what causes these distinctive features? This engaging, easy-to-follow resource gives readers insight into Uranus, from its discovery in 1781 to the latest insights about it gained from satellite images, explaining its features, conditions, rings, and moons. Sidebars define challenging vocabulary words and pose thought-provoking questions to stimulate critical thinking about the universe.

  15. Why is it so difficult to tilt Uranus?

    Science.gov (United States)

    Rogoszinski, Zeeve; Hamilton, Douglas

    2018-04-01

    The leading hypothesis for the origin of Uranus' large obliquity (98°) is a polar strike from an Earth sized object, but to tilt Saturn similarly would require an impactor roughly 10x as massive. A more likely cause for Saturn's tilt (27°) is a spin-orbit resonance with Neptune (Ward & Hamilton, 2004; Hamilton & Ward, 2004); might the same process work for Uranus? It initially seems unlikely, as at its current location Uranus' axial precession period is too long to resonate with any of the giant planets' orbital precession frequencies. If we place Uranus between Jupiter and Saturn, however, then Uranus' spin axis would precess much more quickly. Thommes et al. (1999, 2002, 2003) first postulated that Uranus and Neptune were formed between Jupiter and Saturn because the conditions there allow the ice giants to be built rapidly. A resonance for our closer Uranus still requires a distant planet, nevertheless, a condition that can be satisfied if Neptune is ejected from Jupiter and Saturn first with Uranus following significantly later. This scenario, while contrived, is consistent with at least some versions of the Nice model and allows us to fully test the resonance hypothesis. We discovered that even with these optimistic assumptions, i) a resonance capture requires a migration timescale on the order of 100 Myr, and ii) it is impossible to tilt Uranus past 90°. Increasing Neptune's migration speed precludes resonant capture, and instead results in a resonance kick. In the most favorable cases, a resonance kick could raise Uranus' obliquity by 40° on a time span of about 50 Myr. We conclude that even in our best scenario, a resonance cannot fully account for Uranus' tilt. We have investigated some scenarios that include both resonances and collisions, and will report on our findings.

  16. Neptune

    CERN Document Server

    Roza, Greg

    2017-01-01

    This accessible and engaging book teaches young readers the fundamentals of Neptune, one of the most intriguing planets in our solar system. They will learn about Neptune's physical features, it's super storms that can reach 1,500 miles per hour, its ring system, the Voyager missions, and its status as one of the gas giants. Since the book includes images directly from NASA and with those taken by the Voyager missions themselves, readers can feel like they're really there, traveling to the planet and observing its physical features close up.

  17. CHAOTIC CAPTURE OF NEPTUNE TROJANS

    International Nuclear Information System (INIS)

    Nesvorny, David; Vokrouhlicky, David

    2009-01-01

    Neptune Trojans (NTs) are swarms of outer solar system objects that lead/trail planet Neptune during its revolutions around the Sun. Observations indicate that NTs form a thick cloud of objects with a population perhaps ∼10 times more numerous than that of Jupiter Trojans and orbital inclinations reaching ∼25 deg. The high inclinations of NTs are indicative of capture instead of in situ formation. Here we study a model in which NTs were captured by Neptune during planetary migration when secondary resonances associated with the mean-motion commensurabilities between Uranus and Neptune swept over Neptune's Lagrangian points. This process, known as chaotic capture, is similar to that previously proposed to explain the origin of Jupiter's Trojans. We show that chaotic capture of planetesimals from an ∼35 Earth-mass planetesimal disk can produce a population of NTs that is at least comparable in number to that inferred from current observations. The large orbital inclinations of NTs are a natural outcome of chaotic capture. To obtain the ∼4:1 ratio between high- and low-inclination populations suggested by observations, planetary migration into a dynamically excited planetesimal disk may be required. The required stirring could have been induced by Pluto-sized and larger objects that have formed in the disk.

  18. Jupiter and the Voyager mission

    Science.gov (United States)

    Soderblom, L.; Spall, Henry

    1980-01-01

    In 1977, the United States launched two unmanned Voyager spacecraft that were to take part in an extensive reconnaissance of the outer planets over a 12-year period visiting the environs of Jupiter, Saturn, Uranus, and Neptune. Their first encounter was with the complex Jupiter planetary system 400 million miles away. Sweeping by Jupiter and its five moons in 1979, the two spacecraft have sent back to Earth an enormous amount of data that will prove to be vital in understanding our solar system. Voyager 1 is scheduled to fly past Saturn on November 13 of this year; Voyager 2, in August of the following year. 

  19. Super-Earths, Warm-Neptunes, and Hot-Jupiters: Transmission Spectroscopy for Comparative Planetology

    Science.gov (United States)

    Fraine, Jonathan D.; Deming, Drake; Knutson, Heather; Jordán, Andrés

    2014-11-01

    We used the Kepler, Hubble, and Spitzer Space Telescopes to probe the diversity of exoplanetary atmospheres with transmission spectroscopy, constraining atomic and molecular absorption in Jupiter- and Neptune-sized exoplanets. The detections and non-detections of molecular species such as water, methane, and carbon monoxide lead to greater understanding of planet formation and evolution. Recent significant advances in both theoretical and observational discoveries from planets like HD189733b, HD209458b, GJ436, as well as our own work with HAT-P-11b and GJ1214b, have shown that the range of measurable atmospheric properties spans from clear, molecular absorption dominated worlds to opaque worlds, with cloudy, hazy, or high mean molecular weight atmospheres. Characterization of these significant non-detections allows us to infer the existence of cloud compositions at high altitudes, or mean molecular weights upwards of ~1000x solar. Neither scenario was expected from extrapolations of solar system analogs. We present here our published results from GJ1214b and HAT-P-11b, as well as our recent work on HAT-P-7b and HAT-P-13b. We search for evidence of atmospheric hazes and clouds, and place constraints on the relative abundance of water vapor, methane, and carbon monoxide-- in the case of cloud-free atmospheres. We conclude by discussing how our results compare to transmission spectra obtained for other similar planets, and use these combined data to develop a better understanding for the nature of these distant and alien worlds.

  20. Using collisions and resonances to tilting Uranus

    Science.gov (United States)

    Rogoszinski, Zeeve; Hamilton, Douglas

    2018-01-01

    Uranus’ large obliquity (98°) is widely thought to have occurred from a polar strike with an Earth sized object. Morbidelli et al. (2012) argue that two or more collisions are required in order to explain the prograde motion of Uranus’ satellites. These impactors could have been less massive by about a factor of ten, but multiple polar strikes are still improbable as even larger mass impactors would be needed for more equatorial collisions. Here we explore an alternative non-collisional model inspired by the explanation to Saturn’s significant tilt (27°). Ward and Hamilton (2004) & Hamilton and Ward (2004) argue that a secular resonance currently between Saturn’s spin axis and Neptune’s orbital pole is responsible for Saturn’s large obliquity. Unfortunately, Uranus’ axial precession frequency today is too long to match any of the current planets’ fundamental frequencies. Boué and Laskar (2010) explain that Uranus may have harbored an improbably large moon in the past which could have sped up the planet’s axial precession frequency enough to resonate with the regression of its own orbital pole. We explore another scenario which requires only the interactions between the giant planets.Thommes et al. (1999, 2002, 2003) argue that at least the cores of Uranus and Neptune were formed in between Jupiter and Saturn, as the density of the protoplanetary disk was greater there. If Neptune was scattered outward before Uranus, then a secular spin-orbit resonance between the two planets is possible. However, driving Uranus’ obliquity to near 90° with a resonance capture requires a timescale on the order of 100 Myr. If Neptune migrated out quicker or its orbital inclination was initially larger, then we find that the resulting resonance kick can tilt Uranus more than 40° in a reasonable timespan. This could replace one of the impactors required in the collisional scenario described by Morbidelli et al. (2012), but in most situations the effect of such a

  1. Hot plasma parameters in Neptune's magnetosphere

    International Nuclear Information System (INIS)

    Krimigis, S.M.; Mauk, B.H.; Cheng, A.F.; Keath, E.P.; Kane, M.; Armstrong, T.P.; Gloeckler, G.; Lanzerotti, L.J.

    1990-01-01

    Energy spectra of energetic protons and electrons (E p approx-gt 28 keV, E e approx-gt 22 keV, respectively) obtained with the Low Energy Charged Particle (LECP) instrument during the Voyager 2 encounter with Neptune on August 24-25, 1989 are presented. The proton spectral form was a power law (dj/dE = KE -γ ), outside the orbit of Triton (∼14.3 R N ); inside that distance, it was found to be a hot (kT ≅ 60 keV) Maxwellian distribution. Such distributions, observed in other planets as well, have yet to be explained theoretically. Similarly, the electron spectral form changed from a simple power law outside Triton to a two-slope power law with a high energy tail inside. Intensity and spectral features in both proton and electron fluxes were identified in association with the crossings of the Triton and 1989 N1 L-shells, but these features do not occur simultaneously in both species. Such signatures were manifested by relative peaks in both kT and γ spectral indices. Peak proton pressures of ∼2x10 -9 dynes cm -2 , and β ∼ 0.2 were measured at successive magnetic equatorial crossings, both inbound and outbound. These parameters show Neptune's magnetosphere to be relatively undistorted by hot plasma loading, similar to that of Uranus and unlike those of Saturn and Jupiter. Trapped electron fluxes at Neptune, as at Uranus, exceed the whistler mode stably trapped flux limit. Whistler-induced pitch angle scattering of energetic electrons in the radiation belts can yield a precipitating energy flux sufficient to drive Neptune's aurora

  2. Problems of simulation of large, long-lived vortices in the atmospheres of the giant planets (jupiter, saturn, neptune)

    Science.gov (United States)

    Nezlin, Michael V.; Sutyrin, Georgi G.

    1994-01-01

    Large, long-lived vortices are abundant in the atmospheres of the giant planets. Some of them survive a few orders of magnitude longer than the dispersive linear Rossby wave packets, e.g. the Great Red Spot (GRS), Little Red Spot (LRS) and White Ovals (WO) of Jupiter, Big Bertha, Brown Spot and Anne's Spot of Saturn, the Great Dark Spot (GDS) of Neptune, etc. Nonlinear effects which prevent their dispersion spreading are the main subject of our consideration. Particular emphasis is placed on determining the dynamical processes which may explain the remarkable properties of observed vortices such as anticyclonic rotation in preference to cyclonic one and the uniqueness of the GRS, the largest coherent vortex, along the perimeter of Jupiter at corresponding latitude. We review recent experimental and theoretical studies of steadily translating solitary Rossby vortices (anticyclones) in a rotating shallow fluid. Two-dimensional monopolar solitary vortices trap fluid which is transported westward. These dualistic structures appear to be vortices, on the one hand, and solitary “waves”, on the other hand. Owing to the presence of the trapped fluid, such solitary structures collide inelastically and have a memory of the initial disturbance which is responsible for the formation of the structure. As a consequence, they have no definite relationship between the amplitude and characteristic size. Their vortical properties are connected with geostrophic advection of local vorticity. Their solitary properties (nonspreading and stationary translation) are due to a balance between Rossby wave dispersion and nonlinear effects which allow the anticyclones, with an elevation of a free surface, to propagate faster than the linear waves, without a resonance with linear waves, i.e. without wave radiation. On the other hand, cyclones, with a depression of a free surface, are dispersive and nonstationary features. This asymmetry in dispersion-nonlinear properties of cyclones and

  3. Capture of irregular satellites at Jupiter

    International Nuclear Information System (INIS)

    Nesvorný, David; Vokrouhlický, David; Deienno, Rogerio

    2014-01-01

    The irregular satellites of outer planets are thought to have been captured from heliocentric orbits. The exact nature of the capture process, however, remains uncertain. We examine the possibility that irregular satellites were captured from the planetesimal disk during the early solar system instability when encounters between the outer planets occurred. Nesvorný et al. already showed that the irregular satellites of Saturn, Uranus, and Neptune were plausibly captured during planetary encounters. Here we find that the current instability models present favorable conditions for capture of irregular satellites at Jupiter as well, mainly because Jupiter undergoes a phase of close encounters with an ice giant. We show that the orbital distribution of bodies captured during planetary encounters provides a good match to the observed distribution of irregular satellites at Jupiter. The capture efficiency for each particle in the original transplanetary disk is found to be (1.3-3.6) × 10 –8 . This is roughly enough to explain the observed population of jovian irregular moons. We also confirm Nesvorný et al.'s results for the irregular satellites of Saturn, Uranus, and Neptune.

  4. The origin of CO in the stratosphere of Uranus

    Science.gov (United States)

    Cavalié, Thibault; Moreno, R.; Lellouch, E.; Hartogh, P.; Venot, O.; Orton, G. S.; Jarchow, C.; Encrenaz, T.; Selsis, F.; Hersant, F.; Fletcher, L. N.

    2013-10-01

    Oxygen-rich deep interiors of the Giant Planets cannot explain the discovery of H2O and CO2 in the stratospheres of the Giant Planets by Feuchtgruber et al. (1997) because these species are trapped by condensation around their tropopause levels (except CO2 in Jupiter and Saturn). Therefore, several sources in the direct or far environment of the Giant Planets have been proposed: icy rings and/or satellites, interplanetary dust particles and large comet impacts. CO does not condense at the tropopauses of Giant Planets, so that oxygen-rich interiors are a valid source. An internal component has indeed been observed in the vertical profile of CO in Jupiter (Bézard et al., 2002) and in Neptune (Lellouch et al., 2005), while an upper limit has been set on its magnitude by for Saturn (Cavalié et al., 2009). In addition to interiors, large comets seem to be the dominant external source, as shown by various studies: Bézard et al. (2002) for Jupiter, Cavalié et al. (2010) for Saturn and Lellouch et al. (2005) for Neptune. The first detection of CO in Uranus was obtained by Encrenaz et al. (2004) from fluorescent emission at 4.7 microns. Assuming a uniform distribution, a mixing ratio of 2x10-8 was derived. Despite this first detection almost a decade ago, the situation has remained unclear ever since. In this paper, we will present the first submillimeter detection of CO in Uranus, carried out with Herschel in 2011-2012. Using a simple diffusion model, we review the various possible sources of CO (internal and external). We show that CO is mostly external. We also derive an upper limit for the internal source. And with the thermochemical model of Venot et al. (2012), adapted to the interior of Uranus, we derive an upper limit on its deep O/H ratio from it. Acknowledgments T. Cavalié acknowledges support from CNES and the European Research Council (Starting Grant 209622: E3ARTHs). References Bézard et al., 2002. Icarus, 159, 95-111. Cavalié et al., 2009. Icarus, 203

  5. Jupiter

    CERN Document Server

    Penne, Barbra

    2017-01-01

    Our solar system's largest planet is huge enough that all of the system's other planets could fit inside it. Although Jupiter has been known since ancient times, scientists are still learning exciting new information about the planet and its satellites today. In fact, several of its moons are now believed to have oceans below their icy surfaces. Chapters focus on topics such as Jupiter's orbit and rotation, rings, atmosphere, and moons, as well as on the space missions that have helped us get a closer look at the planet and its moons over the past decades.

  6. Jupiter

    Science.gov (United States)

    1990-01-01

    This processed color image of Jupiter was produced in 1990 by the U.S. Geological Survey from a Voyager image captured in 1979. The colors have been enhanced to bring out detail. Zones of light-colored, ascending clouds alternate with bands of dark, descending clouds. The clouds travel around the planet in alternating eastward and westward belts at speeds of up to 540 kilometers per hour. Tremendous storms as big as Earthly continents surge around the planet. The Great Red Spot (oval shape toward the lower-left) is an enormous anticyclonic storm that drifts along its belt, eventually circling the entire planet.

  7. Magnetic fields at Neptune

    International Nuclear Information System (INIS)

    Ness, N.F.; Acuna, M.H.; Burlaga, L.F.; Connerney, J.E.P.; Lepping, R.P.; Neubauer, F.M.

    1989-01-01

    The National Aeronautics and Space Administration Goddard Space Flight Center-University of Delaware Bartol Research Institute magnetic field experiment on the Voyager 2 spacecraft discovered a strong and complex intrinsic magnetic field of Neptune and an associated magnetosphere and magnetic tail. A maximum magnetic field of nearly 10,000 nanoteslas (1 nanotesla = 10 -5 gauss) was observed near closest approach, at a distance of 1.18 R N . The planetary magnetic field between 4 and 15 R N can be well represented by an offset tilted magnetic dipole (OTD), displaced from the center of Neptune by the surprisingly large amount of 0.55 R N and inclined by 47 degrees with respect to the rotation axis. Within 4 R N , the magnetic field representation must include localized sources or higher order magnetic multipoles, or both, which are not yet well determined. As the spacecraft exited the magnetosphere, the magnetic tail appeared to be monopolar, and no crossings of an imbedded magnetic field reversal or plasma neutral sheet were observed. The auroral zones are most likely located far from the rotation poles and may have a complicated geometry. The rings and all the known moons of Neptune are imbedded deep inside the magnetosphere, except for Nereid, which is outside when sunward of the planet. The radiation belts will have a complex structure owing to the absorption of energetic particles by the moons and rings of Neptune and losses associated with the significant changes in the diurnally varying magnetosphere configuration. In an astrophysical context, the magnetic field of Neptune, like that of Uranus, may be described as that of an oblique rotator

  8. The quest for H_3^+ at Neptune: deep burn observations with NASA IRTF iSHELL

    Science.gov (United States)

    Melin, H.; Fletcher, L. N.; Stallard, T. S.; Johnson, R. E.; O'Donoghue, J.; Moore, L.; Donnelly, P. T.

    2018-03-01

    Emission from the molecular ion H_3^+ is a powerful diagnostic of the upper atmosphere of Jupiter, Saturn, and Uranus, but it remains undetected at Neptune. In search of this emission, we present near-infrared spectral observations of Neptune between 3.93 and 4.00 μm taken with the newly commissioned iSHELL instrument on the NASA Infrared Telescope Facility in Hawaii, obtained 2017 August 17-20. We spent 15.4 h integrating across the disc of the planet, yet were unable to unambiguously identify any H_3^+ line emissions. Assuming a temperature of 550 K, we derive an upper limit on the column integrated density of 1.0^{+1.2}_{-0.8}× 10^{13} m-2, which is an improvement of 30 per cent on the best previous observational constraint. This result means that models are overestimating the density by at least a factor of 5, highlighting the need for renewed modelling efforts. A potential solution is strong vertical mixing of polyatomic neutral species from Neptune's upper stratosphere to the thermosphere, reacting with H_3^+, thus greatly reducing the column integrated H_3^+ densities. This upper limit also provide constraints on future attempts at detecting H_3^+ using the James Webb Space Telescope.

  9. The rings of Uranus

    Science.gov (United States)

    Elliot, J. L.; Dunham, E.; Mink, D.

    1977-01-01

    A description is given of the observation of five brief occultations of the star SAO 158687 which occurred both before and after its occultation by Uranus on March 10, 1977. The events were observed with a three-channel occultation photometer, attached to a 91-cm telescope. The observations indicate that at least five rings encircle the planet Uranus. Possible reasons for the narrowness of the Uranus rings are discussed.

  10. EVIDENCE FROM THE ASTEROID BELT FOR A VIOLENT PAST EVOLUTION OF JUPITER'S ORBIT

    International Nuclear Information System (INIS)

    Morbidelli, Alessandro; Brasser, Ramon; Gomes, Rodney; Levison, Harold F.; Tsiganis, Kleomenis

    2010-01-01

    We use the current orbital structure of large (>50 km) asteroids in the main asteroid belt to constrain the evolution of the giant planets when they migrated from their primordial orbits to their current ones. Minton and Malhotra showed that the orbital distribution of large asteroids in the main belt can be reproduced by an exponentially decaying migration of the giant planets on a timescale of τ ∼ 0.5 Myr. However, self-consistent numerical simulations show that the planetesimal-driven migration of the giant planets is inconsistent with an exponential change in their semi-major axes on such a short timescale. In fact, the typical timescale is τ ≥ 5 Myr. When giant planet migration on this timescale is applied to the asteroid belt, the resulting orbital distribution is incompatible with the observed one. However, the planet migration can be significantly sped up by planet-planet encounters. Consider an evolution where both Jupiter and Saturn have close encounters with a Neptune-mass planet (presumably Uranus or Neptune itself) and where this third planet, after being scattered inward by Saturn, is scattered outward by Jupiter. This scenario leads to a very rapid increase in the orbital separation between Jupiter and Saturn which we show here to have only mild effects on the structure of the asteroid belt. This type of evolution is called a 'jumping-Jupiter' case. Our results suggest that the total mass and dynamical excitation of the asteroid belt before migration were comparable to those currently observed. Moreover, they imply that, before migration, the orbits of Jupiter and Saturn were much less eccentric than their current ones.

  11. Did Triton Destroy Neptune's First Moons?

    Science.gov (United States)

    Kohler, Susanna

    2017-11-01

    Neptunes moon system is not what we would expect for a gas giant in our solar system. Scientists have now explored the possibility that Neptune started its life with an ordinary system of moons that was later destroyed by the capture of its current giant moon, Triton.An Odd SystemOur current understanding of giant-planet formation predicts a period of gas accretion to build up the large size of these planets. According to models, the circumplanetary gas disks that surround the planets during this time then become the birthplaces of the giant planets satellite systems, producing systems of co-planar and prograde (i.e., orbiting in the same direction as the planets rotation) satellites similar to the many-moon systems of Jupiter or Saturn.Tritons orbit is tilted relative to the inner Neptunian satellite orbits. [NASA, ESA, and A. Feild (STScI)]Neptune, however, is quirky. This gas giant has surprisingly few satellites only 14 compared to, say, the nearly 70 moons of Jupiter and most of them are extremely small. One of Neptunes moons is an exception to this, however: Triton, which contains 99.7% of the mass of Neptunes entire satellite system!Tritons orbit has a number of unusual properties. The orbit is retrograde Triton orbits in the opposite direction as Neptunes rotation which is unique behavior among large moons in our solar system. Tritons orbit is also highly inclined, and yet the moons path is nearly circular and lies very close to Neptune.The distribution of impact velocities in the authors simulations for primordial satellite interactions with Triton, in three cases of different satellite mass ratios. In the low-mass case a third of the mass ratio of the Uranian satellite system 88% of simulations ended with Triton surviving on its high-inclination orbit. The survival rate was only 12% in the high-mass case. [Adapted from Rufu et al. 2017]How did this monster of a satellite get its strange properties, and why is Neptunes system so odd compared to what we

  12. The NEPTUNE Network

    DEFF Research Database (Denmark)

    Blanke, M.; Nielsen, Jens Frederik Dalsgaard; Degre, T.

    The main aim for NEPTUNE is the establishing of an "open" European network of universities and research institutes engaged in research, training and education for waterborne (maritime and inland navigation) transport. This network should constitute an European knowledge base to support....... For the support to the objectives of NEPTUNE the association is developing the NEPTUNE Information Network. A pilot demonstration on the basis of the world wide web technique on Internet has been established. Two NEPTUNE server, on the premises of ISL in Bremen and NTUA in Athens, can be adressed via the URL......=http://www.isl.uni-bremen.de/NEPTUNE/ and URL=http://www.maritime.deslab.naval.ntua.gr/neptune/framelayout.html The pilot will be enlarged concerning the number of NEPTUNE servers as well as regarding the scope of information provided by the various servers. The implementation and operating of such an European Waterborne Information Network...

  13. Atmospheric Entry Studies for Uranus

    Science.gov (United States)

    Agrawal, P.; Allen, G. A.; Hwang, H. H.; Marley, M. S.; McGuire, M. K.; Garcia, J. A.; Sklyanskiy, E.; Huynh, L. C.; Moses, R. W.

    2014-07-01

    To better understand the technology requirements for Uranus atmospheric entry probe, Entry Vehicle Technology project funded an internal study with a multidisciplinary team from NASA Ames, Langley and JPL. The results of this study are communicated.

  14. Detection of CS in Neptune's atmosphere from ALMA observations

    Science.gov (United States)

    Moreno, R.; Lellouch, E.; Cavalié, T.; Moullet, A.

    2017-12-01

    Context. The large and vertically non-uniform abundance of CO in Neptune's atmosphere has been interpreted as the result of past cometary impact(s), either single or distributed in size and time, which could also be at the origin of Neptune's HCN. Aims: We aim to provide observational support for this scenario by searching for other comet-induced species, in particular carbon sulfide (CS) which has been observed continuously in Jupiter since the 1994 Shoemaker-Levy 9 impacts. Methods: In April 2016 we used the ALMA interferometer to search for CS(7-6) at 342.883 GHz in Neptune. Results: We report on the detection of CS in Neptune's atmosphere, the first unambiguous observation of a sulfur-bearing species in a giant planet beyond Jupiter. Carbon sulfide appears to be present only at submillibar levels, with a column density of (2.0-3.1) × 1012 cm-2, and a typical mixing ratio of (2-20) × 10-11 that depends on its precise vertical location. The favoured origin of CS is deposition by a putative large comet impact several centuries ago, and the strong depletion of CS with respect to CO - compared to the Jupiter case - is likely due to the CS sticking to aerosols or clustering to form polymers in Neptune's lower stratosphere. Conclusions: The CS detection, along with recent analyses of the CO profile, reinforces the presumption of a large comet impact into Neptune 1000 yr ago, that delivered CO, CS, and HCN at the same time.

  15. Atmospheric tides on Neptune

    International Nuclear Information System (INIS)

    Dement'ev, M.S.; Morozhenko, A.V.

    1989-01-01

    The dependence of the equivalent width of the methane absorption band at 619 nm in the Neptune's spectrum upon the Triton's orbital position is discovered. It is assumed that observed changes of the equivalent width of the band and colour index (J - K) (Belton et al., 1981; Brown et al., 1981; Cruikshank, 1978) are due to atmospheric tides (period 2 d .9375) and Neptune's rotation (period 10 h .14)

  16. Neptune's microwave spectrum from 1 mm to 20 cm

    International Nuclear Information System (INIS)

    De Pater, I.; Richmond, M.

    1989-01-01

    Total flux densities and disk-averaged brightness temperatures have been tabulated on the basis of VLA observations of Neptune at 1.3, 2, 6, and 20 cm wavelengths; a recalibration is also conducted of previous observations in order to accurately ascertain the spectral shape of this planet, which is found to have increasing brightness temperature with increasing wavelength, in contrast with that of Uranus. If all the detected emission is atmospheric thermal radiation, ammonia abundance must either be a factor of about 50 lower than the solar N value throughout the Neptune atmosphere, or the planet must emit about 0.3-0.5 mJy synchrotron radiation at 20 cm; the latter possibility is consistent with a planetary magnetic field strength of about 0.5 G at the surface. 39 refs

  17. Magnetosphere of Uranus: plasma sources, convection, and field configuration

    International Nuclear Information System (INIS)

    Voigt, G.; Hill, T.W.; Dessler, A.J.

    1983-01-01

    At the time of the Voyager 2 flyby of Uranus, the planetary rotational axis will be roughly antiparallel to the solar wind flow. If Uranus has a magnetic dipole moment that is approximately aligned with its spin axis, and if the heliospheric shock has not been encountered, we will have the rare opportunity to observe a ''pole-on'' magnetosphere as discussed qualitatively by Siscoe. Qualitative arguments based on analogy with Earth, Jupiter, and Saturn suggest that the magnetosphere of Uranus may lack a source of plasma adequate to produce significant internal currents, internal convection, and associated effects. In order to provide a test of this hypothesis with the forthcoming Voyager measurements, we have constructed a class of approximately self-consistent quantitative magnetohydrostatic equilibrium configurations for a pole-on magnetosphere with variable plasma pressure parameters. Given a few simplifying assumptions, the geometries of the magnetic field and of the tail current sheet can be computed for a given distribution of trapped plasma pressure. The configurations have a single funnel-shaped polar cusp that points directly into the solar wind and a cylindrical tail plasma sheet whose currents close within the tail rather than on the tail magnetopause, and whose length depends on the rate of decrease of thermal plasma pressure down the tail. Interconnection between magnetospheric and interplanetary fields results in a highly asymmetric tail-field configuration. These features were predicted qualtitatively by Siscoe; the quantitative models presented here may be useful in the interpretation of Voyager encounter results

  18. ISO celebrates its prolonged life with a video of Jupiter

    Science.gov (United States)

    1997-07-01

    This is excellent news for astronomers and especially for the multinational teams, with leaders in France, Germany, the Netherlands and the United Kingdom, who spent many years devising the four instruments served by ISO's telescope. The camera ISOCAM, the photometer ISOPHOT, the Short Wavelength Spectrometer and the Long Wavelength Spectrometer span between them an unprecedented range of infrared wavelengths from 2 to 200 microns. The atmosphere of Jupiter is one of the cool and cloudy places attracting ISO's attention, and ESA today releases a video of unprecedented images of Jupiter. The planet changes its appearance drastically as the camera ISOCAM scans a range of 90 different infrared wavelengths. Picture by picture, ISOCAM picks out different features of the atmosphere's composition and behaviour. These and other results from ISO will enable scientists to sharpen their ideas about how Jupiter's weather works. "ISO is giving us a new impression of the giant planets of the Solar System," comments Roger Bonnet, ESA's director of science. "Not just Jupiter, but Saturn, Uranus and Neptune too. By observing the planets across its very wide range of infrared wavelengths, ISO can see features overlooked even by spacecraft visiting the planets. The remarkable movie of Jupiter released today represents only a few per cent of ISO's wavelength range, yet every image tells its own story." More information about the Jupiter video appears later in this Information Note. How ISO's cold telescope beat the calendar The need to keep ISO's telescope and instruments chilled to a very low temperature sets a limit to their useful operating life. ISO was supplied with more than 2000 litres of superfluid helium to cool it. Slow evaporation maintains key parts of the spacecraft at temperatures close to absolute zero, below minus 271 degrees C. The rate of loss of helium was expected to be about 3 litres a day, but the cryogenic system could not be tested in exactly the conditions

  19. Voyager 2 Uranus targeting strategy

    Science.gov (United States)

    Cesarone, R. J.; Gray, D. L.; Potts, C. L.; Francis, K.

    1986-01-01

    One of the major challenges involved in the Voyager 2 Uranus flyby is to deliver the spacecraft to an appropriate aimpoint at the optimum time, so as to maximize the science return of the mission, while yet keeping propellant expenditure low. An unusual targeting strategy has been devised to satisfy these requirements. Its complexity arises from the great distance of the planet Uranus and the limited performance capabilities of Voyager. This selected strategy is developed in relation to a set of candidate strategies, mission requirements and shifting science objectives. The analysis of these candidates is conducted via a Monte Carlo simulation, the results of which yield data for the comparative evaluation and eventual and selection of the actual targeting strategy to be employed.

  20. MODELS OF NEPTUNE-MASS EXOPLANETS: EMERGENT FLUXES AND ALBEDOS

    International Nuclear Information System (INIS)

    Spiegel, David S.; Burrows, Adam; Ibgui, Laurent; Hubeny, Ivan; Milsom, John A.

    2010-01-01

    There are now many known exoplanets with Msin i within a factor of 2 of Neptune's, including the transiting planets GJ 436b and HAT-P-11b. Planets in this mass range are different from their more massive cousins in several ways that are relevant to their radiative properties and thermal structures. By analogy with Neptune and Uranus, they are likely to have metal abundances that are an order of magnitude or more greater than those of larger, more massive planets. This increases their opacity, decreases Rayleigh scattering, and changes their equation of state. Furthermore, their smaller radii mean that fluxes from these planets are roughly an order of magnitude lower than those of otherwise identical gas giant planets. Here, we compute a range of plausible radiative equilibrium models of GJ 436b and HAT-P-11b. In addition, we explore the dependence of generic Neptune-mass planets on a range of physical properties, including their distance from their host stars, their metallicity, the spectral type of their stars, the redistribution of heat in their atmospheres, and the possible presence of additional optical opacity in their upper atmospheres.

  1. A COLD NEPTUNE-MASS PLANET OGLE-2007-BLG-368Lb: COLD NEPTUNES ARE COMMON

    International Nuclear Information System (INIS)

    Sumi, T.; Abe, F.; Fukui, A.

    2010-01-01

    We present the discovery of a Neptune-mass planet OGLE-2007-BLG-368Lb with a planet-star mass ratio of q = [9.5 ± 2.1] x 10 -5 via gravitational microlensing. The planetary deviation was detected in real-time thanks to the high cadence of the Microlensing Observations in Astrophysics survey, real-time light-curve monitoring and intensive follow-up observations. A Bayesian analysis returns the stellar mass and distance at M l = 0.64 +0.21 -0.26 M sun and D l = 5.9 +0.9 -1.4 kpc, respectively, so the mass and separation of the planet are M p = 20 +7 -8 M + and a = 3.3 +1.4 -0.8 AU, respectively. This discovery adds another cold Neptune-mass planet to the planetary sample discovered by microlensing, which now comprises four cold Neptune/super-Earths, five gas giant planets, and another sub-Saturn mass planet whose nature is unclear. The discovery of these 10 cold exoplanets by the microlensing method implies that the mass ratio function of cold exoplanets scales as dN pl /dlog q ∝ q -0.7±0.2 with a 95% confidence level upper limit of n pl /dlog q ∝ q n ). As microlensing is most sensitive to planets beyond the snow-line, this implies that Neptune-mass planets are at least three times more common than Jupiters in this region at the 95% confidence level.

  2. OCEANUS: A high science return Uranus orbiter with a low-cost instrument suite

    Science.gov (United States)

    Elder, C. M.; Bramson, A. M.; Blum, L. W.; Chilton, H. T.; Chopra, A.; Chu, C.; Das, A.; Davis, A. B.; Delgado, A.; Fulton, J.; Jozwiak, L. M.; Khayat, A.; Landis, M. E.; Molaro, J. L.; Slipski, M.; Valencia, S.; Watkins, J.; Young, C. L.; Budney, C. J.; Mitchell, K. L.

    2018-07-01

    Ice-giant-sized planets are the most common type of observed exoplanet, yet the two ice giants in our own solar system (Uranus and Neptune) are the least explored class of planet, having only been observed through ground-based observations and a single flyby each by Voyager 2 approximately 30 years ago. These single flybys were unable to characterize the spatial and temporal variability in ice giant magnetospheres, some of the most odd and intriguing magnetospheres in the solar system. They also offered only limited constraints on the internal structure of ice giants; understanding the internal structure of a planet is important for understanding its formation and evolution. The most recent planetary science Decadal Survey by the U.S. National Academy of Sciences, "Vision and Voyages for Planetary Science in the Decade 2013-2022," identified the ice giant Uranus as the third highest priority for a Flagship mission in the decade 2013-2022. However, in the event that NASA or another space agency is unable to fly a Flagship-class mission to an ice giant in the next decade, this paper presents a mission concept for a focused, lower cost Uranus orbiter called OCEANUS (Origins and Composition of the Exoplanet Analog Uranus System). OCEANUS would increase our understanding of the interior structure of Uranus, its magnetosphere, and how its magnetic field is generated. These goals could be achieved with just a magnetometer and the spacecraft's radio system. This study shows that several of the objectives outlined by the Decadal Survey, including one of the two identified as highest priority, are within reach for a New-Frontiers-class mission.

  3. Kepler constraints on planets near hot Jupiters

    Science.gov (United States)

    Steffen, Jason H.; Ragozzine, Darin; Fabrycky, Daniel C.; Carter, Joshua A.; Ford, Eric B.; Holman, Matthew J.; Rowe, Jason F.; Welsh, William F.; Borucki, William J.; Boss, Alan P.; Ciardi, David R.; Quinn, Samuel N.

    2012-01-01

    We present the results of a search for planetary companions orbiting near hot Jupiter planet candidates (Jupiter-size candidates with orbital periods near 3 d) identified in the Kepler data through its sixth quarter of science operations. Special emphasis is given to companions between the 2∶1 interior and exterior mean-motion resonances. A photometric transit search excludes companions with sizes ranging from roughly two-thirds to five times the size of the Earth, depending upon the noise properties of the target star. A search for dynamically induced deviations from a constant period (transit timing variations) also shows no significant signals. In contrast, comparison studies of warm Jupiters (with slightly larger orbits) and hot Neptune-size candidates do exhibit signatures of additional companions with these same tests. These differences between hot Jupiters and other planetary systems denote a distinctly different formation or dynamical history. PMID:22566651

  4. Kepler constraints on planets near hot Jupiters.

    Science.gov (United States)

    Steffen, Jason H; Ragozzine, Darin; Fabrycky, Daniel C; Carter, Joshua A; Ford, Eric B; Holman, Matthew J; Rowe, Jason F; Welsh, William F; Borucki, William J; Boss, Alan P; Ciardi, David R; Quinn, Samuel N

    2012-05-22

    We present the results of a search for planetary companions orbiting near hot Jupiter planet candidates (Jupiter-size candidates with orbital periods near 3 d) identified in the Kepler data through its sixth quarter of science operations. Special emphasis is given to companions between the 21 interior and exterior mean-motion resonances. A photometric transit search excludes companions with sizes ranging from roughly two-thirds to five times the size of the Earth, depending upon the noise properties of the target star. A search for dynamically induced deviations from a constant period (transit timing variations) also shows no significant signals. In contrast, comparison studies of warm Jupiters (with slightly larger orbits) and hot Neptune-size candidates do exhibit signatures of additional companions with these same tests. These differences between hot Jupiters and other planetary systems denote a distinctly different formation or dynamical history.

  5. BLEACHING NEPTUNE BALLS

    Directory of Open Access Journals (Sweden)

    BONET Maria Angeles

    2014-05-01

    Full Text Available Posidonia Oceanic is a seaweed from Mediterranean Sea and it is more concentrated at the Balerian SEA. This implies the Valencian Community also. It forms vaste underwater meadows in the sea and are part of the Mediterranean ecosystem. It is a sea-grass specie with fruits and flowers. Leaves are ribbon-like and they grow in winter and at the end of summer some of them are separated and arrive to some sea line. Fuit is separated and can floate, it is known as “the olive of the sea” mainly in Italy, or as the Neptune Balls. As it can be used in different fields, it is is being studied in order ro have the precitice tests. Some authors have reported the manufacturing of fully bio-based comites with a gluten matrix by hot-press molding. And it has been considered as an effective insulator for building industry or even though to determine the presence of mercure in the Mediterranean sea some years ago. As many applications can be designed from that fibers, it has been considered to be bleached in order to used them in fashionable products. Consequently, its original brown color is not the most suitable one and it should be bleached as many other cellulosic fibers. The aim of this paper is to bleache neptune balls however, the inner fibers were not accessible at all and it implied not to bleach the inner fibers in the neptune ball. Further studiesd will consider bleaching the individualized fibers.

  6. Uranus atmospheric dynamics and circulation

    Science.gov (United States)

    Allison, Michael; Beebe, Reta F.; Conrath, Barney J.; Hinson, David P.; Ingersoll, Andrew P.

    1991-01-01

    The observations, models, and theories relevant to the atmospheric dynamics and meteorology of Uranus are discussed. The available models for the large-scale heat transport and atmospheric dynamics as well as diagnostic interpretations of the Voyager data are reviewed. Some pertinent ideas and questions regarding the global circulation balance are considered, partly in comparison with other planetary atmospheres. The available data indicate atmospheric rotation at midlatitudes nearly 200 m/s faster than that of the planetary magnetic field. Analysis of the dynamical deformation of the shape and size of isobaric surfaces measured by the Voyager radio-occultation experiment suggests a subrotating equator at comparable altitudes. Infrared temperature retrievals above the cloud deck indicate a smaller equator-to-pole contrast than expected for purely radiative-convective equilibrium, but show local variations implying a latitudinally correlated decrease with altitude in the cloud-tracked wind.

  7. Ethane abundance on Neptune

    Science.gov (United States)

    Kostiuk, Theodor; Espenak, Fred; Romani, Paul; Zipoy, David; Goldstein, Jeff

    1990-01-01

    IR spectroscopic measurements of the C2H6 RR (4,5) emission line at 840.9764/cm have been used to infer Neptune's ethane mole fractions; while the resulting value is lower than that obtained by Orton et al. (1987), it lies within their 2-sigma error bounds. The present results are also found to require 2.0-5.8 times more ethane in the 0.02-2 mbar pressure region than predicted by the Romani and Atreya (1989) photochemical model. Better agreement is obtainable through a reduction of eddy mixing in the lower stratosphere and/or an increase of stratospheric temperature by more than 10 K above the 6-mbar level.

  8. The upper atmosphere of Uranus - Mean temperature and temperature variations

    Science.gov (United States)

    Dunham, E.; Elliot, J. L.; Gierasch, P. J.

    1980-01-01

    The number-density, pressure, and temperature profiles of the Uranian atmosphere in the pressure interval from 0.3 to 30 dynes/sq cm are derived from observations of the occultation of SAO 158687 by Uranus on 1977 March 10, observations made from the Kuiper Airborne Observatory and the Cape Town station of the South African Astronomical Observatory. The mean temperature is found to be about 95 K, but peak-to-peak variations from 10 K to 20 K or more exist on a scale of 150 km or 3 scale heights. The existence of a thermal inversion is established, but the inversion is much weaker than the analogous inversion on Neptune. The mean temperature can be explained by solar heating in the 3.3 micron methane band with a methane mixing ratio of 4 x 10 to the -6th combined with the cooling effect of ethane with a mixing ratio of not greater than 4 x 10 to the -6th. The temperature variations are probably due to a photochemical process that has formed a Chapman layer.

  9. Voyager 2 Neptune targeting strategy

    Science.gov (United States)

    Potts, C. L.; Francis, K.; Matousek, S. E.; Cesarone, R. J.; Gray, D. L.

    1989-01-01

    The success of the Voyager 2 flybys of Neptune and Triton depends upon the ability to correct the spacecraft's trajectory. Accurate spacecraft delivery to the desired encounter conditions will promote the maximum science return. However, Neptune's great distance causes large a priori uncertainties in Neptune and Triton ephemerides and planetary system parameters. Consequently, the 'ideal' trajectory is unknown beforehand. The targeting challenge is to utilize the gradually improving knowledge as the spacecraft approaches Neptune to meet the science objectives, but with an overriding concern for spacecraft safety and a desire to limit propellant expenditure. A unique targeting strategy has been developed in response to this challenge. Through the use of a Monte Carlo simulation, candidate strategies are evaluated by the degree to which they meet these objectives and are compared against each other in determining the targeting strategy to be adopted.

  10. Energetic charged particles in the magnetosphere of Neptune

    International Nuclear Information System (INIS)

    Stone, E.C.; Cummings, A.C.; Looper, M.D.; Selesnick, R.S.; Lal, N.; McDonald, F.B.; Trainor, J.H.; Chenette, D.L.

    1989-01-01

    The Voyager 2 cosmic ray system (CRS) measured significant fluxes of energetic [approx-lt 1 megaelectron volt (MeV)] trapped electrons and protons in the magnetosphere of Neptune. The intensities at maximum near a magnetic L shell of 7, decreasing closer to the planet because of absorption by satellites and rings. In the region of the inner satellites of Neptune, the radiation belts have a complicated structure, which provides some constraints on the magnetic field geometry of the inner magnetosphere. Electron phase-space densities have a positive radial gradient, indicating that they diffuse inward from a source in the outer magnetosphere. Electron spectra from 1 to 5 MeV are generally well represented by power laws with indices near 6, which harden in the region of peak flux to power law indices of 4 to 5. Protons have significantly lower fluxes than electrons throughout the magnetosphere, with large anisotropies due to radial intensity gradients. The radiation belts resemble those of Uranus to the extent allowed by the different locations of the satellites, which limit the flux at each planet

  11. The atmospheric structure and dynamical properties of Neptune derived from ground-based and IUE spectrophotometry

    Science.gov (United States)

    Baines, Kevin H.; Smith, Wm. Hayden

    1990-01-01

    A wide range of recent full-disk spectral observations is used to constrain the atmospheric structure and dynamical properties of Neptune; analytical determinations are made of the abundances of such spectrally active gas species as the deep-atmosphere CH4 molar fraction and the mean ortho/para hydrogen ratio in the visible atmosphere, as well as stratospheric and tropospheric aerosol properties. Compared to Uranus, the greater abundance and shorter lifetimes of Neptunian particulates in the stratospheric region irradiated by the solar UV flux indicate that such radiation is the darkening agent of stratospheric aerosols on both planets.

  12. The atmosphere of Neptune - Results of radio occultation measurements with the Voyager 2 spacecraft

    Science.gov (United States)

    Lindal, G. F.; Lyons, J. R.; Sweetnam, D. N.; Eshleman, V. R.; Hinson, D. P.

    1990-01-01

    This paper presents the vertical temperature and composition profiles of Neptune's troposphere and stratosphere, covering an altitude of 250 km, obtained from radio tracking data that were acquired during Voyager-2's occultation by Neptune, which began near 62 deg N planetographic latitude and ended near 45 deg S latitude. In the computations, the He/H2 abundance ratio 15/85 was adapted, which is consistent with solar abundance estimates and with recent results from Uranus. It was assumed that aerosols and heavier gases such as CH4, NH3, H2S, and H2O have a negligible effect on the microwave refractivity above the 0.5 bar pressure level.

  13. Jupiter: as a planet

    International Nuclear Information System (INIS)

    1975-01-01

    The planet Jupiter, its planetary mass and atmosphere, radio waves emitted from Jupiter, thermal radiation, internal structure of Jupiter, and the possibility of life on Jupiter are discussed. Educational study projects are included

  14. rosuvastatin (JUPITER)

    DEFF Research Database (Denmark)

    Ridker, Paul M; MacFadyen, Jean G; Fonseca, Francisco A H

    2009-01-01

    were calculated across a range of end points, timeframes, and subgroups using data from Justification for the Use of statins in Prevention: an Intervention Trial Evaluating Rosuvastatin (JUPITER), a randomized evaluation of rosuvastatin 20 mg versus placebo conducted among 17 802 apparently healthy men...... infarction, stroke, revascularization, or death, the 5-year NNT within JUPITER was 20 (95% CI, 14 to 34). All subgroups had 5-year NNT values for this end point below 50; as examples, 5-year NNT values were 17 for men and 31 for women, 21 for whites and 19 for nonwhites, 18 for those with body mass index 300...

  15. Blackbody Radiation from Isolated Neptunes

    Science.gov (United States)

    Ginzburg, Sivan; Sari, Re'em; Loeb, Abraham

    2016-05-01

    Recent analyses of the orbits of some Kuiper belt objects hypothesize the presence of an undiscovered Neptune-size planet at a very large separation from the Sun. The energy budget of Neptunes on such distant orbits is dominated by the internal heat released by their cooling rather than solar irradiation (making them effectively “isolated”). The blackbody radiation that these planets emit as they cool may provide the means for their detection. Here, we use an analytical toy model to study the cooling and radiation of isolated Neptunes. This model can translate a detection (or a null detection) to a constraint on the size and composition of the hypothesized “Planet Nine.” Specifically, the thick gas atmosphere of Neptune-like planets serves as an insulating blanket that slows down their cooling. Therefore, a measurement of the blackbody temperature, {T}{{eff}}˜ 50 {{K}}, at which a Neptune emits, can be used to estimate the mass of its atmosphere, {M}{{atm}}. Explicitly, we find the relation {T}{{eff}}\\propto {M}{{atm}}1/12. Despite this weak relation, a measurement of the flux at the Wien tail can constrain the atmospheric mass, at least to within a factor of a few, and provide useful limits to possible formation scenarios of these planets. Finally, we constrain the size and composition of Planet Nine by combining our model with the null results of recent all-sky surveys.

  16. Saturn-like system around Uranus

    International Nuclear Information System (INIS)

    Bhattacharyya, J.C.; Bappu, M.K.V.

    1977-01-01

    It is stated that observations made at Kavalur (India) of the occultation of SAO158687 by Uranus on 10 March 1977 showed, in addition to the occultation by a satellite system termed the epsilon ring, a dimming of the light of the star close to the time when the atmosphere of the planet could have caused the phenomenon. Since then, the identities of the α β γ delta rings have also become well established, and a theoretical interpretation of their origin has been proposed. A close examination of the Kavalur photoelectric record is here described and several new features of the satellite ring system of Uranus are noted. (author)

  17. Uranus, Neptune, and Pluto and how to observe them and how to observe them

    CERN Document Server

    Schmude, Jr, Richard

    2009-01-01

    This fascinating volume is unique in that it gives a completely up-to-date summary of our current knowledge of the remote planets, and also explains how amateur astronomers can contribute to our knowledge of the remote planets.

  18. Some matters relating to the documentary evidence of the discovery of Neptune

    Science.gov (United States)

    Foster, N.

    2014-04-01

    The discovery of the planet Neptune was regarded as one of the greatest discoveries of the nineteenth century. Its existence was first detected, not by eye or with telescope, but by the mathematical analysis of the orbit of the planet Uranus. The perturbations of Uranus were under investigation by John Couch Adams (1819-92) in Cambridge, and Urban Le Verrier (1811-77) in Paris. Both these astronomers believed that the irregularities in the motion of Uranus could only be attributed to the action of an unknown planet of the Solar System. However, the circumstances of the discovery have once again become a matter of dispute and contention by some recent historians. My aim is to review the essential facts and the interpretation placed on them and to examine the conspiracy theories that have arisen from an examination of the documentary evidence. These conspiracy theories have detracted from Adams, the true merit of his early researches and his place in the history of the discovery. There has also been speculative allegations made of the character of Adams based on selected documentary evidence, which I believe is not necessarily a true representation of the facts. In presenting a fair portrayal of Adams's researches, I have reconstructed his 1845 October solution in a way that has not been done before.

  19. Significance of large Neptune-crossing objects for terrestrial catastrophism

    Science.gov (United States)

    Steel, D.

    2014-07-01

    Over the past few decades a substantial number of objects have been discovered on orbits beyond Neptune (i.e. transneptunian objects, in various sub-classes), crossing Neptune's orbit (here: the Neptune-crossers of interest), and also others crossing the orbits of any or all of the jovian planets (i.e. Centaurs). These range in size from tens of kilometres across to hundreds of kilometres and more. Although formally classified as minor planets/asteroids, plus a few dwarf planets, the physical reality of these objects is that they are giant comets. That is, they seem to be composed largely of ices and if they were to enter the inner solar system then they would demonstrate the commonly-observed behaviour of comets such as outgassing, and the formation of ion and dust tails. Commonly-observed cometary behaviour, however, also includes fragmentation events and sometimes complete disintegration for no apparent cause (such as tidal disruption or thermal stresses). One might therefore wonder what the implications would be for life on Earth and terrestrial catastrophism if and when one of these objects, say 100 to 500 kilometres in size, dropped into a short-period orbit with perihelion distance (q) less than 1 au; or even q ˜ 5 au, given what Jupiter's gravity might do to it. How often might such events occur? One way to address that question would be to conduct numerical integrations of suitable test orbits and identify how often small-q orbits result, but this comes up against the problem of identifying very-infrequent events (with annual probabilities per object perhaps of order 10^{-12}-10^{-10}. For example, Emel'yanenko et al. [1] recently followed test orbits for approximately 5 × 10^{14} particle-years (8,925 objects with 200 clones of each, for 300 Myr) but because these were selected on the basis of initial values of q only below 36 (rather than ˜30) au many were not immediately Neptune-crossers; however, many test particles did eventually migrate into small

  20. Trailing (L5) Neptune Trojans: 2004 KV18 and 2008 LC18

    International Nuclear Information System (INIS)

    Guan Pu; Zhou Liyong; Li Jian

    2012-01-01

    The population of Neptune Trojans is believed to be bigger than that of Jupiter Trojans and that of asteroids in the main belt, although only eight members of this distant asteroid swarm have been observed up to now. Six leading Neptune Trojans around the Lagrange point L 4 discovered earlier have been studied in detail, but two trailing ones found recently around the L 5 point, 2004 KV18 and 2008 LC18, have not yet been investigated. We report our investigations on the dynamical behaviors of these two new Neptune Trojans. Our calculations show that the asteroid 2004 KV18 is a temporary Neptune Trojan. Most probably, it was captured into the trailing Trojan cloud no earlier than 2.03 × 10 5 yr ago, and it will not maintain this position later than 1.65 × 10 5 yr in the future. Based on the statistics from our orbital simulations, we argue that this object is more like a scattered Kuiper belt object. By contrast, the orbit of 2008 LC18 is much more stable. Among the clone orbits spreading within the orbital uncertainties, a considerable portion of clones may survive on the L 5 tadpole orbits for 4 Gyr. The strong dependence of the stability on the semimajor axis and resonant angle suggests that further observations are badly required to constrain the orbit in the stable region. We also discuss the implications of the existence and dynamics of these two trailing Trojans over the history of the solar system.

  1. Equatorial waves in the stratosphere of Uranus

    Science.gov (United States)

    Hinson, David P.; Magalhaes, Julio A.

    1991-01-01

    Analyses of radio occultation data from Voyager 2 have led to the discovery and characterization of an equatorial wave in the Uranus stratosphere. The observed quasi-periodic vertical atmospheric density variations are in close agreement with theoretical predictions for a wave that propagates vertically through the observed background structure of the stratosphere. Quantitative comparisons between measurements obtained at immersion and at emersion yielded constraints on the meridional and zonal structure of the wave; the fact that the two sets of measurements are correlated suggests a wave of planetary scale. Two equatorial wave models are proposed for the wave.

  2. A retrieved upper limit of CS in Neptune's atmosphere

    Science.gov (United States)

    Iino, T.; Mizuno, A.; Nagahama, T.; Hirota, A.; Nakajima, T.

    2012-12-01

    We present our new result of CS(J=7-6), CO(J=3-2) observations of Neptune's atmosphere carried out with 10-m ASTE sub-mm waveband telescope on August 2010. As a result, while CS line was not detected with 6.4 mK 1-sigma r.m.s. noise level, CO line was detected as 282 mK with 9.7 mK noise level in antenna temperature scale. All of the observations were carried out with 512 MHz bandwidth and 500 kHz resolution, the total integration time for CS and CO were 23 m 40 s and 11 m 00 s, respectively. Abundances have been obtained from the comparison between the intensity and the synthesis spectra modeled by plane parallel 1-D radiative transfer code assuming various mixing ratio of each gas. The retrieved upper limit of CS mixing ratio was 0.03 ppb throughout tropopause to stratosphere. CO mixing ratio have been retrieved 1.0 ppm with errors +0.3 and -0.2 ppm, and the result was consistent with previous observation [1]. The origin of abundant CO in Neptune's atmosphere has been long discussed since its mixing ratio is 30 - 500 times higher than the value of other gas giants [2][3][4]. Assuming that all of CO is produced by thermochemical equilibrium process in deep interior of Neptune, required O/H value in interior is 440 times higher than the solar value [5]. For this reason, it is claimed that the external CO supply source, such as the impact of comet or asteroid, is also the possible candidates of the origin of CO along with the internal supply source [6]. In this observation, we searched the remnant gas of cometary impact in Neptune's atmosphere. Along with CO and HCN, CS could be one of the possible candidate of the remnant gas of cometary impact since CS was largely produced after the impact of comet SL/9 on Jupiter while many other major sulfur compounds have not been detected. Actually, derived L37-40. [7]Moreno et al., 2003. Planetary and Space Sciences 51, 591-611 [8]Zahnle et al.,1995. GRL 22, 1593-1596 [9]Feuchtgruber et al., 1999. Proceeding of the conference

  3. Three Temperate Neptunes Orbiting Nearby Stars

    Science.gov (United States)

    Fulton, Benjamin J.; Howard, Andrew W.; Weiss, Lauren M.; Sinukoff, Evan; Petigura, Erik A.; Isaacson, Howard; Hirsch, Lea; Marcy, Geoffrey W.; Henry, Gregory W.; Grunblatt, Samuel K.; Huber, Daniel; von Braun, Kaspar; Boyajian, Tabetha S.; Kane, Stephen R.; Wittrock, Justin; Horch, Elliott P.; Ciardi, David R.; Howell, Steve B.; Wright, Jason T.; Ford, Eric B.

    2016-10-01

    We present the discovery of three modestly irradiated, roughly Neptune-mass planets orbiting three nearby Solar-type stars. HD 42618 b has a minimum mass of 15.4 ± 2.4 {M}\\oplus , a semimajor axis of 0.55 au, an equilibrium temperature of 337 K, and is the first planet discovered to orbit the solar analogue host star, HD 42618. We also discover new planets orbiting the known exoplanet host stars HD 164922 and HD 143761 (ρ CrB). The new planet orbiting HD 164922 has a minimum mass of 12.9 ± 1.6 {M}\\oplus and orbits interior to the previously known Jovian mass planet orbiting at 2.1 au. HD 164922 c has a semimajor axis of 0.34 au and an equilibrium temperature of 418 K. HD 143761 c orbits with a semimajor axis of 0.44 au, has a minimum mass of 25 ± 2 {M}\\oplus , and is the warmest of the three new planets with an equilibrium temperature of 445 K. It orbits exterior to the previously known warm Jupiter in the system. A transit search using space-based CoRoT data and ground-based photometry from the Automated Photometric Telescopes (APTs) at Fairborn Observatory failed to detect any transits, but the precise, high-cadence APT photometry helped to disentangle planetary-reflex motion from stellar activity. These planets were discovered as part of an ongoing radial velocity survey of bright, nearby, chromospherically inactive stars using the Automated Planet Finder (APF) telescope at Lick Observatory. The high-cadence APF data combined with nearly two decades of radial velocity data from Keck Observatory and gives unprecedented sensitivity to both short-period low-mass, and long-period intermediate-mass planets. Based on observations obtained at the W. M. Keck Observatory, which is operated jointly by the University of California and the California Institute of Technology. Keck time was granted for this project by the University of Hawai‘I, the University of California, and NASA.

  4. Hot Jupiters and cool stars

    International Nuclear Information System (INIS)

    Villaver, Eva; Mustill, Alexander J.; Livio, Mario; Siess, Lionel

    2014-01-01

    Close-in planets are in jeopardy, as their host stars evolve off the main sequence (MS) to the subgiant and red giant phases. In this paper, we explore the influences of the stellar mass (in the range 1.5-2 M ☉ ), mass-loss prescription, planet mass (from Neptune up to 10 Jupiter masses), and eccentricity on the orbital evolution of planets as their parent stars evolve to become subgiants and red giants. We find that planet engulfment along the red giant branch is not very sensitive to the stellar mass or mass-loss rates adopted in the calculations, but quite sensitive to the planetary mass. The range of initial separations for planet engulfment increases with decreasing mass-loss rates or stellar masses and increasing planetary masses. Regarding the planet's orbital eccentricity, we find that as the star evolves into the red giant phase, stellar tides start to dominate over planetary tides. As a consequence, a transient population of moderately eccentric close-in Jovian planets is created that otherwise would have been expected to be absent from MS stars. We find that very eccentric and distant planets do not experience much eccentricity decay, and that planet engulfment is primarily determined by the pericenter distance and the maximum stellar radius.

  5. Global magnetic anomaly and aurora of Neptune

    International Nuclear Information System (INIS)

    Cheng, A.F.

    1990-01-01

    The large offset and tilt of Neptune's dipole magnetic field combine to create a global magnetic anomaly, analogous to but much more important than Earth's South Atlantic Anomaly. Energetic particle precipitation loss within the Neptune anomaly creates atmospheric drift shadows within which particle fluxes are greatly reduced. The energetic particle dropout observed by Voyager near closest approach occurred near the predicted times when Voyager passed within the atmospheric drift shadow. Extremely soft, structured bursts of ions and electrons within the drift shadow may result from plasma wave-induced pitch angle scattering of trapped particles confined near the magnetic equator. The dropout does not necessarily imply that Voyager passed through an Earth-like discrete auroral zone, as earlier reported. The ion and electron fluxes observed within the dropout period correspond to particles that must precipitate to Neptune's atmosphere within the anomaly region. This anomaly precipitation can account for a major portion of the ultraviolet emissions previously identified as Neptune aurora

  6. 2011 HM{sub 102}: DISCOVERY OF A HIGH-INCLINATION L5 NEPTUNE TROJAN IN THE SEARCH FOR A POST-PLUTO NEW HORIZONS TARGET

    Energy Technology Data Exchange (ETDEWEB)

    Parker, Alex H.; Holman, Matthew J.; McLeod, Brian A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Buie, Marc W.; Borncamp, David M.; Spencer, John R.; Stern, S. Alan [Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238 (United States); Osip, David J. [Carnegie Observatories, Las Campanas Observatory, Casilla 601, La Serena (Chile); Gwyn, Stephen D. J.; Fabbro, Sebastian; Kavelaars, J. J. [Canadian Astronomy Data Centre, National Research Council of Canada, 5071 W. Saanich Road, Victoria, BC V9E 2E7 (Canada); Benecchi, Susan D.; Sheppard, Scott S. [Department of Terrestrial Magnetism, Carnegie Institute of Washington, 5251 Broad Branch Road NW, Washington, DC 20015 (United States); Binzel, Richard P.; DeMeo, Francesca E. [Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Fuentes, Cesar I.; Trilling, David E. [Department of Physics and Astronomy, Northern Arizona University, S San Francisco St, Flagstaff, AZ 86011 (United States); Gay, Pamela L. [Center for Science, Technology, Engineering and Mathematics (STEM) Research, Education, and Outreach, Southern Illinois University, 1220 Lincoln Dr, Carbondale, IL 62901 (United States); Petit, Jean-Marc [CNRS, UTINAM, Universite de Franche Comte, Route de Gray, F-25030 Besancon Cedex, (France); Tholen, David J., E-mail: aparker@cfa.harvard.edu [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Dr, Honolulu, HI 96822 (United States); and others

    2013-04-15

    We present the discovery of a long-term stable L5 (trailing) Neptune Trojan in data acquired to search for candidate trans-Neptunian objects for the New Horizons spacecraft to fly by during an extended post-Pluto mission. This Neptune Trojan, 2011 HM{sub 102}, has the highest inclination (29. Degree-Sign 4) of any known member of this population. It is intrinsically brighter than any single L5 Jupiter Trojan at H{sub V} {approx} 8.18. We have determined its gri colors (a first for any L5 Neptune Trojan), which we find to be similar to the moderately red colors of the L4 Neptune Trojans, suggesting similar surface properties for members of both Trojan clouds. We also present colors derived from archival data for two L4 Neptune Trojans (2006 RJ{sub 103} and 2007 VL{sub 305}), better refining the overall color distribution of the population. In this document we describe the discovery circumstances, our physical characterization of 2011 HM{sub 102}, and this object's implications for the Neptune Trojan population overall. Finally, we discuss the prospects for detecting 2011 HM{sub 102} from the New Horizons spacecraft during its close approach in mid- to late-2013.

  7. 2011 HM102: DISCOVERY OF A HIGH-INCLINATION L5 NEPTUNE TROJAN IN THE SEARCH FOR A POST-PLUTO NEW HORIZONS TARGET

    International Nuclear Information System (INIS)

    Parker, Alex H.; Holman, Matthew J.; McLeod, Brian A.; Buie, Marc W.; Borncamp, David M.; Spencer, John R.; Stern, S. Alan; Osip, David J.; Gwyn, Stephen D. J.; Fabbro, Sébastian; Kavelaars, J. J.; Benecchi, Susan D.; Sheppard, Scott S.; Binzel, Richard P.; DeMeo, Francesca E.; Fuentes, Cesar I.; Trilling, David E.; Gay, Pamela L.; Petit, Jean-Marc; Tholen, David J.

    2013-01-01

    We present the discovery of a long-term stable L5 (trailing) Neptune Trojan in data acquired to search for candidate trans-Neptunian objects for the New Horizons spacecraft to fly by during an extended post-Pluto mission. This Neptune Trojan, 2011 HM 102 , has the highest inclination (29.°4) of any known member of this population. It is intrinsically brighter than any single L5 Jupiter Trojan at H V ∼ 8.18. We have determined its gri colors (a first for any L5 Neptune Trojan), which we find to be similar to the moderately red colors of the L4 Neptune Trojans, suggesting similar surface properties for members of both Trojan clouds. We also present colors derived from archival data for two L4 Neptune Trojans (2006 RJ 103 and 2007 VL 305 ), better refining the overall color distribution of the population. In this document we describe the discovery circumstances, our physical characterization of 2011 HM 102 , and this object's implications for the Neptune Trojan population overall. Finally, we discuss the prospects for detecting 2011 HM 102 from the New Horizons spacecraft during its close approach in mid- to late-2013.

  8. Particle excitation, airglow and H2 vibrational disequilibrium in the atmosphere of Jupiter

    International Nuclear Information System (INIS)

    Shemansky, D.E.

    1984-09-01

    The extreme ultraviolet EUV emission produced by particle excitation of the hydrogen atmospheres of Jupiter and Saturn is examined using model calculations to determine the nature of the energy deposition process and the effect of such processes on atmospheric structure. Tasks ranging from examination of phenomenologically related processes on Saturn and Titan to analysis of experimental laboratory data required to allow accurate modeling of emissions from hydrogenic atmospheres are investigated. An explanation of the hydrogen H Ly(alpha) bulge in Jupiter's emission from the equatorial region is presented. It is proposed that Saturn, rather than Titan is the major source of the extended hydrogen cloud. The atomic hydrogen detected at the rings of Saturn may originate predominantly from the same source. A cross calibration is obtained between the Pioneer 10 EUV photometer and the Voyager EUV spectrometers, thus providing a direct measure of the temporal morphology of Jupiter between a minimum and a maximum in solar activity. Atomic and molecular data required for the research program are analyzed. An extrapolation of conditions in the upper atmospheres of Jupiter and Saturn produces a predicted condition at Uranus in terms of excitation and hydrogen escape rates that may be observed at Voyager-Uranus encounter

  9. Orbits of the inner satellites of Neptune

    Science.gov (United States)

    Brozovic, Marina; Showalter, Mark R.; Jacobson, Robert Arthur; French, Robert S.; de Pater, Imke; Lissauer, Jack

    2018-04-01

    We report on the numerically integrated orbits of seven inner satellites of Neptune, including S/2004 N1, the last moon of Neptune to be discovered by the Hubble Space Telescope (HST). The dataset includes Voyager imaging data as well as the HST and Earth-based astrometric data. The observations span time period from 1989 to 2016. Our orbital model accounts for the equatorial bulge of Neptune, perturbations from the Sun and the planets, and perturbations from Triton. The initial orbital integration assumed that the satellites are massless, but the residuals improved significantly as the masses adjusted toward values that implied that the density of the satellites is in the realm of 1 g/cm3. We will discuss how the integrated orbits compare to the precessing ellipses fits, mean orbital elements, current orbital uncertainties, and the need for future observations.

  10. Voyage to Jupiter.

    Science.gov (United States)

    Morrison, David; Samz, Jane

    This publication illustrates the features of Jupiter and its family of satellites pictured by the Pioneer and the Voyager missions. Chapters included are: (1) "The Jovian System" (describing the history of astronomy); (2) "Pioneers to Jupiter" (outlining the Pioneer Mission); (3) "The Voyager Mission"; (4)…

  11. On the existence of a comet belt beyond Neptune

    International Nuclear Information System (INIS)

    Fernandez, J.A.

    1980-01-01

    The possible existence of a comet belt in connection with the origin of the short-period comets is analysed. It is noted that the current theory - that these comets originate as near-parabolic comets captured by Jupiter and the other giant planets - implies an excessive wastage of comets lost in hyperbolic orbits, which is avoided in the present model. The following picture is predicted. Solid conglomerates up to approximately 10 18 g were formed by gravitational instabilities in the belt region (about 35 to 50 AU). A further fragmentation-accretion process led to a power-law mass distribution similar to that observed in the asteroids. Since then, close encounters between members of the belt have provoked the diffusion of some of them with the effect that they have become subject to the strong perturbations of Neptune. Of these a small number pass from one planet to the next inside and end as short-period comets. By means of a Monte Carlo method, the influence of close encounters between belt comets is then studied in relation to the diffusion of their orbits. It is concluded that if such a belt contains members with masses equal to or greater than that of Ceres, the orbital diffusion could proceed fast enough to maintain the number of observed short-period comets in a steady state. (author)

  12. Concerning the mass of the suggested sixth satellite of Uranus

    International Nuclear Information System (INIS)

    Steigmann, G.A.

    1979-01-01

    Comparison of the strength of resonances arising from the known satellites of Uranus in the vicinity of the α and γ rings, with the strengths of probable resonances at the β and delta rings, suggest that the β and delta rings might be associated with an undiscovered satellite of mass approximately 0.4 mass of Miranda. This satellite is predicted to be a 17 to 18 mag object moving in a near-circular orbit, of low inclination to the plane of the rings, at a distance of 105 221 km from Uranus. (author)

  13. Expectations for Particulate Contamination Relevant to in Situ Atmospheric Sampling for Compositional Analysis at Uranus

    Science.gov (United States)

    Wong, M. H.

    2017-12-01

    NASA and ESA are considering options for in situ science with atmospheric entry probes to the ice giants Uranus and Neptune. Nominal probe entry mass is in the 300-kg range, although a miniaturized secondary probe option is being studied in the 30-kg range. In all cases, compositional sampling would commence near the 100-mbar level at Uranus, after ejection of the heat shield and deployment of the descent parachute. In this presentation, I review existing literature on the composition, mass loading, and vertical distribution of condensed material that the probe may encounter. Sample inlets for measurement of the gas composition should be heated to avoid potential buildup of condensate, which would block the flow of atmospheric gas into composition sensors. Heating rate and temperature values -- sufficient to keep sample inlets clean under various assumptions -- will be presented. Three main types of condensed material will be considered: Stratospheric hydrocarbon ices: Solar UV photolyzes CH4, leading to the production of volatile hydrocarbons with higher C/H ratios. These species diffuse from their production regions into colder levels where the ices of C2H2, C2H6, and C4H2 condense. Some studies have also considered condensation of C3H8, C4H10, C6H6, and C6H2. Gunk: The hydrocarbon ices are thought to become polymerized due to irradiation from solar UV. The exact composition of the resulting gunk is not known. Solid-state photochemical processing may produce the traces of reddish (blue-absorbing) haze material, present in the troposphere at temperatures warm enough to sublimate the simple hydrocarbon ices. Tropospheric ices: In the region accessible to probes under study (P < 10 bar), much thicker condensation clouds may form from volatile gases CH4, NH3, and H2S. If large amounts of NH3 are sequestered in the deeper H2O liquid cloud, then the S/N ratio could exceed 1 in the probe-accessible region of the atmosphere, leading to NH4SH and H2S ices below the CH4

  14. Jupiter Environment Tool

    Science.gov (United States)

    Sturm, Erick J.; Monahue, Kenneth M.; Biehl, James P.; Kokorowski, Michael; Ngalande, Cedrick,; Boedeker, Jordan

    2012-01-01

    The Jupiter Environment Tool (JET) is a custom UI plug-in for STK that provides an interface to Jupiter environment models for visualization and analysis. Users can visualize the different magnetic field models of Jupiter through various rendering methods, which are fully integrated within STK s 3D Window. This allows users to take snapshots and make animations of their scenarios with magnetic field visualizations. Analytical data can be accessed in the form of custom vectors. Given these custom vectors, users have access to magnetic field data in custom reports, graphs, access constraints, coverage analysis, and anywhere else vectors are used within STK.

  15. Radio emission from Jupiter

    International Nuclear Information System (INIS)

    Velusamy, T.

    1976-01-01

    The basic features of the different radio emissions from the planet Jupiter are reviewed. These radio emissions characterized into three types as thermal, decimetric and decametric, are discussed. The coherent emission mechanism for the origin of the decametric bursts and the acceleration mechanism for relativistic electrons in the decimetric radiation have not been properly understood. The emissions are much related to the magnetic field of Jupiter. The system III rotation period for Jupiter has been calculated as 092 55 m 29.74 S. (A.K.)

  16. Results of modern processing of the photographic observations of Uranus and Neptune from Archives of UkrVO

    Science.gov (United States)

    Protsyuk, Yu. I.; Kovylianska, O. E.; Protsyuk, S. V.; Yizhakevych, O. M.; Andruk, V. M.; Golovnia, V. V.; Yuldoshev, Q. K.

    2017-02-01

    The bulk of planet observations was obtained in RI MAO and MAO NASU from 1961 to 1994. Plates from AI UAS were also used. Each plate of NAO was scanned 6 times, in other observatories - only once. All images are processed, most of them are identified and the equatorial coordinates of all objects were obtained. Positional accuracy of the reference stars has value of 0.04"-0.30". Standard deviation of the planets' position is in the range 0.10-0.12 pixels, that corresponds, depending on the scale, from 0".08 to 0".26. The comparison of the new topocentric positions of the planets with JPL/HORIZONS ephemeris was made. Calculation of (O-C) values and their standard deviation is obtained.

  17. SECULAR CHAOS AND THE PRODUCTION OF HOT JUPITERS

    International Nuclear Information System (INIS)

    Wu Yanqin; Lithwick, Yoram

    2011-01-01

    In a planetary system with two or more well-spaced, eccentric, inclined planets, secular interactions may lead to chaos. The innermost planet may gradually become very eccentric and/or inclined as a result of the secular degrees of freedom drifting toward equipartition of angular momentum deficit. Secular chaos is known to be responsible for the eventual destabilization of Mercury in our own solar system. Here we focus on systems with three giant planets. We characterize the secular chaos and demonstrate the criterion for it to occur, but leave a detailed understanding of secular chaos to a companion paper. After an extended period of eccentricity diffusion, the inner planet's pericenter can approach the star to within a few stellar radii. Strong tidal interactions and ensuing tidal dissipation extract orbital energy from the planet and pull it inward, creating a hot Jupiter. In contrast to other proposed channels for the production of hot Jupiters, such a scenario (which we term 'secular migration') explains a range of observations: the pile-up of hot Jupiters at 3 day orbital periods, the fact that hot Jupiters are in general less massive than other radial velocity planets, that they may have misaligned inclinations with respect to stellar spin, and that they have few easily detectable companions (but may have giant companions in distant orbits). Secular migration can also explain close-in planets as low in mass as Neptune; and an aborted secular migration can explain the 'warm Jupiters' at intermediate distances. In addition, the frequency of hot Jupiters formed via secular migration increases with stellar age. We further suggest that secular chaos may be responsible for the observed eccentricities of giant planets at larger distances and that these planets could exhibit significant spin-orbit misalignment.

  18. The light-water-reactor version of the Uranus integral fuel-rod code

    International Nuclear Information System (INIS)

    Moreno, A.; Lassmann, K.

    1977-01-01

    The LWR of the Uranus code, a digital computer programme for the thermal and mechanical analysis of fuel rods, is presented. Material properties are discussed and their effect on integral fuel rod behaviour elaborated via Uranus results for some carefully selected reference experiments. The numerical results do not represent post-irradiation analysis of in-pile experiments, they illustrate rather typical and diverse Uranus capabilities. The performance test shows that Uranus is reliable and efficient, thus the code is a most valuable tool in fuel fod analysis work. K. Lassmann developed the LWR version of the Uranus code, material properties were reviewed and supplied by A. Moreno. (author)

  19. Jupiter Laser Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Jupiter Laser Facility is an institutional user facility in the Physical and Life Sciences Directorate at LLNL. The facility is designed to provide a high degree...

  20. The Jupiter program

    International Nuclear Information System (INIS)

    Ramirez, J.J.

    1995-01-01

    Jupiter is a Sandia initiative to develop the next generation of fast Z-pinch drivers for applications to high energy density physics, inertial confinement fusion, and radiation effects simulation. Jupiter will also provide unique capabilities for science research in a broad spectrum of areas involving ultra high magnetic fields, hot/dense plasmas, x-ray physics, intense neutron sources, etc. The program is based on the premise that a single facility using magnetically driven implosions can meet the needs in these multiple program areas. Jupiter requires a 450-500 TW, 8-10 MV, ∼ 100 ns pulsed power generator to impart - 15 MJ kinetic energy to an imploding plasma load. The baseline concept uses a highly modular, robust architecture with demonstrated performance reliability. The design also has the flexibility to drive longer implosion times. This paper describes the Jupiter accelerator concept, and the research underway to establish the technological readiness to proceed with construction of the facility

  1. Jupiter and planet Earth

    International Nuclear Information System (INIS)

    1975-01-01

    The evolution of Jupiter and Earth are discussed along with their atmospheres, the radiation belts around both planets, natural satellites, the evolution of life, and the Pioneer 10. Educational study projects are also included

  2. Seismology of the Jupiter

    International Nuclear Information System (INIS)

    Vorontsov, S.V.; Gudkova, T.V.; Zharkov, V.N.

    1989-01-01

    The structure and diagnostic properties of the spectrum of free oscillations of the models of the Jupiter are discussed. The spectrum is very sensitive to the properties of the inner core and density discontinuities in the interior of the planet. It is shown that in seismology of the Jupiter unlike to solar seismology, it is not possible to use the asymptotic theory for investigation of the high-frequency part of the acoustic spectrum

  3. Properties of the Irregular Satellite System around Uranus Inferred from K2 , Herschel , and Spitzer Observations

    Energy Technology Data Exchange (ETDEWEB)

    Farkas-Takács, A.; Kiss, Cs.; Pál, A.; Molnár, L.; Szabó, Gy. M.; Hanyecz, O.; Sárneczky, K.; Szabó, R.; Marton, G.; Szakáts, R.; Kiss, L. L. [Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, Konkoly Thege Miklós út 15-17, H-1121 Budapest (Hungary); Mommert, M. [Department of Physics and Astronomy, Northern Arizona University, P.O. Box 6010, Flagstaff, AZ 86011 (United States); Müller, T., E-mail: farkas.aniko@csfk.mta.hu [Max-Plank-Institut für extraterrestrsiche Pyhsik, Garching (Germany)

    2017-09-01

    In this paper, we present visible-range light curves of the irregular Uranian satellites Sycorax, Caliban, Prospero, Ferdinand, and Setebos taken with the Kepler Space Telescope over the course of the K2 mission. Thermal emission measurements obtained with the Herschel /PACS and Spitzer /MIPS instruments of Sycorax and Caliban were also analyzed and used to determine size, albedo, and surface characteristics of these bodies. We compare these properties with the rotational and surface characteristics of irregular satellites in other giant planet systems and also with those of main belt and Trojan asteroids and trans-Neptunian objects. Our results indicate that the Uranian irregular satellite system likely went through a more intense collisional evolution than the irregular satellites of Jupiter and Saturn. Surface characteristics of Uranian irregular satellites seem to resemble the Centaurs and trans-Neptunian objects more than irregular satellites around other giant planets, suggesting the existence of a compositional discontinuity in the young solar system inside the orbit of Uranus.

  4. Properties of the Irregular Satellite System around Uranus Inferred from K2, Herschel, and Spitzer Observations

    Science.gov (United States)

    Farkas-Takács, A.; Kiss, Cs.; Pál, A.; Molnár, L.; Szabó, Gy. M.; Hanyecz, O.; Sárneczky, K.; Szabó, R.; Marton, G.; Mommert, M.; Szakáts, R.; Müller, T.; Kiss, L. L.

    2017-09-01

    In this paper, we present visible-range light curves of the irregular Uranian satellites Sycorax, Caliban, Prospero, Ferdinand, and Setebos taken with the Kepler Space Telescope over the course of the K2 mission. Thermal emission measurements obtained with the Herschel/PACS and Spitzer/MIPS instruments of Sycorax and Caliban were also analyzed and used to determine size, albedo, and surface characteristics of these bodies. We compare these properties with the rotational and surface characteristics of irregular satellites in other giant planet systems and also with those of main belt and Trojan asteroids and trans-Neptunian objects. Our results indicate that the Uranian irregular satellite system likely went through a more intense collisional evolution than the irregular satellites of Jupiter and Saturn. Surface characteristics of Uranian irregular satellites seem to resemble the Centaurs and trans-Neptunian objects more than irregular satellites around other giant planets, suggesting the existence of a compositional discontinuity in the young solar system inside the orbit of Uranus.

  5. Alfven waves and associated energetic ions downstream from Uranus

    International Nuclear Information System (INIS)

    Zhang, Ming; Belcher, J.W.; Richardson, J.D.; Smith, C.W.

    1991-01-01

    The authors report the observation of low-frequency waves in the solar wind downstream from Uranus. These waves are observed by the Voyager spacecraft for more than 2 weeks after the encounter with Uranus and are present during this period whenever the interplanetary magnetic field is oriented such that the field lines intersect the Uranian bow shock. The magnetic field and velocity components transverse to the background field are strongly correlated, consistent with the interpretation that these waves are Alfvenic and/or fast-mode waves. The waves have a spacecraft frame frequency of about 10 -3 Hz, and when first observed near the bow shock have an amplitude comparable to the background field. As the spacecraft moves farther from Uranus, the amplitude decays. The waves appear to propagate along the magnetic field lines outward from Uranus and are right-hand polarized. Theory suggests that these waves are generated in the upstream region by a resonant instability with a proton beam streaming along the magnetic field lines. The solar wind subsequently carries these waves downstream to the spacecraft location. These waves are associated with the presence of energetic (> 28 keV) ions observed by the low-energy charged particle instrument. These ions appear two days after the start of the wave activity and occur thereafter whenever the Alfven waves occur, increasing in intensity away from Uranus. The ions are argued to originate in the Uranian magnetosphere, but pitch-angle scattering in the upstream region is required to bring them downstream to the spacecraft location

  6. Status of JUPITER Program

    International Nuclear Information System (INIS)

    Inoue, Teruji; Shirakata, Keisho; Kinjo, Katsuya; Ikegami, Tetsuo; Yamamoto, Masaaki.

    1981-01-01

    The criticality experiment program for large fast reactors by the joint research of the Power Reactor and Nuclear Fuel Development Corp. and the Department of Energy, USA, is called JUPITER Program. The experiment was carried out from April, 1978, to August, 1979, using the zero power plutonium reactor in ANL, and the analysis is carried out independently in Japan and USA. The experiment this time was carried out with two assemblies, ZPPR-9 and 10, and it is called JUPITER Phase 1. Two engineers were dispatched from PNC to ANL-Idaho for two years from August, 1978, and they took part in the planning, execution and analysis of the experiment to obtain the informations. The FBR Core Design Committee was installed in PNC, and has studied the core plan, experimental plan and the course of analysis. The JUPITER Phase 1 is the bench mark experiment to obtain the informations required at the initial stage of the nuclear design of demonstration reactor cores. The rating, object and progress of the JUPITER Phase 1, the outline of experiment, and the present state of the analysis of experiment are described. Hereafter, the general evaluation of the JUPITER Phase 1 will be carried out to clarify the problems when the present method of analysis is applied to large homogeneous reactors. Also the bench mark experiment on large heterogeneous reactors will be planned. (Kako, I.)

  7. Exploring the diversity of Jupiter-class planets.

    Science.gov (United States)

    Fletcher, Leigh N; Irwin, Patrick G J; Barstow, Joanna K; de Kok, Remco J; Lee, Jae-Min; Aigrain, Suzanne

    2014-04-28

    Of the 900+ confirmed exoplanets discovered since 1995 for which we have constraints on their mass (i.e. not including Kepler candidates), 75% have masses larger than Saturn (0.3 MJ), 53% are more massive than Jupiter and 67% are within 1 AU of their host stars. When Kepler candidates are included, Neptune-sized giant planets could form the majority of the planetary population. And yet the term 'hot Jupiter' fails to account for the incredible diversity of this class of astrophysical object, which exists on a continuum of giant planets from the cool jovians of our own Solar System to the highly irradiated, tidally locked hot roasters. We review theoretical expectations for the temperatures, molecular composition and cloud properties of hydrogen-dominated Jupiter-class objects under a variety of different conditions. We discuss the classification schemes for these Jupiter-class planets proposed to date, including the implications for our own Solar System giant planets and the pitfalls associated with compositional classification at this early stage of exoplanetary spectroscopy. We discuss the range of planetary types described by previous authors, accounting for (i) thermochemical equilibrium expectations for cloud condensation and favoured chemical stability fields; (ii) the metallicity and formation mechanism for these giant planets; (iii) the importance of optical absorbers for energy partitioning and the generation of a temperature inversion; (iv) the favoured photochemical pathways and expectations for minor species (e.g. saturated hydrocarbons and nitriles); (v) the unexpected presence of molecules owing to vertical mixing of species above their quench levels; and (vi) methods for energy and material redistribution throughout the atmosphere (e.g. away from the highly irradiated daysides of close-in giants). Finally, we discuss the benefits and potential flaws of retrieval techniques for establishing a family of atmospheric solutions that reproduce the

  8. Neptune's 5:2 mean motion resonance in the Kuiper Belt

    Science.gov (United States)

    Lan, Lei; Malhotra, Renu

    2018-04-01

    Recent observations of distant Kuiper belt objects (KBOs) in Neptune's 5:2 mean motion resonance (MMR) present two dynamical puzzles: this third order MMR, located at a semi-major axis of about 55 AU, hosts a surprisingly large population, comparable to the well-known and prominent populations of Plutinos and Twotinos in the 3:2 and the 2:1 MMRs, respectively; secondly, the eccentricities of these resonant KBOs are concentrated near ∼0.4. To shed light on these puzzles, we investigate the phase space structure near this resonance with use of Poincaré sections of the circular planar restricted three body model, for the full range of eccentricities, (0—1). With this non-perturbative numerical analysis, we find that the resonance width in semi-major axis is narrow for very small eccentricities, but widens dramatically for eccentricities ≥ 0.2. The resonance width reaches a maximum near eccentricity 0.4, where it is similar to the maximum widths of the 2:1 and 3:2 MMRs. We confirm these results with numerical simulations of the three dimensional N-body problem of KBOs in the gravitational field of the Sun and the four giant planets; our simulations include a wide range of orbital inclinations of the KBOs relative to the solar system’s invariable plane. From these simulations, we find that the boundaries of the stable zone of the 5:2 MMR in the semimajor axis—eccentricity plane are very similar to those found with the simplified circular planar restricted three body model of the Sun-Neptune-KBO, with the caveat that orbits of eccentricity above ~0.55 are long term unstable; such orbits, which have perihelion distance less than ~25 AU, are phase-protected from close encounters with Neptune but not from destabilizing encounters with Uranus. Additionally, the numerical simulations show that the long term stability of KBOs in Neptune’s 5:2 MMR is only mildly sensitive to KBO inclination. We conclude that the two dynamical puzzles presented by the observations

  9. Sharpening Up Jupiter

    Science.gov (United States)

    2008-10-01

    New image-correction technique delivers sharpest whole-planet ground-based picture ever A record two-hour observation of Jupiter using a superior technique to remove atmospheric blur has produced the sharpest whole-planet picture ever taken from the ground. The series of 265 snapshots obtained with the Multi-Conjugate Adaptive Optics Demonstrator (MAD) prototype instrument mounted on ESO's Very Large Telescope (VLT) reveal changes in Jupiter's smog-like haze, probably in response to a planet-wide upheaval more than a year ago. Sharpening Up Jupiter ESO PR Photo 33/08 Sharpening Up Jupiter Being able to correct wide field images for atmospheric distortions has been the dream of scientists and engineers for decades. The new images of Jupiter prove the value of the advanced technology used by MAD, which uses two or more guide stars instead of one as references to remove the blur caused by atmospheric turbulence over a field of view thirty times larger than existing techniques [1]. "This type of adaptive optics has a big advantage for looking at large objects, such as planets, star clusters or nebulae," says lead researcher Franck Marchis, from UC Berkeley and the SETI Institute in Mountain View, California, USA. "While regular adaptive optics provides excellent correction in a small field of view, MAD provides good correction over a larger area of sky. And in fact, were it not for MAD, we would not have been able to perform these amazing observations." MAD allowed the researchers to observe Jupiter for almost two hours on 16 and 17 August 2008, a record duration, according to the observing team. Conventional adaptive optics systems using a single Jupiter moon as reference cannot monitor Jupiter for so long because the moon moves too far from the planet. The Hubble Space Telescope cannot observe Jupiter continuously for more than about 50 minutes, because its view is regularly blocked by the Earth during Hubble's 96-minute orbit. Using MAD, ESO astronomer Paola Amico

  10. Extreme Worlds of the Outer Solar System: Dynamic Processes on Uranus & Io

    Science.gov (United States)

    Kleer, Katherine Rebecca de

    A central goal of planetary science is the creation of a framework within which the properties of each solar system body can be understood as the product of initial conditions acted on by fundamental physical processes. The solar system's extreme worlds -- those objects that lie at the far ends of the spectrum in terms of planetary environment -- bring to light our misconceptions and present us with opportunities to expand and generalize this framework. Unraveling the processes at work in diverse planetary environments contextualizes our understanding of Earth, and provides a basis for interpreting specific signatures from planets beyond our own solar system. Uranus and Io, with their unusual planetary environments, present two examples of such worlds in the outer solar system. Uranus, one of the outer solar system's ice giants, produces an anomalously low heat flow and orbits the sun on its side. Its relative lack of bright storm features and its bizarre multi-decadal seasons provide insight into the relative effects of internal heat flow and time- varying solar insolation on atmospheric dynamics, while its narrow rings composed of dark, macroscopic particles encode the history of bombardment and satellite disruption within the system. Jupiter's moon Io hosts the most extreme volcanic activity anywhere in the solar system. Its tidally-powered geological activity provides a window into this satellite's interior, permitting rare and valuable investigations into the exchange of heat and materials between interiors and surfaces. In particular, Io provides a laboratory for studying the process of tidal heating, which shapes planets and satellites in our solar system and beyond. A comparison between Earth and Io contextualizes the volcanism at work on our home planet, revealing the effects of planetary size, atmospheric density, and plate tectonics on the style and mechanisms of geological activity. This dissertation investigates the processes at work on these solar

  11. Uranus: a rapid prototyping tool for FPGA embedded computer vision

    Science.gov (United States)

    Rosales-Hernández, Victor; Castillo-Jimenez, Liz; Viveros-Velez, Gilberto; Zuñiga-Grajeda, Virgilio; Treviño Torres, Abel; Arias-Estrada, M.

    2007-01-01

    The starting point for all successful system development is the simulation. Performing high level simulation of a system can help to identify, insolate and fix design problems. This work presents Uranus, a software tool for simulation and evaluation of image processing algorithms with support to migrate them to an FPGA environment for algorithm acceleration and embedded processes purposes. The tool includes an integrated library of previous coded operators in software and provides the necessary support to read and display image sequences as well as video files. The user can use the previous compiled soft-operators in a high level process chain, and code his own operators. Additional to the prototyping tool, Uranus offers FPGA-based hardware architecture with the same organization as the software prototyping part. The hardware architecture contains a library of FPGA IP cores for image processing that are connected with a PowerPC based system. The Uranus environment is intended for rapid prototyping of machine vision and the migration to FPGA accelerator platform, and it is distributed for academic purposes.

  12. Jupiter's Big Bang.

    Science.gov (United States)

    McDonald, Kim A.

    1994-01-01

    Collision of a comet with Jupiter beginning July 16, 1994 will be observed by astronomers worldwide, with computerized information relayed to a center at the University of Maryland, financed by the National Aeronautics and Space Administration and National Science Foundation. Geologists and paleontologists also hope to learn more about earth's…

  13. Investigation of atmospheric waves on Neptune

    Science.gov (United States)

    Eshleman, Von R.; Hinson, David P.

    1994-01-01

    This document constitutes the final report for grant NAGW-2442 of the Neptune Data Analysis Program, which supported research concerning atmospheric dynamics on Neptune. Professor Von R. Eshleman was the principal investigator. David P. Hinson was a Co-Investigator. The grant covered the period 1 March 1991 through 31 August 1994, including a six month no-cost extension. Funding from this grant resulted in publication of one journal article and one book chapter as well as presentation of results at two conferences and in numerous seminars. A complete bibliography is given below. A copy of the journal article is attached along with abstracts from the book chapter and the conference presentations. With support from this grant we extended our analysis and interpretation of the Voyager Project. This research contributed to an improvement in our basic understanding of atmospheric dynamics on Neptune. The highlight was the discovery and characterization of inertio-gravity waves in the troposphere and stratosphere. Results include measures of basic wave properties, such as amplitudes and vertical wavelengths, as well as estimates of the effect of the waves on the photochemistry and momentum balance of the stratosphere. This investigation also yielded a better understanding of the potential of radio occultation experiments for studies of atmospheric waves. At the same time we developed new methods of data analysis for exploiting these capabilities. These are currently being applied to radio occultation data obtained with the Magellan spacecraft to study waves in the atmosphere of Venus. Future planetary missions, such as Mars Global Surveyor and Cassini, will benefit from these accomplishments.

  14. Progress on the NEPTUNE Canada Seismograph Network

    Science.gov (United States)

    Rogers, G. C.; Meldrum, R. D.; Heesemann, M.; Mulder, T. L.; Brillon, C. D.; Cassidy, J. F.

    2012-12-01

    NEPTUNE Canada is the world's first deep-sea regional multi-disciplinary scientific cabled ocean observatory. In the fall of 2007 an 800 kilometer ring of powered fiber optic cable was laid on the seafloor over the northern part of the Juan de Fuca plate and connected to a shore facility near Port Alberni on Vancouver Island. In September 2009, three broadband OBS packages were deployed in the form of a large triangle with apexes at mid plate near ODP 1027 (water depth of 2654m) and two sites on the continental slope, near ODP 889 (1256m) and Barkley Canyon (396m). The broadband systems comprise a broadband seismometer and strong motion accelerometer in a spherical titanium case surficially buried in a caisson backfilled with glass beads. Noise levels observed are as expected with the spectra being similar to, or quieter than, coastal seismograph stations in approximately the 10 to 20 second period range. The OBS's have higher noise levels at longer periods where ocean swells and the resultant infragravity waves dominate the noise spectra, and in the 1-10 Hz bandwidth typically used for locating local earthquakes. The shallowest site at Barkley Canyon has the highest noise levels. A small array, about 6 km in maximum dimension, is under construction on the Endeavour segment of the Juan de Fuca Ridge to record earthquake activity in the vicinity of the many NEPTUNE Canada multi-disciplinary ridge experiments. Two short period instruments were installed there in 2010. A broadband instrument and two additional short period instruments are planned to complete the initial ridge array. Even though the NEPTUNE Canada seismograph network is not yet complete, measured by the use of its data, it is a success already. The data are routinely used along with data from land seismographs of the Canadian National Seismograph Network for locating earthquakes in the region. However, the smallest seismic arrivals picked on the land stations cannot be routinely picked on the OBS

  15. NEPTUNE: a modular system for light-water reactor calculation

    International Nuclear Information System (INIS)

    Bouchard, J.; Kanevoky, A.; Reuss, P.

    1975-01-01

    A complete modular system of light water reactor calculations has been designed. It includes basic nuclear data processing, the APOLLO phase: transport calculations for cells, multicells, fuel assemblies or reactors, the NEPTUNE phase: reactor calculations. A fuel management module, devoted to the automatic determination of the best shuffling strategy is included in NEPTUNE [fr

  16. THE COLOR DIFFERENCES OF KUIPER BELT OBJECTS IN RESONANCE WITH NEPTUNE

    International Nuclear Information System (INIS)

    Sheppard, Scott S.

    2012-01-01

    The optical colors of 58 objects in mean motion resonance with Neptune were obtained. The various Neptune resonant populations were found to have significantly different surface color distributions. The 5:3 and 7:4 resonances have semimajor axes near the middle of the main Kuiper Belt and both are dominated by ultra-red material (spectral gradient: S ∼> 25). The 5:3 and 7:4 resonances have statistically the same color distribution as the low-inclination 'cold' classical belt. The inner 4:3 and distant 5:2 resonances have objects with mostly moderately red colors (S ∼ 15), similar to the scattered and detached disk populations. The 2:1 resonance, which is near the outer edge of the main Kuiper Belt, has a large range of colors with similar numbers of moderately red and ultra-red objects at all inclinations. The 2:1 resonance was also found to have a very rare neutral colored object showing that the 2:1 resonance is really a mix of all object types. The inner 3:2 resonance, like the outer 2:1, has a large range of objects from neutral to ultra-red. The Neptune Trojans (1:1 resonance) are only slightly red (S ∼ 9), similar to the Jupiter Trojans. The inner 5:4 resonance only has four objects with measured colors but shows equal numbers of ultra-red and moderately red objects. The 9:5, 12:5, 7:3, 3:1, and 11:3 resonances do not have reliable color distribution statistics since few objects have been observed in these resonances, though it appears noteworthy that all three of the measured 3:1 objects have only moderately red colors, similar to the 4:3 and 5:2 resonances. The different color distributions of objects in mean motion resonance with Neptune are likely a result from the disruption of the primordial Kuiper Belt from the scattering and migration of the giant planets. The few low-inclination objects known in the outer 2:1 and 5:2 resonances are mostly only moderately red. This suggests if the 2:1 and 5:2 have a cold low-inclination component, the objects

  17. Further development of NEPTUN photon tagging facility

    Energy Technology Data Exchange (ETDEWEB)

    Symochko, Dmytro; Arnould, Michaela; Aumann, Thomas; Baumann, Martin; Pietralla, Norbert; Scheit, Heiko; Semmler, Diego; Walz, Christopher [Institut fuer Kernphysik, Darmstadt Univ. (Germany)

    2016-07-01

    The low-energy photon tagging facility NEPTUN at the superconducting Darmstadt linear accelerator (SDALINAC) has been constructed with the aim to study the photoabsorption cross section of the nuclei in the energy regions of Pygmy Dipole and Giant Dipole Resonances. Recently it went through the series of commissioning runs, which proved the concept and the ability of NEPTUN to tag the discreet nuclear states. Also, based on the results of the commissioning, major upgrade was developed to optimize the setup. Upgraded tagger will be able to operate with 60 MeV electron beam and will have extended focal plane with energy bite of more than 10 MeV. After completion of upgrade it will be possible to perform total dipole response measurement in the energy region 5-35 MeV for one target using only 2-3 settings of the spectrometer. Presentation will focus on the analysis results of commissioning runs and details of the proposed upgrade plan.

  18. The Composition and Chemistry of the Deep Tropospheres of Saturn and Uranus from Ground-Based Radio Observations

    Science.gov (United States)

    Hofstadter, M. D.; Adumitroaie, V.; Atreya, S. K.; Butler, B.

    2017-12-01

    Ground-based radio observations of the giant planets at wavelengths from 1 millimeter to 1 meter have long been the primary means to study the deep tropospheres of both gas- and ice-giant planets (e.g. de Pater and Massie 1985, Icarus 62; Hofstadter and Butler 2003, Icarus 165). Most recently, radiometers aboard the Cassini and Juno spacecraft at Saturn and Jupiter, respectively, have demonstrated the ability of spaceborne systems to study composition and weather beneath the visible cloud tops with high spatial resolution (Janssen et al. 2013, Icarus 226; Bolton et al. 2016, this meeting). Ground-based observations remain, however, an excellent way to study the tropospheres of the ice giants, particularly the temporal and spatial distribution of condensible species, and to study the deep troposphere of Saturn in the region of the water cloud. This presentation focuses on two ground-based data sets, one for Uranus and one for Saturn. The Uranus data were all collected near the 2007 equinox, and span wavelengths from 0.1 to 20 cm. These data provide a snapshot of atmospheric composition at a single season. The Saturn observations were recently made with the EVLA observatory at wavelengths from 3 to 90 cm, augmented by published observations at shorter and longer wavelengths. It is expected that these data will allow us to constrain conditions in the water cloud region on Saturn. At the time of this writing, both data sets are being analyzed using an optimal estimation retrieval algorithm fed with the latest published information on the chemical and electrical properties of relevant atmospheric species (primarily H2O, NH3, H2S, PH3, and free electrons). At Uranus, we find that—consistent with previously published work—ammonia in the 1 to 50-bar range is strongly depleted from solar values. The relative volume mixing ratios of the above species satisfy PH3 < NH3 < H2S < H2O, which is interesting because based on cosmic abundances one would expect H2S < NH3. At the

  19. Super-Earths, Warm Neptunes, and Hot Jupiters: Transmission Spectroscopy for Comparative Planetology

    Science.gov (United States)

    Fraine, Jonathan D.; Deming, Drake; Jordan, Andres; Knutson, Heather

    2015-01-01

    The detections and non-detections of molecular species in transiting planets-- such as water, methane, and carbon monoxide-- lead to greater understanding of planet formation and evolution. Recent significant advances in both theoretical and observational discoveries from planets like HD189733b, HD209458b, GJ436b, as well as our own work with HAT-P-11b and GJ1214b, have shown that the range of measurable atmospheric properties spans from clear, molecular absorption dominated worlds to opaque worlds, with cloudy, hazy, or high mean molecular weight atmospheres. Characterization of significant non-detections allowed us to infer the existence of opaque cloud layers at very high altitudes or mean molecular weights upwards of ~1000x solar. The prevalence of these atmospheres was unexpected from extrapolations of solar system analogs. I will present our published results from GJ1214b and HAT-P-11b, as well as our recent work using both Spitzer and Magellan. Our results, combined with transmission spectra obtained for other similar planets, connect to develop a better understanding about the nature of these distant and alien worlds

  20. A PRELIMINARY JUPITER MODEL

    International Nuclear Information System (INIS)

    Hubbard, W. B.; Militzer, B.

    2016-01-01

    In anticipation of new observational results for Jupiter's axial moment of inertia and gravitational zonal harmonic coefficients from the forthcoming Juno orbiter, we present a number of preliminary Jupiter interior models. We combine results from ab initio computer simulations of hydrogen–helium mixtures, including immiscibility calculations, with a new nonperturbative calculation of Jupiter's zonal harmonic coefficients, to derive a self-consistent model for the planet's external gravity and moment of inertia. We assume helium rain modified the interior temperature and composition profiles. Our calculation predicts zonal harmonic values to which measurements can be compared. Although some models fit the observed (pre-Juno) second- and fourth-order zonal harmonics to within their error bars, our preferred reference model predicts a fourth-order zonal harmonic whose absolute value lies above the pre-Juno error bars. This model has a dense core of about 12 Earth masses and a hydrogen–helium-rich envelope with approximately three times solar metallicity

  1. A PRELIMINARY JUPITER MODEL

    Energy Technology Data Exchange (ETDEWEB)

    Hubbard, W. B. [Lunar and Planetary Laboratory, The University of Arizona, Tucson, AZ 85721 (United States); Militzer, B. [Department of Earth and Planetary Science, Department of Astronomy, University of California, Berkeley, CA 94720 (United States)

    2016-03-20

    In anticipation of new observational results for Jupiter's axial moment of inertia and gravitational zonal harmonic coefficients from the forthcoming Juno orbiter, we present a number of preliminary Jupiter interior models. We combine results from ab initio computer simulations of hydrogen–helium mixtures, including immiscibility calculations, with a new nonperturbative calculation of Jupiter's zonal harmonic coefficients, to derive a self-consistent model for the planet's external gravity and moment of inertia. We assume helium rain modified the interior temperature and composition profiles. Our calculation predicts zonal harmonic values to which measurements can be compared. Although some models fit the observed (pre-Juno) second- and fourth-order zonal harmonics to within their error bars, our preferred reference model predicts a fourth-order zonal harmonic whose absolute value lies above the pre-Juno error bars. This model has a dense core of about 12 Earth masses and a hydrogen–helium-rich envelope with approximately three times solar metallicity.

  2. JUICE space mission to Jupiter

    CERN Document Server

    CERN. Geneva

    2018-01-01

    JUICE - JUpiter ICy moons Explorer - is the first large-class mission in ESA's Cosmic Vision 2015-2025 programme. Planned for launch in 2022 and arrival at Jupiter in 2029, it will spend at least three years making detailed observations of the giant gaseous planet Jupiter and three of its largest moons, Ganymede, Callisto and Europa. JUICE will perform detailed investigations of Jupiter and its system in all their inter-relations and complexity with particular emphasis on Ganymede as a planetary body and potential habitat. Investigations of Europa and Callisto would complete a comparative picture of the Galilean moons. Jupiter is the archetype for the giant planets of the Solar System and for the numerous giant planets now known to orbit other stars. Moreover, Jupiter's diverse Galilean satellites - three of which are believed to harbour internal oceans - are central to understanding the habitability of icy worlds. JUICE spacecraft will carry the most powerful remote sensing, geophysical, and in situ paylo...

  3. The Light-Water-Reactor Version of the URANUS Integral fuel-rod code

    Energy Technology Data Exchange (ETDEWEB)

    Labmann, K; Moreno, A

    1977-07-01

    The LWR version of the URANUS code, a digital computer programme for the thermal and mechanical analysis of fuel rods, is presented. Material properties are discussed and their effect on integral fuel rod behaviour elaborated via URANUS results for some carefully selected reference experiments. The numerical results do not represent post-irradiation analyses of in-pile experiments, they illustrate rather typical and diverse URANUS capabilities. The performance test shows that URANUS is reliable and efficient, thus the code is a most valuable tool in fuel rod analysis work. K. LaBmann developed the LWR version of the URANUS code, material properties were reviewed and supplied by A. Moreno. (Author) 41 refs.

  4. Model tests in RAMONA and NEPTUN

    International Nuclear Information System (INIS)

    Hoffmann, H.; Ehrhard, P.; Weinberg, D.; Carteciano, L.; Dres, K.; Frey, H.H.; Hayafune, H.; Hoelle, C.; Marten, K.; Rust, K.; Thomauske, K.

    1995-01-01

    In order to demonstrate passive decay heat removal (DHR) in an LMR such as the European Fast Reactor, the RAMONA and NEPTUN facilities, with water as a coolant medium, were used to measure transient flow data corresponding to a transition from forced convection (under normal operation) to natural convection under DHR conditions. The facilities were 1:20 and 1:5 models, respectively, of a pool-type reactor including the IHXs, pumps, and immersed coolers. Important results: The decay heat can be removed from all parts of the primary system by natural convection, even if the primary fluid circulation through the IHX is interrupted. This result could be transferred to liquid metal cooling by experiments in models with thermohydraulic similarity. (orig.)

  5. A New Dark Vortex on Neptune

    Science.gov (United States)

    Wong, Michael H.; Tollefson, Joshua; Hsu, Andrew I.; de Pater, Imke; Simon, Amy A.; Hueso, Ricardo; Sánchez-Lavega, Agustín; Sromovsky, Lawrence; Fry, Patrick; Luszcz-Cook, Statia; Hammel, Heidi; Delcroix, Marc; de Kleer, Katherine; Orton, Glenn S.; Baranec, Christoph

    2018-03-01

    An outburst of cloud activity on Neptune in 2015 led to speculation about whether the clouds were convective in nature, a wave phenomenon, or bright companions to an unseen dark vortex (similar to the Great Dark Spot studied in detail by Voyager 2). The Hubble Space Telescope (HST) finally answered this question by discovering a new dark vortex at 45 degrees south planetographic latitude, named SDS-2015 for “southern dark spot discovered in 2015.” SDS-2015 is only the fifth dark vortex ever seen on Neptune. In this paper, we report on imaging of SDS-2015 using HST’s Wide Field Camera 3 across four epochs: 2015 September, 2016 May, 2016 October, and 2017 October. We find that the size of SDS-2015 did not exceed 20 degrees of longitude, more than a factor of two smaller than the Voyager dark spots, but only slightly smaller than previous northern-hemisphere dark spots. A slow (1.7–2.5 deg/year) poleward drift was observed for the vortex. Properties of SDS-2015 and its surroundings suggest that the meridional wind shear may be twice as strong at the deep level of the vortex as it is at the level of cloud-tracked winds. Over the 2015–2017 period, the dark spot’s contrast weakened from about -7 % to about -3 % , while companion clouds shifted from offset to centered, a similar evolution to some historical dark spots. The properties and evolution of SDS-2015 highlight the diversity of Neptune’s dark spots and the need for faster cadence dark spot observations in the future.

  6. Pitch-angle diffusion coefficients from resonant interactions with electrostatic electron cyclotron harmonic waves in planetary magnetospheres

    Directory of Open Access Journals (Sweden)

    A. K. Tripathi

    2011-02-01

    Full Text Available Pitch-angle diffusion coefficients have been calculated for resonant interaction with electrostatic electron cyclotron harmonic (ECH waves in the magnetospheres of Earth, Jupiter, Saturn, Uranus and Neptune. Calculations have been performed at two radial distances of each planet. It is found that observed wave electric field amplitudes in the magnetospheres of Earth and Jupiter are sufficient to put electrons on strong diffusion in the energy range of less than 100 eV. However, for Saturn, Uranus and Neptune, the observed ECH wave amplitude are insufficient to put electrons on strong diffusion at any radial distance.

  7. Detection of hydrogen sulfide above the clouds in Uranus's atmosphere

    Science.gov (United States)

    Irwin, Patrick G. J.; Toledo, Daniel; Garland, Ryan; Teanby, Nicholas A.; Fletcher, Leigh N.; Orton, Glenn A.; Bézard, Bruno

    2018-04-01

    Visible-to-near-infrared observations indicate that the cloud top of the main cloud deck on Uranus lies at a pressure level of between 1.2 bar and 3 bar. However, its composition has never been unambiguously identified, although it is widely assumed to be composed primarily of either ammonia or hydrogen sulfide (H2S) ice. Here, we present evidence of a clear detection of gaseous H2S above this cloud deck in the wavelength region 1.57-1.59 μm with a mole fraction of 0.4-0.8 ppm at the cloud top. Its detection constrains the deep bulk sulfur/nitrogen abundance to exceed unity (>4.4-5.0 times the solar value) in Uranus's bulk atmosphere, and places a lower limit on the mole fraction of H2S below the observed cloud of (1.0 -2.5 ) ×1 0-5. The detection of gaseous H2S at these pressure levels adds to the weight of evidence that the principal constituent of 1.2-3-bar cloud is likely to be H2S ice.

  8. Detection of hydrogen sulfide above the clouds in Uranus's atmosphere

    Science.gov (United States)

    Irwin, Patrick G. J.; Toledo, Daniel; Garland, Ryan; Teanby, Nicholas A.; Fletcher, Leigh N.; Orton, Glenn A.; Bézard, Bruno

    2018-05-01

    Visible-to-near-infrared observations indicate that the cloud top of the main cloud deck on Uranus lies at a pressure level of between 1.2 bar and 3 bar. However, its composition has never been unambiguously identified, although it is widely assumed to be composed primarily of either ammonia or hydrogen sulfide (H2S) ice. Here, we present evidence of a clear detection of gaseous H2S above this cloud deck in the wavelength region 1.57-1.59 μm with a mole fraction of 0.4-0.8 ppm at the cloud top. Its detection constrains the deep bulk sulfur/nitrogen abundance to exceed unity (>4.4-5.0 times the solar value) in Uranus's bulk atmosphere, and places a lower limit on the mole fraction of H2S below the observed cloud of (1.0 -2.5 ) ×1 0-5. The detection of gaseous H2S at these pressure levels adds to the weight of evidence that the principal constituent of 1.2-3-bar cloud is likely to be H2S ice.

  9. Main-belt Asteroids in the K2 Uranus Field

    Science.gov (United States)

    Molnár, L.; Pál, A.; Sárneczky, K.; Szabó, R.; Vinkó, J.; Szabó, Gy. M.; Kiss, Cs.; Hanyecz, O.; Marton, G.; Kiss, L. L.

    2018-02-01

    We present the K2 light curves of a large sample of untargeted main-belt asteroids (MBAs) detected with the Kepler Space Telescope. The asteroids were observed within the Uranus superstamp, a relatively large, continuous field with a low stellar background designed to cover the planet Uranus and its moons during Campaign 8 of the K2 mission. The superstamp offered the possibility of obtaining precise, uninterrupted light curves of a large number of MBAs and thus determining unambiguous rotation rates for them. We obtained photometry for 608 MBAs, and were able to determine or estimate rotation rates for 90 targets, of which 86 had no known values before. In an additional 16 targets we detected incomplete cycles and/or eclipse-like events. We found the median rotation rate to be significantly longer than that of the ground-based observations, indicating that the latter are biased toward shorter rotation rates. Our study highlights the need and benefits of further continuous photometry of asteroids.

  10. NEPTUNE Helping Program Managers Understand Their Program Customers

    National Research Council Canada - National Science Library

    Uriell, Zannette

    2004-01-01

    .... This annotated brief outlines some of these studies and discusses in greater detail a recent project that assessed a number of dissimilar programs, leading to the creation of the NEPTUNE System...

  11. LAMOST telescope reveals that Neptunian cousins of hot Jupiters are mostly single offspring of stars that are rich in heavy elements.

    Science.gov (United States)

    Dong, Subo; Xie, Ji-Wei; Zhou, Ji-Lin; Zheng, Zheng; Luo, Ali

    2018-01-09

    We discover a population of short-period, Neptune-size planets sharing key similarities with hot Jupiters: both populations are preferentially hosted by metal-rich stars, and both are preferentially found in Kepler systems with single-transiting planets. We use accurate Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) Data Release 4 (DR4) stellar parameters for main-sequence stars to study the distributions of short-period [Formula: see text] Kepler planets as a function of host star metallicity. The radius distribution of planets around metal-rich stars is more "puffed up" compared with that around metal-poor hosts. In two period-radius regimes, planets preferentially reside around metal-rich stars, while there are hardly any planets around metal-poor stars. One is the well-known hot Jupiters, and the other one is a population of Neptune-size planets ([Formula: see text]), dubbed "Hoptunes." Also like hot Jupiters, Hoptunes occur more frequently in systems with single-transiting planets although the fraction of Hoptunes occurring in multiples is larger than that of hot Jupiters. About [Formula: see text] of solar-type stars host Hoptunes, and the frequencies of Hoptunes and hot Jupiters increase with consistent trends as a function of [Fe/H]. In the planet radius distribution, hot Jupiters and Hoptunes are separated by a "valley" at approximately Saturn size (in the range of [Formula: see text]), and this "hot-Saturn valley" represents approximately an order-of-magnitude decrease in planet frequency compared with hot Jupiters and Hoptunes. The empirical "kinship" between Hoptunes and hot Jupiters suggests likely common processes (migration and/or formation) responsible for their existence.

  12. Jupiter: Lord of the Planets.

    Science.gov (United States)

    Kaufmann, William

    1984-01-01

    Presents a chapter from an introductory college-level astronomy textbook in which full-color photographs and numerous diagrams highlight an extensive description of the planet Jupiter. Topics include Jupiter's geology, rotation, magnetic field, atmosphere (including clouds and winds), and the Great Red Spot. (DH)

  13. Hot Jupiters around M dwarfs

    Directory of Open Access Journals (Sweden)

    Murgas F.

    2013-04-01

    Full Text Available The WFCAM Transit Survey (WTS is a near-infrared transit survey running on the United Kingdom Infrared Telescope (UKIRT. We conduct Monte Carlo transit injection and detection simulations for short period (<10 day Jupiter-sized planets to characterize the sensitivity of the survey. We investigate the recovery rate as a function of period and magnitude in 2 hypothetical star-planet cases: M0–2 + hot Jupiter, M2–4 + hot Jupiter. We find that the WTS lightcurves are very sensitive to the presence of Jupiter-sized short-period transiting planets around M dwarfs. The non-detection of a hot-Jupiter around an M dwarf by the WFCAM Transit Survey allows us to place a firm upper limit of 1.9 per cent (at 95 per cent confidence on the planet occurrence rate.

  14. Seismology of Giant Planets: General Overview and Results from the Kepler K2 Observations of Neptune

    Directory of Open Access Journals (Sweden)

    Gaulme Patrick

    2017-01-01

    Full Text Available For this invited contribution, I was asked to give an overview about the application of helio and aster-oseismic techniques to study the interior of giant planets, and to specifically present the recent observations of Neptune by Kepler K2. Seismology applied to giant planets could drastically change our understanding of their deep interiors, as it has happened with the Earth, the Sun, and many main-sequence and evolved stars. The study of giant planets' composition is important for understanding both the mechanisms enabling their formation and the origins of planetary systems, in particular our own. Unfortunately, its determination is complicated by the fact that their interior is thought not to be homogeneous, so that spectroscopic determinations of atmospheric abundances are probably not representative of the planet as a whole. Instead, the determination of their composition and structure must rely on indirect measurements and interior models. Giant planets are mostly fluid and convective, which makes their seismology much closer to that of solar-like stars than that of terrestrial planets. Hence, helioseismology techniques naturally transfer to giant planets. In addition, two alternative methods can be used: photometry of the solar light reflected by planetary atmospheres, and ring seismology in the specific case of Saturn. The current decade has been promising thanks to the detection of Jupiter's acoustic oscillations with the ground-based imaging-spectrometer SYMPA and indirect detection of Saturn's f-modes in its rings by the NASA Cassini orbiter. This has motivated new projects of ground-based and space-borne instruments that are under development. The K2 observations represented the first opportunity to search for planetary oscillations with visible photometry. Despite the excellent quality of K2 data, the noise level of the power spectrum of the light curve was not low enough to detect Neptune's oscillations. The main results from the

  15. Seismology of Giant Planets: General Overview and Results from the Kepler K2 Observations of Neptune

    Science.gov (United States)

    Gaulme, Patrick

    2017-10-01

    For this invited contribution, I was asked to give an overview about the application of helio and aster-oseismic techniques to study the interior of giant planets, and to specifically present the recent observations of Neptune by Kepler K2. Seismology applied to giant planets could drastically change our understanding of their deep interiors, as it has happened with the Earth, the Sun, and many main-sequence and evolved stars. The study of giant planets' composition is important for understanding both the mechanisms enabling their formation and the origins of planetary systems, in particular our own. Unfortunately, its determination is complicated by the fact that their interior is thought not to be homogeneous, so that spectroscopic determinations of atmospheric abundances are probably not representative of the planet as a whole. Instead, the determination of their composition and structure must rely on indirect measurements and interior models. Giant planets are mostly fluid and convective, which makes their seismology much closer to that of solar-like stars than that of terrestrial planets. Hence, helioseismology techniques naturally transfer to giant planets. In addition, two alternative methods can be used: photometry of the solar light reflected by planetary atmospheres, and ring seismology in the specific case of Saturn. The current decade has been promising thanks to the detection of Jupiter's acoustic oscillations with the ground-based imaging-spectrometer SYMPA and indirect detection of Saturn's f-modes in its rings by the NASA Cassini orbiter. This has motivated new projects of ground-based and space-borne instruments that are under development. The K2 observations represented the first opportunity to search for planetary oscillations with visible photometry. Despite the excellent quality of K2 data, the noise level of the power spectrum of the light curve was not low enough to detect Neptune's oscillations. The main results from the K2 observations are

  16. Hubble Space Telescope Wide Field Planetary Camera 2 Observations of Neptune

    Science.gov (United States)

    1995-01-01

    across the planet's disk, revealing wind speeds as large as 325 meters per second (730 miles per hour). The largest of the giant, dark storm systems, called the 'Great Dark Spot', received special attention because it resembled Jupiter's Great Red Spot, a storm that has persisted for more than three centuries. The lifetime of Neptune's Great Dark Spot could not be determined from the Voyager data alone, however, because the encounter was too brief. Its evolution was impossible to monitor with ground-based telescopes, because it could not be resolved on Neptune's tiny disk, and its contribution to the disk-integrated brightness of Neptune confused by the presence of a rapidly-varying bright cloud feature, called the 'Bright Companion' that usually accompanied the Great Dark spot.The repaired Hubble Space Telescope provides new opportunities to monitor these and other phenomena in the atmosphere of the most distant planet. Images taken with WFPC-2's Planetary Camera (PC) can resolve Neptune's disk as well as most ground-based telescopes can resolve the disk of Jupiter. The spatial resolution of the HST WFPC-2 images is not as high as that obtained by the Voyager-2 Narrow-Angle Camera during that spacecraft's closest approach to Neptune, but they have a number of other assets that enhance their scientific value, including improved ultra-violet and infrared sensitivity, better signal-to-noise, and, and greater photometric accuracy.The images of Neptune acquired by the WFPC-2 Science team in late June clearly demonstrate these capabilities. The side of the planet facing the Earth at the start of the program (11:36 Universal Time on July 27) was imaged in color filters spanning the ultraviolet (255 and 300-nm), visible (467, 588, 620, and 673- nm), and near-infrared (890-nm) parts of the spectrum. The planet then rotated 180 degrees in longitude, and the opposite hemisphere was imaged in a subset of these colors (300, 467, 588, 620, and 673-nm). The HST/WFPC-2 program more

  17. Lightning activity on Jupiter

    Science.gov (United States)

    Borucki, W. J.; Bar-Nun, A.; Scarf, F. L.; Look, A. F.; Hunt, G. E.

    1982-01-01

    Photographic observations of the nightside of Jupiter by the Voyager 1 spacecraft show the presence of extensive lightning activity. Detection of whistlers by the plasma wave analyzer confirms the optical observations and implies that many flashes were not recorded by the Voyager camera because the intensity of the flashes was below the threshold sensitivity of the camera. Measurements of the optical energy radiated per flash indicate that the observed flashes had energies similar to that for terrestrial superbolts. The best estimate of the lightning energy dissipation rate of 0.0004 W/sq m was derived from a consideration of the optical and radiofrequency measurements. The ratio of the energy dissipated by lightning compared to the convective energy flux is estimated to be between 0.000027 and 0.00005. The terrestrial value is 0.0001.

  18. Voyager radio science observations of Neptune and triton

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, G.L.; Eshleman, V.R.; Gresh, D.L.; Gurrola, E.M.; Hinson, D.P.; Marouf, E.A.; Rosen, P.A.; Simpson, R.A. (Stanford Univ. (USA)); Sweetnam, D.N.; Anderson, J.D.; Borutzki, S.E.; Campbell, J.K.; Kursinski, E.R.; Levy, G.S.; Lindal, G.F.; Lyons, J.R.; Wood, G.E. (California Institute of Technology, Pasadena (USA)); Kawashima, N. (Institute of Space and Astronautical Science, Sagamihara (Japan))

    1989-12-15

    The Voyager 2 encounter with the Neptune system included radio science investigations of the masses and densities of Neptune and Triton, the low-order gravitational harmonics of Neptune, the vertical structures of the atmospheres and ionospheres of Neptune and Triton, the composition of the atmosphere of Neptune, and characteristics of ring material. Demanding experimental requirements were met successfully, and study of the large store of collected data has begun. Neptune's atmosphere was probed to a pressure level of about 5 x 10{sup 5} pascals, and effects of a methane cloud region and probable ammonia absorption below the cloud are evident in the data. Results for the mixing ratios of helium and ammonia are still being investigated; the methane abundance below the clouds is at least 1 percent by volume. Derived temperature-pressure profiles to 1.2 x 10{sup 5} pascals and 78 kelvins (K) show a lapse rate corresponding to frozen equilibrium of the para- and ortho-hydrogen states. Neptune's ionosphere exhibits an extended topside at a temperature of 950 {plus minus} 160 K if H{sup +} is the dominant ion, and narrow ionization layers of the type previously seen at the other three giant planets. Triton has a dense ionosphere with a peak electron concentration of 46 x 10{sup 9} per cubic meter at an altitude of 340 kilometers measured during occultation egress. Its topside plasma temperature is about 80 {plus minus} 16 K in N{sub 2}{sup +} is the principal ion. The tenuous neutral atmosphere of Triton produced distinct signatures in the occultation data; however, the accuracy of the measurements is limited by uncertainties in the frequency of the spacecraft reference oscillator. Preliminary values for the surface pressure of 1.6 {plus minus} 0.3 pascals and an equivalent isothermal temperature of 48 {plus minus} 5 K are suggested, on the assumption that molecular nitrogen dominates the atmosphere.

  19. A Neptune-sized transiting planet closely orbiting a 5–10-million-year-old star.

    Science.gov (United States)

    David, Trevor J; Hillenbrand, Lynne A; Petigura, Erik A; Carpenter, John M; Crossfield, Ian J M; Hinkley, Sasha; Ciardi, David R; Howard, Andrew W; Isaacson, Howard T; Cody, Ann Marie; Schlieder, Joshua E; Beichman, Charles A; Barenfeld, Scott A

    2016-06-30

    Theories of the formation and early evolution of planetary systems postulate that planets are born in circumstellar disks, and undergo radial migration during and after dissipation of the dust and gas disk from which they formed. The precise ages of meteorites indicate that planetesimals—the building blocks of planets—are produced within the first million years of a star’s life. Fully formed planets are frequently detected on short orbital periods around mature stars. Some theories suggest that the in situ formation of planets close to their host stars is unlikely and that the existence of such planets is therefore evidence of large-scale migration. Other theories posit that planet assembly at small orbital separations may be common. Here we report a newly born, transiting planet orbiting its star with a period of 5.4 days. The planet is 50 per cent larger than Neptune, and its mass is less than 3.6 times that of Jupiter (at 99.7 per cent confidence), with a true mass likely to be similar to that of Neptune. The star is 5–10 million years old and has a tenuous dust disk extending outward from about twice the Earth–Sun separation, in addition to the fully formed planet located at less than one-twentieth of the Earth–Sun separation.

  20. GUST86 - An analytical ephemeris of the Uranian satellites. [General Uranus Satellite Theory

    Science.gov (United States)

    Laskar, J.; Jacobson, R. A.

    1987-01-01

    The General Uranus Satellite Theory GUST (Laskar, 1986) is used for the construction of an analytical ephemeris for the Uranian satellites. The theory is fitted against earth-based observations from 1911 to 1986, and all radio and optical data obtained during Voyager encounter with Uranus. Earth-based observations alone allow the determination of masses which are within 15 percent of the values determined by the Uranus flyby. The analysis of all the observations confirm the values of the masses obtained during the encounter (Stone and Miner, 1986) and give a complete set of dynamical parameters for the analytical theory. An analytical ephemeris, GUST86, with an estimated precision of about 100 km with respect to Uranus is obtained.

  1. On internal constitution of Jupiter

    International Nuclear Information System (INIS)

    Kozyrev, N.A.

    1977-01-01

    Jupiter internal construction is considered. The density and pressure inside a cosmic body can be calculated from the known values of the mass and radius. For Jupiter, the inertia moment calculated from the motion of the satellites permits to determine the degree of uniformity of its structure and to find more precise values of density and pressure in the center of the planet. In assumption that the matter of Jupiter consists of hydrogen only, the dependence of pressure on temperature was calculated with accounting for the degeneracy of gas and electrostatic interactions. Hence the central temperature, calculated from pressure and density, appears to be equal to 165.000 deg K. At the thermal conductivity by free electrons such a temperature at the center is to result in a thermal flux of about 1.0x10 4 erg/cm 2 from Jupiter's surface, which was observed during the flights of the ''Pioneer'' stations

  2. Ulysses dust measurements near Jupiter.

    Science.gov (United States)

    Grün, E; Zook, H A; Baguhl, M; Fechtig, H; Hanner, M S; Kissel, J; Lindblad, B A; Linkert, D; Linkert, G; Mann, I B

    1992-09-11

    Submicrometer- to micrometer-sized particles were recorded by the Ulysses dust detector within 40 days of the Jupiter flyby. Nine impacts were recorded within 50 Jupiter radii with most of them recorded after closest approach. Three of these impacts are consistent with particles on prograde orbits around Jupiter and the rest are believed to have resulted from gravitationally focused interplanetary dust. From the ratio of the impact rate before the Jupiter flyby to the impact rate after the Jupiter flyby it is concluded that interplanetary dust particles at the distance of Jupiter move on mostly retrograde orbits. On 10 March 1992, Ulysses passed through an intense dust stream. The dust detector recorded 126 impacts within 26 hours. The stream particles were moving on highly inclined and apparently hyperbolic orbits with perihelion distances of >5 astronomical units. Interplanetary dust is lost rather quickly from the solar system through collisions and other mechanisms and must be almost continuously replenished to maintain observed abundances. Dust flux measurements, therefore, give evidence of the recent rates of production from sources such as comets, asteroids, and moons, as well as the possible presence of interstellar grains.

  3. HELIUM ATMOSPHERES ON WARM NEPTUNE- AND SUB-NEPTUNE-SIZED EXOPLANETS AND APPLICATIONS TO GJ 436b

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Renyu; Yung, Yuk L. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Seager, Sara, E-mail: renyu.hu@jpl.nasa.gov [Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2015-07-01

    Warm Neptune- and sub-Neptune-sized exoplanets in orbits smaller than Mercury’s are thought to have experienced extensive atmospheric evolution. Here we propose that a potential outcome of this atmospheric evolution is the formation of helium-dominated atmospheres. The hydrodynamic escape rates of Neptune- and sub-Neptune-sized exoplanets are comparable to the diffusion-limited escape rate of hydrogen, and therefore the escape is heavily affected by diffusive separation between hydrogen and helium. A helium atmosphere can thus be formed—from a primordial hydrogen–helium atmosphere—via atmospheric hydrodynamic escape from the planet. The helium atmosphere has very different abundances of major carbon and oxygen species from those of a hydrogen atmosphere, leading to distinctive transmission and thermal emission spectral features. In particular, the hypothesis of a helium-dominated atmosphere can explain the thermal emission spectrum of GJ 436b, a warm Neptune-sized exoplanet, while also being consistent with the transmission spectrum. This model atmosphere contains trace amounts of hydrogen, carbon, and oxygen, with the predominance of CO over CH{sub 4} as the main form of carbon. With our atmospheric evolution model, we find that if the mass of the initial atmosphere envelope is 10{sup −3} planetary mass, hydrodynamic escape can reduce the hydrogen abundance in the atmosphere by several orders of magnitude in ∼10 billion years. Observations of exoplanet transits may thus detect signatures of helium atmospheres and probe the evolutionary history of small exoplanets.

  4. HELIUM ATMOSPHERES ON WARM NEPTUNE- AND SUB-NEPTUNE-SIZED EXOPLANETS AND APPLICATIONS TO GJ 436b

    International Nuclear Information System (INIS)

    Hu, Renyu; Yung, Yuk L.; Seager, Sara

    2015-01-01

    Warm Neptune- and sub-Neptune-sized exoplanets in orbits smaller than Mercury’s are thought to have experienced extensive atmospheric evolution. Here we propose that a potential outcome of this atmospheric evolution is the formation of helium-dominated atmospheres. The hydrodynamic escape rates of Neptune- and sub-Neptune-sized exoplanets are comparable to the diffusion-limited escape rate of hydrogen, and therefore the escape is heavily affected by diffusive separation between hydrogen and helium. A helium atmosphere can thus be formed—from a primordial hydrogen–helium atmosphere—via atmospheric hydrodynamic escape from the planet. The helium atmosphere has very different abundances of major carbon and oxygen species from those of a hydrogen atmosphere, leading to distinctive transmission and thermal emission spectral features. In particular, the hypothesis of a helium-dominated atmosphere can explain the thermal emission spectrum of GJ 436b, a warm Neptune-sized exoplanet, while also being consistent with the transmission spectrum. This model atmosphere contains trace amounts of hydrogen, carbon, and oxygen, with the predominance of CO over CH 4 as the main form of carbon. With our atmospheric evolution model, we find that if the mass of the initial atmosphere envelope is 10 −3 planetary mass, hydrodynamic escape can reduce the hydrogen abundance in the atmosphere by several orders of magnitude in ∼10 billion years. Observations of exoplanet transits may thus detect signatures of helium atmospheres and probe the evolutionary history of small exoplanets

  5. First Earth-based observations of Neptune's satellite Proteus

    Science.gov (United States)

    Colas, F.; Buil, C.

    1992-08-01

    Proteus (Neptune III) was discovered from Voyager Spacecraft images in 1989 (Smith, 1989). It was never observed from ground-based observatories because of its magnitude (m = 20.3) and closeness to Neptune (maximum elongation = 6 arcsec). In October 1991, we used the 2.2 m telescope at the European Southern Observatory (La Silla, Chile) to look for it. The observation success is mainly due to the use of an anti blooming CCD and to good seeing conditions (less than 1 arcsec). We give the differential positions of Proteus referred to Neptune and we compare with theoretical positions issued from Voyager's data (Owen et al., 1991). We found that the rms orbital residual was about 0.1 arcsec.

  6. Model tests in RAMONA and NEPTUN; Modellversuche in RAMONA und NEPTUN

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, H.; Ehrhard, P.; Weinberg, D.; Carteciano, L.; Dres, K.; Frey, H.H.; Hayafune, H.; Hoelle, C.; Marten, K.; Rust, K.; Thomauske, K.

    1995-08-01

    In order to demonstrate passive decay heat removal (DHR) in an LMR such as the European Fast Reactor, the RAMONA and NEPTUN facilities, with water as a coolant medium, were used to measure transient flow data corresponding to a transition from forced convection (under normal operation) to natural convection under DHR conditions. The facilities were 1:20 and 1:5 models, respectively, of a pool-type reactor including the IHXs, pumps, and immersed coolers. Important results: The decay heat can be removed from all parts of the primary system by natural convection, even if the primary fluid circulation through the IHX is interrupted. This result could be transferred to liquid metal cooling by experiments in models with thermohydraulic similarity. (orig.)

  7. THE EVOLUTION OF ASTEROIDS IN THE JUMPING-JUPITER MIGRATION MODEL

    Energy Technology Data Exchange (ETDEWEB)

    Roig, Fernando [Observatòrio Nacional, Rua Gal. Jose Cristino 77, Rio de Janeiro, RJ 20921-400 (Brazil); Nesvorný, David, E-mail: froig@on.br, E-mail: davidn@boulder.swri.edu [Southwest Research Institute, 1050 Walnut St., Suite 300, Boulder, CO 80302 (United States)

    2015-12-15

    In this work, we investigate the evolution of a primordial belt of asteroids, represented by a large number of massless test particles, under the gravitational effect of migrating Jovian planets in the framework of the jumping-Jupiter model. We perform several simulations considering test particles distributed in the Main Belt, as well as in the Hilda and Trojan groups. The simulations start with Jupiter and Saturn locked in the mutual 3:2 mean motion resonance plus three Neptune-mass planets in a compact orbital configuration. Mutual planetary interactions during migration led one of the Neptunes to be ejected in less than 10 Myr of evolution, causing Jupiter to jump by about 0.3 AU in semimajor axis. This introduces a large-scale instability in the studied populations of small bodies. After the migration phase, the simulations are extended over 4 Gyr, and we compare the final orbital structure of the simulated test particles to the current Main Belt of asteroids with absolute magnitude H < 9.7. The results indicate that, in order to reproduce the present Main Belt, the primordial belt should have had a distribution peaked at ∼10° in inclination and at ∼0.1 in eccentricity. We discuss the implications of this for the Grand Tack model. The results also indicate that neither primordial Hildas, nor Trojans, survive the instability, confirming the idea that such populations must have been implanted from other sources. In particular, we address the possibility of implantation of Hildas and Trojans from the Main Belt population, but find that this contribution should be minor.

  8. Hubble Images Reveal Jupiter's Auroras

    Science.gov (United States)

    1996-01-01

    These images, taken by the Hubble Space Telescope, reveal changes in Jupiter's auroral emissions and how small auroral spots just outside the emission rings are linked to the planet's volcanic moon, Io. The images represent the most sensitive and sharply-detailed views ever taken of Jovian auroras.The top panel pinpoints the effects of emissions from Io, which is about the size of Earth's moon. The black-and-white image on the left, taken in visible light, shows how Io and Jupiter are linked by an invisible electrical current of charged particles called a 'flux tube.' The particles - ejected from Io (the bright spot on Jupiter's right) by volcanic eruptions - flow along Jupiter's magnetic field lines, which thread through Io, to the planet's north and south magnetic poles. This image also shows the belts of clouds surrounding Jupiter as well as the Great Red Spot.The black-and-white image on the right, taken in ultraviolet light about 15 minutes later, shows Jupiter's auroral emissions at the north and south poles. Just outside these emissions are the auroral spots. Called 'footprints,' the spots are created when the particles in Io's 'flux tube' reach Jupiter's upper atmosphere and interact with hydrogen gas, making it fluoresce. In this image, Io is not observable because it is faint in the ultraviolet.The two ultraviolet images at the bottom of the picture show how the auroral emissions change in brightness and structure as Jupiter rotates. These false-color images also reveal how the magnetic field is offset from Jupiter's spin axis by 10 to 15 degrees. In the right image, the north auroral emission is rising over the left limb; the south auroral oval is beginning to set. The image on the left, obtained on a different date, shows a full view of the north aurora, with a strong emission inside the main auroral oval.The images were taken by the telescope's Wide Field and Planetary Camera 2 between May 1994 and September 1995.This image and other images and data

  9. Galileo's Telescopy and Jupiter's Tablet

    Science.gov (United States)

    Usher, P. D.

    2003-12-01

    A previous paper (BAAS 33:4, 1363, 2001) reported on the dramatic scene in Shakespeare's Cymbeline that features the descent of the deity Jupiter. The paper suggested that the four ghosts circling the sleeping Posthumus denote the four Galilean moons of Jupiter. The god Jupiter commands the ghosts to lay a tablet upon the prone Posthumus, but says that its value should not be overestimated. When Posthumus wakens he notices the tablet, which he calls a "book." Not only has the deity's "tablet" become the earthling's "book," but it appears that the book has covers which Posthumus evidently recognizes because without even opening the book he ascribes two further properties to it: rarity, and the very property that Jupiter had earlier attributed, viz. that one must not read too much into it. The mystery deepens when the Jovian gift undergoes a second metamorphosis, to "label." With the help of the OED, the potentially disparate terms "tablet," "book," and "label," may be explained by terms appropriate either to supernatural or worldly beings. "Tablet" may recognize the Mosaic artifact, whereas "book" and "label" are probably mundane references to Galileo's Sidereus Nuncius which appeared shortly before Cymbeline. The message of the Olympian god indicates therefore that the book is unique even as its contents have limited value. The first property celebrates the fact that Galileo's book is the first of its kind, and the second advises that all results except the discovery of Jupiter's moons have been reported earlier, in Hamlet.

  10. Jovian atmospheres

    International Nuclear Information System (INIS)

    Allison, M.; Travis, L.D.

    1986-10-01

    A conference on the atmosphere of Jupiter produced papers in the areas of thermal and ortho-para hydrogen structure, clouds and chemistry, atmospheric structure, global dynamics, synoptic features and processes, atmospheric dynamics, and future spaceflight opportunities. A session on the atmospheres of Uranus and Neptune was included, and the atmosphere of Saturn was discussed in several papers

  11. Building a Geologic Map of Neptune's Moon Triton

    Science.gov (United States)

    Martin, E. S.; Patthoff, D. A.; Bland, M. T.; Watters, T. R.; Collins, G. C.; Becker, T.

    2018-06-01

    Triton serves as a bridge between KBOs and icy satellites, and characterization of its terrains is important for advancing comparative planetological studies. We aim to create a geologic map of the Neptune-facing side of Triton at a scale of 1:5M.

  12. First results of Herschel-PACS observations of Neptune

    NARCIS (Netherlands)

    Lellouch, E.; Hartogh, P.; Feuchtgruber, H.; Vandenbussche, B.; de Graauw, Th.; Moreno, R.; Jarchow, C.; Cavalie, T.; Orton, G.; Banaszkiewicz, M.; Blecka, M. I.; Bockelee-Morvan, D.; Crovisier, J.; Encrenaz, T.; Fulton, T.; Kueppers, M.; Lara, L. M.; Lis, D. C.; Medvedev, A. S.; Rengel, M.; Sagawa, H.; Swinyard, B.; Szutowicz, S.; Bensch, F.; Bergin, E.; Billebaud, F.; Biver, N.; Blake, G. A.; Blommaert, J. A. D. L.; Cernicharo, J.; Courtin, R.; Davis, G. R.; Decin, L.; Encrenaz, P.; Gonzalez, A.; Jehin, E.; Kidger, M.; Naylor, D.; Portyankina, G.; Schieder, R.; Sidher, S.; Thomas, N.; de Val-Borro, M.; Verdugo, E.; Waelkens, C.; Aarts, H.; Comito, C.; Kawamura, J. H.; Maestrini, A.; Peacocke, T.; Teipen, R.; Tils, T.; Wildeman, K.; Walker, H.; Blake, G.A.

    2010-01-01

    We report on the initial analysis of a Herschel-PACS full range spectrum of Neptune, covering the 51-220 mu m range with a mean resolving power of similar to 3000, and complemented by a dedicated observation of CH(4) at 120 mu m. Numerous spectral features due to HD (R(0) and R(1)), H(2)O, CH(4),

  13. Scientists Revise Thinking on Comets, Planet Jupiter

    Science.gov (United States)

    Chemical and Engineering News, 1974

    1974-01-01

    Discusses scientific information obtained from Pioneer 10's Jupiter flyby and the comet Kohoutek's first trip around the sun, including the high hydrogen emission of Jupiter's principal moon, Io. (CC)

  14. Jupiter radiation belt models (July 1974)

    International Nuclear Information System (INIS)

    Divine, N.

    1974-01-01

    Flux profiles which were derived from data returned by Pioneer 10 during Jupiter encounter, form the basis for a new set of numerical models for the energy spectra of electrons and protons in Jupiter's inner magnetosphere

  15. FROM HOT JUPITERS TO SUPER-EARTHS VIA ROCHE LOBE OVERFLOW

    Energy Technology Data Exchange (ETDEWEB)

    Valsecchi, Francesca; Rasio, Frederic A.; Steffen, Jason H. [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States)

    2014-09-20

    Through tidal dissipation in a slowly spinning host star, the orbits of many hot Jupiters may decay down to the Roche limit. We expect that the ensuing mass transfer will be stable in most cases. Using detailed numerical calculations, we find that this evolution is quite rapid, potentially leading to the complete removal of the gaseous envelope in a few gigayears, and leaving behind an exposed rocky core (a {sup h}ot super-Earth{sup )}. Final orbital periods are quite sensitive to the details of the planet's mass-radius relation and to the effects of irradiation and photo-evaporation, but could be as short as a few hours or as long as several days. Our scenario predicts the existence of planets with intermediate masses ({sup h}ot Neptunes{sup )} that should be found precisely at their Roche limit and in the process of losing mass through Roche lobe overflow. The observed excess of small single-planet candidate systems observed by Kepler may also be the result of this process. If so, the properties of their host stars should track those of the hot Jupiters. Moreover, the number of systems that produced hot Jupiters could be two to three times larger than one would infer from contemporary observations.

  16. Study of Jupiter polarization properties

    International Nuclear Information System (INIS)

    Bolkvadze, O.R.

    1980-01-01

    Investigations into polarization properties of the Jupiter reflected light were carried on at the Abastumani astrophysical observatory in 1967, 1968 and 1969 in the four spectral ranges: 4000, 4800, 5400 and 6600 A deg. Data on light polarization in different parts of the Jupiter visible disk are given. Curves of dependence of the planet light polarization degree on a phase angle are plotted. It is shown that in the central part of the visible planet disk the polarization degree is low. Atmosphere is in a stable state in this part of Jupiter. Mean radius of particles of a cloud layer is equal to 0.26μ, and optical thickness of overcloud atmosphere tau=0.05. Height of transition boundary of the cloud layer into overcloud gas atmosphere changes from year to year at the edges of the equatorial zone. Optical thickness of overcloud atmosphere changes also with changing height of a transient layer. The polar Jupiter regions possess a high degree of polarization which depends on a latitude. Polarization increases monotonously with the latitude and over polar regions accepts a maximum value [ru

  17. Jupiter: Cosmic Jekyll and Hyde.

    Science.gov (United States)

    Grazier, Kevin R

    2016-01-01

    It has been widely reported that Jupiter has a profound role in shielding the terrestrial planets from comet impacts in the Solar System, and that a jovian planet is a requirement for the evolution of life on Earth. To evaluate whether jovians, in fact, shield habitable planets from impacts (a phenomenon often referred to as the "Jupiter as shield" concept), this study simulated the evolution of 10,000 particles in each of the jovian inter-planet gaps for the cases of full-mass and embryo planets for up to 100 My. The results of these simulations predict a number of phenomena that not only discount the "Jupiter as shield" concept, they also predict that in a Solar System like ours, large gas giants like Saturn and Jupiter had a different, and potentially even more important, role in the evolution of life on our planet by delivering the volatile-laden material required for the formation of life. The simulations illustrate that, although all particles occupied "non-life threatening" orbits at their onset of the simulations, a significant fraction of the 30,000 particles evolved into Earth-crossing orbits. A comparison of multiple runs with different planetary configurations revealed that Jupiter was responsible for the vast majority of the encounters that "kicked" outer planet material into the terrestrial planet region, and that Saturn assisted in the process far more than has previously been acknowledged. Jupiter also tends to "fix" the aphelion of planetesimals at its orbit irrespective of their initial starting zones, which has the effect of slowing their passages through the inner Solar System, and thus potentially improving the odds of accretion of cometary material by terrestrial planets. As expected, the simulations indicate that the full-mass planets perturb many objects into the deep outer Solar System, or eject them entirely; however, planetary embryos also did this with surprising efficiency. Finally, the simulations predict that Jupiter's capacity to

  18. Neptune's Discovery: Le Verrier, Adams, and the Assignment of Credit

    Science.gov (United States)

    Sheehan, William

    2011-01-01

    As one of the most significant achievements of 19th century astronomy, the discovery of Neptune has been the subject of a vast literature. A large part of this literature--beginning with the period immediately after the optical discovery in Berlin--has been the obsession with assigning credit to the two men who attempted to calculate the planet's position (and initially this played out against the international rivalry between France and England). Le Verrier and Adams occupied much different positions in the Scientific Establishments of their respective countries; had markedly different personalities; and approached the investigation using different methods. A psychiatrist and historian of astronomy tries to provide some new contexts to the familiar story of the discovery of Neptune, and argues that the personalities of these two men played crucial roles in their approaches to the problem they set themselves and the way others reacted to their stimuli. Adams had features of high-functioning autism, while Le Verrier's domineering, obsessive, orderly personality--though it allowed him to be immensely productive--eventually led to serious difficulties with his peers (and an outright revolt). Though it took extraordinary smarts to calculate the position of Neptune, the discovery required social skills that these men lacked--and thus the process to discovery was more bumbling and adventitious than it might have been. The discovery of Neptune occurred at a moment when astronomy was changing from that of heroic individuals to team collaborations involving multiple experts, and remains an object lesson in the sociological aspects of scientific endeavor.

  19. Neptune's New Dark Vortex: Aerosol Properties from Optical Data

    Science.gov (United States)

    Tollefson, J.; Luszcz-Cook, S.; Wong, M. H.; De Pater, I.

    2016-12-01

    Over the past year, amateur and professional astronomers alike have monitored the appearance of a new dark vortex on Neptune, dubbed SDS-2015 for "southern dark spot discovered in 2015" (Wong et al. 2016; CBET 4278). The discovery of SDS-2015 is fortuitous, being one of only five dark spots observed on Neptune since Voyager 2 imaged the Great Dark Spot (Smith et al. 1989, Science 246, 1422). A companion abstract (Wong et al., this meeting) will present Hubble Space Telescope images of SDS-2015, showcasing the discovery of the vortex in September 2015 and subsequent observations in May 2016. These observations span the optical regime. Longer wavelengths track bright companion clouds thought to form as air is diverted around SDS-2015. Shorter wavelengths reveal the dark spot itself. Combined, these data probe the vertical extent of the dark spot and Neptune's surrounding upper atmosphere. We present preliminary radiative transfer analyses of SDS-2015 using our multispectral data. Our model is the same as that in Luszcz-Cook et al. (2016, Icarus 276, 52) but extended to optical wavelengths. Prior to this work, little was known about the composition and vertical extent of Neptune's dark spots. Only data at optical wavelengths reveal these vortices, suggesting they consist of clearings in the background of fine, evenly-distributed haze particle. Alternatively, the spots may consist of low-albedo aerosols, causing their apparent darkness. Radiative transfer modeling is also one way to determine the vortex top altitude. Simulations of the Great Dark Spot by Stratman et al. (2001, Icarus 151, 275) found that the vortex top altitude is coupled to the brightness of companion clouds, where cloud opacity weakened as the top of the vortex reached higher into the tropopause region. The modeling presented here will compare these hypotheses and provide the first glimpses into the vertical structure of SDS-2015.

  20. Dynamical evolution of a fictitious population of binary Neptune Trojans

    Science.gov (United States)

    Brunini, Adrián

    2018-03-01

    We present numerical simulations of the evolution of a synthetic population of Binary Neptune Trojans, under the influence of the solar perturbations and tidal friction (the so-called Kozai cycles and tidal friction evolution). Our model includes the dynamical influence of the four giant planets on the heliocentric orbit of the binary centre of mass. In this paper, we explore the evolution of initially tight binaries around the Neptune L4 Lagrange point. We found that the variation of the heliocentric orbital elements due to the libration around the Lagrange point introduces significant changes in the orbital evolution of the binaries. Collisional processes would not play a significant role in the dynamical evolution of Neptune Trojans. After 4.5 × 109 yr of evolution, ˜50 per cent of the synthetic systems end up separated as single objects, most of them with slow diurnal rotation rate. The final orbital distribution of the surviving binary systems is statistically similar to the one found for Kuiper Belt Binaries when collisional evolution is not included in the model. Systems composed by a primary and a small satellite are more fragile than the ones composed by components of similar sizes.

  1. Featured Image: A New Dark Vortex on Neptune

    Science.gov (United States)

    Kohler, Susanna

    2018-03-01

    This remarkable series of images by the Hubble Space Telescope (click for the full view) track a dark vortex only the fifth ever observed on Neptune as it evolves in Neptunes atmosphere. These Hubble images, presented in a recent study led by Michael Wong (University of California, Berkeley), were taken in 2015 September, 2016 May, 2016 October, and 2017 October; the observations have monitored the evolution of the vortex as it has gradually weakened and drifted polewards. Confirmation of the vortex solved a puzzle that arose in 2015, when astronomers spotted an unexplained outburst of cloud activity on Neptune. This outburst was likely a group of bright companion clouds that form as air flows over high-pressure dark vortices, causing gases to freeze into methane ice crystals. To learn more about what the authors have since learned by studying this vortex, check out the paper below.CitationMichael H. Wong et al 2018 AJ 155 117. doi:10.3847/1538-3881/aaa6d6

  2. HAT-P-11b: A SUPER-NEPTUNE PLANET TRANSITING A BRIGHT K STAR IN THE KEPLER FIELD

    International Nuclear Information System (INIS)

    Bakos, G. A.; Torres, G.; Pal, A.; Hartman, J.; Noyes, R. W.; Latham, D. W.; Sasselov, D. D.; Sipocz, B.; Esquerdo, G. A.; Kovacs, Gabor; Fernandez, J.; Kovacs, Geza; Moor, A.; Fischer, D. A.; Isaacson, H.; Johnson, J. A.; Marcy, G. W.; Howard, A.; Butler, R. P.; Vogt, S.

    2010-01-01

    blended transiting hot Jupiter mimicking a transiting hot Neptune, and proves that HAT-P-11b is not such a blend.

  3. Atmospheres of Jupiter and Saturn

    International Nuclear Information System (INIS)

    Hunt, G.E.

    1981-01-01

    In this paper the current knowledge of the atmospheres of Jupiter and Saturn are reviewed making use of the extensive telescopic studies, International Ultraviolet Explorer Satellite observations and the measurements made during the recent Pioneer and Voyager flybys which have been supported by detailed theoretical studies. A detailed discussion is given of the composition of these atmospheres and the abundance ratios which provide insight into their original state and their evolution. The Voyager observations indicate a surprisingly close similarity between the weather systems of the Earth and the giant planets. Although both Jupiter and Saturn have internal heat sources, and are therefore star-like in their interiors, they appear to produce terrestrial-style weather systems. A detailed discussion is given of this work, which forms a major study of the Laboratory for Planetary Atmospheres at University College London. (author)

  4. Cold Hole Over Jupiter's Pole

    Science.gov (United States)

    2002-01-01

    Observations with two NASA telescopes show that Jupiter has an arctic polar vortex similar to a vortex over Earth's Antarctica that enables depletion of Earth's stratospheric ozone.These composite images of Jupiter's north polar region from the Hubble Space Telescope (right) and the Infrared Telescope Facility (left) show a quasi-hexagonal shape that extends vertically from the stratosphere down into the top of the troposphere. A sharp temperature drop, compared to surrounding air masses, creates an eastward wind that tends to keep the polar atmosphere, including the stratospheric haze, isolated from the rest of the atmosphere.The linear striations in the composite projections are artifacts of the image processing. The area closest to the pole has been omitted because it was too close to the edge of the planet in the original images to represent the planet reliably.The composite on the right combines images from the Wide Field and Planetary Camera 2 of the Hubble Space Telescope taken at a wavelength of 890 nanometers, which shows stratospheric haze particles.The sharp boundary and wave-like structure of the haze layer suggest a polar vortex and a similarity to Earth's stratospheric polar clouds. Images of Jupiter's thermal radiation clinch that identification. The composite on the left, for example, is made from images taken with Jet Propulsion Laboratory's Mid-Infrared Large-Well Imager at NASA's Infrared Telescope Facility at a wavelength of 17 microns. It shows polar air mass that is 5 to 6 degrees Celsius (9 to 10 degrees Fahrenheit) colder than its surroundings, with the same border as the stratospheric haze. Similar observations at other infrared wavelengths show the cold air mass extends at least as high as the middle stratosphere down to the top of the troposphere.These images were taken Aug. 11 through Aug. 13, 1999, near a time when Jupiter's north pole was most visible from Earth. Other Infrared Telescope Facility images at frequencies sensitive to the

  5. Dynamics of a plasma in laboratory models of magnetospheres of the Earth and Uranus

    International Nuclear Information System (INIS)

    Podgornyj, I.M.; Dubinin, Eh.M.; Izrajlevich, P.L.; Potanin, Yu.N.

    1977-01-01

    The plasma convection schema in the artificial magnetosphere of the Earth and Uranus has been studied, the magnetic convection schema being not connected with the readjustment of the magnetic field. The data on the modelling of the conditions of the Earth and the Uranus are presented. In modelling the magnetosphere of the Earth, various pictures of the convection of plasma in the equatorial and the meridional planes have been considered; the distributions of the intensities of fields are presented. In modelling the magnetosphere of the Uranus, several models are considered. The magnetosphere possessing the tubular tail is shown to be possible. A possibility has been checked that at the magnetic tail of the Uranus not cylindrical, but a flat current layer may exist, which has been built of the principle of readjustment of the magnetic field. The schemes illustrating the configuration of the magnetic tail, magnetic field, and plasma penetration areas are presented. Presented are the dependences of the component of the magnetic field intensity, which is parallel to the velocity vector, and at various inclination angles. An analysis of the results of laboratory tests and of the data of measurements in the cosmic space has been carried out

  6. TIDALLY DRIVEN ROCHE-LOBE OVERFLOW OF HOT JUPITERS WITH MESA

    Energy Technology Data Exchange (ETDEWEB)

    Valsecchi, Francesca; Rasio, Frederic A. [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), and Northwestern University, Department of Physics and Astronomy, Evanston, IL 60208 (United States); Rappaport, Saul [Department of Physics, and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Marchant, Pablo [Argelander-Institut für Astronomie, Universität Bonn, Auf dem Hgel 71, D-53121 Bonn (Germany); Rogers, Leslie A., E-mail: francesca@u.northwestern.edu, E-mail: rasio@northwestern.edu, E-mail: sar@mit.edu, E-mail: pablo@astro.uni-bonn.de, E-mail: larogers@caltech.edu [Department of Astronomy and Department of Geophysics and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States)

    2015-11-10

    Many exoplanets have now been detected in orbits with ultra-short periods very close to the Roche limit. Building upon our previous work, we study the possibility that mass loss through Roche lobe overflow (RLO) may affect the evolution of these planets, and could possibly transform a hot Jupiter into a lower-mass planet (hot Neptune or super-Earth). We focus here on systems in which the mass loss occurs slowly (“stable mass transfer” in the language of binary star evolution) and we compute their evolution in detail with the binary evolution code Modules for Experiments in Stellar Astrophysics. We include the effects of tides, RLO, irradiation, and photo-evaporation (PE) of the planet, as well as the stellar wind and magnetic braking. Our calculations all start with a hot Jupiter close to its Roche limit, in orbit around a Sun-like star. The initial orbital decay and onset of RLO are driven by tidal dissipation in the star. We confirm that such a system can indeed evolve to produce lower-mass planets in orbits of a few days. The RLO phase eventually ends and, depending on the details of the mass transfer and on the planetary core mass, the orbital period can remain around a few days for several Gyr. The remnant planets have rocky cores and some amount of envelope material, which is slowly removed via PE at a nearly constant orbital period; these have properties resembling many of the observed super-Earths and sub-Neptunes. For these remnant planets, we also predict an anti-correlation between mass and orbital period; very low-mass planets (M{sub pl} ≲ 5 M{sub ⊕}) in ultra-short periods (P{sub orb} < 1 day) cannot be produced through this type of evolution.

  7. SPITZER SPACE TELESCOPE MID-IR LIGHT CURVES OF NEPTUNE

    Energy Technology Data Exchange (ETDEWEB)

    Stauffer, John; Rebull, Luisa; Carey, Sean J.; Krick, Jessica; Ingalls, James G.; Lowrance, Patrick; Glaccum, William [Spitzer Science Center (SSC), California Institute of Technology, Pasadena, CA 91125 (United States); Marley, Mark S. [NASA Ames Research Center, Space Sciences and Astrobiology Division, MS245-3, Moffett Field, CA 94035 (United States); Gizis, John E. [Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Kirkpatrick, J. Davy [Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Simon, Amy A. [NASA Goddard Space Flight Center, Solar System Exploration Division (690.0), 8800 Greenbelt Road, Greenbelt, MD 20771 (United States); Wong, Michael H. [University of California, Department of Astronomy, Berkeley CA 94720-3411 (United States)

    2016-11-01

    We have used the Spitzer Space Telescope in 2016 February to obtain high cadence, high signal-to-noise, 17 hr duration light curves of Neptune at 3.6 and 4.5 μ m. The light curve duration was chosen to correspond to the rotation period of Neptune. Both light curves are slowly varying with time, with full amplitudes of 1.1 mag at 3.6 μ m and 0.6 mag at 4.5 μ m. We have also extracted sparsely sampled 18 hr light curves of Neptune at W1 (3.4 μ m) and W2 (4.6 μ m) from the Wide-feld Infrared Survey Explorer ( WISE )/ NEOWISE archive at six epochs in 2010–2015. These light curves all show similar shapes and amplitudes compared to the Spitzer light curves but with considerable variation from epoch to epoch. These amplitudes are much larger than those observed with Kepler / K 2 in the visible (amplitude ∼0.02 mag) or at 845 nm with the Hubble Space Telescope ( HST ) in 2015 and at 763 nm in 2016 (amplitude ∼0.2 mag). We interpret the Spitzer and WISE light curves as arising entirely from reflected solar photons, from higher levels in Neptune’s atmosphere than for K 2. Methane gas is the dominant opacity source in Neptune’s atmosphere, and methane absorption bands are present in the HST 763 and 845 nm, WISE W1, and Spitzer 3.6 μ m filters.

  8. Parametric Simulations of the Great Dark Spots of Neptune

    Science.gov (United States)

    Deng, Xiaolong; Le Beau, R.

    2006-09-01

    Observations by Voyager II and the Hubble Space Telescope of the Great Dark Spots (GDS) of Neptune suggest that large vortices with lifespans of years are not uncommon occurrences in the atmosphere of Neptune. The variability of these features over time, in particular the complex motions of GDS-89, make them challenging candidates to simulate in atmospheric models. Previously, using the Explicit Planetary Isentropic-Coordinate (EPIC) General Circulation Model, LeBeau and Dowling (1998) simulated the GDS-like vortex features. Qualitatively, the drift, oscillation, and tail-like features of GDS-89 were recreated, although precise numerical matches were only achieved for the meridional drift rate. In 2001, Stratman et al. applied EPIC to simulate the formation of bright companion clouds to the Great Dark Spots. In 2006, Dowling et al. presented a new version of EPIC, which includes hybrid vertical coordinate, cloud physics, advanced chemistry, and new turbulence models. With the new version of EPIC, more observation results, and more powerful computers, it is the time to revisit CFD simulations of the Neptune's atmosphere and do more detailed work on GDS-like vortices. In this presentation, we apply the new version of EPIC to simulate GDS-89. We test the influences of different parameters in the EPIC model: potential vorticity gradient, wind profile, initial latitude, vortex shape, and vertical structure. The observed motions, especially the latitudinal drift and oscillations in orientation angle and aspect ratio, are used as diagnostics of these unobserved atmospheric conditions. Increased computing power allows for more refined and longer simulations and greater coverage of the parameter space than previous efforts. Improved quantitative results have been achieved, including voritices with near eight-day oscillations and comparable variations in shape to GDS-89. This research has been supported by Kentucky NASA EPSCoR.

  9. Strange Isotope Ratios in Jupiter

    Science.gov (United States)

    Manuel, O.; Ragland, D.; Windler, K.; Zirbel, J.; Johannes, L.; Nolte, A.

    1998-05-01

    At the January AAS meeting, Dr. Daniel Goldin ordered the release of isotopic data from the 1995 Galileo probe into Jupiter. This probe took mass readings for mass numbers 2-150, which includes all of the noble gas isotopes. A certain few noble gas isotopes, specifically those at mass/charge = 21, 40, 78, 124, and 126, are difficult to distinguish from background, while interference causes some variation in signals for noble gas isotopes at mass/charge = 20, 22, 36, 38, 40, 80, 82, 83, 84 and 86. Some contamination was caused by incomplete adsorption of low mass hydrocarbons by Carbosieve, the material used in the concentration cells [Space Sci. Rev. 60, 120 (1992)]. Thus, preliminary results are most reliable in the high mass region that includes xenon. The Galileo Probe provided the first direct measurements from a planet with a chemical composition drastically different from Earth. Our preliminary analyses indicate that Jupiter contains Xe-X [Nature 240, 99 (1972)], which differs significantly from Earth's xenon. Xe-X and primordial He are tightly coupled on the microscopic scale of meteorite minerals [Science 195, 208 (1977); Meteoritics 15, 117 (1980)]. The presence today of Xe-X in the He-rich atmosphere of Jupiter suggests that the primordial linkage of Xe-X with He extended across the protosolar nebula, on a planetary scale [Comments Astrophys. 18, 335 (1997)]. Contamination by hydrocarbons and other gases does not necessarily remove light noble gases from further consideration. Currently, isolation of signals of these elements from interference continues and may result in the presentation of many other interesting observations at the conference.

  10. Variability of ethane on Jupiter

    Science.gov (United States)

    Kostiuk, Theodor; Espenak, Fred; Mumma, Michael J.; Deming, Drake; Zipoy, David

    1987-01-01

    Varying stratospheric temperature profiles and C2H6 altitude distributions furnish contexts for the evaluation of ethane abundances and distributions in the Jupiter stratosphere. Substantial ethane line emission and retrieved mole fraction variability is noted near the footprint of Io's flux tube, as well as within the auroral regions. It is suggested that this and other observed phenomena are due to the modification of local stratospheric chemistry by higher-order effects, which are in turn speculated to be due to the precipitation of charged particles along magnetic field lines.

  11. Status of the hydrogen and deuterium atomic beam polarized target for NEPTUN experiment

    International Nuclear Information System (INIS)

    Balandikov, N.I.; Ershov, V.P.; Fimushkin, V.V.; Kulikov, M.V.; Pilipenko, Y.K.; Shutov, V.B.

    1995-01-01

    NEPTUN-NEPTUN-A is a polarized experiment at Accelerating and Storage Complex (UNK, IHEP) with two internal targets. Status of the atomic beam polarized target that is being developed at the Joint Institute for Nuclear Research, Dubna is presented. copyright 1995 American Institute of Physics

  12. Jupiter's magnetosphere and radiation belts

    Science.gov (United States)

    Kennel, C. F.; Coroniti, F. V.

    1979-01-01

    Radioastronomy and Pioneer data reveal the Jovian magnetosphere as a rotating magnetized source of relativistic particles and radio emission, comparable to astrophysical cosmic ray and radio sources, such as pulsars. According to Pioneer data, the magnetic field in the outer magnetosphere is radially extended into a highly time variable disk-shaped configuration which differs fundamentally from the earth's magnetosphere. The outer disk region, and the energetic particles confined in it, are modulated by Jupiter's 10 hr rotation period. The entire outer magnetosphere appears to change drastically on time scales of a few days to a week. In addition to its known modulation of the Jovian decametric radio bursts, Io was found to absorb some radiation belt particles and to accelerate others, and most importantly, to be a source of neutral atoms, and by inference, a heavy ion plasma which may significantly affect the hydrodynamic flow in the magnetosphere. Another important Pioneer finding is that the Jovian outer magnetosphere generates, or permits to escape, fluxes of relativistic electrons of such intensities that Jupiter may be regarded as the dominant source of 1 to 30 MeV cosmic ray electrons in the heliosphere.

  13. An extrasolar planetary system with three Neptune-mass planets.

    Science.gov (United States)

    Lovis, Christophe; Mayor, Michel; Pepe, Francesco; Alibert, Yann; Benz, Willy; Bouchy, François; Correia, Alexandre C M; Laskar, Jacques; Mordasini, Christoph; Queloz, Didier; Santos, Nuno C; Udry, Stéphane; Bertaux, Jean-Loup; Sivan, Jean-Pierre

    2006-05-18

    Over the past two years, the search for low-mass extrasolar planets has led to the detection of seven so-called 'hot Neptunes' or 'super-Earths' around Sun-like stars. These planets have masses 5-20 times larger than the Earth and are mainly found on close-in orbits with periods of 2-15 days. Here we report a system of three Neptune-mass planets with periods of 8.67, 31.6 and 197 days, orbiting the nearby star HD 69830. This star was already known to show an infrared excess possibly caused by an asteroid belt within 1 au (the Sun-Earth distance). Simulations show that the system is in a dynamically stable configuration. Theoretical calculations favour a mainly rocky composition for both inner planets, while the outer planet probably has a significant gaseous envelope surrounding its rocky/icy core; the outer planet orbits within the habitable zone of this star.

  14. A resonant chain of four transiting, sub-Neptune planets.

    Science.gov (United States)

    Mills, Sean M; Fabrycky, Daniel C; Migaszewski, Cezary; Ford, Eric B; Petigura, Erik; Isaacson, Howard

    2016-05-26

    Surveys have revealed many multi-planet systems containing super-Earths and Neptunes in orbits of a few days to a few months. There is debate whether in situ assembly or inward migration is the dominant mechanism of the formation of such planetary systems. Simulations suggest that migration creates tightly packed systems with planets whose orbital periods may be expressed as ratios of small integers (resonances), often in a many-planet series (chain). In the hundreds of multi-planet systems of sub-Neptunes, more planet pairs are observed near resonances than would generally be expected, but no individual system has hitherto been identified that must have been formed by migration. Proximity to resonance enables the detection of planets perturbing each other. Here we report transit timing variations of the four planets in the Kepler-223 system, model these variations as resonant-angle librations, and compute the long-term stability of the resonant chain. The architecture of Kepler-223 is too finely tuned to have been formed by scattering, and our numerical simulations demonstrate that its properties are natural outcomes of the migration hypothesis. Similar systems could be destabilized by any of several mechanisms, contributing to the observed orbital-period distribution, where many planets are not in resonances. Planetesimal interactions in particular are thought to be responsible for establishing the current orbits of the four giant planets in the Solar System by disrupting a theoretical initial resonant chain similar to that observed in Kepler-223.

  15. Theoretical interpretation of the D-COM blind problem using the URANUS code

    International Nuclear Information System (INIS)

    Lassmann, K.; Preusser, T.

    1984-01-01

    A description of the URANUS code with emphasise on the sub-models of gas release, swelling and grain growth is given. The recently developed steady state and transient gas release model URGAS is briefly outlined. The URANUS code was used to analyse a blind problem on fission gas release which was defined within the framework of an IAEA sponsored coordinated research programme for ''The Development of Computer Models for Fuel Element Behaviour in Water Reactors (D-COM)''. The blind predictions and the predictions made after 15 April 1983 are compared. Sensitivity studies are presented which include the results obtained with different gas release models as well as the effects of varying the input data in some selected cases. (author)

  16. Current status of the transient integral fuel element performance code URANUS

    International Nuclear Information System (INIS)

    Preusser, T.; Lassmann, K.

    1983-01-01

    To investigate the behavior of fuel pins during normal and off-normal operation, the integral fuel rod code URANUS has been extended to include a transient version. The paper describes the current status of the program system including a presentation of newly developed models for hypothetical accident investigation. The main objective of current development work is to improve the modelling of fuel and clad material behavior during fast transients. URANUS allows detailed analysis of experiments until the onset of strong material transport phenomena. Transient fission gas analysis is carried out due to the coupling with a special version of the LANGZEIT-KURZZEIT-code (KfK). Fuel restructuring and grain growth kinetics models have been improved recently to better characterize pre-experimental steady-state operation; transient models are under development. Extensive verification of the new version has been carried out by comparison with analytical solutions, experimental evidence, and code-to-code evaluation studies. URANUS, with all these improvements, has been successfully applied to difficult fast breeder fuel rod analysis including TOP, LOF, TUCOP, local coolant blockage and specific carbide fuel experiments. Objective of further studies is the description of transient PCMI. It is expected that the results of these developments will contribute significantly to the understanding of fuel element structural behavior during severe transients. (orig.)

  17. The Atacama Cosmology Telescope: Beam Measurements and the Microwave Brightness Temperatures of Uranus and Saturn

    Science.gov (United States)

    Hasselfield, Matthew; Moodley, Kavilan; Bond, J. Richard; Das, Sudeep; Devlin, Mark J.; Dunkley, Joanna; Dunner, Rolando; Fowler, Joseph W.; Gallardo, Patricio; Gralla, Megan B.; hide

    2013-01-01

    We describe the measurement of the beam profiles and window functions for the Atacama Cosmology Telescope (ACT), which operated from 2007 to 2010 with kilopixel bolometer arrays centered at 148, 218, and 277 GHz. Maps of Saturn are used to measure the beam shape in each array and for each season of observations. Radial profiles are transformed to Fourier space in a way that preserves the spatial correlations in the beam uncertainty to derive window functions relevant for angular power spectrum analysis. Several corrections are applied to the resulting beam transforms, including an empirical correction measured from the final cosmic microwave background (CMB) survey maps to account for the effects of mild pointing variation and alignment errors. Observations of Uranus made regularly throughout each observing season are used to measure the effects of atmospheric opacity and to monitor deviations in telescope focus over the season. Using the WMAP-based calibration of the ACT maps to the CMB blackbody, we obtain precise measurements of the brightness temperatures of the Uranus and Saturn disks at effective frequencies of 149 and 219 GHz. For Uranus we obtain thermodynamic brightness temperatures T(149/U) = 106.7 +/- 2.2 K and T(219/U) = 100.1 +/- 3.1 K. For Saturn, we model the effects of the ring opacity and emission using a simple model and obtain resulting (unobscured) disk temperatures of T(149/S) = 137.3 +/- 3.2 K and T(219/S) = 137.3 +/- 4.7 K.

  18. Jupiter's evolution with primordial composition gradients

    Science.gov (United States)

    Vazan, Allona; Helled, Ravit; Guillot, Tristan

    2018-02-01

    Recent formation and structure models of Jupiter suggest that the planet can have composition gradients and not be fully convective (adiabatic). This possibility directly affects our understanding of Jupiter's bulk composition and origin. In this Letter we present Jupiter's evolution with a primordial structure consisting of a relatively steep heavy-element gradient of 40 M⊕. We show that for a primordial structure with composition gradients, most of the mixing occurs in the outer part of the gradient during the early evolution (several 107 yr), leading to an adiabatic outer envelope (60% of Jupiter's mass). We find that the composition gradient in the deep interior persists, suggesting that 40% of Jupiter's mass can be non-adiabatic with a higher temperature than the one derived from Jupiter's atmospheric properties. The region that can potentially develop layered convection in Jupiter today is estimated to be limited to 10% of the mass. Movies associated to Figs. 1-3 are available at http://https://www.aanda.org

  19. A new look at Jupiter: results at the now frontier

    International Nuclear Information System (INIS)

    1975-01-01

    Pioneer 10's encounter with Jupiter is discussed along with the interplanetary space beyond the orbit of Mars. Other topics discussed include the size of Jupiter, the Galilean satellites, the magnetic field of Jupiter, radiation belts, Jupiter's weather and interior, and future exploration possibilities. Educational projects are also included

  20. The infrared spectrum of Jupiter

    Science.gov (United States)

    Ridgway, S. T.; Larson, H. P.; Fink, U.

    1976-01-01

    The principal characteristics of Jupiter's infrared spectrum are reviewed with emphasis on their significance for our understanding of the composition and temperature structure of the Jovian upper atmosphere. The spectral region from 1 to 40 microns divides naturally into three regimes: the reflecting region, thermal emission from below the cloud deck (5-micron hot spots), and thermal emission from above the clouds. Opaque parts of the Jovian atmosphere further subdivide these regions into windows, and each is discussed in the context of its past or potential contributions to our knowledge of the planet. Recent results are incorporated into a table of atmospheric composition and abundance which includes positively identified constituents as well as several which require verification. The limited available information about spatial variations of the infrared spectrum is presented

  1. Detection of water vapor on Jupiter

    Science.gov (United States)

    Larson, H. P.; Fink, U.; Treffers, R.; Gautier, T. N., III

    1975-01-01

    High-altitude (12.4 km) spectroscopic observations of Jupiter at 5 microns from the NASA 91.5 cm airborne infrared telescope have revealed 14 absorptions assigned to the rotation-vibration spectrum of water vapor. Preliminary analysis indicates a mixing ratio about 1 millionth for the vapor phase of water. Estimates of temperature (greater than about 300 K) and pressure (less than 20 atm) suggest observation of water deep in Jupiter's hot spots responsible for its 5 micron flux. Model-atmosphere calculations based on radiative-transfer theory may change these initial estimates and provide a better physical picture of Jupiter's atmosphere below the visible cloud tops.

  2. Stratospheric ethane on Neptune - Comparison of groundbased and Voyager IRIS retrievals

    Science.gov (United States)

    Kostiuk, Theodor; Romani, Paul; Espenak, Fred; Bezard, Bruno

    1992-01-01

    Near-simultaneous ground and spacecraft measurements of 12-micron ethane emission spectra during the Voyager encounter with Neptune have furnished bases for the determination of stratospheric ethane abundance and the testing and constraining of Neptune methane-photochemistry models. The ethane retrievals were sensitive to the thermal profile used. Contribution functions for warm thermal profiles peaked at higher altitudes, as expected, with the heterodyne functions covering lower-pressure regions. Both constant- and nonconstant-with-height profiles remain candidate distributions for Neptune's stratospheric ethane.

  3. NEPTUNE: A new software platform for advanced nuclear thermal hydraulics

    International Nuclear Information System (INIS)

    Guelfi, A.; Boucker, M.; Herard, J.M.; Peturaud, P.; Bestion, D.; Boudier, P.; Hervieu, E.; Fillion, P.; Grandotto, M.

    2007-01-01

    The NEPTUNE project constitutes the thermal-hydraulic part of the long-term Electricite de France and Commissariat a l'Energie Atomique joint research and development program for the next generation of nuclear reactor simulation tools. This program is also financially supported by the Institut de Radioprotection et Surete Nucleaire and AREVA NP. The project aims at developing a new software platform for advanced two-phase flow thermal hydraulics covering the whole range of modeling scales and allowing easy multi-scale and multidisciplinary calculations. NEPTUNE is a fully integrated project that covers the following fields: software development, research in physical modeling and numerical methods, development of advanced instrumentation techniques, and performance of new experimental programs. The analysis of the industrial needs points out that three main simulation scales are involved. The system scale is dedicated to the overall description of the reactor. The component or subchannel scale allows three-dimensional computations of the main components of the reactors: cores, steam generators, condensers, and heat exchangers. The current generation of system and component codes has reached a very high level of maturity for industrial applications. The third scale, computational fluid dynamics (CFD) in open medium, allows one to go beyond the limits of the component scale for a finer description of the flows. This scale opens promising perspectives for industrial simulations, and the development and validation of the NEPTUNE CFD module have been a priority since the beginning of the project. It is based on advanced physical models (two-fluid or multi field model combined with interfacial area transport and two-phase turbulence) and modern numerical methods (fully unstructured finite volume solvers). For the system and component scales, prototype developments have also started, including new physical models and numerical methods. In addition to scale

  4. Validation of NEPTUNE-CFD on ULPU-V experiments

    Energy Technology Data Exchange (ETDEWEB)

    Jamet, Mathieu, E-mail: mathieu.jamet@edf.fr; Lavieville, Jerome; Atkhen, Kresna; Mechitoua, Namane

    2015-11-15

    In-vessel retention (IVR) of molten corium through external cooling of the reactor pressure vessel is one possible means of severe accident mitigation for a class of nuclear power plants. The aim is to successfully terminate the progression of a core melt within the reactor vessel. The probability of success depends on the efficacy of the cooling strategy; hence one of the key aspects of an IVR demonstration relates to the heat removal capability through the vessel wall by convection and boiling in the external water flow. This is only possible if the in-vessel thermal loading is lower than the local critical heat flux expected along the outer wall of the vessel, which is in turn highly dependent on the flow characteristics between the vessel and the insulator. The NEPTUNE-CFD multiphase flow solver is used to obtain a better understanding at local scale of the thermal hydraulics involved in this situation. The validation of the NEPTUNE-CFD code on the ULPU-V facility experiments carried out at the University of California Santa Barbara is presented as a first attempt of using CFD codes at EDF to address such an issue. Two types of computation are performed. On the one hand, a steady state algorithm is used to compute natural circulation flow rates and differential pressures and, on the other, a transient algorithm computation reveals the oscillatory nature of the pressure data recorded in the ULPU facility. Several dominant frequencies are highlighted. In both cases, the CFD simulations reproduce reasonably well the experimental data for these quantities.

  5. D/H ratio for Jupiter

    International Nuclear Information System (INIS)

    Smith, H.; Schempp, W.V.; Baines, K.H.

    1989-01-01

    Observations of Jupiter's spectrum near the R5(0) HD line at 6063.88 A are reported. A feature with an equivalent width of 0.065 + or - 0.021 mA is coincident with the expected line. This feature is compared with HD profiles computed for inhomogeneous scattering models for Jupiter to yield a range for the Jovian D/H ratio of 1.0-2.9 x 10 to the -5th. This D/H ratio is in the lower range of previously reported D/H values for Jupiter and corresponds to an essentially solar D/H ratio for Jupiter. The detection of HD features in the presence of probable blends with spectral features of minor atmospheric hydrocarbon molecules is discussed. Such blends may make unambiguous identification of HD features difficult. 26 references

  6. Terrestrial magnetosphere and comparison with Jupiter's

    International Nuclear Information System (INIS)

    Michel, F.C.

    1974-01-01

    A review of the characteristics of Jupiter's magnetosphere, with comparisons to the earth's is given. Radio observations of Jupiter indicate that energetic electrons are trapped in its magnetic field. The interaction of the trapped radiation with the satellite Io and the centrifugal instability of Jupiter's magnetosphere are discussed. Jupiter's outer magnetosphere is constantly accreting plasma at an uncertain rate. Various mechanisms for supplying ions to the outer magnetosphere are discussed, including: gravitational and centrifugal forces acting on corotating particles; field-line diffusion; photoelectron injection; excitation by Io or other satellites; and viscous interaction with the solar wind. The over-all morphology of the Jovian magnetosphere seems to be highly distorted by centrifugal forces and is easily compressed or deflected by the solar wind

  7. Astronomers find distant planet like Jupiter

    CERN Multimedia

    2003-01-01

    Astronomers searching for planetary systems like our solar system have found a planet similar to Jupiter orbiting a nearby star similar to our Sun, about 90 light-years from Earth, according to researchers (1/2 page).

  8. Analysis of JUPITER experiment in ZPPR-9

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1980-09-15

    Information and data from the ZPPR-9 reactor JUPITER experiment are presented concerning a general description of data and methods; criticality; reaction rate ratio and reaction rate distribution; Doppler and sample reactivity worth; sodium void worth; and control rod worth.

  9. Jupiter's Multi-level Clouds

    Science.gov (United States)

    1997-01-01

    Clouds and hazes at various altitudes within the dynamic Jovian atmosphere are revealed by multi-color imaging taken by the Near-Infrared Mapping Spectrometer (NIMS) onboard the Galileo spacecraft. These images were taken during the second orbit (G2) on September 5, 1996 from an early-morning vantage point 2.1 million kilometers (1.3 million miles) above Jupiter. They show the planet's appearance as viewed at various near-infrared wavelengths, with distinct differences due primarily to variations in the altitudes and opacities of the cloud systems. The top left and right images, taken at 1.61 microns and 2.73 microns respectively, show relatively clear views of the deep atmosphere, with clouds down to a level about three times the atmospheric pressure at the Earth's surface.By contrast, the middle image in top row, taken at 2.17 microns, shows only the highest altitude clouds and hazes. This wavelength is severely affected by the absorption of light by hydrogen gas, the main constituent of Jupiter's atmosphere. Therefore, only the Great Red Spot, the highest equatorial clouds, a small feature at mid-northern latitudes, and thin, high photochemical polar hazes can be seen. In the lower left image, at 3.01 microns, deeper clouds can be seen dimly against gaseous ammonia and methane absorption. In the lower middle image, at 4.99 microns, the light observed is the planet's own indigenous heat from the deep, warm atmosphere.The false color image (lower right) succinctly shows various cloud and haze levels seen in the Jovian atmosphere. This image indicates the temperature and altitude at which the light being observed is produced. Thermally-rich red areas denote high temperatures from photons in the deep atmosphere leaking through minimal cloud cover; green denotes cool temperatures of the tropospheric clouds; blue denotes cold of the upper troposphere and lower stratosphere. The polar regions appear purplish, because small-particle hazes allow leakage and reflectivity

  10. Deliverable 4.1 Homogeneous LCA methodology agreed by NEPTUNE and INNOWATECH

    DEFF Research Database (Denmark)

    Larsen, Henrik Fred; Hauschild, Michael Zwicky; Wenzel, Henrik

    2007-01-01

    In order to do a life cycle assessment (LCA) of a waste water treatment technique, a system to handle the mapped inventory data and a life cycle impact assessment (LCIA) method/model is needed. Besides NEPTUNE, another EU-funded project has the same methodology need namely INNOWATECH (contract No....... 036882) running in parallel with NEPTUNE but focusing on industrial waste water. With the aim of facilitating cooperation between the two projects a common LCA methodology framework has been worked out and is described in the following. This methodology work has been done as a joint effort between...... NEPTUNE WP4 and INNOWATECH WP4 represented by the WP4 lead partner IVL. The aim of the co-operation is to establish common methodologies and/or LCA models and/or tools in order to achieve a homogenous approach in INNOWATECH and NEPTUNE. Further, the aim is to facilitate possibilities of data exchange...

  11. ASEA-ATOM's URANUS system for production control, economic control and safeguards

    International Nuclear Information System (INIS)

    Mattson, J.C.

    1983-01-01

    ASEA-ATOM needs a system for production and economic control because: (1) the uranium is the valuable property of the customer; (2) short delivery times are a prime means of competition; (3) the manufacture of fuel necessitates frequent enrichment changes and much enrichment blending; (4) minimizing uranium stock reduces interest costs. A system which meets the above needs will with minor modifications meet safeguard requirements. URANUS is an integrated man/computer system with manual input and automatic data treatment and reporting of information. The man/computer interface is monitored by the automatic checking for plausibility of all input. An item is a quantity of material which is treated as a unit in production. Each item receives a unique identification number which may be used only once. If the qualitative properties of an item are changed a new item number is issued. Items are reported on forms and fed into URANUS by authorized personnel using personal passwords or are directly reported by terminal from certain operations. Pertinent information is entered for each project. The URANUS computer system consists of terminal activated on-line and batch modules which are briefly described. Output is information for planning, economic control and safeguards. Safeguards information consists of the following. For flow and blending control: delivery information; change of nominal enrichment; enrichment blending; internal transactions that change an enrichment/origin account; material status report (MSR); item inventory per MBA; general ledger. For physical inventory: material balance report (MBR); book item inventory per MBA; physical item inventory per MBA; uranium balance per origin and enrichment

  12. THE ATACAMA COSMOLOGY TELESCOPE: BEAM MEASUREMENTS AND THE MICROWAVE BRIGHTNESS TEMPERATURES OF URANUS AND SATURN

    Energy Technology Data Exchange (ETDEWEB)

    Hasselfield, Matthew [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544 (United States); Moodley, Kavilan [Astrophysics and Cosmology Research Unit, School of Mathematics, Statistics, and Computer Science, University of KwaZulu-Natal, Durban 4041 (South Africa); Bond, J. Richard; Hajian, Amir; Hincks, Adam D.; Nolta, Michael R. [Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, ON M5S 3H8 (Canada); Das, Sudeep [High Energy Physics Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439 (United States); Devlin, Mark J.; Marsden, Danica; Schmitt, Benjamin L. [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Dunkley, Joanna [Department of Astrophysics, Oxford University, Oxford OX1 3RH (United Kingdom); Dünner, Rolando; Gallardo, Patricio [Departamento de Astronomía y Astrofísica, Facultad de Física, Pontificía Universidad Católica, Casilla 306, Santiago 22 (Chile); Fowler, Joseph W.; Niemack, Michael D. [NIST Quantum Devices Group, 325 Broadway Mailcode 817.03, Boulder, CO 80305 (United States); Gralla, Megan B.; Marriage, Tobias A. [Department of Physics and Astronomy, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218-2686 (United States); Halpern, Mark [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Page, Lyman A. [Joseph Henry Laboratories of Physics, Jadwin Hall, Princeton University, Princeton, NJ 08544 (United States); Partridge, Bruce [Department of Physics and Astronomy, Haverford College, Haverford, PA 19041 (United States); and others

    2013-11-01

    We describe the measurement of the beam profiles and window functions for the Atacama Cosmology Telescope (ACT), which operated from 2007 to 2010 with kilopixel bolometer arrays centered at 148, 218, and 277 GHz. Maps of Saturn are used to measure the beam shape in each array and for each season of observations. Radial profiles are transformed to Fourier space in a way that preserves the spatial correlations in the beam uncertainty to derive window functions relevant for angular power spectrum analysis. Several corrections are applied to the resulting beam transforms, including an empirical correction measured from the final cosmic microwave background (CMB) survey maps to account for the effects of mild pointing variation and alignment errors. Observations of Uranus made regularly throughout each observing season are used to measure the effects of atmospheric opacity and to monitor deviations in telescope focus over the season. Using the WMAP-based calibration of the ACT maps to the CMB blackbody, we obtain precise measurements of the brightness temperatures of the Uranus and Saturn disks at effective frequencies of 149 and 219 GHz. For Uranus we obtain thermodynamic brightness temperatures T{sub U}{sup 149}= 106.7 ± 2.2 K and T{sub U}{sup 219}= 100.1 ± 3.1 K. For Saturn, we model the effects of the ring opacity and emission using a simple model and obtain resulting (unobscured) disk temperatures of T{sub S}{sup 149}= 137.3 ± 3.2 K and T{sub S}{sup 219}= 137.3 ± 4.7 K.

  13. URANUS - a computer programme for the thermal and mechanical analysis of the fuel rods in a nuclear reactor

    International Nuclear Information System (INIS)

    Lassmann, K.

    1978-01-01

    The URANUS code, a digital computer programme for the thermal and mechanical analysis of integral fuel rods, is described. With this code the fuel rods found in the majority of power reactors can be analyzed. URANUS is built around a quasi two-dimensional analysis of fuel and cladding. The mechanical analysis can accommodate seven components of strain: elastic, time-independent plastic, creep and thermal strains, as well as strains due to swelling, cracking and densification. The heat generation and temperature distribution, cladding/fuel gap closure, pellet cracking and crack healing, fission-gas release, corrosion, O/M-distribution and plutonium redistribution are modelled. Geometric non-linearities (large displacements) are included; steady state or transient loading (pressure, temperature) is possible. In this paper special attention is paid to a theory for determining crack structures. The present status of the URANUS computer programme and a critical comparison with other fuel rod codes as well as sample analyses are given. (Auth.)

  14. A parallel code named NEPTUNE for 3D fully electromagnetic and pic simulations

    International Nuclear Information System (INIS)

    Dong Ye; Yang Wenyuan; Chen Jun; Zhao Qiang; Xia Fang; Ma Yan; Xiao Li; Sun Huifang; Chen Hong; Zhou Haijing; Mao Zeyao; Dong Zhiwei

    2010-01-01

    A parallel code named NEPTUNE for 3D fully electromagnetic and particle-in-cell (PIC) simulations is introduced, which could run on the Linux system with hundreds to thousand CPUs. NEPTUNE is suitable to simulate entire 3D HPM devices; many HPM devices are simulated and designed by using it. In NEPTUNE code, the electromagnetic fields are updated by using the finite-difference in time domain (FDTD) method of solving Maxwell equations and the particles are moved by using Buneman-Boris advance method of solving relativistic Newton-Lorentz equation. Electromagnetic fields and particles are coupled by using liner weighing interpolation PIC method, and the electric filed components are corrected by using Boris method of solve Poisson equation in order to ensure charge-conservation. NEPTUNE code could construct many complicated geometric structures, such as arbitrary axial-symmetric structures, plane transforming structures, slow-wave-structures, coupling holes, foils, and so on. The boundary conditions used in NEPTUNE code are introduced in brief, including perfectly electric conductor boundary, external wave boundary, and particle boundary. Finally, some typical HPM devices are simulated and test by using NEPTUNE code, including MILO, RBWO, VCO, and RKA. The simulation results are with correct and credible physical images, and the parallel efficiencies are also given. (authors)

  15. Characterization of Duplex steel Uranus 76N during deformation and heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Lecomte-Beckers, J.; Carton, M. [ASMA Department - Sector, Special Metallic Materials, University of Liege, Chemin des Chevreuils 1, 4000 Liege 1 (Belgium); Moureaux, P.; Habraken, A.M. [M and S Department - Sector, Mechanic of Solids and Material, University of Liege, Chemin des Chevreuils 1, 4000 Liege 1 (Belgium)

    2006-12-15

    Duplex Uranus 76N is characterized by metallography, thermal and mechanical analysis. The investigation shows that the microstructure of such a Duplex strongly depends on the cooling conditions determining the quantity of austenite formed in the ferrite matrix. Numerical simulations of 76N behavior during the rolling process and service life require the knowledge of the recrystallization state during rolling steps at high temperature, thermal parameters such as dilatation, density, specific heat, thermal diffusivity, thermal conductivity and mechanical constitutive laws. These material parameters are determined and presented in this study. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Far-infrared and submillimeter brightness temperatures of the giant planets

    International Nuclear Information System (INIS)

    Hildebrand, R.H.; Loewenstein, R.F.; Harper, D.A.; Orton, G.S.; Keene, J.; Yerkes Observatory, Williams Bay, WI; California Institute of Technology, Jet Propulsion Laboratory, Pasadena; California Institute of Technology, Pasadena)

    1985-01-01

    The brightness temperatures of Jupiter, Saturn, Uranus, and Neptune were measured in the 35-1000 micron range with the 3-m NASA Infrared Telescope Facility (at wavelengths greater than 350 microns) and with the Kuiper Airborne Observatory (at wavelengths less than 350 microns). The data indicate the presence in Jupiter's spectrum of excess radiation (compared to theoretical models) at 300-400 microns. In addition, slightly less flux was observed from Saturn at 200 microns than predicted by atmospheric models, which suggests the possible presence of an unmodeled absorber. The submillimeter fluxes from Uranus and Neptune appear to be most consistent with low mixing ratios (less than 1 percent) of CH 4 in their deep atmospheres. 73 refs

  17. Giant Planets of Our Solar System Atmospheres, Composition, and Structure

    CERN Document Server

    Irwin, Patrick G. J

    2009-01-01

    This book reviews the current state of knowledge of the atmospheres of the giant gaseous planets: Jupiter, Saturn, Uranus, and Neptune. The current theories of their formation are reviewed and their recently observed temperature, composition and cloud structures are contrasted and compared with simple thermodynamic, radiative transfer and dynamical models. The instruments and techniques that have been used to remotely measure their atmospheric properties are also reviewed, and the likely development of outer planet observations over the next two decades is outlined. This second edition has been extensively updated following the Cassini mission results for Jupiter/Saturn and the newest ground-based measurements for Uranus/Neptune as well as on the latest development in the theories on planet formation.

  18. THE LICK-CARNEGIE EXOPLANET SURVEY: A URANUS-MASS FOURTH PLANET FOR GJ 876 IN AN EXTRASOLAR LAPLACE CONFIGURATION

    International Nuclear Information System (INIS)

    Rivera, Eugenio J.; Laughlin, Gregory; Vogt, Steven S.; Meschiari, Stefano; Butler, R. Paul; Haghighipour, Nader

    2010-01-01

    Continued radial velocity (RV) monitoring of the nearby M4V red dwarf star GJ 876 with Keck/High Resolution Echelle Spectrograph has revealed the presence of a Uranus-mass fourth planetary companion in the system. The new planet has a mean period of P e = 126.6 days (over the 12.6-year baseline of the RV observations), and a minimum mass of m e sin i e = 12.9 ± 1.7 M + . The detection of the new planet has been enabled by significant improvements to our RV data set for GJ 876. The data have been augmented by 36 new high-precision measurements taken over the past five years. In addition, the precision of all of the Doppler measurements have been significantly improved by the incorporation of a high signal-to-noise template spectrum for GJ 876 into the analysis pipeline. Implementation of the new template spectrum improves the internal rms errors for the velocity measurements taken during 1998-2005 from 4.1 m s -1 to 2.5 m s -1 . Self-consistent, N-body fits to the RV data set show that the four-planet system has an invariable plane with an inclination relative to the plane of the sky of i = 59. 0 5. The fit is not significantly improved by the introduction of a mutual inclination between the planets 'b' and 'c', but the new data do confirm a non-zero eccentricity, e d = 0.207 ± 0.055 for the innermost planet, 'd'. In our best-fit coplanar model, the mass of the new component is m e = 14.6 ± 1.7 M + . Our best-fitting model places the new planet in a three-body resonance with the previously known giant planets (which have mean periods of P c = 30.4 and P b = 61.1 days). The critical argument, ψ Laplace = λ c - 3λ b + 2λ e , for the Laplace resonance librates with an amplitude of Δψ Laplace = 40 0 ± 13 0 about ψ Laplace = 0 0 . Numerical integration indicates that the four-planet system is stable for at least a billion years (at least for the coplanar cases). This resonant configuration of three giant planets orbiting an M dwarf primary differs from the

  19. Observations and models of the decimetric radio emission from Jupiter

    International Nuclear Information System (INIS)

    Pater, I. de.

    1980-01-01

    The high energy electron distribution as a function of energy, pitch angle and spatial coordinates in Jupiter's inner magnetosphere was derived from a comparison of radio data and model calculations of Jupiter's synchrotron radiation. (Auth.)

  20. On possible life on Jupiter's satellite Io

    Science.gov (United States)

    Vidmachenko, A. P.

    2018-05-01

    Some of the satellites of Jupiter may well be suitable both for mastering, and for finding possible traces of life there. Among them such satellite like Io - nearest Galilean satellite of Jupiter, and one of the most volcanically active bodies in the solar system. Warming of the mantle is caused by a powerful tidal force from the side of Jupiter. This leads to the heating of some parts of the mantle to a temperature above 1800 K, with an average surface temperature of about 140 K. But under its surface can be safe and even comfortable shelters, where life could once have come from the outside (even in a very primitive form), and could survive to this day. Moreover, according to some model's assumptions, Io could sometime be formed in another part of the Solar system, where the water could exist. Note that on neighboring Galilean satellites now exist significant amounts of water .

  1. Thermal tides on a hot Jupiter

    Directory of Open Access Journals (Sweden)

    Hsieh H.-F.

    2011-07-01

    Full Text Available Following the linear analysis laid out by Gu & Ogilvie 2009 (hereafter GO09, we investigate the dynamical response of a non-synchronized hot Jupiter to stellar irradiation. Besides the internal and Rossby waves considered by GO09, we study the Kelvin waves excited by the diurnal Fourier harmonic of the prograde stellar irradiation. We also present a 2-dimensional plot of internal waves excited by the semi-diurnal component of the stellar irradiation and postulate that thermal bulges may arise in a hot Jupiter. Whether our postulation is valid and is consistent with the recent results from Arras & Socrates (2009b requires further investigation.

  2. Lucy: Navigating a Jupiter Trojan Tour

    Science.gov (United States)

    Stanbridge, Dale; Williams, Ken; Williams, Bobby; Jackman, Coralie; Weaver, Hal; Berry, Kevin; Sutter, Brian; Englander, Jacob

    2017-01-01

    In January 2017, NASA selected the Lucy mission to explore six Jupiter Trojan asteroids. These six bodies, remnants of the primordial material that formed the outer planets, were captured in the Sun-Jupiter L4 and L5 Lagrangian regions early in the solar system formation. These particular bodies were chosen because of their diverse spectral properties and the chance to observe up close for the first time two orbiting approximately equal mass binaries, Patroclus and Menoetius. KinetX, Inc. is the primary navigation supplier for the Lucy mission. This paper describes preliminary navigation analyses of the approach phase for each Trojan encounter.

  3. QATAR-2: A K DWARF ORBITED BY A TRANSITING HOT JUPITER AND A MORE MASSIVE COMPANION IN AN OUTER ORBIT

    International Nuclear Information System (INIS)

    Bryan, Marta L.; Alsubai, Khalid A.; Latham, David W.; Quinn, Samuel N.; Carter, Joshua A.; Berlind, Perry; Brown, Warren R.; Calkins, Michael L.; Esquerdo, Gilbert A.; Fűrész, Gábor; Stefanik, Robert P.; Torres, Guillermo; Parley, Neil R.; Collier Cameron, Andrew; Horne, Keith D.; Fulton, Benjamin J.; Street, Rachel A.; Buchhave, Lars A.; Jørgensen, Uffe Gråe; West, Richard G.

    2012-01-01

    We report the discovery and initial characterization of Qatar-2b, a hot Jupiter transiting a V = 13.3 mag K dwarf in a circular orbit with a short period, P b = 1.34 days. The mass and radius of Qatar-2b are M P = 2.49 M J and R P = 1.14 R J , respectively. Radial-velocity monitoring of Qatar-2 over a span of 153 days revealed the presence of a second companion in an outer orbit. The Systemic Console yielded plausible orbits for the outer companion, with periods on the order of a year and a companion mass of at least several M J . Thus, Qatar-2 joins the short but growing list of systems with a transiting hot Jupiter and an outer companion with a much longer period. This system architecture is in sharp contrast to that found by Kepler for multi-transiting systems, which are dominated by objects smaller than Neptune, usually with tightly spaced orbits that must be nearly coplanar.

  4. The science case for an orbital mission to Uranus: Exploring the origins and evolution of ice giant planets

    Czech Academy of Sciences Publication Activity Database

    Arridge, C. S.; Achilleos, N.; Agarwal, J.; Agnor, C. B.; Ambrosi, R.; André, N.; Badman, S. V.; Baines, K.; Banfield, D.; Barthélémy, M.; Bisi, M. M.; Blum, J.; Bocanegra-Bahamon, T.; Bonfond, B.; Bracken, C.; Brandt, P.; Briand, C.; Briois, C.; Brooks, S.; Castillo-Rogez, J.; Cavalié, T.; Christophe, B.; Coates, A. J.; Collinson, G.; Cooper, J. F.; Costa-Sitja, M.; Courtin, R.; Daglis, I. A.; de Pater, I.; Desai, M.; Dirkx, D.; Dougherty, M. K.; Ebert, R. W.; Filacchione, G.; Fletcher, L. N.; Fortney, J.; Gerth, I.; Grassi, D.; Grodent, D.; Grün, E.; Gustin, J.; Hedman, M.; Helled, R.; Henri, P.; Hess, S.; Hillier, J. K.; Hofstadter, M. H.; Holme, R.; Horanyi, M.; Hospodarsky, G.; Hsu, S.; Irwin, P.; Jackman, C. M.; Karatekin, O.; Kempf, S.; Khalisi, E.; Konstantinidis, K.; Krüger, H.; Kurth, W. S.; Labrianidis, C.; Lainey, V.; Lamy, L. L.; Laneuville, M.; Lucchesi, D.; Luntzer, A.; MacArthur, B.; Maier, A.; Masters, A.; McKenna-Lawlor, S.; Melin, H.; Milillo, A.; Moragas-Klostermeyer, G.; Morschhauser, A.; Moses, J. I.; Mousis, O.; Nettelmann, N.; Neubauer, F. M.; Nordheim, T.; Noyelles, B.; Orton, G. S.; Owens, M.; Peron, M.; Plainaki, C.; Postberg, F.; Rambaux, N.; Retherford, K.; Reynaud, S.; Roussos, E.; Russell, C. T.; Rymer, A. M.; Sallantin, R.; Sánchez-Lavega, A.; Santolík, Ondřej; Saur, J.; Sayanagi, K. M.; Schenk, P.; Schubert, J.; Sergis, N.; Sittler, E. C.; Smith, A.; Spahn, F.; Srama, R.; Stallard, B.; Sterken, V.; Sternovsky, Z.; Tiscareno, M.; Tobie, G.; Tosi, F.; Trielof, M.; Turrini, D.; Turtle, E. P.; Vinatier, S.; Wilson, R.; Zarka, P.

    2014-01-01

    Roč. 104, SI (2014), s. 122-140 ISSN 0032-0633 Institutional support: RVO:68378289 Keywords : Uranus * magnetosphere * atmosphere * natural satellites * rings * planetary interior Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 1.875, year: 2014 http://www.sciencedirect.com/science/article/pii/S0032063314002335#

  5. Precision flux density measurements of the giant planets at 8420 MHz

    Science.gov (United States)

    Turegano, J. A.; Klein, M. J.

    1981-01-01

    Precision measurements of the 3.56 cm flux densities of Jupiter, Saturn, Uranus, and Neptune are reported. The results are compared with previously published measurements as a means of: remotely sensing long-term changes in the microwave emission from the atmospheres of these planets and measuring the effects of Saturn's rings on the disk temperature as observed from earth at different ring inclination angles.

  6. Properties of planetary fluids at high pressure and temperature

    International Nuclear Information System (INIS)

    Nellis, W.J.; Hamilton, D.C.; Holmes, N.C.; Radousky, H.B.; Ree, F.H.; Ross, M.; Young, D.A.; Nicol, M.

    1987-01-01

    In order to derive models of the interiors of Uranus, Neptune, Jupiter and Saturn, researchers studied equations of state and electrical conductivities of molecules at high dynamic pressures and temperatures. Results are given for shock temperature measurements of N 2 and CH 4 . Temperature data allowed demonstration of shock induced cooling in the the transition region and the existence of crossing isotherms in P-V space

  7. NEPTUNE'S DYNAMIC ATMOSPHERE FROM KEPLER K2 OBSERVATIONS: IMPLICATIONS FOR BROWN DWARF LIGHT CURVE ANALYSES.

    Science.gov (United States)

    Simon, Amy A; Rowe, Jason F; Gaulme, Patrick; Hammel, Heidi B; Casewell, Sarah L; Fortney, Jonathan J; Gizis, John E; Lissauer, Jack J; Morales-Juberias, Raul; Orton, Glenn S; Wong, Michael H; Marley, Mark S

    2016-02-01

    Observations of Neptune with the Kepler Space Telescope yield a 49 day light curve with 98% coverage at a 1 minute cadence. A significant signature in the light curve comes from discrete cloud features. We compare results extracted from the light curve data with contemporaneous disk-resolved imaging of Neptune from the Keck 10-m telescope at 1.65 microns and Hubble Space Telescope visible imaging acquired nine months later. This direct comparison validates the feature latitudes assigned to the K2 light curve periods based on Neptune's zonal wind profile, and confirms observed cloud feature variability. Although Neptune's clouds vary in location and intensity on short and long timescales, a single large discrete storm seen in Keck imaging dominates the K2 and Hubble light curves; smaller or fainter clouds likely contribute to short-term brightness variability. The K2 Neptune light curve, in conjunction with our imaging data, provides context for the interpretation of current and future brown dwarf and extrasolar planet variability measurements. In particular we suggest that the balance between large, relatively stable, atmospheric features and smaller, more transient, clouds controls the character of substellar atmospheric variability. Atmospheres dominated by a few large spots may show inherently greater light curve stability than those which exhibit a greater number of smaller features.

  8. Validation of NEPTUNE-CFD two-phase flow models using experimental data

    International Nuclear Information System (INIS)

    Perez-Manes, Jorge; Sanchez Espinoza, Victor Hugo; Bottcher, Michael; Stieglitz, Robert; Sergio Chiva Vicent

    2014-01-01

    This paper deals with the validation of the two-phase flow models of the CFD code NEPTUNE-CFD using experimental data provided by the OECD BWR BFBT and PSBT Benchmark. Since the two-phase models of CFD codes are extensively being improved, the validation is a key step for the acceptability of such codes. The validation work is performed in the frame of the European NURISP Project and it was focused on the steady state and transient void fraction tests. The influence of different NEPTUNE-CFD model parameters on the void fraction prediction is investigated and discussed in detail. Due to the coupling of heat conduction solver SYRTHES with NEPTUNE-CFD, the description of the coupled fluid dynamics and heat transfer between the fuel rod and the fluid is improved significantly. The averaged void fraction predicted by NEPTUNE-CFD for selected PSBT and BFBT tests is in good agreement with the experimental data. Finally, areas for future improvements of the NEPTUNE-CFD code were identified, too. (authors)

  9. Dramatic Change in Jupiter's Great Red Spot

    Science.gov (United States)

    Simon, A. A.; Wong, M. H.; Rogers, J. H.; Orton, G. S.; de Pater, I.; Asay-Davis, X.; Carlson, R. W.; Marcus, P. S.

    2015-01-01

    Jupiter's Great Red Spot (GRS) is one of its most distinct and enduring features, having been continuously observed since the 1800's. It currently spans the smallest latitude and longitude size ever recorded. Here we show analyses of 2014 Hubble spectral imaging data to study the color, structure and internal dynamics of this long-live storm.

  10. From Basking Ridge to the Jupiter Trojans

    Science.gov (United States)

    Englander, Jacob

    2017-01-01

    This presentation describes the activities of the Global Trajectory Optimization Lab, a subdivision of the Navigation and Mission Design Branch at NASA GSFC. The students will learn the basics of interplanetary trajectory optimization and then, as an example, the Lucy mission to the Jupiter Trojans will be described from both a science and engineering perspective.

  11. Jupiter Environmental Research & Field Studies Academy.

    Science.gov (United States)

    Huttemeyer, Bob

    1996-01-01

    Describes the development and workings of the Jupiter Environmental Research and Field Studies Academy that focuses on enabling both teachers and students to participate in real-life learning experiences. Discusses qualifications for admittance, curriculum, location, ongoing projects, students, academics, preparation for life, problem solving, and…

  12. JUPITER PROJECT - MERGING INVERSE PROBLEM FORMULATION TECHNOLOGIES

    Science.gov (United States)

    The JUPITER (Joint Universal Parameter IdenTification and Evaluation of Reliability) project seeks to enhance and build on the technology and momentum behind two of the most popular sensitivity analysis, data assessment, calibration, and uncertainty analysis programs used in envi...

  13. Jupiter Quest: A Path to Scientific Discovery.

    Science.gov (United States)

    Bollman, Kelly A.; Rodgers, Mark H.; Mauller, Robert L.

    2001-01-01

    To experience the world of professional science, students must have access to the scientific community and be allowed to become real scientists. A partnership involving the National Aeronautics and Space Administration, the Jet Propulsion Laboratory, and the Lewis Center for Educational Research has produced Jupiter Quest, an engaging curriculum…

  14. Meteorite Dichotomy Implies that Jupiter Formed Early

    Science.gov (United States)

    Kruijer, T. S.; Burkhardt, C.; Budde, G.; Kleine, T.

    2018-05-01

    Meteorites derive from two distinct nebular reservoirs that co-existed and remained spatially separated between 1 and 3–4 Ma after CAIs. This can most easily be explained if Jupiter acted as a barrier and formed early, within less than 1 Ma.

  15. Baby Jupiters Must Gain Weight Fast

    Science.gov (United States)

    2009-01-01

    This photograph from NASA's Spitzer Space Telescope shows the young star cluster NGC 2362. By studying it, astronomers found that gas giant planet formation happens very rapidly and efficiently, within less than 5 million years, meaning that Jupiter-like worlds experience a growth spurt in their infancy.

  16. Comet Shoemaker-Levy 9 meets Jupiter.

    Science.gov (United States)

    Levy, D. H.; Shoemaker, E. M.; Shoemaker, C. S.

    1995-08-01

    The impact of comet D/1993 F2 (Shoemaker-Levy 9) with Jupiter was unforgettable, an event probably not to be repeated for millennia to come. One year later the astronomers who first spotted the comet reflect on their discovery, on the anxious months of anticipation before the collision and on what has been learned since.

  17. Origin and evolution of Jupiter and Saturn

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S S [Virginia Univ., Charlottesville (USA)

    1977-07-01

    Arguments are presented which make it very unlikely that Jupiter and Saturn were formed by contraction from initially extended gaseous states. Formation of these and other planets (in the solar system) by the mechanism of accretion does not appear to present any difficulties.

  18. Juno's first peek at Jupiter's interior

    Science.gov (United States)

    Guillot, Tristan; Miguel, Yamila; Hubbard, William B.; Kaspi, Yohai; Reese, Daniel; Helled, Ravit; Galanti, Eli; Militzer, Burkhard; Wahl, Sean; Folkner, William M.; Anderson, John; Iess, Luciano; Durante, Daniele; Parisi, Marzia; Stevenson, David J.

    2017-04-01

    The first orbits of Juno around Jupiter have led to a considerable improvement in the measurement of the planet's even gravitational moments. We will discuss how this leads to better constraints on jovian interior models, and how internal differential rotation and equations of state play an important part in the analysis.

  19. Why Are Hot Jupiters So Lonely?

    Science.gov (United States)

    Kohler, Susanna

    2017-10-01

    Jupiter-like planets with blisteringly close-in orbits are generally friendless, with no nearbyplanets transiting along with them. Giant planets with orbits a little further out, on the other hand, often have at least one companion. A new study examines the cause of hot Jupiters loneliness.Forming Close-In GiantsArtists impression of a planet forming within a protoplanetary disk. [NAOJ]Though weve studied close-in giant planets for decades now, we still dont fully understand how these objects form and evolve. Jupiter-like giant planets could form in situ next to their host stars, or they could form further out in the system beyond the ice line and then migrate inwards. And if they do migrate, this migration could occur early, while the protoplanetary disk still exists, or long after, via excitation of large eccentricities.We can try to resolve this mystery by examining the statistics of the close-in giant planets weve observed, but this often raises more questions than it answers. A prime example: the properties of close-in giants that have close-in companion planets orbiting in the same plane (i.e., co-transiting).About half of warm Jupiters Jupiter-like planets with periods of 1030 days appear to have close-in, co-transiting companions. In contrast, almost no hot Jupiters Jupiter-like planets with periods of less than 10 days have such companions. What causes this dichotomy?Schematic of the authors model, in which the close-in giant (m1) encounters a resonance with its host star, causing the orbit of the exterior companion (m2) to become tilted. [Spalding Batygin 2017]Friendless Hot JupitersWhile traditional models have argued that the two types of planets form via different pathways warm Jupiters form in situ, or else migrate inward early and smoothly, whereas hot Jupiters migrate inward late and violently, losing their companions in the process a new study casts doubt on this picture.Two scientists from the California Institute of Technology, Christopher

  20. NEPTUNE: a modular scheme for the calculation of light water reactors

    International Nuclear Information System (INIS)

    Kavenoky, A.

    1975-01-01

    The NEPTUNE modular scheme has been developed to provide the physicist and the design engineer with a single system of codes for the calculation of light water reactors. The APOLLO code is included in NEPTUNE for the multigroup transport treatment of cells, groups of cells and complete fuel assemblies; few groups cross section libraries are automatically transmitted to the reactor multidimensional diffusion modules. In the reactor phase, 1D and 2D diffusion calculations can be performed by use of the finite difference method; 2D and 3D calculations are done respectively by the BILAN and TRIDENT modules using the finite element method. For the depletion calculation coarse and refined computations are offered. NEPTUNE is characterized by two special features for the data processing: the OTOMAT system which provides a virtual memory simulation and the intervention Monitor which allow to disconnect the computation modules and the control modules [fr

  1. Photometry of occultation candidate stars. I - Uranus 1985 and Saturn 1985-1991

    Science.gov (United States)

    French, L. M.; Morales, G.; Dalton, A. S.; Klavetter, J. J.; Conner, S. R.

    1985-01-01

    Photometric observations of five stars to be occulted by the rings around Uranus are presented. The four stars to be occulted by Saturn or its rings during the period 1985-1991 were also observed. The observations were carried out with a CCD detector attached to the Kitt Peak McGraw-Hill 1.30-m telescope. Landolt standards of widely ranging V-I color indices were used to determine the extinction coefficients, transformation coefficients, and zero points of the stars. Mean extinction coefficients are given for each night of observation. K magnitudes for each star were estimated on the basis of the results of Johnson (1967). The complete photometric data set is given in a series of tables.

  2. The atmosphere of Uranus - Results of radio occultation measurements with Voyager 2

    Science.gov (United States)

    Lindal, G. F.; Lyons, J. R.; Sweetnam, D. N.; Eshleman, V. R.; Hinson, D. P.

    1987-01-01

    The Uranian atmosphere is investigated on the basis of S-band and X-band occultation observations (including measurements of Doppler frequency perturbations) obtained during the Voyager 2 encounter with Uranus in January 1986. The data are presented in extensive tables and graphs and characterized in detail. The atmosphere is assumed to have an H2/He abundance ratio of about 85/15, but also to contain small amounts of CH4 at above-cloud relative humidity 30 percent, cloud-base relative humidity 78 percent, and below-cloud mixing ratio 2.3 percent by number density. Other parameters estimated include magnetic-field rotation period 17.24 h, 1-bar equatorial radius 25,559 + or - 4 km, polar radius 24,973 + or - 20 km, equatorial acceleration of gravity 8.69 + or - 0.01 m/sec sq, and atmospheric temperature 76 + or - 2 K (assuming 85 + or - 3 percent H2).

  3. Development of the Neptune Deepwater Port: The Importance of Key Stakeholder Involvement and Benefits

    Energy Technology Data Exchange (ETDEWEB)

    Silver, Marc

    2010-09-15

    In 2005, a subsidiary of GDF SUEZ began developing the Neptune LNG Deepwater Port off the coast of Massachusetts. The project met with minimal opposition and maintained a very aggressive timeline. The reasons? Productive involvement with key stakeholders and well-defined benefits. This paper outlines the systematic approach to stakeholder outreach and mitigation planning that Neptune LNG LLC took to garner project acceptance. Details of the pre-planning phase, the stakeholder outreach phase, and the project mitigation phase are all discussed. The result was a major energy project that took less than 3.5 years to permit and 1.5 years to build.

  4. Evaluation of the Trac-PF1 code for simulating the Neptun reflooding experiment

    International Nuclear Information System (INIS)

    Pontedeiro, A.C.; Galetti, M.R.S.

    1991-01-01

    The present work presents an assessment of the TRAC-BF1 code using the results of the NEPTUN experiment which simulates the reflooding in a loss-of-coolant accident (LOCA) in a PWR. The NEPTUN experiment is composed of an array of electrically-heated tubes where the reflooding condition can be tested. Two types of tests results are presented and compared with the values obtained with the TRAC-BF1 code. From this comparison it is concluded that TRAC is suitable for verifying accident analysis. (author)

  5. Chemical fingerprints of hot Jupiter planet formation

    Science.gov (United States)

    Maldonado, J.; Villaver, E.; Eiroa, C.

    2018-05-01

    Context. The current paradigm to explain the presence of Jupiter-like planets with small orbital periods (P involves their formation beyond the snow line following inward migration, has been challenged by recent works that explore the possibility of in situ formation. Aims: We aim to test whether stars harbouring hot Jupiters and stars with more distant gas-giant planets show any chemical peculiarity that could be related to different formation processes. Methods: Our methodology is based on the analysis of high-resolution échelle spectra. Stellar parameters and abundances of C, O, Na, Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, and Zn for a sample of 88 planet hosts are derived. The sample is divided into stars hosting hot (a 0.1 au) Jupiter-like planets. The metallicity and abundance trends of the two sub-samples are compared and set in the context of current models of planet formation and migration. Results: Our results show that stars with hot Jupiters have higher metallicities than stars with cool distant gas-giant planets in the metallicity range +0.00/+0.20 dex. The data also shows a tendency of stars with cool Jupiters to show larger abundances of α elements. No abundance differences between stars with cool and hot Jupiters are found when considering iron peak, volatile elements or the C/O, and Mg/Si ratios. The corresponding p-values from the statistical tests comparing the cumulative distributions of cool and hot planet hosts are 0.20, products from observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 072.C-0033(A), 072.C-0488(E), 074.B-0455(A), 075.C-0202(A), 077.C-0192(A), 077.D-0525(A), 078.C-0378(A), 078.C-0378(B), 080.A-9021(A), 082.C-0312(A) 082.C-0446(A), 083.A-9003(A), 083.A-9011(A), 083.A-9011(B), 083.A-9013(A), 083.C-0794(A), 084.A-9003(A), 084.A-9004(B), 085.A-9027(A), 085.C-0743(A), 087.A-9008(A), 088.C-0892(A), 089.C-0440(A), 089.C-0444(A), 089.C-0732(A), 090.C-0345(A), 092.A-9002(A), 192.C-0852

  6. A New Approach to Modeling Jupiter's Magnetosphere

    Science.gov (United States)

    Fukazawa, K.; Katoh, Y.; Walker, R. J.; Kimura, T.; Tsuchiya, F.; Murakami, G.; Kita, H.; Tao, C.; Murata, K. T.

    2017-12-01

    The scales in planetary magnetospheres range from 10s of planetary radii to kilometers. For a number of years we have studied the magnetospheres of Jupiter and Saturn by using 3-dimensional magnetohydrodynamic (MHD) simulations. However, we have not been able to reach even the limits of the MHD approximation because of the large amount of computer resources required. Recently thanks to the progress in supercomputer systems, we have obtained the capability to simulate Jupiter's magnetosphere with 1000 times the number of grid points used in our previous simulations. This has allowed us to combine the high resolution global simulation with a micro-scale simulation of the Jovian magnetosphere. In particular we can combine a hybrid (kinetic ions and fluid electrons) simulation with the MHD simulation. In addition, the new capability enables us to run multi-parameter survey simulations of the Jupiter-solar wind system. In this study we performed a high-resolution simulation of Jovian magnetosphere to connect with the hybrid simulation, and lower resolution simulations under the various solar wind conditions to compare with Hisaki and Juno observations. In the high-resolution simulation we used a regular Cartesian gird with 0.15 RJ grid spacing and placed the inner boundary at 7 RJ. From these simulation settings, we provide the magnetic field out to around 20 RJ from Jupiter as a background field for the hybrid simulation. For the first time we have been able to resolve Kelvin Helmholtz waves on the magnetopause. We have investigated solar wind dynamic pressures between 0.01 and 0.09 nPa for a number of IMF values. These simulation data are open for the registered users to download the raw data. We have compared the results of these simulations with Hisaki auroral observations.

  7. Modeling Magnetospheric Fields in the Jupiter System

    OpenAIRE

    Saur, Joachim; Chané, Emmanuel; Hartkorn, Oliver

    2018-01-01

    The various processes which generate magnetic fields within the Jupiter system are exemplary for a large class of similar processes occurring at other planets in the solar system, but also around extrasolar planets. Jupiter’s large internal dynamo magnetic field generates a gigantic magnetosphere, which in contrast to Earth’s magnetosphere is strongly rotational driven and possesses large plasma sources located deeply within the magnetosphere. The combination of the latter two effects is the ...

  8. Mutagenesis of mNeptune Red-Shifts Emission Spectrum to 681-685 nm.

    Science.gov (United States)

    Li, ZhaoYang; Zhang, ZhiPing; Bi, LiJun; Cui, ZongQiang; Deng, JiaoYu; Wang, DianBing; Zhang, Xian-En

    2016-01-01

    GFP-like fluorescent proteins with diverse emission wavelengths have been developed through mutagenesis, offering many possible choices in cellular and tissue imaging, such as multi-targets imaging, deep tissue imaging that require longer emission wavelength. Here, we utilized a combined approach of random mutation and structure-based rational design to develop new NIR fluorescent proteins on the basis of a far-red fluorescent protein, mNeptune (Ex/Em: 600/650 nm). We created a number of new monomeric NIR fluorescent proteins with the emission range of 681-685 nm, which exhibit the largest Stocks shifts (77-80 nm) compared to other fluorescent proteins. Among them, mNeptune681 and mNeptune684 exhibit more than 30 nm redshift in emission relative to mNeptune, owing to the major role of the extensive hydrogen-bond network around the chromophore and contributions of individual mutations to the observed redshift. Furthermore, the two variants still maintain monomeric state in solution, which is a trait crucial for their use as protein tags. In conclusion, our results suggest that there is untapped potential for developing fluorescent proteins with desired properties.

  9. Understanding the mass-radius relation for sub-Neptunes: radius as a proxy for composition

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Eric D.; Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)

    2014-09-01

    Transiting planet surveys like Kepler have provided a wealth of information on the distribution of planetary radii, particularly for the new populations of super-Earth- and sub-Neptune-sized planets. In order to aid in the physical interpretation of these radii, we compute model radii for low-mass rocky planets with hydrogen-helium envelopes. We provide model radii for planets 1-20 M {sub ⊕}, with envelope fractions 0.01%-20%, levels of irradiation 0.1-1000 times Earth's, and ages from 100 Myr to 10 Gyr. In addition we provide simple analytic fits that summarize how radius depends on each of these parameters. Most importantly, we show that at fixed H/He envelope fraction, radii show little dependence on mass for planets with more than ∼1% of their mass in their envelope. Consequently, planetary radius is to a first order a proxy for planetary composition, i.e., H/He envelope fraction, for Neptune- and sub-Neptune-sized planets. We recast the observed mass-radius relationship as a mass-composition relationship and discuss it in light of traditional core accretion theory. We discuss the transition from rocky super-Earths to sub-Neptune planets with large volatile envelopes. We suggest ∼1.75 R {sub ⊕} as a physically motivated dividing line between these two populations of planets. Finally, we discuss these results in light of the observed radius occurrence distribution found by Kepler.

  10. Aerospace Engineering Space Mission Concept Feasibility Study: A Neptune Mission Design Example

    Science.gov (United States)

    Esper, Jaime

    2007-01-01

    This viewgraph document reviews the feasibility study of a mission to Neptune. Included are discussions of the science instruments, the design methodology, the trajectory, the spacecraft design, the alternative propulsion systems, (chemical, solar electric (SEP)), the communications systems, the power systems, the thermal system.

  11. Triple Microlens OGLE-2008-BLG-092L: Binary Stellar System with a Circumprimary Uranus-type Planet

    Science.gov (United States)

    Poleski, Radosław; Skowron, Jan; Udalski, Andrzej; Han, Cheongho; Kozłowski, Szymon; Wyrzykowski, Łukasz; Dong, Subo; Szymański, Michał K.; Kubiak, Marcin; Pietrzyński, Grzegorz; Soszyński, Igor; Ulaczyk, Krzysztof; Pietrukowicz, Paweł; Gould, Andrew

    2014-11-01

    We present the gravitational microlensing discovery of a 4 M Uranus planet that orbits a 0.7 M ⊙ star at ≈18 AU. This is the first known analog of Uranus. Similar planets, i.e., cold ice giants, are inaccessible to either radial velocity or transit methods because of the long orbital periods, while low reflected light prevents direct imaging. We discuss how similar planets may contaminate the sample of the very short microlensing events that are interpreted as free-floating planets with an estimated rate of 1.8 per main-sequence star. Moreover, the host star has a nearby stellar (or brown dwarf) companion. The projected separation of the planet is only about three times smaller than that of the companion star, suggesting significant dynamical interactions.

  12. Triple microlens OGLE-2008-BLG-092L: binary stellar system with a circumprimary uranus-type planet

    Energy Technology Data Exchange (ETDEWEB)

    Poleski, Radosław; Gould, Andrew [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Skowron, Jan; Udalski, Andrzej; Kozłowski, Szymon; Wyrzykowski, Łukasz; Szymański, Michał K.; Kubiak, Marcin; Pietrzyński, Grzegorz; Soszyński, Igor; Ulaczyk, Krzysztof; Pietrukowicz, Paweł [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Han, Cheongho [Department of Physics, Chungbuk National University, Cheongju 371-763 (Korea, Republic of); Dong, Subo, E-mail: poleski@astronomy.ohio-state.edu [Kavli Institute for Astronomy and Astrophysics, Peking University, Yi He Yuan Road 5, Hai Dian District, Beijing 100871 (China)

    2014-11-01

    We present the gravitational microlensing discovery of a 4 M {sub Uranus} planet that orbits a 0.7 M {sub ☉} star at ≈18 AU. This is the first known analog of Uranus. Similar planets, i.e., cold ice giants, are inaccessible to either radial velocity or transit methods because of the long orbital periods, while low reflected light prevents direct imaging. We discuss how similar planets may contaminate the sample of the very short microlensing events that are interpreted as free-floating planets with an estimated rate of 1.8 per main-sequence star. Moreover, the host star has a nearby stellar (or brown dwarf) companion. The projected separation of the planet is only about three times smaller than that of the companion star, suggesting significant dynamical interactions.

  13. CAPTURE OF TROJANS BY JUMPING JUPITER

    International Nuclear Information System (INIS)

    Nesvorný, David; Vokrouhlický, David; Morbidelli, Alessandro

    2013-01-01

    Jupiter Trojans are thought to be survivors of a much larger population of planetesimals that existed in the planetary region when planets formed. They can provide important constraints on the mass and properties of the planetesimal disk, and its dispersal during planet migration. Here, we tested a possibility that the Trojans were captured during the early dynamical instability among the outer planets (aka the Nice model), when the semimajor axis of Jupiter was changing as a result of scattering encounters with an ice giant. The capture occurs in this model when Jupiter's orbit and its Lagrange points become radially displaced in a scattering event and fall into a region populated by planetesimals (that previously evolved from their natal transplanetary disk to ∼5 AU during the instability). Our numerical simulations of the new capture model, hereafter jump capture, satisfactorily reproduce the orbital distribution of the Trojans and their total mass. The jump capture is potentially capable of explaining the observed asymmetry in the number of leading and trailing Trojans. We find that the capture probability is (6-8) × 10 –7 for each particle in the original transplanetary disk, implying that the disk contained (3-4) × 10 7 planetesimals with absolute magnitude H disk ∼ 14-28 M Earth , is consistent with the mass deduced from recent dynamical simulations of the planetary instability.

  14. A retrograde object near Jupiter's orbit

    Science.gov (United States)

    Connors, M.; Wiegert, P.

    2018-02-01

    Asteroid 2007 VW266 is among the rare objects with a heliocentric retrograde orbit, and its semimajor axis is within a Hill sphere radius of that of Jupiter. This raised the interesting possibility that it could be in co-orbital retrograde resonance with Jupiter, a second "counter-orbital" object in addition to recently discovered 2015 BZ509. We find instead that the object is in 13/14 retrograde mean motion resonance (also referred to as 13/-14). The object is shown to have entered its present orbit about 1700 years ago, and it will leave it in about 8000 years, both through close approach to Jupiter. Entry and exit states both avoid 1:1 retrograde resonance, but the retrograde nature is preserved. The temporary stable state is due to an elliptic orbit with high inclination keeping nodal passages far from the associated planet. We discuss the motion of this unusual object based on modeling and theory, and its observational prospects.

  15. Boil-off experiments with the EIR-NEPTUN Facility: Analysis and code assessment overview report

    International Nuclear Information System (INIS)

    Aksan, S.N.; Stierli, F.; Analytis, G.T.

    1992-03-01

    The NEPTUN data discussed in this report are from core uncovery (boil-off) experiments designed to investigate the mixture level decrease and the heat up of the fuel rod simulators above the mixture level for conditions simulating core boil-off for a nuclear reactor under small break loss-of-coolant accident conditions. The first series of experiments performed in the NEPTUN test facility consisted of ten boil-off (uncovery) and one adiabatic heat-up tests. In these tests three parameters were varied: rod power, system pressure and initial coolant subcooling. The NEPTUN experiments showed that the external surface thermocouples do not cause a significant cooling influence in the rods to which they are attached under boil-off conditions. The reflooding tests performed later on indicated that the external surface thermocouples have some effect during reflooding for NEPTUN electrically heated rod bundle. Peak cladding temperatures are reduced by about 30--40C and quench times occur 20--70 seconds earlier than rods with embedded thermocouples. Additionally, the external surface-thermocouples give readings up to 20 K lower than those obtained with internal surface thermocouples (in the absence of external thermocouples) in the peak cladding temperature zone. Some of the boil-off data obtained from the NEPTUN test facility are used for the assessment of the thermal-hydraulic transient computer codes. These calculations were performed extensively using the frozen version of TRAC-BD1/MOD1 (version 22). A limited number of assessment calculations were done with RELAP5/MOD2 (version 36.02). In this report the main results and conclusions of these calculations are presented with the identification of problem areas in relation to models relevant to boil-off phenomena. On the basis of further analysis and calculations done, changing some of the models such as the bubbly/slug flow interfacial friction correlation which eliminate some of the problems are recommended

  16. A component architecture for the two-phase flows simulation system Neptune

    Energy Technology Data Exchange (ETDEWEB)

    Bechaud, C; Boucker, M; Douce, A [Electricite de France (EDF-RD/MFTT), 78 - Chatou (France); Grandotto, M [CEA Cadarache (DEN/DTP/STH), 13 - Saint-Paul-lez-Durance (France); Tajchman, M [CEA Saclay (DEN/DM2S/SFME), 91 - Gif-sur-Yvette (France)

    2003-07-01

    Electricite de France (EdF) and the French atomic energy commission (Cea) have planed a large project to build a new set of software in nuclear reactors analysis. One of the main idea is to allow coupled calculations in which several scientific domains are involved. This paper presents the software architecture of the two-phase flows simulation Neptune project. Neptune should allow computations of two-phase flows in 3 dimensions under normal operating conditions as well as safety conditions. Three scales are identified: the local scale where there is only homogenization between the two phases, an intermediate scale where solid internal structures are homogenized with the fluid and the system scale where some parts of the geometry under study are considered point-wise or subject to one dimensional simplifications. The main properties of this architecture are as follow: -) coupling with scientific domains, and between different scales, -) re-using of quite all or parts of existing validated codes, -) components usable by the different scales, -) easy introducing of new physical modeling as well as new numerical methods, -) local, distributed and parallel computing. The Neptune architecture is based on the component concept with stable and well suited interface. In the case of a distributed application the components are managed through a Corba bus. The building of the components is organized in shell: a programming shell (Fortran or C++ routines), a managing shell (C++ language), an interpreted shell (Python language), a Corba shell and a global driving shell (C++ or Python). Neptune will use the facilities offered by the Salome project: pre and post processors and controls. A data model has been built to have a common access to the information exchanged between the components (meshes, fields, physical and technical information). This architecture has first been setup and tested on some simple but significant cases and is now currently in use to build the Neptune

  17. A component architecture for the two-phase flows simulation system Neptune

    International Nuclear Information System (INIS)

    Bechaud, C.; Boucker, M.; Douce, A.; Grandotto, M.; Tajchman, M.

    2003-01-01

    Electricite de France (EdF) and the French atomic energy commission (Cea) have planed a large project to build a new set of software in nuclear reactors analysis. One of the main idea is to allow coupled calculations in which several scientific domains are involved. This paper presents the software architecture of the two-phase flows simulation Neptune project. Neptune should allow computations of two-phase flows in 3 dimensions under normal operating conditions as well as safety conditions. Three scales are identified: the local scale where there is only homogenization between the two phases, an intermediate scale where solid internal structures are homogenized with the fluid and the system scale where some parts of the geometry under study are considered point-wise or subject to one dimensional simplifications. The main properties of this architecture are as follow: -) coupling with scientific domains, and between different scales, -) re-using of quite all or parts of existing validated codes, -) components usable by the different scales, -) easy introducing of new physical modeling as well as new numerical methods, -) local, distributed and parallel computing. The Neptune architecture is based on the component concept with stable and well suited interface. In the case of a distributed application the components are managed through a Corba bus. The building of the components is organized in shell: a programming shell (Fortran or C++ routines), a managing shell (C++ language), an interpreted shell (Python language), a Corba shell and a global driving shell (C++ or Python). Neptune will use the facilities offered by the Salome project: pre and post processors and controls. A data model has been built to have a common access to the information exchanged between the components (meshes, fields, physical and technical information). This architecture has first been setup and tested on some simple but significant cases and is now currently in use to build the Neptune

  18. Interplanetary electrons: what is the strength of the Jupiter source

    International Nuclear Information System (INIS)

    Fillius, W.; Ip, Wing-Huen; Knickerbocker, P.

    1977-01-01

    Because there is not enough information to support a rigorous answer, we use a phenomenological approach and conservative assumptions to address the source strength of Jupiter for interplanetary electrons. We estimate that Jupiter emits approximately 10 24 - 10 26 electrons s -1 of energy > 6 MeV, which source may be compared with the population of approximately 3 x 10 28 electrons of the same energy in Jupiter's outer magnetosphere. We conclude that Jupiter accelerates particles at a rate exceeding that of ordinary trapped particle dynamical processes. (author)

  19. Study of Power Options for Jupiter and Outer Planet Missions

    Science.gov (United States)

    Landis, Geoffrey A.; Fincannon, James

    2015-01-01

    Power for missions to Jupiter and beyond presents a challenging goal for photovoltaic power systems, but NASA missions including Juno and the upcoming Europa Clipper mission have shown that it is possible to operate solar arrays at Jupiter. This work analyzes photovoltaic technologies for use in Jupiter and outer planet missions, including both conventional arrays, as well as analyzing the advantages of advanced solar cells, concentrator arrays, and thin film technologies. Index Terms - space exploration, spacecraft solar arrays, solar electric propulsion, photovoltaic cells, concentrator, Fresnel lens, Jupiter missions, outer planets.

  20. ESO Observations of New Moon of Jupiter

    Science.gov (United States)

    2000-08-01

    Two astronomers, both specialists in minor bodies in the solar system, have performed observations with ESO telescopes that provide important information about a small moon, recently discovered in orbit around the solar system's largest planet, Jupiter. Brett Gladman (of the Centre National de la Recherche Scientifique (CNRS) and working at Observatoire de la Cote d'Azur, France) and Hermann Boehnhardt ( ESO-Paranal) obtained detailed data on the object S/1999 J 1 , definitively confirming it as a natural satellite of Jupiter. Seventeen Jovian moons are now known. The S/1999 J 1 object On July 20, 2000, the Minor Planet Center (MPC) of the International Astronomical Union (IAU) announced on IAU Circular 7460 that orbital computations had shown a small moving object, first seen in the sky in 1999, to be a new candidate satellite of Jupiter. The conclusion was based on several positional observations of that object made in October and November 1999 with the Spacewatch Telescope of the University of Arizona (USA). In particular, the object's motion in the sky was compatible with that of an object in orbit around Jupiter. Following the official IAU procedure, the IAU Central Bureau for Astronomical Telegrams designated the new object as S/1999 J 1 (the 1st candidate Satellite of Jupiter to be discovered in 1999). Details about the exciting detective story of this object's discovery can be found in an MPC press release and the corresponding Spacewatch News Note. Unfortunately, Jupiter and S/1999 J 1 were on the opposite side of the Sun as seen from the Earth during the spring of 2000. The faint object remained lost in the glare of the Sun in this period and, as expected, a search in July 2000 through all available astronomical data archives confirmed that it had not been seen since November 1999, nor before that time. With time, the extrapolated sky position of S/1999 J 1 was getting progressively less accurate. New observations were thus urgently needed to "recover

  1. Report of Some Comets: The Discovery of Uranus and Comets by William, Caroline, and John Herschel

    Science.gov (United States)

    Pasachoff, Jay M.; Olson, R. J. M.

    2011-01-01

    We report on the discovery and drawings of comets by William, Caroline, and John Herschel. The first discovery, by William Herschel, in 1781 from Bath, published in the Philosophical Transactions of the Royal Society with the title "Report of a Comet," turned out to be Uranus, the first planet ever discovered, Mercury through Saturn having been known since antiquity. William's sister Caroline was given duties of sweeping the skies and turned out to be a discoverer of 8 comets in her own right, in addition to keeping William's notes. Caroline's comets were discovered from Slough between 1786 and 1797. In the process, we also discuss original documents from the archives of the Royal Society and of the Royal Astronomical Society. We conclude by showing comet drawings that we have recently attributed to John Herschel, including Halley's Comet from 1836, recently located in the Ransom Center of the University of Texas at Austin. Acknowledgments: Planetary astronomy at Williams College is supported in part by grant NNX08AO50G from NASA Planetary Astronomy. We thank Peter Hingley of the Royal Astronomical Society and Richard Oram of the Harry Ransom Center of The University of Texas at Austin for their assistance.

  2. JUPITER and satellites: Clinical implications of the JUPITER study and its secondary analyses.

    Science.gov (United States)

    Kostapanos, Michael S; Elisaf, Moses S

    2011-07-26

    THE JUSTIFICATION FOR THE USE OF STATINS IN PREVENTION: an intervention trial evaluating rosuvastatin (JUPITER) study was a real breakthrough in primary cardiovascular disease prevention with statins, since it was conducted in apparently healthy individuals with normal levels of low-density lipoprotein cholesterol (LDL-C JUPITER, rosuvastatin was associated with significant reductions in cardiovascular outcomes as well as in overall mortality compared with placebo. In this paper the most important secondary analyses of the JUPITER trial are discussed, by focusing on their novel findings regarding the role of statins in primary prevention. Also, the characteristics of otherwise healthy normocholesterolemic subjects who are anticipated to benefit more from statin treatment in the clinical setting are discussed. Subjects at "intermediate" or "high" 10-year risk according to the Framingham score, those who exhibit low post-treatment levels of both LDL-C (JUPITER added to our knowledge that statins may be effective drugs in the primary prevention of cardiovascular disease in normocholesterolemic individuals at moderate-to-high risk. Also, statin treatment may reduce the risk of venous thromboembolism and preserve renal function. An increase in physician-reported diabetes represents a major safety concern associated with the use of the most potent statins.

  3. Shock Synthesis in the Atmosphere of Jupiter

    Science.gov (United States)

    Khare, B. N.; Sagan, C.; McDonald, G. D.; de Vanssay, E.; Borucki, W. J.; McKay, C. P.; Bernstein, M. P.; Hartman, T. G.; Lech, J.

    1996-09-01

    We have previously investigated an approximate simulation of the Jupiter troposphere at the 1 bar NH_3 cloud level using Laser Induced Plasma (LIP) for shock synthesis in a 84.62:13.3:1.07:1.01 H_2:He:CH_4:NH_3 gas mixture, and found by GC/MS that HCN is the most abundant product, more abundant than all the major product hydrocarbons (C_2H_6, C_2H_2, C_3H_8, and C_4H10) combined. Using purge and trap isolation techniques on the LIP gas mixture using two absorbent traps in tandem, thermal desorption GC/MS has revealed a large array of product molecules starting from simple hydrocarbons such as C_2H_2, C_2H_4, etc., simple nitriles such as HCN, CH_3CN, etc., to molecules up to C13 (e.g. C13H23N). Here we report the results of our more accurate simulation of Jupiter at the 5 bar level using LIP with a 88:11.7:0.2:0.1 H_2:He:CH_4:NH_3 mixture, for comparison with mass spectral data from the Galileo probe. We detect in this more acurate simulation of Jupiter many of the same compounds, such as HCN, dimethylaminoacetonitrile, and dimethylcyanamide, as in the previous lower dilution experiment. We will compare the present results with those from low-pressure continuous flow plasma discharge experiments (McDonald et al. 1992, al Icarus 99, 131). We will also discuss the relevance of our data in light of the significant discrepancies between standard models of the jovian atmosphere and the compositional data returned by the Galileo entry probe.

  4. The Interiors of Jupiter and Saturn

    Science.gov (United States)

    Helled, Ravit

    2018-05-01

    Probing the interiors of the giant planets in our Solar System is not an easy task. This requires a set of observations combined with theoretical models that are used to infer the planetary composition and its depth dependence. The masses of Jupiter and Saturn are 318 and 96 Earth masses, respectively, and since a few decades, we know that they mostly consist of hydrogen and helium. It is the mass of heavy elements (all elements heavier than helium) that is not well determined, as well as its distribution within the planets. While the heavy elements are not the dominating materials in Jupiter and Saturn, they are the key for our understanding of their formation and evolution histories. The planetary internal structure is inferred to fit the available observational constraints including the planetary masses, radii, 1-bar temperatures, rotation rates, and gravitational fields. Then, using theoretical equations of states (EOSs) for hydrogen, helium, their mixtures, and heavier elements (typically rocks and/or ices), a structure model is developed. However, there is no unique solution for the planetary structure, and the results depend on the used EOSs and the model assumptions imposed by the modeler. Standard interior models of Jupiter and Saturn include three main regions: (1) the central region (core) that consists of heavy elements, (2) an inner metallic hydrogen envelope that is helium rich, and (3) an outer molecular hydrogen envelope depleted with helium. The distribution of heavy elements can be either homogenous or discontinuous between the two envelopes. Major model assumptions that can affect the derived internal structure include the number of layers, the heat transport mechanism within the planet (and its entropy), the nature of the core (compact vs. diluted), and the location/pressure where the envelopes are divided. Alternative structure models assume a less distinct division between the layers and/or a less non-homogenous distribution of the heavy

  5. Jupiter Europa Orbiter Architecture Definition Process

    Science.gov (United States)

    Rasmussen, Robert; Shishko, Robert

    2011-01-01

    The proposed Jupiter Europa Orbiter mission, planned for launch in 2020, is using a new architectural process and framework tool to drive its model-based systems engineering effort. The process focuses on getting the architecture right before writing requirements and developing a point design. A new architecture framework tool provides for the structured entry and retrieval of architecture artifacts based on an emerging architecture meta-model. This paper describes the relationships among these artifacts and how they are used in the systems engineering effort. Some early lessons learned are discussed.

  6. HET/JUPITER project assessment report

    International Nuclear Information System (INIS)

    Baxter, B.J.; Harrington, F.E.; Kaiser, G.G.; Wolf, J.

    1979-05-01

    This report is an assessment of the United States' Hot Engineering Test (HET) and the Federal Republic of Germany's Juelich Pilot Plant Thorium Element Reprocessing (JUPITER) Projects. The assessment was conducted with a view to developing mutually supportive roles in the achievement of hot engineering test objectives. Conclusions of the assessment are positive and identify several technical areas with potential for US/FRG cooperation. Recommendations presented in this report support a cost-effective US/FRG program to jointly develop high temperature gas-cooled reactor fuel recycle technology. (orig.) [de

  7. Recent advances in modeling and validation of nuclear thermal-hydraulics applications with NEPTUNE CFD - 15471

    International Nuclear Information System (INIS)

    Guingo, M.; Baudry, C.; Hassanaly, M.; Lavieville, J.; Mechitouna, N.; Merigoux, N.; Mimouni, S.; Bestion, D.; Coste, P.; Morel, C.

    2015-01-01

    NEPTUNE CFD is a Computational Multi-(Fluid) Dynamics code dedicated to the simulation of multiphase flows, primarily targeting nuclear thermo-hydraulics applications, such as the departure from nuclear boiling (DNB) or the two-phase Pressurized Thermal Shock (PTS). It is co-developed within the joint research/development project NEPTUNE (AREVA, CEA, EDF, IRSN) since 2001. Over the years, to address the aforementioned applications, dedicated physical models and numerical methods have been developed and implemented in the code, including specific sets of models for turbulent boiling flows and two-phase non-adiabatic stratified flows. This paper aims at summarizing the current main modeling capabilities of the code, and gives an overview of the associated validation database. A brief summary of emerging applications of the code, such as containment simulation during a potential severe accident or in-vessel retention, is also provided. (authors)

  8. Neptune: An astrophysical smooth particle hydrodynamics code for massively parallel computer architectures

    Science.gov (United States)

    Sandalski, Stou

    Smooth particle hydrodynamics is an efficient method for modeling the dynamics of fluids. It is commonly used to simulate astrophysical processes such as binary mergers. We present a newly developed GPU accelerated smooth particle hydrodynamics code for astrophysical simulations. The code is named neptune after the Roman god of water. It is written in OpenMP parallelized C++ and OpenCL and includes octree based hydrodynamic and gravitational acceleration. The design relies on object-oriented methodologies in order to provide a flexible and modular framework that can be easily extended and modified by the user. Several pre-built scenarios for simulating collisions of polytropes and black-hole accretion are provided. The code is released under the MIT Open Source license and publicly available at http://code.google.com/p/neptune-sph/.

  9. ECCENTRIC JUPITERS VIA DISK–PLANET INTERACTIONS

    International Nuclear Information System (INIS)

    Duffell, Paul C.; Chiang, Eugene

    2015-01-01

    Numerical hydrodynamics calculations are performed to determine the conditions under which giant planet eccentricities can be excited by parent gas disks. Unlike in other studies, Jupiter-mass planets are found to have their eccentricities amplified—provided their orbits start off as eccentric. We disentangle the web of co-rotation, co-orbital, and external resonances to show that this finite-amplitude instability is consistent with that predicted analytically. Ellipticities can grow until they reach of order of the disk's aspect ratio, beyond which the external Lindblad resonances that excite eccentricity are weakened by the planet's increasingly supersonic epicyclic motion. Forcing the planet to still larger eccentricities causes catastrophic eccentricity damping as the planet collides into gap walls. For standard parameters, the range of eccentricities for instability is modest; the threshold eccentricity for growth (∼0.04) is not much smaller than the final eccentricity to which orbits grow (∼0.07). If this threshold eccentricity can be lowered (perhaps by non-barotropic effects), and if the eccentricity driving documented here survives in 3D, it may robustly explain the low-to-moderate eccentricities ≲0.1 exhibited by many giant planets (including Jupiter and Saturn), especially those without planetary or stellar companions

  10. The Occurrence Rate of Hot Jupiters

    Science.gov (United States)

    Rampalli, Rayna; Catanzarite, Joseph; Batalha, Natalie M.

    2017-01-01

    As the first kind of exoplanet to be discovered, hot Jupiters have always been objects of interest. Despite being prevalent in radial velocity and ground-based surveys, they were found to be much rarer based on Kepler observations. These data show a pile-up at radii of 9-22 Rearth and orbital periods of 1-10 days. Computing accurate occurrence rates can lend insight into planet-formation and migration-theories. To get a more accurate look, the idea of reliability was introduced. Each hot Jupiter candidate was assigned a reliability based on its location in the galactic plane and likelihood of being a false positive. Numbers were updated if ground-based follow-up indicated a candidate was indeed a false positive. These reliabilities were introduced into an occurrence rate calculation and yielded about a 12% decrease in occurrence rate for each period bin examined and a 25% decrease across all the bins. To get a better idea of the cause behind the pileup, occurrence rates based on parent stellar metallicity were calculated. As expected from previous work, higher metallicity stars yield higher occurrence rates. Future work includes examining period distributions in both the high metallicity and low metallicity sample for a better understanding and confirmation of the pile-up effect.

  11. The Jovian rings as observed from Jupiter.

    Science.gov (United States)

    Malinnikova Bang, A.; Joergensen, J. L.; Joergensen, P. S.; Denver, T.; Connerney, J. E. P.; Bolton, S. J.; Levin, S.

    2017-12-01

    Juno entered a highly eliptic orbit around Jupiter on the 4. July 2016. Since then, it has completed 8 perijove passages. The Magnetometer experiment consists of two measurement platforms mounted 10m and 12m from the spacecraft spin axis, on one of three large solar panels. Each magnetometer platform is equipped with two star trackers to provide accurate attitude information to the vector magnetometers. The star trackers are pointed 13deg from the (anti) spin vector, and clocked 180deg to avoid simultaneous blinding effects from bright Jupiter only 6000km away, during perijove. This brings Juno well inside the innermost known satellite, Metis. The star trackers pointing close to, and above the Jovian horizon for most of each rotation of Juno, has an excellent view of the Jovian ring systems with a beta-angle close to 180deg. We report on the ring imaging performed during the first 8 orbits, discuss the structure, optical depth and moon sheparding of the inner rings as measured so far.

  12. Haze production rates in super-Earth and mini-Neptune atmosphere experiments

    Science.gov (United States)

    Hörst, Sarah M.; He, Chao; Lewis, Nikole K.; Kempton, Eliza M.-R.; Marley, Mark S.; Morley, Caroline V.; Moses, Julianne I.; Valenti, Jeff A.; Vuitton, Véronique

    2018-04-01

    Numerous Solar System atmospheres possess photochemically generated hazes, including the characteristic organic hazes of Titan and Pluto. Haze particles substantially impact atmospheric temperature structures and may provide organic material to the surface of a world, potentially affecting its habitability. Observations of exoplanet atmospheres suggest the presence of aerosols, especially in cooler (diversity in haze production rates, as some—but not all—super-Earth and mini-Neptune atmospheres will possess photochemically generated haze.

  13. What is Neptune's D/H ratio really telling us about its water abundance?

    Science.gov (United States)

    Ali-Dib, Mohamad; Lakhlani, Gunjan

    2018-05-01

    We investigate the deep-water abundance of Neptune using a simple two-component (core + envelope) toy model. The free parameters of the model are the total mass of heavy elements in the planet (Z), the mass fraction of Z in the envelope (fenv), and the D/H ratio of the accreted building blocks (D/Hbuild).We systematically search the allowed parameter space on a grid and constrain it using Neptune's bulk carbon abundance, D/H ratio, and interior structure models. Assuming solar C/O ratio and cometary D/H for the accreted building blocks are forming the planet, we can fit all of the constraints if less than ˜15 per cent of Z is in the envelope (f_{env}^{median} ˜ 7 per cent), and the rest is locked in a solid core. This model predicts a maximum bulk oxygen abundance in Neptune of 65× solar value. If we assume a C/O of 0.17, corresponding to clathrate-hydrates building blocks, we predict a maximum oxygen abundance of 200× solar value with a median value of ˜140. Thus, both cases lead to oxygen abundance significantly lower than the preferred value of Cavalié et al. (˜540× solar), inferred from model-dependent deep CO observations. Such high-water abundances are excluded by our simple but robust model. We attribute this discrepancy to our imperfect understanding of either the interior structure of Neptune or the chemistry of the primordial protosolar nebula.

  14. MIGRATION THEN ASSEMBLY: FORMATION OF NEPTUNE-MASS PLANETS INSIDE 1 AU

    International Nuclear Information System (INIS)

    Hansen, Brad M. S.; Murray, Norm

    2012-01-01

    We demonstrate that the observed distribution of 'hot Neptune'/'super-Earth' systems is well reproduced by a model in which planet assembly occurs in situ, with no significant migration post-assembly. This is achieved only if the amount of mass in rocky material is ∼50-100 M ⊕ interior to 1 AU. Such a reservoir of material implies that significant radial migration of solid material takes place, and that it occurs before the stage of final planet assembly. The model not only reproduces the general distribution of mass versus period but also the detailed statistics of multiple planet systems in the sample. We furthermore demonstrate that cores of this size are also likely to meet the criterion to gravitationally capture gas from the nebula, although accretion is rapidly limited by the opening of gaps in the gas disk. If the mass growth is limited by this tidal truncation, then the scenario sketched here naturally produces Neptune-mass objects with substantial components of both rock and gas, as is observed. The quantitative expectations of this scenario are that most planets in the 'hot Neptune/super-Earth' class inhabit multiple-planet systems, with characteristic orbital spacings. The model also provides a natural division into gas-rich (hot Neptune) and gas-poor (super-Earth) classes at fixed period. The dividing mass ranges from ∼3 M ⊕ at 10 day orbital periods to ∼10 M ⊕ at 100 day orbital periods. For orbital periods <10 days, the division is less clear because a gas atmosphere may be significantly eroded by stellar radiation.

  15. MIGRATION THEN ASSEMBLY: FORMATION OF NEPTUNE-MASS PLANETS INSIDE 1 AU

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Brad M. S. [Department of Physics and Astronomy and Institute of Geophysics and Planetary Physics, University of California Los Angeles, Los Angeles, CA 90095 (United States); Murray, Norm, E-mail: hansen@astro.ucla.edu [Canadian Institute for Theoretical Astrophysics, 60 St. George Street, Toronto, Ontario (Canada)

    2012-06-01

    We demonstrate that the observed distribution of 'hot Neptune'/'super-Earth' systems is well reproduced by a model in which planet assembly occurs in situ, with no significant migration post-assembly. This is achieved only if the amount of mass in rocky material is {approx}50-100 M{sub Circled-Plus} interior to 1 AU. Such a reservoir of material implies that significant radial migration of solid material takes place, and that it occurs before the stage of final planet assembly. The model not only reproduces the general distribution of mass versus period but also the detailed statistics of multiple planet systems in the sample. We furthermore demonstrate that cores of this size are also likely to meet the criterion to gravitationally capture gas from the nebula, although accretion is rapidly limited by the opening of gaps in the gas disk. If the mass growth is limited by this tidal truncation, then the scenario sketched here naturally produces Neptune-mass objects with substantial components of both rock and gas, as is observed. The quantitative expectations of this scenario are that most planets in the 'hot Neptune/super-Earth' class inhabit multiple-planet systems, with characteristic orbital spacings. The model also provides a natural division into gas-rich (hot Neptune) and gas-poor (super-Earth) classes at fixed period. The dividing mass ranges from {approx}3 M{sub Circled-Plus} at 10 day orbital periods to {approx}10 M{sub Circled-Plus} at 100 day orbital periods. For orbital periods <10 days, the division is less clear because a gas atmosphere may be significantly eroded by stellar radiation.

  16. Multi-scale analysis of nuclear reactor thermal-hydraulics-first applications using the NEPTUNE platform

    International Nuclear Information System (INIS)

    Guelfi, A.; Boucker, M.; Mimouni, S.; Bestion, D.; Boudier, P.

    2005-01-01

    The NEPTUNE project aims at building a new two-phase flow thermal-hydraulics platform for nuclear reactor simulation. EDF (Electricite de France) and CEA (Commissariat a l'Energie Atomique) with the co-sponsorship of IRSN (Institut de Radioprotection et Surete Nucleaire) and FRAMATOME-ANP, are jointly developing the NEPTUNE multi-scale platform that includes new physical models and numerical methods for each of the computing scales. One usually distinguishes three different scales for industrial simulations: the 'system' scale, the 'component' scale (subchannel analysis) and CFD (Computational Fluid Dynamics). In addition DNS (Direct Numerical Simulation) can provide information at a smaller scale that can be useful for the development of the averaged scales. The NEPTUNE project also includes work on software architecture and research on new numerical methods for coupling codes since both are required to improve industrial calculations. All these R and D challenges have been defined in order to meet industrial needs and the underlying stakes (mainly the competitiveness and the safety of Nuclear Power Plants). This paper focuses on three high priority needs: DNB (Departure from Nucleate Boiling) prediction, directly linked to fuel performance; PTS (Pressurized Thermal Shock), a key issue when studying the lifespan of critical components and LBLOCA (Large Break Loss of Coolant Accident), a reference accident for safety studies. For each of these industrial applications, we provide a review of the last developments within the NEPTUNE platform and we present the first results. A particular attention is also given to physical validation and the needs for further experimental data. (authors)

  17. NEPTUN/5052, PWR LOCA Cooling Heat Transfer Tests for Loft, Reflood Test

    International Nuclear Information System (INIS)

    Richner, M.; Analytis, G.Th.; Aksan, S.N.

    1993-01-01

    1 - Description of test facility: NEPTUN is designed to perform PWR LOCA simulation experiments, which provide the full length emergency cooling heat transfer tests for LOFT. Therefore the NEPTUN heater bundle with 33 electrical heater elements and 4 guide tubes simulates a section of the LOFT nuclear core. The main test loop also contains measuring systems for the carry-over rate and for the steam expelled, and a back-pressure control system. A water loop brings the water to the initial reflooding conditions. In addition, auxiliary systems maintain normal operating conditions. 2 - Description of test: Test 5052 is one of a series of 40 reflood tests performed in NEPTUN. Before the start of the test, the flooding water in its circuit is brought to the following conditions: pressure = 4.1 bar; velocity = 2.5 cm/sec; subcooling temperature = 78 C; single rod power = 2.45 kW; maximal initial cladding temperature = 867 C. 3 - Status: CSNI1013/01, 21-Jul-1993 Arrived at NEADB

  18. A comparison of the basic photon and electron dosimetry data for Neptun 10PC linear accelerators

    International Nuclear Information System (INIS)

    Shokrani, P.; Monadi, S.

    2008-01-01

    In recent years the similarity of dosimetric characteristics of modern linear accelerators with the same make, model and nominal energy, has become more common. The goal of this study was to quantitatively investigate the reproducibility of the basic photon and electron dosimetry data from Neptun 10PC accelerators across the institutions. In the current study, the photon and electron dosimetry data collected during acceptance and initial commissioning of six Neptun 10PC linear accelerators are analyzed. The dates of original installations of these six machines were evenly spread out over a 5 year period and the series of measurements were conducted during an average of 1-2 months after original installations. All units had identical energies and beam modifiers. For photon beams, the collected data include depth dose data, output factors and beam profile data in water. For electron beams, in addition to depth dose data and output factors, the effective source skin distance for 10 x 10 cm field size is also presented. For most beam parameters the variation (one standard deviation), was less than 1.0% (less than 2% for 2 parameters). A variation of this magnitude is expected to be observed during annual calibration of well-maintained accelerators. In conclusion, this study is presenting a consistent set of data for Neptun 10PC linear accelerators. This consistency implies that for this model, a standard data set of basic photon and electron dosimetry could be established, as a guide for future commissioning, beam modeling and quality assurance purposes. (authors)

  19. Preliminary applications of the new Neptune two-phase CFD solver to pressurized thermal shock investigations

    International Nuclear Information System (INIS)

    Boucker, M.; Laviaville, J.; Martin, A.; Bechaud, C.; Bestion, D.; Coste, P.

    2004-01-01

    The objective of this communication is to present some preliminary applications to pressurized thermal shock (PTS) investigations of the CFD (Computational Fluid Dynamics) two-phase flow solver of the new NEPTUNE thermal-hydraulics platform. In the framework of plant life extension, the Reactor Pressure Vessel (RPV) integrity is a major concern, and an important part of RPV integrity assessment is related to PTS analysis. In the case where the cold legs are partially filled with steam, it becomes a two-phase problem and new important effects occur, such as condensation due to the Emergency Core Cooling (ECC) injections of sub-cooled water. Thus, an advanced prediction of RPV thermal loading during these transients requires sophisticated two-phase, local scale, 3-dimensional codes. In that purpose, a program has been set up to extend the capabilities of the NEPTUNE two-phase CFD solver. A simple set of turbulence and condensation model for free surface steam-water flow has been tested in simulation of an ECC high pressure injection representing facility, using a full 3-dimensional mesh and the new NEPTUNE solver. Encouraging results have been obtained but it should be noticed that several sources of error can compensate for one another. Nevertheless, the computation presented here allows to be reasonable confident in the use of two-phase CFD in order to carry out refined analysis of two-phase PTS scenarios within the next years

  20. Dust ablation on the giant planets: Consequences for stratospheric photochemistry

    Science.gov (United States)

    Moses, Julianne I.; Poppe, Andrew R.

    2017-11-01

    Ablation of interplanetary dust supplies oxygen to the upper atmospheres of Jupiter, Saturn, Uranus, and Neptune. Using recent dynamical model predictions for the dust influx rates to the giant planets (Poppe et al., 2016), we calculate the ablation profiles and investigate the subsequent coupled oxygen-hydrocarbon neutral photochemistry in the stratospheres of these planets. We find that dust grains from the Edgeworth-Kuiper Belt, Jupiter-family comets, and Oort-cloud comets supply an effective oxygen influx rate of 1.0-0.7+2.2 ×107 O atoms cm-2 s-1 to Jupiter, 7.4-5.1+16 ×104 cm-2 s-1 to Saturn, 8.9-6.1+19 ×104 cm-2 s-1 to Uranus, and 7.5-5.1+16 ×105 cm-2 s-1 to Neptune. The fate of the ablated oxygen depends in part on the molecular/atomic form of the initially delivered products, and on the altitude at which it was deposited. The dominant stratospheric products are CO, H2O, and CO2, which are relatively stable photochemically. Model-data comparisons suggest that interplanetary dust grains deliver an important component of the external oxygen to Jupiter and Uranus but fall far short of the amount needed to explain the CO abundance currently seen in the middle stratospheres of Saturn and Neptune. Our results are consistent with the theory that all of the giant planets have experienced large cometary impacts within the last few hundred years. Our results also suggest that the low background H2O abundance in Jupiter's stratosphere is indicative of effective conversion of meteoric oxygen to CO during or immediately after the ablation process - photochemistry alone cannot efficiently convert the H2O into CO on the giant planets.

  1. Energetic electrons at Uranus: Bimodal diffusion in a satellite limited radiation belt

    International Nuclear Information System (INIS)

    Selesnick, R.S.; Stone, E.C.

    1991-01-01

    The Voyager 2 cosmic ray experiment observed intense electron fluxes in the middle magnetosphere of Uranus. High counting rates in several of the solid-state detectors precluded in the normal multiple coincidence analysis used for cosmic ray observations, and the authors have therefore performed laboratory measurements of the single-detector response to electrons. These calibrations allow a deconvolution from the counting rate data of the electron energy spectrum between energies of about 0.7 and 2.5 MeV. They present model fits to the differential intensity spectra from observations between L values of 6 and 15. The spectra are well represented by power laws in kinetic energy with spectral indices between 5 and 7. The phase space density at fixed values of the first two adiabatic invariants generally increases with L, indicative of an external source. However, there are also local minima associated with the satellites Ariel and Umbriel, indicating either a local source or an effective source due to nonconservation of the first two adiabatic invariants. For electrons which mirror at the highest magnetic latitudes, the local minimum associated with Ariel is radically displaced from the minimum L of that satellite by ∼0.5. The latitude variation of the satellite absorption efficiency predicts that if satellite losses are replenished primarily by radial diffusion there should be an increasing pitch angle anisotropy with decreasing L. The uniformity in the observed anisotropy outside the absorption regions then suggests that it is maintained by pitch angle diffusion. The effective source due to pitch angle diffusion is insufficient to cause the phase space density minimum associated with Ariel. Model solutions of the simultaneous radial and pitch angle diffusion equation show that the displacement of the high-latitude Ariel signature is also consistent with a larger effective source

  2. Small inner companions of warm Jupiters: Lifetimes and legacies

    International Nuclear Information System (INIS)

    Van Laerhoven, Christa; Greenberg, Richard

    2013-01-01

    Although warm Jupiters are generally too far from their stars for tides to be important, the presence of an inner planetary companion to a warm Jupiter can result in tidal evolution of the system. Insight into the process and its effects comes form classical secular theory of planetary perturbations. The lifetime of the inner planet may be shorter than the age of the system, because the warm Jupiter maintains its eccentricity and hence promotes tidal migration into the star. Thus a warm Jupiter observed to be alone in its system might have previously cleared away any interior planets. Before its demise, even if an inner planet is of terrestrial scale, it may promote damping of the warm Jupiter's eccentricity. Thus any inferences of the initial orbit of an observed warm Jupiter must include the possibility of a greater initial eccentricity than would be estimated by assuming it had always been alone. Tidal evolution involving multiple planets also enhances the internal heating of the planets, which readily exceeds that of stellar radiation for the inner planet, and may be great enough to affect the internal structure of warm Jupiters. Secular theory gives insight into the tidal processes, providing, among other things, a way to constrain eccentricities of transiting planets based on estimates of the tidal parameter Q.

  3. A Secular Resonant Origin for the Loneliness of Hot Jupiters

    Science.gov (United States)

    Spalding, Christopher; Batygin, Konstantin

    2017-09-01

    Despite decades of inquiry, the origin of giant planets residing within a few tenths of an astronomical unit from their host stars remains unclear. Traditionally, these objects are thought to have formed further out before subsequently migrating inwards. However, the necessity of migration has been recently called into question with the emergence of in situ formation models of close-in giant planets. Observational characterization of the transiting subsample of close-in giants has revealed that “warm” Jupiters, possessing orbital periods longer than roughly 10 days more often possess close-in, co-transiting planetary companions than shorter period “hot” Jupiters, that are usually lonely. This finding has previously been interpreted as evidence that smooth, early migration or in situ formation gave rise to warm Jupiter-hosting systems, whereas more violent, post-disk migration pathways sculpted hot Jupiter-hosting systems. In this work, we demonstrate that both classes of planet may arise via early migration or in situ conglomeration, but that the enhanced loneliness of hot Jupiters arises due to a secular resonant interaction with the stellar quadrupole moment. Such an interaction tilts the orbits of exterior, lower-mass planets, removing them from transit surveys where the hot Jupiter is detected. Warm Jupiter-hosting systems, in contrast, retain their coplanarity due to the weaker influence of the host star’s quadrupolar potential relative to planet-disk interactions. In this way, hot Jupiters and warm Jupiters are placed within a unified theoretical framework that may be readily validated or falsified using data from upcoming missions, such as TESS.

  4. Positional Catalogues of Saturn's and Jupiter's Moons

    Science.gov (United States)

    Yizhakevych, O.; Andruk, V.; Pakuliak, L.; Lukianchuk, V.; Shatokhina, S.

    In the framework of the UkrVO national project (http://ukr-vo.org/) we have started the processing of photographic observations of Saturn's (S1-S8) and Jupiter's (J6-J8) moons. Observations were conducted during 1961-1993 with three astrographs DLFA, DWA, DAZ and Z600 reflector. Plate images were digitized as tif-files with commercial scanners. Image processing was carried out by specific software package in the LINUX-MIDAS-ROMAFOT environment with Tycho2 as reference. The software was developed at the MAO NASU. Obtained positions of objects were compared with theoretically predicted ones in IMCCE (Paris) (www.imcce.fr/sat) online. Rms error of divergence between observed and calculated positions is of 0.20' - 0.35'.

  5. Magnetosphere - Ionosphere - Thermosphere (MIT) Coupling at Jupiter

    Science.gov (United States)

    Yates, J. N.; Ray, L. C.; Achilleos, N.

    2017-12-01

    Jupiter's upper atmospheric temperature is considerably higher than that predicted by Solar Extreme Ultraviolet (EUV) heating alone. Simulations incorporating magnetosphere-ionosphere coupling effects into general circulation models have, to date, struggled to reproduce the observed atmospheric temperatures under simplifying assumptions such as azimuthal symmetry and a spin-aligned dipole magnetic field. Here we present the development of a full three-dimensional thermosphere model coupled in both hemispheres to an axisymmetric magnetosphere model. This new coupled model is based on the two-dimensional MIT model presented in Yates et al., 2014. This coupled model is a critical step towards to the development of a fully coupled 3D MIT model. We discuss and compare the resulting thermospheric flows, energy balance and MI coupling currents to those presented in previous 2D MIT models.

  6. Does Io's ionosphere influence Jupiter's radio bursts.

    Science.gov (United States)

    Webster, D. L.; Alksne, A. Y.; Whitten, R. C.

    1972-01-01

    Goldreich and Lynden-Bell's theory of Jupiter's Io-correlated decametric radiation sets a lower limit to Io's conductivity, high enough to carry the current associated with the radiated power. Dermott's analysis of conductivities of rocks and ice shows no such conductivity at Io's temperature. However, we show that if Io has even a small atmosphere, say of methane as suggested by Binder and Cruikshank, or of argon or nitrogen, it will have an ionosphere with adequate conductivity to meet the above criterion. A requirement for higher conductivity was found by Goldreich and Lynden-Bell on the basis of motion of magnetic lines past Io. This requirement appears to us unnecessary in view of experiments which prove that motion of the lines is not the source of the electromotance.

  7. The European SL-9/JUPITER Workshop

    Science.gov (United States)

    1995-02-01

    During the past six months, many astronomers - observational as well theoretical - have been busy interpreting the many data taken during the impacts and thereafter. This is a very labour-intensive task and although the first conclusions have begun to emerge, it has also become obvious that extensive consultations between the various groups are necessary before it will be possible to understand the very complex processes during the impacts and thereafter. In order to further the interaction among the involved scientists, it has been decided to hold a three-day "European SL-9/Jupiter Workshop" at the Headquarters of the European Southern Observatory. More than 100 astronomers will meet on February 13-15, 1995, and close to 100 reports will be delivered on this occasion. Although most come from European countries, the major groups on other continents are also well represented. This meeting will give the participants the opportunity to exchange information about their individual programmes and will serve to establish future collaborative efforts. SL-9/JUPITER PRESS CONFERENCE In this connection, ESO is pleased to invite the media to a Press Conference: Wednesday, February 15, 1995, 17:30 CET ESO Headquarters, Karl-Schwarzschild-Strasse 2, D-85748 Garching, Germany This conference will be held at the end of the Workshop and will provide a thorough overview of the latest results, as presented during the meeting. Media representatives who are interested in participating in this Press Conference are requested to register with the ESO Information Service (Mrs. E. Völk, Tel.: +49-89-32006276; Fax: +49-89-3202362), at the latest on Friday, February 10, 1995. ESO Press Information is made available on the World-Wide Web (URL: http://www.hq.eso.org/) and on CompuServe (space science and astronomy area, GO SPACE).

  8. The Jupiter system through the eyes of Voyager 1

    Science.gov (United States)

    Smith, B.A.; Soderblom, L.A.; Johnson, T.V.; Ingersoll, A.P.; Collins, S.A.; Shoemaker, E.M.; Hunt, G.E.; Masursky, H.; Carr, M.H.; Davies, M.E.; Cook, A.F.; Boyce, J.; Danielson, G.E.; Owen, Timothy W.; Sagan, C.; Beebe, R.F.; Veverka, J.; Strom, R.G.; McCauley, J.F.; Morrison, D.; Briggs, G.A.; Suomi, V.E.

    1979-01-01

    The cameras aboard Voyager I have provided a closeup view of the Jupiter system, revealing heretofore unknown characteristics and phenomena associated with the planet's atmosphere and the surfaces of its five major satellites. On Jupiter itself, atmospheric motions-the interaction of cloud systems-display complex vorticity. On its dark side, lightning and auroras are observed. A ring was discovered surrounding Jupiter. The satellite surfaces display dramatic differences including extensive active volcanismn on Io, complex tectonism on Ganymnede and possibly Europa, and flattened remnants of enormous impact features on Callisto. Copyright ?? 1979 AAAS.

  9. The high albedo of the hot Jupiter Kepler-7b

    DEFF Research Database (Denmark)

    Demory, B.-O.; Seager, S.; Madhusudhan, N.

    2011-01-01

    Hot Jupiters are expected to be dark from both observations (albedo upper limits) and theory (alkali metals and/or TiO and VO absorption). However, only a handful of hot Jupiters have been observed with high enough photometric precision at visible wavelengths to investigate these expectations....... The NASA Kepler mission provides a means to widen the sample and to assess the extent to which hot Jupiter albedos are low. We present a global analysis of Kepler-7 b based on Q0-Q4 data, published radial velocities, and asteroseismology constraints. We measure an occultation depth in the Kepler bandpass...

  10. Phosphorus Chemistry in the Atmosphere of Jupiter: A Reassessment

    Science.gov (United States)

    Borunov, Sergei; Dorofeeva, Vera; Khodakovsky, Igor; Drossart, Pierre; Lellouch, Emmanuel; Encrenaz, Thérèse

    1995-02-01

    A new distribution of phosphorus compounds in the atmosphere of Jupiter is given, using revised values for the chemical constants. In contrast with previous works, it is shown that phosphine PH 3 remains the most abundant equilibrium gaseous compound even at the upper levels of Jupiter's troposphere. The observed PH 3 abundance is equal to the equilibrium value, at all temperatures above 535 K for solar P and O elemental abundances, and above 600 K for a reasonable range of P and O abundances. P 4O 6 does not take part in the phosphorus cycle on Jupiter.

  11. Searching sequences of resonant orbits between a spacecraft and Jupiter

    International Nuclear Information System (INIS)

    Formiga, J K S; Prado, A F B A

    2013-01-01

    This research shows a study of the dynamical behavior of a spacecraft that performs a series of close approaches with the planet Jupiter. The main idea is to find a sequence of resonant orbits that allows the spacecraft to stay in the region of the space near the orbit of Jupiter around the Sun gaining energy from each passage by the planet. The dynamical model considers the existence of only two massive bodies in the systems, which are the Sun and Jupiter. They are assumed to be in circular orbits around their center of mass. Analytical equations are used to obtain the values of the parameters required to get this sequence of close approaches. Those equations are useful, because they show which orbits are physically possible when taking into account that the periapsis distances have to be above the surface of the Sun and that the closest approach distances during the passage by Jupiter have to be above its surface

  12. JUPITER PROJECT - JOINT UNIVERSAL PARAMETER IDENTIFICATION AND EVALUATION OF RELIABILITY

    Science.gov (United States)

    The JUPITER (Joint Universal Parameter IdenTification and Evaluation of Reliability) project builds on the technology of two widely used codes for sensitivity analysis, data assessment, calibration, and uncertainty analysis of environmental models: PEST and UCODE.

  13. VOYAGER 1 JUPITER POSITION RESAMPLED DATA 48.0 SECONDS

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes Voyager 1 Jupiter encounter position data that have been generated at a 48.0 second sample rate using the NAIF SPICE kernals. The data set is...

  14. VOYAGER 2 JUPITER POSITION RESAMPLED DATA 48.0 SECONDS

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes Voyager 2 Jupiter encounter position data that have been generated at a 48.0 second sample rate using the NAIF SPICE kernals. The data set is...

  15. Jupiter energetic particle experiment ESAD proton sensor design

    International Nuclear Information System (INIS)

    Gruhn, C.R.; Higbie, P.R.

    1977-12-01

    A proton sensor design for the Jupiter Energetic Particle Experiment is described. The sensor design uses avalanche multiplication in order to lower the effective energy threshold. A complete signal-to-noise analysis is given for this design

  16. VOYAGER 2 JUPITER MAGNETOMETER RESAMPLED DATA 48.0 SEC

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes Voyager 2 Jupiter encounter magnetometer data that have been resampled at a 48.0 second sample rate. The data set is composed of 6 columns: 1)...

  17. The Frequency of Hot Jupiters in the Galaxy

    Directory of Open Access Journals (Sweden)

    Sackett P. D.

    2011-02-01

    Full Text Available The frequency of Hot Jupiters around Galactic dwarf stars is determined from the results of the SuperLupus transit survey and realistic Monte Carlo simulations of the survey efficiency. We find that for Hot Jupiters with mean radii of 1.1RJ and periods between 1 and 10 days, the frequency around dwarf stars is just 0.16±0.60.2%.

  18. A Learning Organization approach for Knowledge Management at Jupiter Design.

    OpenAIRE

    Jones, Timothy John

    2006-01-01

    This report has been carried out by a student studying for the degree of a Masters in Business Administration at Nottingham University Business School. The focus of the report is to suggest a knowledge management framework for the client Jupiter Design Limited. Jupiter has experienced considerable success and growth over recent years, evolving from a relatively small but well respected design agency into one of the largest agencies operating outside of London. Due to an expanding clie...

  19. An analysis of Jupiter data from the RAE-1 satellite

    Science.gov (United States)

    Carr, T. D.

    1974-01-01

    The analysis of Radio Astronomy Explorer Satellite data are presented. Radio bursts from Jupiter are reported in the frequency range 4700 KHz to 45 KHz. Strong correlations with lo were found at 4700, 3930, and 2200 KHz, while an equally strong Europa effect was observed at 1300, 900, and 700 KHz. Histograms indicating the relative probability and the successful identification of Jupiter activity were plotted, using automatic computer and visual search techniques.

  20. Overview report of RAMONA-NEPTUN program on passive decay heat removal

    International Nuclear Information System (INIS)

    Weinberg, D.; Rust, K.; Hoffmann, H.

    1996-03-01

    The design of the advanced sodium-cooled European Fast Reactor provides a safety graded decay heat removal concept which ensures the coolability of the primary system by natural convection when forced cooling is lost. The findings of the RAMONA and NEPTUN experiments indicate that the decay heat can be safely removed by natural convection. The operation of the decay heat exchangers being installed in the upper plenum causes the formation of a thermal stratification associated with a pronounced temperature gradient. The vertical extent of the stratification and the qualitity of the gradient are depending on the fact whether a permeable or an impermeable shell covers the above core structure. A delayed startup time of the decay heat exchangers leads only to a slight increase of the temperatures in the upper plenum. A complete failure of half of the decay heat exchangers causes a higher temperature level in the primary system, but does not alter the global temperature distribution. The transient development of the temperatures is faster going on in a three-loop model than in a four-loop model due to the lower amount of heat stored in the compacter primary vessel. If no coolant reaches the core inlet side via the intermediate heat exchangers, the core remains coolable. In this case, cold water of the upper plenum penetrates into the subassemblies (thermosyphon effects) and the interwrapper spaces existing in the NEPTUN core. The core coolability from above is feasible without any difficulty though the temperatures increase to a minor degree at the top end of the core. The thermal hydraulic computer code FLUTAN was applied for the 3D numerical simulation of the majority of the steady state RAMONA and NEPTUN tests as well as for selected transient RAMONA tests. (orig./HP) [de

  1. Verification, validation and application of NEPTUNE-CFD to two-phase Pressurized Thermal Shocks

    Energy Technology Data Exchange (ETDEWEB)

    Mérigoux, N., E-mail: nicolas.merigoux@edf.fr [Electricité de France, R& D Division, 6 Quai Watier, 78401 Chatou (France); Laviéville, J.; Mimouni, S.; Guingo, M.; Baudry, C. [Electricité de France, R& D Division, 6 Quai Watier, 78401 Chatou (France); Bellet, S., E-mail: serge.bellet@edf.fr [Electricité de France, Thermal & Nuclear Studies and Projects Division, 12-14 Avenue Dutriévoz, 69628 Villeurbanne (France)

    2017-02-15

    Nuclear Power Plants are subjected to a variety of ageing mechanisms and, at the same time, exposed to potential Pressurized Thermal Shock (PTS) – characterized by a rapid cooling of the Reactor Pressure Vessel (RPV) wall. In this context, NEPTUNE-CFD is developed and used to model two-phase PTS in an industrial configuration, providing temperature and pressure fields required to assess the integrity of the RPV. Furthermore, when using CFD for nuclear safety demonstration purposes, EDF applies a methodology based on physical analysis, verification, validation and application to industrial scale (V&V), to demonstrate the quality of, and the confidence in results obtained. By following this methodology, each step must be proved to be consistent with the others, and with the final goal of the calculations. To this effect, a chart demonstrating how far the validation step of NEPTUNE-CFD is covering the PTS application will be drawn. A selection of the code verification and validation cases against different experiments will be described. For results consistency, a single and mature set of models – resulting from the knowledge acquired during the code development over the last decade – has been used. From these development and validation feedbacks, a methodology has been set up to perform industrial computations. Finally, the guidelines of this methodology based on NEPTUNE-CFD and SYRTHES coupling – to take into account the conjugate heat transfer between liquid and solid – will be presented. A short overview of the engineering approach will be given – starting from the meshing process, up to the results post-treatment and analysis.

  2. A Generalized turbulent dispersion model for bubbly flow numerical simulation in NEPTUNE-CFD

    Energy Technology Data Exchange (ETDEWEB)

    Laviéville, Jérôme, E-mail: Jerome-marcel.lavieville@edf.fr; Mérigoux, Nicolas, E-mail: nicolas.merigoux@edf.fr; Guingo, Mathieu, E-mail: mathieu.guingo@edf.fr; Baudry, Cyril, E-mail: Cyril.baudry@edf.fr; Mimouni, Stéphane, E-mail: stephane.mimouni@edf.fr

    2017-02-15

    The NEPTUNE-CFD code, based upon an Eulerian multi-fluid model, is developed within the framework of the NEPTUNE project, financially supported by EDF (Electricité de France), CEA (Commissariat à l’Energie Atomique et aux Energies Alternatives), IRSN (Institut de Radioprotection et de Sûreté Nucléaire) and AREVA-NP. NEPTUNE-CFD is mainly focused on Nuclear Safety applications involving two-phase water-steam flows, like two-phase Pressurized Shock (PTS) and Departure from Nucleate Boiling (DNB). Many of these applications involve bubbly flows, particularly, for application to flows in PWR fuel assemblies, including studies related to DNB. Considering a very usual model for interfacial forces acting on bubbles, including drag, virtual mass and lift forces, the turbulent dispersion force is often added to moderate the lift effect in orthogonal directions to the main flow and get the right dispersion shape. This paper presents a formal derivation of this force, considering on the one hand, the fluctuating part of drag and virtual mass, and on the other hand, Turbulent Pressure derivation obtained by comparison between Lagrangian and Eulerian description of bubbles motion. An extension of the Tchen’s theory is used to express the turbulent kinetic energy of bubbles and the two-fluid turbulent covariance tensor in terms of liquid turbulent velocities and time scale. The model obtained by this way, called Generalized Turbulent Dispersion Model (GTD), does not require any user parameter. The model is validated against Liu & Bankoff air-water experiment, Arizona State University (ASU) experiment, DEBORA experiment and Texas A&M University (TAMU) boiling flow experiments.

  3. Monte Carlo Simulation for Neptun 10 PC medical linear accelerator and calculations of electron beam parameters

    International Nuclear Information System (INIS)

    Bahreyni Toossi, M.T.; Hashemi, S.M.; Momen Nezhad, M.

    2008-01-01

    In recent decades, cancer has been one of the main ever increasing causes of death in developed countries. In order to fulfill the aforementioned considerations different techniques have been used, one of which is Monte Carlo simulation technique. High accuracy of the Monte Carlo simulation has been one of the main reason for its wide spread application. In this study, MCNP-4C code was employed to simulate electron mode of the Neptun 10 PC Linac, dosimetric quantities for conventional fields have also been both measured and calculated. Although Neptun 10 PC Linac is no longer licensed for installation in European and some other countries but regrettably nearly 10 of them have been installed in different centers around the country and are in operation. Therefore, in this circumstance, to improve the accuracy of treatment planning, Monte Carlo simulation for Neptun 10 PC was recognized as a necessity. Simulated and measured values of depth dose curves, off axis dose distributions for 6 , 8 and 10 MeV electrons applied for four different size fields, 6 x 6 cm 2 , 10 x 10 cm 2 , 15 x 15 cm 2 and 20 x 20 cm 2 were obtained. The measurements were carried out by a Welhofer-Scanditronix dose scanning system, Semiconductor Detector and Ionization Chamber. The results of this study have revealed that the values of two main dosimetric quantities depth dose curves and off axis dose distributions, acquired by MCNP-4C simulation and the corresponding values achieved by direct measurements are in a very good agreement (within 1% to 2% difference). In general, very good consistency of simulated and measured results, is a good proof that the goal of this work has been accomplished. In other word where measurements of some parameters are not practically achievable, MCNP-4C simulation can be implemented confidently. (author)

  4. First Earth-Based Detection of a Superbolide on Jupiter

    Science.gov (United States)

    Hueso, R.; Wesley, A.; Go, C.; Perez-Hoyos, S.; Wong, M. H.; Fletcher, L. N.; Sanchez-Lavega, A.; Boslough, M. B.; DePater, I.; Orton, G. S.; hide

    2010-01-01

    Cosmic collisions can planets cause detectable optical flashes that range from terrestrial shooting stars to bright fireballs. On 2010 June 3 a bolide in Jupiter's atmosphere was simultaneously observed from the Earth by two amateur astronomers observing Jupiter in red and blue wavelengths, The bolide appeared as a flash of 2 s duration in video recording data of the planet. The analysis of the light carve of the observations results in an estimated energy of the impact of (0.9-4,0) x 10(exp 15) J which corresponds to a colliding body of 8-13 m diameter assuming a mean density of 2 g/cu cm. Images acquired a few days later by the Hubble Space Telescope and other large ground-based facilities did not show any signature of aerosol debris, temperature, or chemical composition anomaly, confirming that the body was small and destroyed in Jupiter's upper atmosphere. Several collisions of this size may happen on Jupiter on a yearly basis. A systematic study of the impact rate and size of these bolides can enable an empirical determination. of the flux of meteoroids in Jupiter with implications for the populations of small bodies in the outer solar system and may allow a better quantification of the threat of impacting bodies to Earth. The serendipitous recording of this optical flash opens a new window in the observation of Jupiter with small telescopes.

  5. FIRST EARTH-BASED DETECTION OF A SUPERBOLIDE ON JUPITER

    International Nuclear Information System (INIS)

    Hueso, R.; Perez-Hoyos, S.; Sanchez-Lavega, A.; Wesley, A.; Go, C.; Wong, M. H.; De Pater, I.; Fletcher, L. N.; Boslough, M. B. E.; Orton, G. S.; Yanamandra-Fisher, P. A.; Simon-Miller, A. A.; Djorgovski, S. G.; Edwards, M. L.; Hammel, H. B.; Clarke, J. T.; Noll, K. S.

    2010-01-01

    Cosmic collisions on planets cause detectable optical flashes that range from terrestrial shooting stars to bright fireballs. On 2010 June 3 a bolide in Jupiter's atmosphere was simultaneously observed from the Earth by two amateur astronomers observing Jupiter in red and blue wavelengths. The bolide appeared as a flash of 2 s duration in video recording data of the planet. The analysis of the light curve of the observations results in an estimated energy of the impact of (0.9-4.0) x 10 15 J which corresponds to a colliding body of 8-13 m diameter assuming a mean density of 2 g cm -3 . Images acquired a few days later by the Hubble Space Telescope and other large ground-based facilities did not show any signature of aerosol debris, temperature, or chemical composition anomaly, confirming that the body was small and destroyed in Jupiter's upper atmosphere. Several collisions of this size may happen on Jupiter on a yearly basis. A systematic study of the impact rate and size of these bolides can enable an empirical determination of the flux of meteoroids in Jupiter with implications for the populations of small bodies in the outer solar system and may allow a better quantification of the threat of impacting bodies to Earth. The serendipitous recording of this optical flash opens a new window in the observation of Jupiter with small telescopes.

  6. Strong tidal dissipation in Io and Jupiter from astrometric observations.

    Science.gov (United States)

    Lainey, Valéry; Arlot, Jean-Eudes; Karatekin, Ozgür; Van Hoolst, Tim

    2009-06-18

    Io is the volcanically most active body in the Solar System and has a large surface heat flux. The geological activity is thought to be the result of tides raised by Jupiter, but it is not known whether the current tidal heat production is sufficiently high to generate the observed surface heat flow. Io's tidal heat comes from the orbital energy of the Io-Jupiter system (resulting in orbital acceleration), whereas dissipation of energy in Jupiter causes Io's orbital motion to decelerate. Here we report a determination of the tidal dissipation in Io and Jupiter through its effect on the orbital motions of the Galilean moons. Our results show that the rate of internal energy dissipation in Io (k(2)/Q = 0.015 +/- 0.003, where k(2) is the Love number and Q is the quality factor) is in good agreement with the observed surface heat flow, and suggest that Io is close to thermal equilibrium. Dissipation in Jupiter (k(2)/Q = (1.102 +/- 0.203) x 10(-5)) is close to the upper bound of its average value expected from the long-term evolution of the system, and dissipation in extrasolar planets may be higher than presently assumed. The measured secular accelerations indicate that Io is evolving inwards, towards Jupiter, and that the three innermost Galilean moons (Io, Europa and Ganymede) are evolving out of the exact Laplace resonance.

  7. Estimating the Magnetic Field Strength in Hot Jupiters

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Rakesh K. [Department of Earth and Planetary Sciences, Harvard University, 20 Oxford Street, Cambridge, MA 02138 (United States); Thorngren, Daniel P., E-mail: rakesh_yadav@fas.harvard.edu [Department of Physics, University of California, Santa Cruz, CA (United States)

    2017-11-01

    A large fraction of known Jupiter-like exoplanets are inflated as compared to Jupiter. These “hot” Jupiters orbit close to their parent star and are bombarded with intense starlight. Many theories have been proposed to explain their radius inflation and several suggest that a small fraction of the incident starlight is injected into the planetary interior, which helps to puff up the planet. How will such energy injection affect the planetary dynamo? In this Letter, we estimate the surface magnetic field strength of hot Jupiters using scaling arguments that relate energy available in planetary interiors to the dynamo-generated magnetic fields. We find that if we take into account the energy injected in the planetary interior that is sufficient to inflate hot Jupiters to observed radii, then the resulting dynamo should be able generate magnetic fields that are more than an order of magnitude stronger than the Jovian values. Our analysis highlights the potential fundamental role of the stellar light in setting the field strength in hot Jupiters.

  8. Shoemaker-Levy 9/JUPITER Collision Update

    Science.gov (United States)

    1994-05-01

    There are many signs that the upcoming collision between comet Shoemaker-Levy 9 and giant planet Jupiter is beginning to catch the imagination of the public. Numerous reports in the various media describe the effects expected during this unique event which according to the latest calculations will start in the evening of July 16 and end in the morning of July 22, 1994. (The times in this Press Release are given in Central European Summer Time (CEST), i.e., Universal Time (UT) + 2 hours. The corresponding local time in Chile is CEST - 6 hours.) Astronomers all over the world are now preparing to observe the associated phenomena with virtually all major telescopes. There will be no less than 12 different investigations at the ESO La Silla observatory during this period. This Press Release updates the information published in ESO PR 02/94 (27 January 1994) and provides details about the special services which will be provided by ESO to the media around this rare astronomical event. SCIENTIFIC EXPECTATIONS The nucleus of comet Shoemaker-Levy 9 broke into many smaller pieces during a near passage of Jupiter in July 1992. They are now moving in parallel orbits around this planet and recent calculations show with close to 100 % certainty that they will all collide with it, just two months from now. At some time, more than 20 individual nuclei were observed. This Press Release is accompanied by a photo that shows this formation, the famous "string of pearls", as it looked like in early May 1994. Both Jupiter and these nuclei have been extensively observed during the past months. A large, coordinated observing programme at La Silla has been active since early April and the first results have become available. However, while we now possess more accurate information about the comet's motion and the times of impact, there is still great uncertainty about the effects which may actually be observed at the time of the impacts. This is first of all due to the fact that it has not

  9. Lessons learned from the NEPTUNE power system, and other deep-sea adventures

    International Nuclear Information System (INIS)

    Kirkham, Harold

    2006-01-01

    The development of underwater science systems presents some challenging technical issues. It seems that the best efforts of the engineers and scientists involved are sometimes inadequate, and projects that once seemed straightforward end up being late or over-budget, or cancelled. This paper will review some of the lessons that may be learned from the examples of three science projects in the deep ocean: the Deep Underwater Muon and Neutrino Detector neutrino detector, the H 2 O observatory, and the power system part of the NEPTUNE regional cabled observatory

  10. A model of Neptune according to the Savic-Kasanin theory

    Science.gov (United States)

    Celebonovic, V.

    1983-10-01

    The structure and the distributions of temperature, pressure and density in the interior of Neptune are calculated using the pressure-ionization model of Savic and Kasanin (1961-1965). The model input data comprise only the mass, radius and moment of inertia; the results are presented in a graph and a table. A four-zone structure is defined, and the parameter values and profiles are found to be in good agreement with those of more complex models. Differences can be attributed to the crudeness of the present model but also to possible errors in the assumptions required by other models.

  11. Magnetohydrodynamic simulations of hot jupiter upper atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Trammell, George B.; Li, Zhi-Yun; Arras, Phil, E-mail: gbt8f@virginia.edu, E-mail: zl4h@virginia.edu, E-mail: arras@virginia.edu [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States)

    2014-06-20

    Two-dimensional simulations of hot Jupiter upper atmospheres including the planet's magnetic field are presented. The goal is to explore magnetic effects on the layer of the atmosphere that is ionized and heated by stellar EUV radiation, and the imprint of these effects on the Lyα transmission spectrum. The simulations are axisymmetric, isothermal, and include both rotation and azimuth-averaged stellar tides. Mass density is converted to atomic hydrogen density through the assumption of ionization equilibrium. The three-zone structure—polar dead zone (DZ), mid-latitude wind zone (WZ), and equatorial DZ—found in previous analytic calculations is confirmed. For a magnetic field comparable to that of Jupiter, the equatorial DZ, which is confined by the magnetic field and corotates with the planet, contributes at least half of the transit signal. For even stronger fields, the gas escaping in the mid-latitude WZ is found to have a smaller contribution to the transit depth than the equatorial DZ. Transmission spectra computed from the simulations are compared to Hubble Space Telescope Space Telescope Imaging Spectrograph and Advanced Camera for Surveys data for HD 209458b and HD 189733b, and the range of model parameters consistent with the data is found. The central result of this paper is that the transit depth increases strongly with magnetic field strength when the hydrogen ionization layer is magnetically dominated, for dipole magnetic field B {sub 0} ≳ 10 G. Hence transit depth is sensitive to magnetic field strength, in addition to standard quantities such as the ratio of thermal to gravitational binding energies. Another effect of the magnetic field is that the planet loses angular momentum orders of magnitude faster than in the non-magnetic case, because the magnetic field greatly increases the lever arm for wind braking of the planet's rotation. Spin-down timescales for magnetized models of HD 209458b that agree with the observed transit depth

  12. ATMOSPHERIC HEAT REDISTRIBUTION ON HOT JUPITERS

    International Nuclear Information System (INIS)

    Perez-Becker, Daniel; Showman, Adam P.

    2013-01-01

    Infrared light curves of transiting hot Jupiters present a trend in which the atmospheres of the hottest planets are less efficient at redistributing the stellar energy absorbed on their daysides—and thus have a larger day-night temperature contrast—than colder planets. To this day, no predictive atmospheric model has been published that identifies which dynamical mechanisms determine the atmospheric heat redistribution efficiency on tidally locked exoplanets. Here we present a shallow-water model of the atmospheric dynamics on synchronously rotating planets that explains why heat redistribution efficiency drops as stellar insolation rises. Our model shows that planets with weak friction and weak irradiation exhibit a banded zonal flow with minimal day-night temperature differences, while models with strong irradiation and/or strong friction exhibit a day-night flow pattern with order-unity fractional day-night temperature differences. To interpret the model, we develop a scaling theory which shows that the timescale for gravity waves to propagate horizontally over planetary scales, τ wave , plays a dominant role in controlling the transition from small to large temperature contrasts. This implies that heat redistribution is governed by a wave-like process, similar to the one responsible for the weak temperature gradients in the Earth's tropics. When atmospheric drag can be neglected, the transition from small to large day-night temperature contrasts occurs when τ wave ∼√(τ rad /Ω), where τ rad is the radiative relaxation time and Ω is the planetary rotation frequency. Alternatively, this transition criterion can be expressed as τ rad ∼ τ vert , where τ vert is the timescale for a fluid parcel to move vertically over the difference in day-night thickness. These results subsume the more widely used timescale comparison for estimating heat redistribution efficiency between τ rad and the horizontal day-night advection timescale, τ adv . Only

  13. Features of Jupiter's Great Red Spot

    Science.gov (United States)

    1996-01-01

    This montage features activity in the turbulent region of Jupiter's Great Red Spot (GRS). Four sets of images of the GRS were taken through various filters of the Galileo imaging system over an 11.5 hour period on 26 June, 1996 Universal Time. The sequence was designed to reveal cloud motions. The top and bottom frames on the left are of the same area, northeast of the GRS, viewed through the methane (732 nm) filter but about 70 minutes apart. The top left and top middle frames are of the same area and at the same time, but the top middle frame is taken at a wavelength (886 nm) where methane absorbs more strongly. (Only high clouds can reflect sunlight in this wavelength.) Brightness differences are caused by the different depths of features in the two images. The bottom middle frame shows reflected light at a wavelength (757 nm) where there are essentially no absorbers in the Jovian atmosphere. The white spot is to the northwest of the GRS; its appearance at different wavelengths suggests that the brightest elements are 30 km higher than the surrounding clouds. The top and bottom frames on the right, taken nine hours apart and in the violet (415 nm) filter, show the time evolution of an atmospheric wave northeast of the GRS. Visible crests in the top right frame are much less apparent 9 hours later in the bottom right frame. The misalignment of the north-south wave crests with the observed northwestward local wind may indicate a shift in wind direction (wind shear) with height. The areas within the dark lines are 'truth windows' or sections of the images which were transmitted to Earth using less data compression. Each of the six squares covers 4.8 degrees of latitude and longitude (about 6000 square kilometers). North is at the top of each frame.Launched in October 1989, Galileo entered orbit around Jupiter on December 7, 1995. The spacecraft's mission is to conduct detailed studies of the giant planet, its largest moons and the Jovian magnetic environment. The

  14. Jupiter Analogs Orbit Stars with an Average Metallicity Close to That of the Sun

    DEFF Research Database (Denmark)

    Buchhave, Lars A.; Bitsch, Bertram; Johansen, Anders

    2018-01-01

    Jupiter played an important role in determining the structure and configuration of the Solar System. Whereas hot-Jupiter type exoplanets preferentially form around metal-rich stars, the conditions required for the formation of planets with masses, orbits, and eccentricities comparable to Jupiter...... (Jupiter analogs) are unknown. Using spectroscopic metallicities, we show that stars hosting Jupiter analogs have an average metallicity close to solar, in contrast to their hot-Jupiter and eccentric cool-Jupiter counterparts, which orbit stars with super-solar metallicities. Furthermore......, the eccentricities of Jupiter analogs increase with host-star metallicity, suggesting that planet-planet scatterings producing highly eccentric cool Jupiters could be more common in metal-rich environments. To investigate a possible explanation for these metallicity trends, we compare the observations to numerical...

  15. Magnetic fields of Jupiter and Saturn

    International Nuclear Information System (INIS)

    Ness, N.F.

    1981-01-01

    The magnetic fields of Jupiter and Saturn and the characteristics of their magnetospheres, formed by interaction with the solar wind, are discussed. The origins of both magnetic fields are associated with a dynamo process deep in the planetary interior. The Jovian magnetosphere is analogous to that of a pulsar magnetosphere: a massive central body with a rapid rotation and an associated intense magnetic field. Its most distinctive feature is its magnetodisk of concentrated plasma and particle flux, and reduced magnetic field intensity. The magnetopause near the subsolar point has been observed at radial distances ranging over 50 to 100 Jovian radii, implying a relatively compressible obstacle to solar wind flow. The composition of an embedded current sheet within the magnetic tail is believed to be influenced by volcanic eruptions and emissions from Io. Spectral troughs of the Jovian radiation belts have been interpreted as possible ring particles. The Saturnian magnetosphere appears to be more like the earth in its topology. It is mainly characterized by a dipole axis parallel to the rotational axis of the planet and a magnetic field intensity much less than expected

  16. Wave propagation in the magnetosphere of Jupiter

    Science.gov (United States)

    Liemohn, H. B.

    1972-01-01

    A systematic procedure is developed for identifying the spatial regimes of various modes of wave propagation in the Jupiter magnetosphere that may be encountered by flyby missions. The Clemmow-Mullaly-Allis (CMA) diagram of plasma physics is utilized to identify the frequency regimes in which different modes of propagation occur in the magnetoplasma. The Gledhill model and the Ioannidis and Brice model of the magnetoplasma are summarized, and configuration-space CMA diagrams are constructed for each model for frequencies from 10 Hz to 1 MHz. The distinctive propagation features, the radio noise regimes, and the wave-particle interactions are discussed. It is concluded that the concentration of plasma in the equatorial plane makes this region of vital importance for radio observations with flyby missions. Local radio noise around the electron cyclotron frequency will probably differ appreciably from its terrestrial counterpart due to the lack of field-line guidance. Hydromagnetic wave properties at frequencies near the ion cyclotron frequency and below will probably be similar to the terrestrial case.

  17. A Binary System in the Hyades Cluster Hosting a Neptune-Sized Planet

    Science.gov (United States)

    Feinstein, Adina; Ciardi, David; Crossfield, Ian; Schlieder, Joshua; Petigura, Erik; David, Trevor J.; Bristow, Makennah; Patel, Rahul; Arnold, Lauren; Benneke, Björn; Christiansen, Jessie; Dressing, Courtney; Fulton, Benjamin; Howard, Andrew; Isaacson, Howard; Sinukoff, Evan; Thackeray, Beverly

    2018-01-01

    We report the discovery of a Neptune-size planet (Rp = 3.0Rearth) in the Hyades Cluster. The host star is in a binary system, comprising a K5V star and M7/8V star with a projected separation of 40 AU. The planet orbits the primary star with an orbital period of 17.3 days and a transit duration of 3 hours. The host star is bright (V = 11.2, J = 9.1) and so may be a good target for precise radial velocity measurements. The planet is the first Neptune-sized planet to be found orbiting in a binary system within an open cluster. The Hyades is the nearest star cluster to the Sun, has an age of 625-750 Myr, and forms one of the fundamental rungs in the distance ladder; understanding the planet population in such a well-studied cluster can help us understand and set contraints on the formation and evolution of planetary systems.

  18. Neptun: an interactive code for calculating doses to man due to radionuclides in acquatic food chains

    International Nuclear Information System (INIS)

    Zach, Reto.

    1980-07-01

    A flexible and interactive code, NEPTUN, has been written in FORTRAN IV for the PDP-10 computer to assess the impact on man of radionuclides in aquatic food chains. NEPTUN is based on an equilibrium model of the linear-chain type, and calculates aquatic food concentrations and doses to man. A decay term is included for the holdup time of the various food types. A total of seven food types can be selected, which include drinking water, freshwater and salt-water plants, inverebrates and fish. Thirty different diets can be implemented and five different dose factor files can be chosen. These include dose conversion factors for infants and adults based on ICRP 2 and ICRP 26 methodologies. All dose factors involve a dose commitment of 50 years, or equivalently, 50 years of chronic exposure. To date, only stochastic ICRP 26 dose caluclations have been implemented. The basic concentration factor file contains data for 211 different radionuclides; the dose factor files are less comprehensive. However, all files can be readily expanded. The output includes tables of concentrations and doses for individual radionuclides, as well as summaries for groups of radionuclides. Existing aquatic food chain models and the sources of currently-used generic concentration factors are briefly reviewed, and dose factors based on ICRP 2 and ICRP 26 methodologies are contrasted. (auth)

  19. The NEPTUN experiments on LOCA thermal-hydraulics for tight-lattice PWRs

    International Nuclear Information System (INIS)

    Dreier, J.; Chawla, R.; Rouge, N.; Yanar, S.

    1990-01-01

    The NEPTUN test facility at the Paul Scherrer Institute is currently being used to provide a broad data base for the validation of thermal-hydraulics codes used in predicting the reflooding behaviour of a tight-lattice PWR (light water highb conversion reactor, LWHCR). The present paper gives a description of the facility and the matrix to be covered in the experimental program. Results are presented from a number of forced-feed, bottom-reflooding experiments, comparisons being made with (a) measurements carried out earlier for standard-PWR geometry and (b) the results of a calculational benchmark exercise conducted in the framework of a Swiss/German LWHCR-development agreement. Rewetting for the tight, hexagonal-geometry (p/d = 1.13) NEPTUN-III test bundle has been found to occur in all tests carried out to date, in which reasonably LWHCR-representative values for the various thermal-hydraulics parameters are used. Results of the calculational benchmark exercise have confirmed the need for further code development efforts for achieving reliable predictions of LWHCR reflooding behaviour. (author) 11 figs., 3 tabs., 3 refs

  20. A Neptune-mass Free-floating Planet Candidate Discovered by Microlensing Surveys

    Science.gov (United States)

    Mróz, Przemek; Ryu, Y.-H.; Skowron, J.; Udalski, A.; Gould, A.; Szymański, M. K.; Soszyński, I.; Poleski, R.; Pietrukowicz, P.; Kozłowski, S.; Pawlak, M.; Ulaczyk, K.; OGLE Collaboration; Albrow, M. D.; Chung, S.-J.; Jung, Y. K.; Han, C.; Hwang, K.-H.; Shin, I.-G.; Yee, J. C.; Zhu, W.; Cha, S.-M.; Kim, D.-J.; Kim, H.-W.; Kim, S.-L.; Lee, C.-U.; Lee, D.-J.; Lee, Y.; Park, B.-G.; Pogge, R. W.; KMTNet Collaboration

    2018-03-01

    Current microlensing surveys are sensitive to free-floating planets down to Earth-mass objects. All published microlensing events attributed to unbound planets were identified based on their short timescale (below two days), but lacked an angular Einstein radius measurement (and hence lacked a significant constraint on the lens mass). Here, we present the discovery of a Neptune-mass free-floating planet candidate in the ultrashort (t E = 0.320 ± 0.003 days) microlensing event OGLE-2016-BLG-1540. The event exhibited strong finite-source effects, which allowed us to measure its angular Einstein radius of θ E = 9.2 ± 0.5 μas. There remains, however, a degeneracy between the lens mass and distance. The combination of the source proper motion and source-lens relative proper motion measurements favors a Neptune-mass lens located in the Galactic disk. However, we cannot rule out that the lens is a Saturn-mass object belonging to the bulge population. We exclude stellar companions up to ∼15 au.

  1. Lifting Transit Signals from the Kepler Noise Floor. I. Discovery of a Warm Neptune

    Science.gov (United States)

    Kunimoto, Michelle; Matthews, Jaymie M.; Rowe, Jason F.; Hoffman, Kelsey

    2018-01-01

    Light curves from the 4-year Kepler exoplanet hunting mission have been searched for transits by NASA’s Kepler team and others, but there are still important discoveries to be made. We have searched the light curves of 400 Kepler Objects of Interest (KOIs) to find transit signals down to signal-to-noise ratio (S/N) ∼ 6, which is under the limit of S/N ∼ 7.1 that has been commonly adopted as a strict threshold to distinguish between a transit candidate and false alarm. We detect four new and convincing planet candidates ranging in radius from near-Mercury-size to slightly larger than Neptune. We highlight the discovery of KOI-408.05 (period = 637 days; radius = 4.9 R ⊕ incident flux = 0.6 S ⊕), a planet candidate within its host star’s Habitable Zone. We dub this planet a “warm Neptune,” a likely volatile-rich world that deserves closer inspection. KOI-408.05 joins 21 other confirmed and candidate planets in the current Kepler sample with semimajor axes a > 1.4 au. These discoveries are significant as a demonstration that the S/N threshold for detection used by the Kepler project is open to debate.

  2. OSSOS. IV. Discovery of a Dwarf Planet Candidate in the 9:2 Resonance with Neptune

    Science.gov (United States)

    Bannister, Michele T.; Alexandersen, Mike; Benecchi, Susan; Chen, Ying-Tung; Delsanti, Audrey; Fraser, Wesley C.; Gladman, Brett; Granvik, Mikael; Grundy, Will M.; Guilbert-Lepoutre, Aurelie; hide

    2016-01-01

    We report the discovery and orbit of a new dwarf planet candidate, 2015 RR245, by the Outer Solar System Origins Survey (OSSOS). The orbit of 2015 RR245 is eccentric (e 0.586), with a semimajor axis near 82 au, yielding a perihelion distance of 34 au. 2015 RR245 has g - r 0.59 +/- 0.11 and absolute magnitude Hr 3.6 +/- 0.1; for an assumed albedo of pV 12, the object has a diameter of approximately 670 km. Based on astrometric measurements from OSSOS and Pan-STARRS1, we find that 2015 RR245 is securely trapped on ten-megayear timescales in the 9:2 mean-motion resonance with Neptune. It is the first trans-Neptunian object (TNO) identied in this resonance. On hundred-megayear timescales, particles in 2015 RR245-like orbits depart and sometimes return to the resonance, indicating that 2015 RR245 likely forms part of the long-lived metastable population of distant TNOs that drift between resonance sticking and actively scattering via gravitational encounters with Neptune. The discovery of a 9:2 TNO stresses the role of resonances in the long-term evolution of objects in the scattering disk and reinforces the view that distant resonances are heavily populated in the current solar system. This object further motivates detailed modeling of the transient sticking population.

  3. Using the Neptune project to benefit Australian aquatic animal health research.

    Science.gov (United States)

    McNamara, M; Ernst, I; Adlard, R D

    2015-06-29

    Diseases of aquatic animals have had, and continue to have, a significant impact on aquatic animal health. In Australia, where fisheries and aquaculture are important industries, aquatic species have been subject to serious disease outbreaks, including pilchard herpesvirus, the cause of one of the largest wild fish kills ever recorded. At the same time, there is a consensus that Australia's parasite fauna are largely unknown, and that aquatic animal health information is difficult to access. Managing aquatic animal diseases is challenging because they may be entirely new, their hosts may be new to aquaculture, and specialist expertise and basic diagnostic tools may be lacking or absent. The Neptune project was created in response to these challenges, and it aims to increase awareness of aquatic animal diseases, improve disease management, and promote communication between aquatic animal health professionals in Australia. The project consists of an online database, a digital microscopy platform containing a whole-slide image library, a community space, and online communications technology. The database contains aquatic animal health information from published papers, government reports, and other sources, while the library contains slides of key diseases both endemic and exotic to Australia. These assets make Neptune a powerful resource for researchers, students, and biosecurity officials.

  4. The photon tagger NEPTUN at S-DALINAC. Current status and research program

    Energy Technology Data Exchange (ETDEWEB)

    Semmler, Diego; Arnold, Michaela; Aumann, Thomas; Baumann, Martin; Beckstein, Michael; Blecher, Alexander; Cvejin, Nebojsa; Hug, Florian; Lehr, Christopher; Pietralla, Norbert; Scheit, Heiko; Symochko, Dmytro; Walz, Christopher; Wessels, Tim [Institut fuer Kernphysik, Darmstadt (Germany)

    2015-07-01

    The low energy photon tagger NEPTUN at the S-DALINAC delivers a quasi-monoenergetic photon beam between about 1MeV and 20MeV with a resolution of approximately 25keV. Tagged photons provide the possibility to measure the full dipole strength of nuclei in the energy range below and above the neutron threshold. The highly efficient LaBr{sub 3}:Ce based spectrometer GALATEA will be used to detect not only the direct decays to the ground state, but also cascading decays can be measured with suitable efficiency. To measure (γ, n)- and (γ, nγ)-reactions the setup will be extended by neutron detectors based on liquid scintillators. The data will be combined with experiments at Duke University, GSI and RIKEN to obtain a complete picture of dipole strength function evolution in Sn isotopes. This talk covers the link between the different experiments and focus on the setup and status of the NEPTUN commissioning program. If available, data from the first runs with Sn will be shown.

  5. Des premiers travaux de Le Verrier à la découverte de Neptune

    Science.gov (United States)

    Laskar, Jacques

    2017-11-01

    Urbain-Jean-Joseph Le Verrier was born in Saint-Lô on March 11, 1811. He entered the "École polytechnique" in 1831, from which he was to emerge eighth of his class two years later. After first devoting himself to chemistry, in 1836 he obtained a position as an astronomy assistant at the "École polytechnique". This choice will decide his future career, which culminates with the discovery of Neptune in 1846. Le Verrier wrote more than 200 contributions to the Comptes rendus de l'Académie des sciences. These contributions are very varied: some original articles, but also reports on publications published elsewhere, sometimes even simple notes of a single page. The whole set gives a very vivid vision of the development of the science of the 19th century. At that time, the Comptes rendus are really a reflection of the debates of the sessions of the Academy. They are published very quickly, and leave a large freedom of speech to the authors. They are therefore a snapshot of the sometimes lively polemics that animated the sessions of the French Academy of Sciences. In this limited essay, we will mainly look at the first years of the career of Le Verrier until the discovery of Neptune.

  6. Transformative ocean science through the VENUS and NEPTUNE Canada ocean observing systems

    International Nuclear Information System (INIS)

    Martin Taylor, S.

    2009-01-01

    The health of the world's oceans and their impact on global environmental and climate change make the development of cabled observing systems vital and timely as a data source and archive of unparalleled importance for new discoveries. The VENUS and NEPTUNE Canada observatories are on the forefront of a new generation of ocean science and technology. Funding of over $100M, principally from the Governments of Canada and BC, for these two observatories supports integrated ocean systems science at a regional scale enabled by new developments in powered sub-sea cable technology and in cyber-infrastructure that streams continuous real-time data to Internet-based web platforms. VENUS is a coastal observatory supporting two instrumented arrays in the Saanich Inlet, near Victoria, and in the Strait of Georgia, off Vancouver. NEPTUNE Canada is an 800 km system on the Juan de Fuca Plate off the west coast of British Columbia, which will have five instrumented nodes in operation over the next 18 months. This paper describes the development and management of these two observatories, the principal research themes, and the applications of the research to public policy, economic development, and public education and outreach. Both observatories depend on partnerships with universities, government agencies, private sector companies, and NGOs. International collaboration is central to the development of the research programs, including partnerships with initiatives in the EU, US, Japan, Taiwan and China.

  7. A theory for narrow-banded radio bursts at Uranus - MHD surface waves as an energy driver

    Science.gov (United States)

    Farrell, W. M.; Curtis, S. A.; Desch, M. D.; Lepping, R. P.

    1992-01-01

    A possible scenario for the generation of the narrow-banded radio bursts detected at Uranus by the Voyager 2 planetary radio astronomy experiment is described. In order to account for the emission burstiness which occurs on time scales of hundreds of milliseconds, it is proposed that ULF magnetic surface turbulence generated at the frontside magnetopause propagates down the open/closed field line boundary and mode-converts to kinetic Alfven waves (KAW) deep within the polar cusp. The oscillating KAW potentials then drive a transient electron stream that creates the bursty radio emission. To substantiate these ideas, Voyager 2 magnetometer measurements of enhanced ULF magnetic activity at the frontside magnetopause are shown. It is demonstrated analytically that such magnetic turbulence should mode-convert deep in the cusp at a radial distance of 3 RU.

  8. The mass disruption of Jupiter Family comets

    Science.gov (United States)

    Belton, Michael J. S.

    2015-01-01

    I show that the size-distribution of small scattered-disk trans-neptunian objects when derived from the observed size-distribution of Jupiter Family comets (JFCs) and other observational constraints implies that a large percentage (94-97%) of newly arrived active comets within a range of 0.2-15.4 km effective radius must physically disrupt, i.e., macroscopically disintegrate, within their median dynamical lifetime. Additional observational constraints include the numbers of dormant and active nuclei in the near-Earth object (NEO) population and the slope of their size distributions. I show that the cumulative power-law slope (-2.86 to -3.15) of the scattered-disk TNO hot population between 0.2 and 15.4 km effective radius is only weakly dependent on the size-dependence of the otherwise unknown disruption mechanism. Evidently, as JFC nuclei from the scattered disk evolve into the inner Solar System only a fraction achieve dormancy while the vast majority of small nuclei (e.g., primarily those with effective radius <2 km) break-up. The percentage disruption rate appears to be comparable with that of the dynamically distinct Oort cloud and Halley type comets (Levison, H.F., Morbidelli, A., Dones, L., Jedicke, R., Wiegert, P.A., Bottke Jr., W.F. [2002]. Science 296, 2212-2215) suggesting that all types of comet nuclei may have similar structural characteristics even though they may have different source regions and thermal histories. The typical disruption rate for a 1 km radius active nucleus is ∼5 × 10-5 disruptions/year and the dormancy rate is typically 3 times less. We also estimate that average fragmentation rates range from 0.01 to 0.04 events/year/comet, somewhat above the lower limit of 0.01 events/year/comet observed by Chen and Jewitt (Chen, J., Jewitt, D.C. [1994]. Icarus 108, 265-271).

  9. Search for the radio occulation flash at Jupiter

    International Nuclear Information System (INIS)

    Martin, J.M.; Tyler, G.L.; Eshleman, V.R.; Wood, G.E.; Lindall, G.F.

    1981-01-01

    The 'evolute flash' a focusing effect caused by the curvature of a planet's limb, was sought in the radio data taken during the occulation of Voyager 1 by Jupiter, using a modified matched-filter technique. The expected frequency structure of the flash signal is double branched, while the intensity structure is highly localized in time. The search for the signal was carried out over a 6.4 s period. The signal parameters were varied to span the uncertainties introduced by imperfect knowledge of the orbit of the spacecraft and the shape of Jupiter. Several peaks at the 8 standard deviation level were present in the filter output. However, these peaks were separated in time by up to 3.3 s, and none could be identified as the flash. From this negative result a lower bound on the absorption along a ray with periapsis near the 4 bar level in Jupiter's atmosphere can be established at 25 dB. Employing the new Voyager results on the structure of the atmosphere of Jupiter and the mixing ratio of the absorbent ammonia, as well as the improved knowledge of flash characteristics resulting from this study, we estimate that the flash would have been detected if the distance behind the planet where the spacecraft trajectory crossed the evolute were at least 20 Jupiter radii, as compared with a value near 7 in the experiment. For focusing at this greater distance, the atmospheric pressure at the ray periapsis would be between 1.5 and 2 bar

  10. Cassini-VIMS at Jupiter: Solar occultation measurements using Io

    Science.gov (United States)

    Formisano, V.; D'Aversa, E.; Bellucci, G.; Baines, K.H.; Bibring, J.-P.; Brown, R.H.; Buratti, B.J.; Capaccioni, F.; Cerroni, P.; Clark, R.N.; Coradini, A.; Cruikshank, D.P.; Drossart, P.; Jaumann, R.; Langevin, Y.; Matson, D.L.; McCord, T.B.; Mennella, V.; Nelson, R.M.; Nicholson, P.D.; Sicardy, B.; Sotin, Christophe; Chamberlain, M.C.; Hansen, G.; Hibbits, K.; Showalter, M.; Filacchione, G.

    2003-01-01

    We report unusual and somewhat unexpected observations of the jovian satellite Io, showing strong methane absorption bands. These observations were made by the Cassini VIMS experiment during the Jupiter flyby of December/January 2000/2001. The explanation is straightforward: Entering or exiting from Jupiter's shadow during an eclipse, Io is illuminated by solar light which has transited the atmosphere of Jupiter. This light, therefore becomes imprinted with the spectral signature of Jupiter's upper atmosphere, which includes strong atmospheric methane absorption bands. Intercepting solar light refracted by the jovian atmosphere, Io essentially becomes a "miffor" for solar occultation events of Jupiter. The thickness of the layer where refracted solar light is observed is so large (more than 3000 km at Io's orbit), that we can foresee a nearly continuous multi-year period of similar events at Saturn, utilizing the large and bright ring system. During Cassini's 4-year nominal mission, this probing tecnique should reveal information of Saturn's atmosphere over a large range of southern latitudes and times. ?? 2003 Elsevier Inc. All rights reserved.

  11. Incidence of urinary retention during treatment with single tablet combinations of solifenacin+tamsulosin OCAS™ for up to 1 year in adult men with both storage and voiding LUTS: A subanalysis of the NEPTUNE/NEPTUNE II randomized controlled studies.

    Directory of Open Access Journals (Sweden)

    Marcus J Drake

    Full Text Available The emergence of urinary retention (UR, specifically acute urinary retention (AUR, has been a concern when treating men with lower urinary tract symptoms (LUTS with antimuscarinic drugs.In NEPTUNE (12-week, double-blind, men (≥45 years with LUTS were randomized to receive tamsulosin oral-controlled absorption system (TOCAS 0.4 mg, fixed-dose combination (FDC of solifenacin (Soli 6 mg + TOCAS 0.4 mg, FDC Soli 9 mg + TOCAS 0.4 mg, or placebo. In NEPTUNE II (40-week, open-label extension of NEPTUNE, continuing patients received 4-week FDC Soli 6 mg + TOCAS, then FDC Soli 6 mg or 9 mg + TOCAS for the remainder of the study, switchable every 3 months.Across both studies, 1208 men received ≥1 dose of FDC Soli 6 mg or 9 mg + TOCAS for up to 52 weeks; 1199 men completed NEPTUNE and 1066 received ≥1 dose in NEPTUNE II. In total, 13 men (1.1%; 95% CI, 0.6%-1.8% reported a UR event while receiving FDC, eight of which were AUR (0.7%; 95% CI, 0.3%-1.3%, incidence 7/1000 man-years. Six men reported UR events while taking Soli 6 mg + TOCAS (three AUR, and seven men reported a UR event while taking Soli 9 mg + TOCAS (five AUR. One man developed AUR while taking TOCAS alone and four reported UR (three AUR during placebo run-in. Most AUR/UR events occurred within 4 months of treatment initiation.FDC Soli and TOCAS was associated with a low rate of UR and AUR in men with LUTS.

  12. Hot Jupiters Aren't As Lonely As We Thought

    Science.gov (United States)

    Kohler, Susanna

    2016-01-01

    The Friends of Hot Jupiters (FOHJ) project is a systematic search for planetary- and stellar-mass companions in systems that have known hot Jupiters short-period, gas-giant planets. This survey has discovered that many more hot Jupiters may have companions than originally believed.Missing FriendsFOHJ was begun with the goal of better understanding the systems that host hot Jupiters, in order to settle several longstanding issues.The first problem was one of observational statistics. We know that roughly half of the Sun-like stars nearby are in binary systems, yet weve only discovered a handful of hot Jupiters around binaries. Are binary systems less likely to host hot Jupiters? Or have we just missed the binary companions in the hot-Jupiter-hosting systems weve seen so far?An additional issue relates to formation mechanisms. Hot Jupiters probably migrated inward from where they formed out beyond the ice lines in protoplanetary disks but how?This median-stacked image, obtained with adaptive optics, shows one of the newly-discovered stellar companions to a star hosting a hot Jupiter. The projected separation is ~180 AU. [Ngo et al. 2015]Observations reveal two populations of hot Jupiters: those with circular orbits aligned with their hosts spins, and those with eccentric, misaligned orbits. The former population support a migration model dominated by local planet-disk interactions, whereas the latter population suggest the hot Jupiters migrated through dynamical interactions with distant companions. A careful determination of the companion rate in hot-Jupiter-hosting systems could help establish the ability of these two models to explain the observed populations.Search for CompanionsThe FOHJ project began in 2012 and studied 51 systems hosting known, transiting hot Jupiters with roughly half on circular, aligned orbits and half on eccentric, misaligned orbits. The survey consisted of three different, complementary components:Study 1Lead author: Heather Knutson

  13. Galileo's first images of Jupiter and the Galilean satellites

    Science.gov (United States)

    Belton, M.J.S.; Head, J. W.; Ingersoll, A.P.; Greeley, R.; McEwen, A.S.; Klaasen, K.P.; Senske, D.; Pappalardo, R.; Collins, G.; Vasavada, A.R.; Sullivan, R.; Simonelli, D.; Geissler, P.; Carr, M.H.; Davies, M.E.; Veverka, J.; Gierasch, P.J.; Banfield, D.; Bell, M.; Chapman, C.R.; Anger, C.; Greenberg, R.; Neukum, G.; Pilcher, C.B.; Beebe, R.F.; Burns, J.A.; Fanale, F.; Ip, W.; Johnson, T.V.; Morrison, D.; Moore, J.; Orton, G.S.; Thomas, P.; West, R.A.

    1996-01-01

    The first images of Jupiter, Io, Europa, and Ganymede from the Galileo spacecraft reveal new information about Jupiter's Great Red Spot (GRS) and the surfaces of the Galilean satellites. Features similar to clusters of thunderstorms were found in the GRS. Nearby wave structures suggest that the GRS may be a shallow atmospheric feature. Changes in surface color and plume distribution indicate differences in resurfacing processes near hot spots on lo. Patchy emissions were seen while Io was in eclipse by Jupiter. The outer margins of prominent linear markings (triple bands) on Europa are diffuse, suggesting that material has been vented from fractures. Numerous small circular craters indicate localized areas of relatively old surface. Pervasive brittle deformation of an ice layer appears to have formed grooves on Ganymede. Dark terrain unexpectedly shows distinctive albedo variations to the limit of resolution.

  14. Launch Opportunities for Jupiter Missions Using the Gravity Assist

    Directory of Open Access Journals (Sweden)

    Young-Joo Song

    2004-06-01

    Full Text Available Interplanetary trajectories using the gravity assists are studied for future Korean interplanetary missions. Verifications of the developed softwares and results were performed by comparing data from ESA's Mars Express mission and previous results. Among the Jupiter exploration mission scenarios, multi-planet gravity assist mission to Jupiter (Earth-Mars-Earth-Jupiter Gravity Assist, EMEJGA trajectory requires minimum launch energy (C3 of 29.231 km2/s2 with 4.6 years flight times. Others, such as direct mission and single-planet(Mars gravity assist mission, requires launch energy (C3 of 75.656 km^2/s^2 with 2.98 years flight times and 63.590 km2/s2 with 2.33 years flight times, respectively. These results show that the planetary gravity assists can reduce launch energy, while EMEJGA trajectory requires the longer flight time than the other missions.

  15. How to distinguish between cloudy mini-Neptunes and water/volatile-dominated super-Earths

    Energy Technology Data Exchange (ETDEWEB)

    Benneke, Björn; Seager, Sara, E-mail: bbenneke@mit.edu [Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2013-12-01

    One of the most profound questions about the newly discovered class of low-density super-Earths is whether these exoplanets are predominately H{sub 2}-dominated mini-Neptunes or volatile-rich worlds with gas envelopes dominated by H{sub 2}O, CO{sub 2}, CO, CH{sub 4}, or N{sub 2}. Transit observations of the super-Earth GJ 1214b rule out cloud-free H{sub 2}-dominated scenarios, but are not able to determine whether the lack of deep spectral features is due to high-altitude clouds or the presence of a high mean molecular mass atmosphere. Here, we demonstrate that one can unambiguously distinguish between cloudy mini-Neptunes and volatile-dominated worlds based on wing steepness and relative depths of absorption features in moderate-resolution near-infrared transmission spectra (R ∼ 100). In a numerical retrieval study, we show for GJ 1214b that an unambiguous distinction between a cloudy H{sub 2}-dominated atmosphere and cloud-free H{sub 2}O atmosphere will be possible if the uncertainties in the spectral transit depth measurements can be reduced by a factor of ∼3 compared to the published Hubble Space Telescope Wide-Field Camera 3 and Very Large Telescope transit observations by Berta et al. and Bean et al. We argue that the required precision for the distinction may be achievable with currently available instrumentation by stacking 10-15 repeated transit observations. We provide a scaling law that scales our quantitative results to other transiting super-Earths and Neptunes such as HD 97658b, 55 Cnc e, GJ 3470b and GJ 436b. The analysis in this work is performed using an improved version of our Bayesian atmospheric retrieval framework. The new framework not only constrains the gas composition and cloud/haze parameters, but also determines our confidence in having detected molecules and cloud/haze species through Bayesian model comparison. Using the Bayesian tool, we demonstrate quantitatively that the subtle transit depth variation in the Berta et al. data is

  16. PENGARUH DARI NEPTUNE KRILL OIL PADA MANAJEMEN DISMINOREA PADA REMAJA PUTRI KELAS X DI SMA NEGERI 1 PRINGSEWU

    Directory of Open Access Journals (Sweden)

    Indri Retno Palupi

    2016-12-01

    Full Text Available Hasil survei Perkumpulan Keluarga Berencana Indonesia (PKBI cabang Bandar Lampung tahun 2014, dismenorhea  menempati urutan pertama keluhan yang sering dialami wanita, sebesar 65,3% selain siklus menstruasi yang tidak teratur. Prevalensi dismenorhea  lebih tinggi pada kelompok usia remaja 10-20 tahun sebesar 71,4%. Tujuan penelitian ini diketahui pengaruh dari neptune krill oil  pada manajemen disminorea pada remaja putri kelas X di SMA Negeri 1 Pringsewu tahun 2016. Jenis penelitian ini adalah kuantitatif dengan menggunakan rancangan desain  eksperimen dengan menggunakan pendekatan one group pre and post test. Populasi dalam penelitian ini adalah seluruh remaja putri kelas X di SMA Negeri 1 Pringsewu yang berjumlah 193 orang, sampel dalam penelitian ini berjumlah 30 orang. Teknik sampling dalam penelitian ini menggunakan teknik accidental. Analisis data yang digunakan dalam penelitian ini univariat dan bivariat dengan uji t-test.Tingkat nyeri dismenorhea  sebelum diberi Neptune krill oil  pada siswi kelas X SMA Negeri 1 Pringsewu memiliki rata-rata tingkatan nyeri yaitu 8,190 (pada skala 1-15, Tingkat nyeri dismenorhea  setelah diberi Neptune krill oil  pada siswi kelas X SMA Negeri 1 Pringsewu memiliki Rata-rata tingkat nyeri yaitu 4,747 (pada skala 1-15. Ada pengaruh pemberian Neptune krill oil  terhadap intensitas nyeri dismenorhea  pada siswi kelas X SMA Negeri 1 Pringsewu Tahun 2016 (p-value=0,000. Diharapkan remaja putri dapat mengetahui bahwa salah satu cara untuk mengurangi nyeri dismenorhea  adalah dengan mengkonsumsi Neptune krill oil. Sehingga remaja putri dapat menerapkannya dirumah saat mengalami dismenorhea.

  17. MULTIPLE-PLANET SCATTERING AND THE ORIGIN OF HOT JUPITERS

    International Nuclear Information System (INIS)

    Beaugé, C.; Nesvorný, D.

    2012-01-01

    Doppler and transit observations of exoplanets show a pile-up of Jupiter-size planets in orbits with a 3 day period. A fraction of these hot Jupiters have retrograde orbits with respect to the parent star's rotation, as evidenced by the measurements of the Rossiter-McLaughlin effect. To explain these observations we performed a series of numerical integrations of planet scattering followed by the tidal circularization and migration of planets that evolved into highly eccentric orbits. We considered planetary systems having three and four planets initially placed in successive mean-motion resonances, although the angles were taken randomly to ensure orbital instability in short timescales. The simulations included the tidal and relativistic effects, and precession due to stellar oblateness. Our results show the formation of two distinct populations of hot Jupiters. The inner population (Population I) is characterized by semimajor axis a 1 Gyr and fits nicely the observed 3 day pile-up. A comparison between our three-planet and four-planet runs shows that the formation of hot Jupiters is more likely in systems with more initial planets. Due to the large-scale chaoticity that dominates the evolution, high eccentricities and/or high inclinations are generated mainly by close encounters between the planets and not by secular perturbations (Kozai or otherwise). The relative proportion of retrograde planets seems of be dependent on the stellar age. Both the distribution of almost aligned systems and the simulated 3 day pile-up also fit observations better in our four-planet simulations. This may suggest that the planetary systems with observed hot Jupiters were originally rich in the number of planets, some of which were ejected. In a broad perspective, our work therefore hints on an unexpected link between the hot Jupiters and recently discovered free floating planets.

  18. Ultraviolet Studies of Jupiter's Hydrocarbons and Aerosols from Galileo

    Science.gov (United States)

    Gladstone, G. Randall

    2001-01-01

    This is the final report for this project. The purpose of this project was to support PI Wayne Pryor's effort to reduce and analyze Galileo UVS (Ultraviolet Spectrometer) data under the JSDAP program. The spectral observations made by the Galileo UVS were to be analyzed to determine mixing ratios for important hydrocarbon species (and aerosols) in Jupiter's stratosphere as a function of location on Jupiter. Much of this work is still ongoing. To date, we have concentrated on analyzing the variability of the auroral emissions rather than the absorption signatures of hydrocarbons, although we have done some work in this area with related HST-STIS data.

  19. Unmasking Europa the search for life on Jupiter's ocean moon

    CERN Document Server

    Greenberg, Richard

    2008-01-01

    Jupiter's ice moon Europa is widely regarded as the most likely place to find extraterrestrial life. This book tells the engaging story of Europa, the oceanic moon. It features a large number of stunning images of the ocean moon's surface, clearly displaying the spectacular crack patterns, extensive rifts and ridges, and refrozen pools of exposed water filled with rafts of displaced ice. Coverage also features firsthand accounts of Galileo's mission to Jupiter and its moons. The book tells the rough and tumble inside story of a very human enterprise in science that lead to the discovery of a f

  20. Recent Simulations of the Late Stages Growth of Jupiter

    Science.gov (United States)

    Lissauer, Jack J.; D'Angelo, Gennaro; Hubickyj, Olenka

    2012-01-01

    Presented by Lissauer et al. (2009, Icarus 199, 338) are used to test the model of capture of Jupiter's irregular satellites within proto-Jupiter's distended and thermally-supported envelope. We find such capture highly unlikely, since the envelope shrinks too slowly for a large number of moons to be retained, and many of those that would be retained would orbit closer to the planet than do the observed Jovian irregulars. Our calculations do not address (and therefore do not exclude) the possibility that the irregular satellites were captured as a result of gas drag within a circumjovian disk. Support for this research from NASA Outer Planets Research Program is gratefully acknowledged.

  1. Analysis of JUPITER critical experiments by JENDL-3.2

    International Nuclear Information System (INIS)

    Ishikawa, Makoto

    1996-01-01

    Applicability of the JENDL-3.2 library to large FBR cores was evaluated using JUPITER experimental data. The nuclear characteristics treated in the present report include criticality, reaction rate ratio, space dependency of C/E values, sodium void reactivity and Doppler reactivity. As a conclusion, JENDL-3.2 is judged to be a well-balanced library for prediction of large FBR core parameters. The unification of integral experimental information from JUPITER and differential nuclear data of JENDL-3.2 will enhance the accuracy and reliability of large FBR core design. (author)

  2. The Hottest Hot Jupiters May Host Atmospheric Dynamos

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, T. M. [Department of Mathematics and Statistics, Newcastle University, Newcastle upon Tyne (United Kingdom); McElwaine, J. N. [Planetary Science Institute, Tucson, AZ 85721 (United States)

    2017-06-01

    Hot Jupiters have proven themselves to be a rich class of exoplanets that test our theories of planetary evolution and atmospheric dynamics under extreme conditions. Here, we present three-dimensional magnetohydrodynamic simulations and analytic results that demonstrate that a dynamo can be maintained in the thin, stably stratified atmosphere of a hot Jupiter, independent of the presumed deep-seated dynamo. This dynamo is maintained by conductivity variations arising from strong asymmetric heating from the planets’ host star. The presence of a dynamo significantly increases the surface magnetic field strength and alters the overall planetary magnetic field geometry, possibly affecting star–planet magnetic interactions.

  3. 76 FR 24513 - Public Land Order No. 7765; Partial Revocation Jupiter Inlet Lighthouse Withdrawal; Florida

    Science.gov (United States)

    2011-05-02

    ...] Public Land Order No. 7765; Partial Revocation Jupiter Inlet Lighthouse Withdrawal; Florida AGENCY... as part of the Jupiter Inlet Lighthouse Outstanding Natural Area. DATES: Effective Date: May 2, 2011... U.S.C. 1787), which created the Jupiter Inlet Lighthouse Outstanding Natural Area, and which...

  4. 77 FR 63722 - Special Local Regulations; Palm Beach World Championship, Atlantic Ocean; Jupiter, FL

    Science.gov (United States)

    2012-10-17

    ...-AA08 Special Local Regulations; Palm Beach World Championship, Atlantic Ocean; Jupiter, FL AGENCY... offshore of Jupiter, Florida during the Palm Beach World Championship, a high speed power boat race. The... Atlantic Ocean, just offshore of Jupiter, Florida. The high speed power boat race event will include...

  5. Epiphytic bryozoans on Neptune grass - a sample-based data set.

    Science.gov (United States)

    Lepoint, Gilles; Heughebaert, André; Michel, Loïc N

    2016-01-01

    The seagrass Posidonia oceanica L. Delile, commonly known as Neptune grass, is an endemic species of the Mediterranean Sea. It hosts a distinctive and diverse epiphytic community, dominated by various macroalgal and animal organisms. Mediterranean bryozoans have been extensively studied but quantitative data assessing temporal and spatial variability have rarely been documented. In Lepoint et al. (2014a, b) occurrence and abundance data of epiphytic bryozoan communities on leaves of Posidonia oceanica inhabiting Revellata Bay (Corsica, Mediterranean Sea) were reported and trophic ecology of Electra posidoniae Gautier assessed. Here, metadata information is provided on the data set discussed in Lepoint et al. (2014a) and published on the GBIF portal as a sampling-event data set: http://ipt.biodiversity.be/resource?r=ulg_bryozoa&v=1.0). The data set is enriched by data concerning species settled on Posidonia scales (dead petiole of Posidonia leaves, remaining after limb abscission).

  6. Closure Report for Corrective Action Unit 574: Neptune, Nevada National Security Site, Nevada

    International Nuclear Information System (INIS)

    2012-01-01

    Corrective Action Unit (CAU) 574 is identified in the Federal Facility Agreement and Consent Order (FFACO) as 'Neptune' and consists of the following two Corrective Action Sites (CASs), located in Area 12 of the Nevada National Security Site: (1) CAS 12-23-10, U12c.03 Crater (Neptune); and (2) CAS 12-45-01, U12e.05 Crater (Blanca). This Closure Report presents information supporting closure of CAU 574 according to the FFACO (FFACO, 1996 [as amended March 2010]) and the Streamlined Approach for Environmental Restoration Plan for CAU 574 (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office [NNSA/NSO], 2011). The following activities were performed to support closure of CAU 574: (1) In situ external dose rate measurements were collected using thermoluminescent dosimeters at CAS 12-45-01, U12e.05 Crater (Blanca). (2) Total effective dose rates were determined at both sites by summing the internal and external dose rate components. (3) A use restriction (UR) was implemented at CAS 12-23-10, U12c.03 Crater (Neptune). Areas that exceed the final action level (FAL) of 25 millirems per year (mrem/yr) based on the Occasional Use Area exposure scenario are within the existing use restricted area for CAU 551. The 25-mrem/yr FAL is not exceeded outside the existing CAU 551 UR for any of the exposure scenarios (Industrial Area, Remote Work Area, and Occasional Use Area). Therefore, the existing UR for CAU 551 is sufficient to bound contamination that exceeds the FAL. (4) An administrative UR was implemented at CAS 12-45-01, U12e.05 Crater (Blanca) as a best management practice (BMP). The 25-mrem/yr FAL was not exceeded for the Remote Work Area or Occasional Use Area exposure scenarios; therefore, a UR is not required. However, because the 25-mrem/yr FAL was exceeded for the Industrial Area exposure scenario, an administrative UR was established as a BMP. UR documentation is included as Appendix B. The UR at CAS 12-23-10, U12c.03 Crater (Neptune

  7. SPITZER PARALLAX OF OGLE-2015-BLG-0966: A COLD NEPTUNE IN THE GALACTIC DISK

    Energy Technology Data Exchange (ETDEWEB)

    Street, R. A.; Bachelet, E. [LCOGT, 6740 Cortona Drive, Suite 102, Goleta, CA 93117 (United States); Udalski, A. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Novati, S. Calchi [NASA Exoplanet Science Institute, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Hundertmark, M. P. G.; Jørgensen, U. G. [Niels Bohr Institute and Centre for Star and Planet Formation, University of Copenhagen, Øster Voldgade 5, DK-1350—Copenhagen K (Denmark); Zhu, W.; Gould, A. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Yee, J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Tsapras, Y. [Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg (ZAH), D-69120 Heidelberg (Germany); Bennett, D. P. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Dominik, M. [SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS (United Kingdom); Andersen, M. I. [Niels Bohr Institute and Dark Cosmology Centre, University of Copenhagen, Juliane Mariesvej 30, DK-2100—Copenhagen Ø (Denmark); Bozza, V. [Dipartimento di Fisica “E.R. Caianiello,” Università di Salerno, Via Giovanni Paolo II 132, I-84084, Fisciano (Italy); Bramich, D. M. [Qatar Environment and Energy Research Institute, Qatar Foundation, P.O. Box 5825, Doha (Qatar); Collaboration: RoboNet Project and MiNDSTEp Consortium; OGLE Project; Spitzer Team; MOA Collaboration; KMTNet Modeling Team; and others

    2016-03-10

    We report the detection of a cold Neptune m{sub planet} = 21 ± 2 M{sub ⊕} orbiting a 0.38 M{sub ⊙} M dwarf lying 2.5–3.3 kpc toward the Galactic center as part of a campaign combining ground-based and Spitzer observations to measure the Galactic distribution of planets. This is the first time that the complex real-time protocols described by Yee et al., which aim to maximize planet sensitivity while maintaining sample integrity, have been carried out in practice. Multiple survey and follow up teams successfully combined their efforts within the framework of these protocols to detect this planet. This is the second planet in the Spitzer Galactic distribution sample. Both are in the near to mid-disk and are clearly not in the Galactic bulge.

  8. Multi scale analysis of thermal-hydraulics of nuclear reactors - the neptune project

    International Nuclear Information System (INIS)

    Bestion, D.

    2004-01-01

    Full text of publication follows:The NEPTUNE project aims at building a new two-phase thermalhydraulic platform for nuclear reactor simulation. It is jointly developed by CEA-DEN and EDF-DRD and also supported by IRSN and FRAMATOME-ANP. NEPTUNE is a new generation multi-scale platform. The system scale models the whole reactor circuit with 0D, 1D and 3D modules and is generally applied with a coarse meshing including about a thousand meshes. The component scale models components like the reactor Core or Steam Generators with a finer nodalization and is generally applied with 10 4 to 10 5 meshes. Since these components contain rod bundles or tube bundles the physical modelling uses a homogenization technique with a porosity. For some specific applications it was found necessary to add a two-phase CFD tool able to zoom on a portion of the circuit where small scale phenomena are of importance for design purpose or safety issues. Here the basic equations are still averaged like in RANS approach for single phase, but the space resolution is finer than in component codes and typical application may require 10 5 to 10 7 meshes. These three scales have to be coupled in order to simulate many reactor transients where both local effects and system effects play a role. In addition, two-phase Direct Numerical Simulation Tools with Interface Tracking Techniques can be used for even smaller scale investigations for a better understanding of basic physical processes and for developing closure relations for averaged models. The main challenges of this project are here presented and some first results are presented. (authors)

  9. A Distant Mirror: Solar Oscillations Observed on Neptune by the Kepler K2 Mission

    Science.gov (United States)

    Gaulme, P.; Rowe, J. F.; Bedding, T. R.; Benomar, O.; Corsaro, E.; Davies, G. R.; Hale, S. J.; Howe, R.; Garcia, R. A.; Huber, D.; hide

    2016-01-01

    Starting in 2014 December, Kepler (K2) observed Neptune continuously for 49 days at a 1-minute cadence. The goals consisted of studying its atmospheric dynamics, detecting its global acoustic oscillations, and those of the Sun, which we report on here. We present the first indirect detection of solar oscillations in intensity measurements. Beyond the remarkable technical performance, it indicates how Kepler would see a star like the Sun. The result from the global asteroseismic approach, which consists of measuring the oscillation frequency at maximum amplitude max velocity and the mean frequency separation between mode overtones delta velocity, is surprising as the max velocity measured from Neptune photometry is larger than the accepted value. Compared to the usual reference max velocity of the sun equal to 3100 microhertz, the asteroseismic scaling relations therefore make the solar mass and radius appear larger by 13.8 plus or minus 5.8 percent and 4.3 plus or minus 1.9 percent, respectively. The higher max velocity is caused by a combination of the value of max velocity of the sun, being larger at the time of observations than the usual reference from SOHO/VIRGO/SPM (Variability of solar IRradiance and Gravity Oscillations / on board SOHO (Solar and Heliospheric Observatory) / Sun PhotoMeters) data (3160 plus or minus 10 microhertz), and the noise level of the K2 time series, being 10 times larger than VIRGO's. The peak-bagging method provides more consistent results: despite a low signal-to-noise ratio (S/N), we model 10 overtones for degrees iota equal 0, 1, 2. We compare the K2 data with simultaneous SOHO/VIRGO/SPM photometry and Bison (Birmingham Solar-Oscillations Network) velocity measurements. The individual frequencies, widths, and amplitudes mostly match those from VIRGO and BiSON within 1 sigma, except for the few peaks with the lowest S/N.

  10. A DISTANT MIRROR: SOLAR OSCILLATIONS OBSERVED ON NEPTUNE BY THE KEPLER K 2 MISSION

    Energy Technology Data Exchange (ETDEWEB)

    Gaulme, P.; Jackiewicz, J. [Department of Astronomy, New Mexico State University, P.O. Box 30001, MSC 4500, Las Cruces, NM 88003-8001 (United States); Rowe, J. F. [Institut de recherche sur les exoplanètes, iREx, Département de physique, Université de Montréal, Montréal, QC H3C 3J7 (Canada); Bedding, T. R.; Huber, D. [Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, Sydney, NSW 2006 (Australia); Benomar, O. [Center for Space Science, NYUAD Institute, New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi (United Arab Emirates); Corsaro, E.; Garcia, R. A. [Laboratoire AIM, CEA/DRF-CNRS, Université Paris 7 Diderot, IRFU/SAp, Centre de Saclay, F-91191 Gif-sur-Yvette (France); Davies, G. R. [INAF—Osservatorio Astrofisico di Catania, Via S. Sofia 78, I-95123 Catania (Italy); Hale, S. J.; Howe, R. [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B152TT (United Kingdom); Jiménez, A. [Instituto de Astrofísica de Canarias, E-38200 La Laguna, Tenerife (Spain); Mathur, S. [Center for Extrasolar Planetary Systems, Space Science Institute, 4750 Walnut Street, Suite #205, Boulder, CO 80301 (United States); Mosser, B. [LESIA, Observatoire de Paris, PSL Research University, CNRS, Université Pierre et Marie Curie, Université Denis Diderot, F-92195 Meudon (France); Appourchaux, T.; Boumier, P.; Leibacher, J., E-mail: gaulme@nmsu.edu [Institut d’Astrophysique Spatiale, Université Paris-Sud and CNRS (UMR 8617), Bâtiment 121, F-91405 Orsay cedex (France); and others

    2016-12-10

    Starting in 2014 December, Kepler K 2 observed Neptune continuously for 49 days at a 1 minute cadence. The goals consisted of studying its atmospheric dynamics, detecting its global acoustic oscillations, and those of the Sun, which we report on here. We present the first indirect detection of solar oscillations in intensity measurements. Beyond the remarkable technical performance, it indicates how Kepler would see a star like the Sun. The result from the global asteroseismic approach, which consists of measuring the oscillation frequency at maximum amplitude ν {sub max} and the mean frequency separation between mode overtones Δ ν , is surprising as the ν {sub max} measured from Neptune photometry is larger than the accepted value. Compared to the usual reference ν {sub max,⊙} = 3100 μ Hz, the asteroseismic scaling relations therefore make the solar mass and radius appear larger by 13.8 ± 5.8% and 4.3 ± 1.9%, respectively. The higher ν {sub max} is caused by a combination of the value of ν {sub max,⊙}, being larger at the time of observations than the usual reference from SOHO /VIRGO/SPM data (3160 ± 10 μ Hz), and the noise level of the K 2 time series, being 10 times larger than VIRGO’s. The peak-bagging method provides more consistent results: despite a low signal-to-noise ratio (S/N), we model 10 overtones for degrees ℓ = 0, 1, 2. We compare the K 2 data with simultaneous SOHO /VIRGO/SPM photometry and BiSON velocity measurements. The individual frequencies, widths, and amplitudes mostly match those from VIRGO and BiSON within 1 σ, except for the few peaks with the lowest S/N.

  11. Ulysses at jupiter: an overview of the encounter.

    Science.gov (United States)

    Smith, E J; Wenzel, K P; Page, D E

    1992-09-11

    In February 1992, the Ulysses spacecraft flew through the giant magnetosphere of Jupiter. The primary objective of the encounter was to use the gravity field of Jupiter to redirect the spacecraft to the sun's polar regions, which will now be traversed in 1994 and 1995. However, the Ulysses scientific investigations were well suited to observations of the Jovian magnetosphere, and the encounter has resulted in a major contribution to our understanding of this complex and dynamic plasma environment. Among the more exciting results are (i) possible entry into the polar cap, (ii) the identification of magnetospheric ions originating from Jupiter's ionosphere, lo, and the solar wind, (iii) observation of longitudinal asymmetries in density and discrete wave-emitting regions of the lo plasma torus, (iv) the presence of counter-streaming ions and electrons, field-aligned currents, and energetic electron and radio bursts in the dusk sector on high-latitude magnetic field lines, and (v) the identification of the direction of the magnetic field in the dusk sector, which is indicative of tailward convection. This overview serves as an introduction to the accompanying reports that present the preliminary scientific findings. Aspects of the encounter that are common to all of the investigations, such as spacecraft capabilities, the flight path past Jupiter, and unique aspects of the encounter, are presented herein.

  12. A nebula of gases from Io surrounding Jupiter.

    Science.gov (United States)

    Krimigis, Stamatios M; Mitchell, Donald G; Hamilton, Douglas C; Dandouras, Jannis; Armstrong, Thomas P; Bolton, Scott J; Cheng, Andrew F; Gloeckler, George; Hsieh, K C; Keath, Edwin P; Krupp, Norbert; Lagg, Andreas; Lanzerotti, Louis J; Livi, Stefano; Mauk, Barry H; McEntire, Richard W; Roelof, Edmond C; Wilken, Berend; Williams, Donald J

    2002-02-28

    Several planetary missions have reported the presence of substantial numbers of energetic ions and electrons surrounding Jupiter; relativistic electrons are observable up to several astronomical units (au) from the planet. A population of energetic (>30[?]keV) neutral particles also has been reported, but the instrumentation was not able to determine the mass or charge state of the particles, which were subsequently labelled energetic neutral atoms. Although images showing the presence of the trace element sodium were obtained, the source and identity of the neutral atoms---and their overall significance relative to the loss of charged particles from Jupiter's magnetosphere---were unknown. Here we report the discovery by the Cassini spacecraft of a fast (>103[?]km[?]s-1) and hot magnetospheric neutral wind extending more than 0.5[?]au from Jupiter, and the presence of energetic neutral atoms (both hot and cold) that have been accelerated by the electric field in the solar wind. We suggest that these atoms originate in volcanic gases from Io, undergo significant evolution through various electromagnetic interactions, escape Jupiter's magnetosphere and then populate the environment around the planet. Thus a 'nebula' is created that extends outwards over hundreds of jovian radii.

  13. First Earth-based Detection of a Superbolide on Jupiter

    Science.gov (United States)

    Hueso, Ricardo; Wesley, A.; Go, C.; Perez-Hoyos, S.; Wong, M. H.; Fletcher, L. N.; Sanchez-Lavega, A.; Boslough, M. B. E.; de Pater, I.; Orton, G. S.; Simon-Miller, A. A.; Djorgovski, S. G.; Edwards, M. L.; Hammel, H. B.; Clarke, J. T.; Noll, K. S.; Yanamandra-Fisher, P. A.

    2010-10-01

    On June 3, 2010 a bolide in Jupiter's atmosphere was observed from the Earth for the first time. The flash was detected by amateur astronomers A. Wesley and C. Go observing in two wavelength ranges. We present an analysis of the light curve of those observations that allow estimating the size of the object to be significantly smaller than the SL9 and the July 2009 Jupiter impact. Observations obtained a few days later by large telescopes including HST, VLT, Keck and Gemini showed no signature of the impact in Jupiter atmosphere confirming the small size of the impact body. A nearly continuous observation campaign based on several small telescopes by amateurs astronomers might allow an empirical determination of the flux of meteoroids in Jupiter with implications for the populations of small bodies in the outer solar system and may allow a better quantification of the threat of impacting bodies to Earth. Acknowledgements: RH, ASL and SPH are supported by the Spanish MICIIN AYA2009-10701 with FEDER and Grupos Gobierno Vasco IT-464-07. LNF is supported by a Glasstone Science Fellowship at the University of Oxford.

  14. First Results of ISO-SWS Grating Observations of Jupiter

    NARCIS (Netherlands)

    Encrenaz, Th.; de Graauw, Th.; Schaeidt, S.; Lellouch, E.; Feuchtgruber, H.; Beintema, D. A.; Bezard, B.; Drossart, P.; Griffin, M.; Heras, A.; Kessler, M.; Leech, K.; Morris, A.; Roelfsema, P. R.; Roos-Serote, M.; Salama, A.; Vandenbussche, B.; Valentijn, E. A.; Davies, G. R.; Naylor, D. A.

    1996-01-01

    The spectrum of Jupiter has been recorded on April 12, 1996, between 2.75 and 14.5 mu m, with the grating mode of the Short-Wavelength Spectrometer of ISO (Infrared Space Observatory). The resolving power is 1500 and the sensitivity limit is better than 1 Jy. The corresponding S/N ratio is better

  15. First results of ISO-SWS observations of Jupiter

    NARCIS (Netherlands)

    Encrenaz, T.; de Graauw, T.; Schaeidt, S.; Lellouch, E.; Feuchtgruber, H.; Beintema, D. A.; Bezard, B.; Drossart, P.; Griffin, M.; Heras, A.; Kessler, M.; Leech, K.; Morris, P.; Roelfsema, P. R.; Roos-Serote, M.; Salama, A.; Vandenbussche, B.; Valentijn, E. A.; Davis, G. R.; Naylor, D. A.

    The spectrum of Jupiter has been recorded between 2.75 and 14.5 mu m with the grating mode of the Short-Wavelength Spectrometer (SWS) of ISO. The resolving power is 1500. The main preliminary results of this observation are (1) at 3 mu m, the first spectroscopic signature, probably associated with

  16. Multi-band characterization of the hot Jupiters

    DEFF Research Database (Denmark)

    Moyano, M.; Almeida, L. A.; von Essen, C.

    2017-01-01

    We have carried out a campaign to characterize the hot Jupiters WASP-5b, WASP-44b and WASP-46b using multiband photometry collected at the Observatorio do Pico Dos Dias in Brazil. We have determined the planetary physical properties and new transit ephemerides for these systems. The new orbital...

  17. James A. Van Allen: The Trip to Jupiter

    Science.gov (United States)

    Jacobsen, Sally

    1973-01-01

    Discusses the research purposes and activities of the Pioneer mission, including the instruments used, data on Jupiter's radiation belt, and information about cosmic ray intensity. Included is a description of the scientist's view about the value of the space program. (CC)

  18. Radiation analysis for manned missions to the Jupiter system.

    Science.gov (United States)

    De Angelis, G; Clowdsley, M S; Nealy, J E; Tripathi, R K; Wilson, J W

    2004-01-01

    An analysis for manned missions targeted to the Jovian system has been performed in the framework of the NASA RASC (Revolutionary Aerospace Systems Concepts) program on Human Exploration beyond Mars. The missions were targeted to the Jupiter satellite Callisto. The mission analysis has been divided into three main phases, namely the interplanetary cruise, the Jupiter orbital insertion, and the surface landing and exploration phases. The interplanetary phase is based on departure from the Earth-Moon L1 point. Interplanetary trajectories based on the use of different propulsion systems have been considered, with resulting overall cruise phase duration varying between two and five years. The Jupiter-approach and the orbital insertion trajectories are considered in detail, with the spacecraft crossing the Jupiter radiation belts and staying around the landing target. In the surface exploration phase the stay on the Callisto surface is considered. The satellite surface composition has been modeled based on the most recent results from the GALILEO spacecraft. In the transport computations the surface backscattering has been duly taken into account. Particle transport has been performed with the HZETRN heavy ion code for hadrons and with an in-house developed transport code for electrons and bremsstrahlung photons. The obtained doses have been compared to dose exposure limits. c2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

  19. Influence of tides on the gravitational field of Jupiter

    International Nuclear Information System (INIS)

    Gavrilov, S.V.; Zharkov, V.N.; Leont'ev, V.V.

    1975-01-01

    The influence of tides on the gravitational field of giant planets is considered quantitatively. The ''gravitational noise'' due to tides can affect the determination of J 8 and J 10 for Jupiter. Tidal sounding of the giant planets is suggested. (author)

  20. The Moons of Jupiter / Journey to the Stars

    Science.gov (United States)

    Litwak, J.; Chatzichristou, E.

    2017-09-01

    The Moons of Jupiter/ Journey to the Stars uses the arts, most particularly theatre arts to inspire curiosity about science education. Using characters which include famous scientists as well as mythological figures, the project provokes thought and offers opportunity for discovery. The play and the subsequent creative teaching tools are accessible to scientists, artists and lay people in an out of the classroom.

  1. Equilibrium and disequilibrium chemistry of adiabatic, solar-composition planetary atmospheres

    Science.gov (United States)

    Lewis, J. S.

    1976-01-01

    The impact of atmospheric and cloud-structure models on the nonequilibrium chemical behavior of the atmospheres of the Jovian planets is discussed. Quantitative constraints on photochemical, lightning, and charged-particle production of organic matter and chromophores are emphasized whenever available. These considerations imply that inorganic chromophore production is far more important than that of organic chromophores, and that lightning is probably a negligibly significant process relative to photochemistry on Jupiter. Production of complex molecules by gas-phase disequilibrium processes on Saturn, Uranus, and Neptune is severely limited by condensation of even simple intermediates.

  2. Magnetotails in the solar system

    CERN Document Server

    Keiling, Andreas; Delamere, Peter

    2014-01-01

    All magnetized planets in our solar system (Mercury, Earth, Jupiter, Saturn, Uranus, and Neptune) interact strongly with the solar wind and possess well developed magnetotails. It is not only the strongly magnetized planets that have magnetotails. Mars and Venus have no global intrinsic magnetic field, yet they possess induced magnetotails. Comets have magnetotails that are formed by the draping of the interplanetary magnetic field. In the case of planetary  satellites (moons), the magnetotail refers to the wake region behind the satellite in the flow of either the solar wind or the magnetosp

  3. Improving a 1 meter telescope in order to follow giant planets in a pro-am collaboration. Next step : an affordable adaptive optic system.=

    Science.gov (United States)

    Dauvergne, J.-L.; Colas, F.; Delcroix, M.; Lecacheux, J.

    2017-09-01

    We already have very good result with the 1 meter telescope of Pic du Midi. Our goal is to have more and more people in the team in order to make a survey has long as possible of Jupiter, Uranus and Neptune. The next step is an OA system, we want to make it work on the 1 meter telescope and also make it available on the market to help other observatories to produce high resolution images of the solar system with middle size telescopes.

  4. Evidence for Quantisation in Planetary Ring Systems

    OpenAIRE

    WAYTE, RICHARD

    2017-01-01

    Absolute radial positions of the main features in Saturn's ring system have been calculated by adapting the quantum theory of atomic spectra. Fine rings superimposed upon broad rings are found to be covered by a harmonic series of the form N α A(r)1/2, where N and A are integers. Fourier analysis of the ring system shows that the spectral amplitude fits a response profile which is characteristic of a resonant system. Rings of Jupiter, Uranus and Neptune also obey the same rules. Involvement o...

  5. Conceptual definition of a 50-100 kWe NEP system for planetary science missions

    Science.gov (United States)

    Friedlander, Alan

    1993-01-01

    The Phase 1 objective of this project is to assess the applicability of a common Nuclear Electric Propulsion (NEP) flight system of the 50-100 kWe power class to meet the advanced transportation requirements of a suite of planetary science (robotic) missions, accounting for differences in mission-specific payloads and delivery requirements. The candidate missions are as follows: (1) Comet Nucleus Sample Return; (2) Multiple Mainbelt Asteroid Rendezvous; (3) Jupiter Grand Tour (Galilean satellites and magnetosphere); (4) Uranus Orbiter/Probe (atmospheric entry and landers); (5) Neptune Orbiter/Probe (atmospheric entry and landers); and (6) Pluto-Charon Orbiter/Lander. The discussion is presented in vugraph form.

  6. An Overview of the Jupiter Europa Orbiter Concept's Europa Science Phase Orbit Design

    Science.gov (United States)

    Lock, Robert E.; Ludwinski, Jan M.; Petropoulos, Anastassios E.; Clark, Karla B.; Pappalardo, Robert T.

    2009-01-01

    Jupiter Europa Orbiter (JEO), the proposed NASA element of the proposed joint NASA-ESA Europa Jupiter System Mission (EJSM), could launch in February 2020 and conceivably arrive at Jupiter in December of 2025. The concept is to perform a multi-year study of Europa and the Jupiter system, including 30 months of Jupiter system science and a comprehensive Europa orbit phase of 9 months. This paper provides an overview of the JEO concept and describes the Europa Science phase orbit design and the related science priorities, model pay-load and operations scenarios needed to conduct the Europa Science phase. This overview is for planning and discussion purposes only.

  7. How Planet Nine could change the fate of the Solar system

    Science.gov (United States)

    Veras, D.

    2017-09-01

    The potential existence of a distant planet ('Planet Nine') in the Solar system has prompted a re-think about the evolution of planetary systems. As the Sun transitions from a main-sequence star into a white dwarf, Jupiter, Saturn, Uranus and Neptune are currently assumed to survive in expanded but otherwise unchanged orbits. However, a sufficiently distant and sufficiently massive extra planet would alter this quiescent end scenario through the combined effects of Solar giant branch mass-loss and Galactic tides. Here I estimate bounds for the mass and orbit of a distant extra planet that would incite future instability in systems with a Sun-like star and giant planets with masses and orbits equivalent to those of Jupiter, Saturn, Uranus and Neptune. I find that this boundary is diffuse and strongly dependent on each of the distant planet's orbital parameters. Nevertheless, I claim that instability occurs more often than not when the planet is as massive as Jupiter and harbours a semimajor axis exceeding about 300 au, or has a mass of a super-Earth and a semimajor axis exceeding about 3000 au. These results hold for orbital pericentres ranging from 100 to at least 400 au. This instability scenario might represent a common occurrence, as potentially evidenced by the ubiquity of metal pollution in white dwarf atmospheres throughout the Galaxy.

  8. Intrinsic luminosities of the Jovian planets

    International Nuclear Information System (INIS)

    Hubbard, W.B.

    1980-01-01

    We review available data and theories on the size and nature of interior power sources in the Jovian planets. Broad band infrared measurements indicate that Jupiter and Saturn have interior heat fluxes about 150 and 50 times larger, respectively, than the terrestrial value. While Neptune has a modest heat flux (approx.5 times terrestrial), it is clearly detected by earth-based measurements. Only Uranus seems to lack a detectable interior heat flow. Various models, ranging from simple cooling to gravitational layering to radioactivity, are discussed. Current evidence seems to favor a cooling model in which the escape of heat is regulated by the atmosphere. This model seems capable of explaining phenomena such as the uniformity of effective temperature over Jupiter's surface and the different emission rates of Uranus and Neptune. In such a model the heat radiated from the atmosphere may derived from depletion of a thermal reservoir in the interior, or it may derive from separation of chemical elements during formation of a core. Calculations indicate that in the earlier stages of cooling, Jupiter and Saturn may have more homogeneous abundances of hydrogen and helium and radiate energy derived from simple cooling. At a subsequent phase (which may be later than the present time), hydrogen and helium will separate and supply grativational energy. Either model is consistent with a hot, high-luminosity origin for the Jovian Planets

  9. The hot plasma environment at jupiter: ulysses results.

    Science.gov (United States)

    Lanzerotti, L J; Armstrong, T P; Gold, R E; Anderson, K A; Krimigis, S M; Lin, R P; Pick, M; Roelof, E C; Sarris, E T; Simnett, G M; Maclennan, C G; Choo, H T; Tappin, S J

    1992-09-11

    Measurements of the hot plasma environment during the Ulysses flyby of Jupiter have revealed several new discoveries related to this large rotating astrophysical system. The Jovian magnetosphere was found by Ulysses to be very extended, with the day-side magnetopause located at approximately 105 Jupiter radii. The heavy ion (sulfur, oxygen, and sodium) population in the day-side magnetosphere increased sharply at approximately 86 Jupiter radii. This is somewhat more extended than the "inner" magnetosphere boundary region identified by the Voyager hot plasma measurements. In the day-side magnetosphere, the ion fluxes have the anisotropy direction expected for corotation with the planet, with the magnitude of the anisotropy increasing when the spacecraft becomes more immersed in the hot plasma sheet. The relative abundances of sulfur, oxygen, and sodium to helium decreased somewhat with decreasing radial distance from the planet on the day-side, which suggests that the abundances of the Jupiter-derived species are dependent on latitude. In the dusk-side, high-latitude region, intense fluxes of counter-streaming ions and electrons were discovered from the edge of the plasma sheet to the dusk-side magnetopause. These beams of electrons and ions were found to be very tightly aligned with the magnetic field and to be superimposed on a time- and space-variable isotropic hot plasma background. The currents carried by the measured hot plasma particles are typically approximately 1.6 x 10(-4) microamperes per square meter or approximately 8 x 10(5) amperes per squared Jupiter radius throughout the high-latitude magnetosphere volume. It is likely that the intense particle beams discovered at high Jovian latitudes produce auroras in the polar caps of the planet.

  10. Tilting Saturn without Tilting Jupiter: Constraints on Giant Planet Migration

    Science.gov (United States)

    Brasser, R.; Lee, Man Hoi

    2015-11-01

    The migration and encounter histories of the giant planets in our solar system can be constrained by the obliquities of Jupiter and Saturn. We have performed secular simulations with imposed migration and N-body simulations with planetesimals to study the expected obliquity distribution of migrating planets with initial conditions resembling those of the smooth migration model, the resonant Nice model and two models with five giant planets initially in resonance (one compact and one loose configuration). For smooth migration, the secular spin-orbit resonance mechanism can tilt Saturn’s spin axis to the current obliquity if the product of the migration timescale and the orbital inclinations is sufficiently large (exceeding 30 Myr deg). For the resonant Nice model with imposed migration, it is difficult to reproduce today’s obliquity values, because the compactness of the initial system raises the frequency that tilts Saturn above the spin precession frequency of Jupiter, causing a Jupiter spin-orbit resonance crossing. Migration timescales sufficiently long to tilt Saturn generally suffice to tilt Jupiter more than is observed. The full N-body simulations tell a somewhat different story, with Jupiter generally being tilted as often as Saturn, but on average having a higher obliquity. The main obstacle is the final orbital spacing of the giant planets, coupled with the tail of Neptune’s migration. The resonant Nice case is barely able to simultaneously reproduce the orbital and spin properties of the giant planets, with a probability ˜ 0.15%. The loose five planet model is unable to match all our constraints (probability <0.08%). The compact five planet model has the highest chance of matching the orbital and obliquity constraints simultaneously (probability ˜0.3%).

  11. Jupiter's Mid-Infrared Aurora: Solar Connection and Minor Constituents

    Science.gov (United States)

    Kostiuk, Theodore; Livengood, T.A.; Fast, K.E.; Hewagama, T.; Schmilling, F.; Sonnabend, G.; Delgado, J.

    2009-01-01

    High spectral resolution in the 12 pin region of the polar regions of Jupiter reveal unique information on auroral phenomena and upper stratospheric composition. Polar aurorae in Jupiter's atmosphere radiate; throughout the electromagnetic spectrum from X-ray through mid-infrared (mid-IR, 5 - 20 micron wavelength). Voyager IRIS data and ground-based. spectroscopic measurements of Jupiter's northern mid-IR aurora acquired since 1982, reveal a correlation between auroral brightness and solar activity that has not been observed in Jovian aurora at other wavelengths. Over nearly three solar cycles, Jupiter auroral ethane, emission brightness and solar 10.7-cm radar flux and sunspot number are positively correlated with high confidence. Ethane line emission intensity varies over tenfold between low and high scalar activity periods. Detailed measurements have been made using the GSFC HIPWAC spectrometer at the NASA IRTF since the last solar maximum, following the mid-IR emission through the declining phase toward solar minimum. An even more convincing correlation with solar activity is evident in these data. The spectra measured contain features that cannot be attributed to ethane and are most likely spectra of minor constituents whose molecular bands overlap the v9 band of ethane. Possible candidates are allene, propane, and other higher order hydrocarbons. These features appear to be enhanced in the active polar regions. Laboratory measurements at comparable spectral resolution of spectra of candidate molecules will be used to identify the constituents. Current analyses of these results will be described, including planned measurements on polar ethane line emission scheduled through the rise of the next solar maximum beginning in 2009, with a steep gradient to a maximum in 2012. This work is relevant to the Juno mission and to the development of the NASA/ESA Europa Jupiter System Mission.

  12. Exterior Companions to Hot Jupiters Orbiting Cool Stars Are Coplanar

    Science.gov (United States)

    Becker, Juliette C.; Vanderburg, Andrew; Adams, Fred C.; Khain, Tali; Bryan, Marta

    2017-12-01

    The existence of hot Jupiters has challenged theories of planetary formation since the first extrasolar planets were detected. Giant planets are generally believed to form far from their host stars, where volatile materials like water exist in their solid phase, making it easier for giant planet cores to accumulate. Several mechanisms have been proposed to explain how giant planets can migrate inward from their birth sites to short-period orbits. One such mechanism, called Kozai-Lidov migration, requires the presence of distant companions in orbits inclined by more than ˜40° with respect to the plane of the hot Jupiter’s orbit. The high occurrence rate of wide companions in hot-Jupiter systems lends support to this theory for migration. However, the exact orbital inclinations of these detected planetary and stellar companions is not known, so it is not clear whether the mutual inclination of these companions is large enough for the Kozai-Lidov process to operate. This paper shows that in systems orbiting cool stars with convective outer layers, the orbits of most wide planetary companions to hot Jupiters must be well aligned with the orbits of the hot Jupiters and the spins of the host stars. For a variety of possible distributions for the inclination of the companion, the width of the distribution must be less than ˜20° to recreate the observations with good fidelity. As a result, the companion orbits are likely well aligned with those of the hot Jupiters, and the Kozai-Lidov mechanism does not enforce migration in these systems.

  13. Comparison of rosuvastatin and atorvastatin for lipid lowering in patients with type 2 diabetes mellitus: results from the URANUS study

    Directory of Open Access Journals (Sweden)

    Berne Christian

    2005-06-01

    Full Text Available Abstract Objective The Use of Rosuvastatin versus Atorvastatin iN type 2 diabetes mellitUS (URANUS study compared rosuvastatin with atorvastatin for the reduction of low-density lipoprotein cholesterol (LDL-C in patients with type 2 diabetes. Methods After a 6-week dietary run-in, patients aged ≥ 18 years with type 2 diabetes and LDL-C ≥ 3.3 mmol/L were randomised to double-blind treatment with rosuvastatin 10 mg (n = 232 or atorvastatin 10 mg (n = 233 for 4 weeks. Doses were then titrated up to a maximum of rosuvastatin 40 mg or atorvastatin 80 mg over 12 weeks to achieve the 1998 European LDL-C goal ( Results Rosuvastatin reduced LDL-C levels significantly more than atorvastatin during the fixed-dose and titration periods (p Conclusion At the start dose and following dose titration, rosuvastatin was significantly more effective than atorvastatin at reducing LDL-C and achieving European LDL-C goals in patients with type 2 diabetes.

  14. Biology on the outer planets. [life possibility in atmospheres and moons

    Science.gov (United States)

    Young, R. S.; Macelroy, R. D.

    1976-01-01

    A brief review is given of information on the structure and composition of the outer planets and the organic reactions that may be occurring on them. The possibility of life arising or surviving in the atmospheres of these planets is considered, and the problem of contamination during future unmanned missions is assessed. Atmospheric models or available atmospheric data are reviewed for Jupiter, Saturn, Uranus, Neptune, Pluto, the Galilean satellites, and Titan. The presence of biologically interesting gases on Jupiter and Saturn is discussed, requirements for life on Jupiter are summarized, and possible sources of biological energy are examined. Proposals are made for protecting these planets and satellites from biological contamination by spacecraftborne terrestrial organisms.

  15. The status of thermal-hydraulic studies on the decay heat removal by natural convection using RAMONA and NEPTUN models

    International Nuclear Information System (INIS)

    Hoffmann, H.; Hain, K.; Marten, K.; Rust, K.; Weinberg, D.; Ohira, H.

    2004-01-01

    Thermal-hydraulic experiments were performed with water in order to simulate the decay heat removal by natural convection in a pool-type sodium-cooled reactor. Two test rigs of different scales were used, namely RAMONA (1:20) and NEPTUN (1:5). RAMONA served to study the transition from nominal operation by forced convection to decay heat removal operation by natural convection. Steady-state similarity tests were carried out in both facilities. The investigations cover nominal and non-nominal operation conditions. These data provide a broad basis for the verification of computer programs. Numerical analyses performed with the three-dimensional FLUTAN code indicated that the thermal-hydraulic processes can be quantitatively simulated even for the very complex geometry of the NEPTUN test rig. (author)

  16. The low energy photon tagger NEPTUN: Toward a detailed study of the Pygmy dipole resonance with real photons

    Energy Technology Data Exchange (ETDEWEB)

    Semmler, Diego; Aumann, T.; Bauer, C.; Baumann, M.; Beckstein, M.; Beller, J.; Blecher, A.; Cvejin, N.; Duchene, M.; Hug, F.; Kahlbow, J.; Knoerzer, M.; Kreis, K.; Kremer, C.; Ries, P.; Romig, C.; Scheit, H.; Schnorrenberger, L.; Symochko, D.; Walz, C. [Institut fuer Kernphysik, Darmstadt (Germany); Lefol, R. [University of Saskatchewan, Saskatoon (Canada); Loeher, B. [ExtreMe Matter Institute EMMI and Research Division, Frankfurt (Germany); Institute for Advanced Studies FIAS, Frankfurt (Germany)

    2014-07-01

    The low energy photon tagger NEPTUN at the S-DALINAC delivers a quasi-monoenergetic photon beam between about 4 MeV and 20 MeV with a resolution of approximately 25 keV. Tagged photons provide the possibility to measure the dipole strength of nuclei in the energy range below and above the neutron threshold. The highly efficient LaBr{sub 3} based spectrometer GALATEA will be used to detect not only the direct decays to the ground state, but also cascading decays can be measured with suitable efficiency. We will measure (γ,n)- and (γ,nγ)-reactions with neutron detectors based on plastic scintillators. This talk provides an overview about setup and goals of the NEPTUN experiment as well as the current state of the commissioning phase. Planned optimizations of the setup, based on the results of a test beam time in June 2013, are also presented.

  17. Mass-radius relations and core-envelope decompositions of super-Earths and sub-Neptunes

    International Nuclear Information System (INIS)

    Howe, Alex R.; Burrows, Adam; Verne, Wesley

    2014-01-01

    Many exoplanets have been discovered with radii of 1-4 R ⊕ , between that of Earth and Neptune. A number of these are known to have densities consistent with solid compositions, while others are 'sub-Neptunes' likely to have significant H 2 -He envelopes. Future surveys will no doubt significantly expand these populations. In order to understand how the measured masses and radii of such planets can inform their structures and compositions, we construct models both for solid layered planets and for planets with solid cores and gaseous envelopes, exploring a range of core masses, H 2 -He envelope masses, and associated envelope entropies. For planets in the super-Earth/sub-Neptune regime for which both radius and mass are measured, we estimate how each is partitioned into a solid core and gaseous envelope, associating a specific core mass and envelope mass with a given exoplanet. We perform this decomposition for both ''Earth-like'' rock-iron cores and pure ice cores, and find that the necessary gaseous envelope masses for this important sub-class of exoplanets must range very widely from zero to many Earth masses, even for a given core mass. This result bears importantly on exoplanet formation and envelope evaporation processes.

  18. Mass-radius relations and core-envelope decompositions of super-Earths and sub-Neptunes

    Energy Technology Data Exchange (ETDEWEB)

    Howe, Alex R.; Burrows, Adam [Department of Astrophysical Sciences, Princeton University, Peyton Hall, Princeton, NJ 08544 (United States); Verne, Wesley, E-mail: arhowe@astro.princeton.edu, E-mail: burrows@astro.princeton.edu [Department of Computer Science, Princeton University, Princeton, NJ 08544 (United States)

    2014-06-01

    Many exoplanets have been discovered with radii of 1-4 R {sub ⊕}, between that of Earth and Neptune. A number of these are known to have densities consistent with solid compositions, while others are 'sub-Neptunes' likely to have significant H{sub 2}-He envelopes. Future surveys will no doubt significantly expand these populations. In order to understand how the measured masses and radii of such planets can inform their structures and compositions, we construct models both for solid layered planets and for planets with solid cores and gaseous envelopes, exploring a range of core masses, H{sub 2}-He envelope masses, and associated envelope entropies. For planets in the super-Earth/sub-Neptune regime for which both radius and mass are measured, we estimate how each is partitioned into a solid core and gaseous envelope, associating a specific core mass and envelope mass with a given exoplanet. We perform this decomposition for both ''Earth-like'' rock-iron cores and pure ice cores, and find that the necessary gaseous envelope masses for this important sub-class of exoplanets must range very widely from zero to many Earth masses, even for a given core mass. This result bears importantly on exoplanet formation and envelope evaporation processes.

  19. A new multi-scale platform for advanced nuclear thermal-hydraulics status and prospects of the Neptune project

    International Nuclear Information System (INIS)

    Bestion, D.; Boudier, P.; Hervieu, E.; Boucker, M.; Peturaud, P.; Guelfi, A.; Fillion, P.; Grandotto, M.; Herard, J.M.

    2005-01-01

    Full text of publication follows: Further to a thorough analysis of the industrial needs and of the limitations of current simulation tools, EDF (Electricite de France) and CEA (Commissariat a l'Energie Atomique) launched in 2001 a new long-term joint development program for the next generation of nuclear reactors simulation tools. The NEPTUNE Project, which constitutes the Thermal-Hydraulics part of this comprehensive program, aims at building a new software platform for advanced two-phase flow thermal-hydraulics allowing easy multi-scale and multi-disciplinary calculations meeting the industrial needs. The NEPTUNE activities include software development, research in physical modeling and numerical methods, the development of advanced instrumentation techniques and performance of new experimental programs. The work focuses on the four different simulation scales: DNS (Direct Numerical Simulation), local CFD (Computational Fluid Dynamics), component (subchannel-type analysis) and system scales. New physical models and numerical methods are being developed for each scale as well as for their coupling. This paper gives an overview of the NEPTUNE activities. It presents the main scientific and technical achievements obtained during Phase 1 (2002-2003) and at the beginning of Phase 2 (2004- 2006). Planned work for the future is also presented. (authors)

  20. Haze production in the atmospheres of super-Earths and mini-Neptunes: Insight from PHAZER lab

    Science.gov (United States)

    Horst, Sarah; He, Chao; Kempton, Eliza; Moses, Julianne I.; Vuitton, Veronique; Lewis, Nikole

    2017-10-01

    Super-Earths and mini-Neptunes (~1.2-3 Earth radii) comprise a large fraction of planets in the universe and TESS (Transiting Exoplanet Survey Satellite) will increase the number that are amenable to atmospheric characterization with observatories like JWST (James Webb Space Telescope). These atmospheres should span a large range of temperature and atmospheric composition phase space, with no solar system analogues. Interpretation of current and future atmospheric observations of super-Earths and mini-Neptunes requires additional knowledge about atmospheric chemistry and photochemical haze production. We have experimentally investigated haze formation for H2, H2O, and CO2 dominated atmospheres (100x, 1000x, and 10000x solar metallicity) for a range of temperatures (300 K, 400 K, and 600 K) using the PHAZER (Planetary Haze Research) experiment at Johns Hopkins University. This is a necessary step in understanding which, if any, super-Earths and mini-Neptunes possess the conditions required for efficient production of photochemical haze in their atmospheres. We find that the production rates vary over a few orders of magnitudes with some higher than our nominal Titan experiments. We therefore expect that planets in this temperature and atmospheric composition phase space will exhibit a range of particle concentrations and some may be as hazy as Titan.

  1. HUBBLE CLICKS IMAGES OF IO SWEEPING ACROSS JUPITER

    Science.gov (United States)

    2002-01-01

    While hunting for volcanic plumes on Io, NASA's Hubble Space Telescope captured these images of the volatile moon sweeping across the giant face of Jupiter. Only a few weeks before these dramatic images were taken, the orbiting telescope snapped a portrait of one of Io's volcanoes spewing sulfur dioxide 'snow.' These stunning images of the planetary duo are being released to commemorate the ninth anniversary of the Hubble telescope's launch on April 24, 1990. All of these images were taken with the Wide Field and Planetary Camera 2. The three overlapping snapshots show in crisp detail Io passing above Jupiter's turbulent clouds. The close-up picture of Io (bottom right) reveal a 120-mile-high (200-kilometer) plume of sulfur dioxide 'snow' emanating from Pillan, one of the moon's active volcanoes. 'Other observations have inferred sulfur dioxide 'snow' in Io's plumes, but this image offers direct observational evidence for sulfur dioxide 'snow' in an Io plume,' explains John R. Spencer of Lowell Observatory in Flagstaff, Ariz. A Trip Around Jupiter The three snapshots of the volcanic moon rounding Jupiter were taken over a 1.8-hour time span. Io is roughly the size of Earth's moon but 2,000 times farther away. In two of the images, Io appears to be skimming Jupiter's cloud tops, but it's actually 310,000 miles (500,000 kilometers) away. Io zips around Jupiter in 1.8 days, whereas the moon circles Earth every 28 days. The conspicuous black spot on Jupiter is Io's shadow and is about the size of the moon itself (2,262 miles or 3,640 kilometers across). This shadow sails across the face of Jupiter at 38,000 mph (17 kilometers per second). The smallest details visible on Io and Jupiter measure 93 miles (150 kilometers) across, or about the size of Connecticut. These images were further sharpened through image reconstruction techniques. The view is so crisp that one would have to stand on Io to see this much detail on Jupiter with the naked eye. The bright patches on Io

  2. Electromagnetically Interacting Dust Streams During Ulysses' Second Jupiter Encounter

    International Nuclear Information System (INIS)

    Krueger, H.; Forsyth, R.J.; Graps, A.L.; Gruen, E.

    2005-01-01

    The Jupiter system is a source of collimated burst-like streams of electrically charged 10-nm dust particles. In 2004 the Ulysses spacecraft had its second flyby at Jupiter and from late 2002 to early 2005 it measured a total of 24 dust streams between 0.8 and 3.4 AU from the planet. The grains show strong coupling to the interplanetary magnetic field: their impact directions correlate with the orientation and strength of the interplanetary magnetic field vector (namely its tangential and radial components) and they occur at 26 day intervals, closely matching the solar rotation period. Ulysses measured the dust streams over a large range in jovian latitude (+75 deg. to -35 deg.). Enhanced dust emission was measured along the jovian equator

  3. A reassessment of Galileo radiation exposures in the Jupiter magnetosphere.

    Science.gov (United States)

    Atwell, William; Townsend, Lawrence; Miller, Thomas; Campbell, Christina

    2005-01-01

    Earlier particle experiments in the 1970s on Pioneer-10 and -11 and Voyager-1 and -2 provided Jupiter flyby particle data, which were used by Divine and Garrett to develop the first Jupiter trapped radiation environment model. This model was used to establish a baseline radiation effects design limit for the Galileo onboard electronics. Recently, Garrett et al. have developed an updated Galileo Interim Radiation Environment (GIRE) model based on Galileo electron data. In this paper, we have used the GIRE model to reassess the computed radiation exposures and dose effects for Galileo. The 34-orbit 'as flown' Galileo trajectory data and the updated GIRE model were used to compute the electron and proton spectra for each of the 34 orbits. The total ionisation doses of electrons and protons have been computed based on a parametric shielding configuration, and these results are compared with previously published results.

  4. Ongoing Analysis of Jupiter's Equatorial Hotspots and Plumes from Cassini

    Science.gov (United States)

    Choi, D. S.; Showmwn, A. P.; Vasavada, A. R.; Simon-Miller, A. A.

    2012-01-01

    We present updated results from our ongoing analysis of Cassini observations of Jupiter's equatorial meteorology. For two months preceding the spacecraft's closest approach of the planet, the ISS instrument onboard Cassini regularly imaged the atmosphere of Jupiter. We created time-lapse movies from this period that show the complex activity and interactions of the equatorial atmosphere. During this period, hot spots exhibited significant variations in size and shape over timescales of days and weeks. Some of these changes appear to be a result of interactions with passing vortex systems in adjacent latitudes. Strong anticyclonic gyres to the southeast of the dark areas converge with flow from the west and appear to circulate into a hot spot at its southwestern corner.

  5. Telecommunications Antennas for the Juno Mission to Jupiter

    Science.gov (United States)

    Vacchione, Joseph D.; Kruid, Ronald C.; Prata, Aluizio, Jr.; Amaro, Luis R.; Mittskus, Anthony P.

    2012-01-01

    The Juno Mission to Jupiter requires a full sphere of coverage throughout its cruise to and mission at Jupiter. This coverage is accommodated through the use of five (5) antennas; forward facing low gain, medium gain, and high gain antennas, and an aft facing low gain antenna along with an aft mounted low gain antenna with a torus shaped antenna pattern. Three of the antennas (the forward low and medium gain antennas) are classical designs that have been employed on several prior NASA missions. Two of the antennas employ new technology developed to meet the Juno mission requirements. The new technology developed for the low gain with torus shaped radiation pattern represents a significant evolution of the bicone antenna. The high gain antenna employs a specialized surface shaping designed to broaden the antenna's main beam at Ka-band to ease the requirements on the spacecraft's attitude control system.

  6. Inferring Temperature Inversions in Hot Jupiters Via Spitzer Emission Spectroscopy

    Science.gov (United States)

    Garhart, Emily; Deming, Drake; Mandell, Avi

    2016-10-01

    We present a systematic study of 35 hot Jupiter secondary eclipses, including 16 hot Jupiters never before characterized via emission, observed at the 3.6 μm and 4.5 μm bandpasses of Warm Spitzer in order to classify their atmospheric structure, namely, the existence of temperature inversions. This is a robust study in that these planets orbit stars with a wide range of compositions, temperatures, and activity levels. This diverse sample allows us to investigate the source of planetary temperature inversions, specifically, its correlation with stellar irradiance and magnetic activity. We correct for systematic and intra-pixel sensitivity effects with a pixel level decorrelation (PLD) method described in Deming et al. (2015). The relationship between eclipse depths and a best-fit blackbody function versus stellar activity, a method described in Knutson et al. (2010), will ultimately enable us to appraise the current hypotheses of temperature inversions.

  7. HOT STARS WITH HOT JUPITERS HAVE HIGH OBLIQUITIES

    International Nuclear Information System (INIS)

    Winn, Joshua N.; Albrecht, Simon; Fabrycky, Daniel; Johnson, John Asher

    2010-01-01

    We show that stars with transiting planets for which the stellar obliquity is large are preferentially hot (T eff > 6250 K). This could explain why small obliquities were observed in the earliest measurements, which focused on relatively cool stars drawn from Doppler surveys, as opposed to hotter stars that emerged more recently from transit surveys. The observed trend could be due to differences in planet formation and migration around stars of varying mass. Alternatively, we speculate that hot-Jupiter systems begin with a wide range of obliquities, but the photospheres of cool stars realign with the orbits due to tidal dissipation in their convective zones, while hot stars cannot realign because of their thinner convective zones. This in turn would suggest that hot Jupiters originate from few-body gravitational dynamics and that disk migration plays at most a supporting role.

  8. Neutron irradiation experiments for fusion reactor materials through JUPITER program

    International Nuclear Information System (INIS)

    Abe, K.; Namba, C.; Wiffen, F.W.; Jones, R.H.

    1998-01-01

    A Japan-USA program of irradiation experiments for fusion research, ''JUPITER'', has been established as a 6 year program from 1995 to 2000. The goal is to study ''the dynamic behavior of fusion reactor materials and their response to variable and complex irradiation environment''. This is phase-three of the collaborative program, which follows RTNS-II program (phase-1: 1982-1986) and FFTF/MOTA program (phase-2: 1987-1994). This program is to provide a scientific basis for application of materials performance data, generated by fission reactor experiments, to anticipated fusion environments. Following the systematic study on cumulative irradiation effects, done through FFTF/MOTA program. JUPITER is emphasizing the importance of dynamic irradiation effects on materials performance in fusion systems. The irradiation experiments in this program include low activation structural materials, functional ceramics and other innovative materials. The experimental data are analyzed by theoretical modeling and computer simulation to integrate the above effects. (orig.)

  9. A reassessment of Galileo radiation exposures in the Jupiter magnetosphere

    International Nuclear Information System (INIS)

    Atwell, W.; Townsend, L.; Miller, T.; Campbell, C.

    2005-01-01

    Earlier particle experiments in the 1970's on Pioneer-10 and -11 and Voyager-1 and -2 provided Jupiter flyby particle data, which were used by Divine and Garrett to develop the first Jupiter trapped radiation environment model. This model was used to establish a baseline radiation effects design limit for the Galileo onboard electronics. Recently, Garrett et al. have developed an updated Galileo Interim Radiation Environment (GIRE) model based on Galileo electron data. In this paper, we have used the GIRE model to reassess the computed radiation exposures and dose effects for Galileo. The 34-orbit 'as flown' Galileo trajectory data and the updated GIRE model were used to compute the electron and proton spectra for each of the 34 orbits. The total ionisation doses of electrons and protons have been computed based on a parametric shielding configuration, and these results are compared with previously published results. Published by Oxford Univ. Press. All right reserved. (authors)

  10. A HOT URANUS ORBITING THE SUPER METAL-RICH STAR HD 77338 AND THE METALLICITY-MASS CONNECTION

    International Nuclear Information System (INIS)

    Jenkins, J. S.; Hoyer, S.; Jones, M. I.; Rojo, P.; Day-Jones, A. C.; Ruiz, M. T.; Jones, H. R. A.; Tuomi, M.; Barnes, J. R.; Pavlenko, Y. V.; Pinfield, D. J.; Murgas, F.; Ivanyuk, O.; Jordán, A.

    2013-01-01

    We announce the discovery of a low-mass planet orbiting the super metal-rich K0V star HD 77338 as part of our ongoing Calan-Hertfordshire Extrasolar Planet Search. The best-fit planet solution has an orbital period of 5.7361 ± 0.0015 days and with a radial velocity semi-amplitude of only 5.96 ± 1.74 ms –1 , we find a minimum mass of 15.9 +4.7 -5.3 M ⊕ . The best-fit eccentricity from this solution is 0.09 +0.25 -0.09 , and we find agreement for this data set using a Bayesian analysis and a periodogram analysis. We measure a metallicity for the star of +0.35 ± 0.06 dex, whereas another recent work finds +0.47 ± 0.05 dex. Thus HD 77338b is one of the most metal-rich planet-host stars known and the most metal-rich star hosting a sub-Neptune-mass planet. We searched for a transit signature of HD 77338b but none was detected. We also highlight an emerging trend where metallicity and mass seem to correlate at very low masses, a discovery that would be in agreement with the core accretion model of planet formation. The trend appears to show that for Neptune-mass planets and below, higher masses are preferred when the host star is more metal-rich. Also a lower boundary is apparent in the super metal-rich regime where there are no very low mass planets yet discovered in comparison to the sub-solar metallicity regime. A Monte Carlo analysis shows that this low-mass planet desert is statistically significant with the current sample of 36 planets at the ∼4.5σ level. In addition, results from Kepler strengthen the claim for this paucity of the lowest-mass planets in super metal-rich systems. Finally, this discovery adds to the growing population of low-mass planets around low-mass and metal-rich stars and shows that very low mass planets can now be discovered with a relatively small number of data points using stable instrumentation.

  11. MOA-2010-BLG-328Lb: A sub-Neptune orbiting very late M dwarf?

    International Nuclear Information System (INIS)

    Furusawa, K.; Abe, F.; Itow, Y.; Masuda, K.; Matsubara, Y.; Udalski, A.; Sumi, T.; Bennett, D. P.; Bond, I. A.; Ling, C. H.; Gould, A.; Jørgensen, U. G.; Snodgrass, C.; Prester, D. Dominis; Albrow, M. D.; Botzler, C. S.; Freeman, M.; Chote, P.; Harris, P.; Fukui, A.

    2013-01-01

    We analyze the planetary microlensing event MOA-2010-BLG-328. The best fit yields host and planetary masses of M h = 0.11 ± 0.01 M ☉ and M p = 9.2 ± 2.2 M ⊕ , corresponding to a very late M dwarf and sub-Neptune-mass planet, respectively. The system lies at D L = 0.81 ± 0.10 kpc with projected separation r = 0.92 ± 0.16 AU. Because of the host's a priori unlikely close distance, as well as the unusual nature of the system, we consider the possibility that the microlens parallax signal, which determines the host mass and distance, is actually due to xallarap (source orbital motion) that is being misinterpreted as parallax. We show a result that favors the parallax solution, even given its close host distance. We show that future high-resolution astrometric measurements could decisively resolve the remaining ambiguity of these solutions

  12. MOA-2010-BLG-328Lb: A sub-Neptune orbiting very late M dwarf?

    Energy Technology Data Exchange (ETDEWEB)

    Furusawa, K.; Abe, F.; Itow, Y.; Masuda, K.; Matsubara, Y. [Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya 464-8601 (Japan); Udalski, A. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Sumi, T. [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043 (Japan); Bennett, D. P. [Department of Physics, 225 Nieuwland Science Hall, University of Notre Dame, Notre Dame, IN 46556 (United States); Bond, I. A.; Ling, C. H. [Institute for Information and Mathematical Sciences, Massey University, Private Bag 102-904, Auckland 1330 (New Zealand); Gould, A. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Jørgensen, U. G. [Niels Bohr Institutet, Københavns Universitet, Juliane Maries Vej 30, 2100 Copenhagen (Denmark); Snodgrass, C. [Max Planck Institute for Solar System Research, Max-Planck-Str. 2, D-37191 Katlenburg-Lindau (Germany); Prester, D. Dominis [Department of Physics, University of Rijeka, Omladinska 14, 51000 Rijeka (Croatia); Albrow, M. D. [Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch 8020 (New Zealand); Botzler, C. S.; Freeman, M. [Department of Physics, University of Auckland, Private Bag 92-019, Auckland 1001 (New Zealand); Chote, P.; Harris, P. [School of Chemical and Physical Sciences, Victoria University, Wellington (New Zealand); Fukui, A., E-mail: furusawa@stelab.nagoya-u.ac.jp, E-mail: liweih@astro.ucla.edu, E-mail: tim.natusch@aut.ac.nz, E-mail: rzellem@lpl.arizona.edu [Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, 3037-5 Honjo, Kamogata, Asakuchi, Okayama 719-0232 (Japan); Collaboration: MOA Collaboration; OGLE Collaboration; μFUN Collaboration; MiNDSTEp Consortium; RoboNet Collaboration; PLANET Collaboration; and others

    2013-12-20

    We analyze the planetary microlensing event MOA-2010-BLG-328. The best fit yields host and planetary masses of M {sub h} = 0.11 ± 0.01 M {sub ☉} and M {sub p} = 9.2 ± 2.2 M {sub ⊕}, corresponding to a very late M dwarf and sub-Neptune-mass planet, respectively. The system lies at D {sub L} = 0.81 ± 0.10 kpc with projected separation r = 0.92 ± 0.16 AU. Because of the host's a priori unlikely close distance, as well as the unusual nature of the system, we consider the possibility that the microlens parallax signal, which determines the host mass and distance, is actually due to xallarap (source orbital motion) that is being misinterpreted as parallax. We show a result that favors the parallax solution, even given its close host distance. We show that future high-resolution astrometric measurements could decisively resolve the remaining ambiguity of these solutions.

  13. Quality assurance program for prototype stereotactic system developed for neptun 10 Pc linac

    International Nuclear Information System (INIS)

    Khoshbin Khoshnazar, A.R.; Bahreyni Toossi, M.T.; Hashemiyan, A.R.; Bahreyni Toossi, M.T.; Salek, R.

    2005-01-01

    A prototype stereotactic radiosurgery set was designed and constructed for a Neptun 10 Pc linac that is currently being used at Imam Reza hospital in Mashad. Materials and Methods: A complete quality assurance program was designed and performed for the constructed system including isocentric accuracy test, localization accuracy test, dose delivery accuracy test and leakage radiation test. Target simulator, control alignment device and plexiglass phantom which were parts of the developed hardware were used to fulfill quality assurance program. Results: The average isocentric shift resulted from the gantry rotation and couch turning were respectively obtained to be 1.4 and 2 mm. The average localization error in the three coordinates was found to be 2.2 mm. The total treatment uncertainty due to all of the probable errors in the system was equal to 4.32 mm. The dose delivery accuracy test was carried out, the result indicated a 3.7% difference between the given and measured dose. Conclusion: The quality assurance tests showed consistent performance of the constructed system within the accepted limits; however, some inconsistency might exist in certain cases. The safety of stereotactic radiosurgery system method is increased when the overall uncertainty is minimized nd the treatment of the lesions adjacent to critical organs is avoided

  14. RAYLEIGH SCATTERING IN THE ATMOSPHERE OF THE WARM EXO-NEPTUNE GJ 3470B

    Energy Technology Data Exchange (ETDEWEB)

    Dragomir, Diana [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive Suite 102, Goleta, CA 93117 (United States); Benneke, Björn [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Pearson, Kyle A. [Department of Physics and Astronomy, Northern Arizona University, Flagstaff, AZ 86001 (United States); Crossfield, Ian J. M.; Barman, Travis [Department of Planetary Sciences, Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States); Eastman, Jason [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Biddle, Lauren I., E-mail: diana@oddjob.uchicago.edu [Gemini Observatory, Northern Operations Center, 670 N. Aohoku Place, Hilo, HI 96720 (United States)

    2015-12-01

    GJ 3470b is a warm Neptune-size planet transiting an M dwarf star. Like the handful of other small exoplanets for which transmission spectroscopy has been obtained, GJ 3470b exhibits a flat spectrum in the near- and mid-infrared. Recently, a tentative detection of Rayleigh scattering in its atmosphere has been reported. This signal manifests itself as an observed increase of the planetary radius as a function of decreasing wavelength in the visible. We set out to verify this detection and observed several transits of this planet with the LCOGT network and the Kuiper telescope in four different bands (Sloan g, Sloan i, Harris B, and Harris V). Our analysis reveals a strong Rayleigh scattering slope, thus confirming previous results. This makes GJ 3470b the smallest known exoplanet with a detection of Rayleigh scattering. We find that the most plausible scenario is a hydrogen/helium-dominated atmosphere covered by clouds which obscure absorption features in the infrared and hazes which give rise to scattering in the visible. Our results demonstrate the feasibility of exoplanet atmospheric characterization from the ground, even with meter-class telescopes.

  15. RAYLEIGH SCATTERING IN THE ATMOSPHERE OF THE WARM EXO-NEPTUNE GJ 3470B

    International Nuclear Information System (INIS)

    Dragomir, Diana; Benneke, Björn; Pearson, Kyle A.; Crossfield, Ian J. M.; Barman, Travis; Eastman, Jason; Biddle, Lauren I.

    2015-01-01

    GJ 3470b is a warm Neptune-size planet transiting an M dwarf star. Like the handful of other small exoplanets for which transmission spectroscopy has been obtained, GJ 3470b exhibits a flat spectrum in the near- and mid-infrared. Recently, a tentative detection of Rayleigh scattering in its atmosphere has been reported. This signal manifests itself as an observed increase of the planetary radius as a function of decreasing wavelength in the visible. We set out to verify this detection and observed several transits of this planet with the LCOGT network and the Kuiper telescope in four different bands (Sloan g, Sloan i, Harris B, and Harris V). Our analysis reveals a strong Rayleigh scattering slope, thus confirming previous results. This makes GJ 3470b the smallest known exoplanet with a detection of Rayleigh scattering. We find that the most plausible scenario is a hydrogen/helium-dominated atmosphere covered by clouds which obscure absorption features in the infrared and hazes which give rise to scattering in the visible. Our results demonstrate the feasibility of exoplanet atmospheric characterization from the ground, even with meter-class telescopes

  16. Photochemical Haze Formation in the Atmospheres of Super-Earths and Mini-Neptunes

    Science.gov (United States)

    He, Chao; Hoerst, Sarah M.; Lewis, Nikole K.; Yu, Xinting; Moses, Julianne I.; Kempton, Eliza M.- R.; Marley, Mark S.; McGuiggan, Patricia; Morley, Caroline V.; Valenti, Jeff A.; hide

    2018-01-01

    UV (ultraviolet) radiation can induce photochemical processes in the atmospheres of exoplanet and produce haze particles. Recent transmission spectra of super-Earths and mini-Neptunes have demonstrated the possibility that exoplanets have haze/cloud layers at high altitudes in their atmospheres. Haze particles play an important role in planetary atmospheres because they affect the chemistry, dynamics, and radiation flux in planetary atmospheres, and may provide a source of organic material to the surface which may impact the origin or evolution of life. However, very little information is known about photochemical processes in cool, high-metallicity exoplanetary atmospheres. We present here photochemical haze formation in laboratory simulation experiments with UV radiation; we explored temperatures ranging from 300 to 600 degrees Kelvin and a range of atmospheric metallicities (100 times, 1000 times, and 10000 times solar metallicity). We find that photochemical hazes are generated in all simulated atmospheres, but the haze production rates appear to be temperature dependent: the particles produced in each metallicity group decrease as the temperature increases. The images taken with an atomic force microscope (AFM) show that the particle size (15 nanometers to 190 nanometers) varies with temperature and metallicity. Our results provide useful laboratory data on the photochemical haze formation and particle properties, which can serve as critical inputs for exoplanet atmosphere modeling, and guide future observations of exoplanets with the Transiting Exoplanet Survey Satellite (TESS), the James Webb Space Telescope (JWST), and the Wide-Field Infrared Survey Telescope (WFIRST).

  17. Variations of Synchrotron Radio Emissions from Jupiter's Inner Radiation Belt

    Science.gov (United States)

    Lou, Y.-Q.

    2017-09-01

    Variations of Synchrotron Radio Emissions from Jupiter's Inner Radiation Belt Yu-Qing Lou* Physics Department, Tsinghua Centre for Astrophysics (THCA), Tsinghua-National Astronomical Observatories of China (NAOC) joint Research Centre for Astrophysics, Tsinghua University, Beijing 100084, China We describe the basic phenommenology of quasi-periodic 40 minute (QP-40) polar burst activities of Jupiter and their close correlation with the solar wind speed variations at the Jovian magnetosphere. Physically, relativistic electrons of QP-40 bursts most likely come from the circumpolar regions of the inner radiation belt (IRB) which gives off intense synchroton radio emissions in a wide wavelength range. Such relativistic electron bursts also give rise to beamed low-frequency radio bursts along polar magnetic field lines with distinct polarizations from Jupiter's two polar regions. Jovian aurora activities are expected to be also affected by such QP-40 burst activities. We present evidence of short-term (typical timescales shorter than an hour) variabilities of the IRB at 6cm wavelength and describe recent joint radio telescope observation campaign to monitor Jupiter in coordination with JUNO spacecraft. Except for low-frequency polarization features, we anticipate JUNO to detect QP-40 activities from both polar regions during the arrival of high-speed solar wind with intermittency. References 1. Y.-Q. Lou, The Astrophysical Journal, 548, 460 (2001). 2. Y.-Q. Lou, and C. Zheng, Mon. Not. Roy. Astron. Soc. Letters, 344, L1 (2003). 3. Y.-Q. Lou, H. G. Song, Y.Y. Liu, and M. Yang, Mon. Not. Roy. Astron. Soc. Letters, 421, L62 (2012). 4. Y.-Q. Lou, Geophysical Research Letters, 23, 609 (1996). 5. Y.-Q. Lou, Journal of Geophysical Research, 99, 14747 (1994). 6. G. R. Gladstone, et al., Nature, 415, 1000 (2002).

  18. Carbon monoxide in jupiter's upper atmosphere: An extraplanetary source

    International Nuclear Information System (INIS)

    Prather, M.J.; Logan, J.A.; McElroy, M.B.

    1978-01-01

    Ablation of meteoroidal material in Jupiter's atmosphere may provide substantial quantities of H 2 O. Subsequent photochemistry can convert H 2 O and CH 4 to CO and H 2 . The associated source of CO could account for the observations by Beer, Larson, Fink, and Treffers, and Beer and Taylor, and would explain the relatively low rotational temperatures inferred by Beer and Taylor. Meteoritic debris might also provide spectroscopically detectable concentrations of SiO

  19. RE-INFLATED WARM JUPITERS AROUND RED GIANTS

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Eric D. [Institute for Astronomy, Royal Observatory Edinburgh, University of Edinburgh, Blackford Hill, Edinburgh (United Kingdom); Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)

    2016-02-10

    Since the discovery of the first transiting hot Jupiters, models have sought to explain the anomalously large radii of highly irradiated gas giants. We now know that the size of hot Jupiter radius anomalies scales strongly with a planet's level of irradiation and numerous models like tidal heating, ohmic dissipation, and thermal tides have since been developed to help explain these inflated radii. In general, however, these models can be grouped into two broad categories: models that directly inflate planetary radii by depositing a fraction of the incident irradiation into the interior and models that simply slow a planet's radiative cooling, allowing it to retain more heat from formation and thereby delay contraction. Here we present a new test to distinguish between these two classes of models. Gas giants orbiting at moderate orbital periods around post-main-sequence stars will experience enormous increases to their irradiation as their host stars move up the sub-giant and red-giant branches. If hot Jupiter inflation works by depositing irradiation into the planet's deep interiors then planetary radii should increase in response to the increased irradiation. This means that otherwise non-inflated gas giants at moderate orbital periods of >10 days can re-inflate as their host stars evolve. Here we explore the circumstances that can lead to the creation of these “re-inflated” gas giants and examine how the existence or absence of such planets can be used to place unique constraints on the physics of the hot Jupiter inflation mechanism. Finally, we explore the prospects for detecting this potentially important undiscovered population of planets.

  20. Planetary perturbations and the origins of short-period comets

    International Nuclear Information System (INIS)

    Quinn, T.; Tremaine, S.; Duncan, M.

    1990-01-01

    To investigate the dynamical plausibility of possible sources for the short-period comets, a representative sample of comet orbits in the field of the sun and the giant planets was integrated, with the aim to determine whether the distribution of orbits from a proposed source that reach observable perihelia (q less than 2.5 AU) matches the observed distribution of short-period orbits. It is found that the majority of the short-period comets, those with orbital period P less than 20 yr (the Jupiter family), cannot arise from isotropic orbits with perihelia near Jupiter's orbit, because the resulting observable comet orbits have the wrong distribution in period, inclination, and argument of perihelion. The simulations also show that Jupiter-family comets cannot arise from isotropic orbits with perihelia in the Uranus-Neptune region. On the other hand, a source of low-inclination Neptune-crossing orbits yields a distribution of observable Jupiter-family comets that is consistent with the data in all respects. These results imply that the Jupiter-family comets arise from a disk source in the outer solar system rather than from the Oort comet cloud. 30 refs

  1. Coloring Jupiter's clouds: Radiolysis of ammonium hydrosulfide (NH4SH)

    Science.gov (United States)

    Loeffler, Mark J.; Hudson, Reggie L.

    2018-03-01

    Here we present our recent studies on the color and spectral reflectance changes induced by ∼0.9 MeV proton irradiation of ammonium hydrosulfide, NH4SH, a compound predicted to be an important tropospheric cloud component of Jupiter and other giant planets. Ultraviolet-visible spectroscopy was used to observe and identify reaction products in the ice sample and digital photography was used to document the corresponding color changes at 10-160 K. Our experiments clearly show that the resulting color of the sample depends not only on the irradiation dose but also the irradiation temperature. Furthermore, unlike in our most recent studies of irradiation of NH4SH at 120 K, which showed that higher irradiation doses caused the sample to appear green, the lower temperature studies now show that the sample becomes red after irradiation. However, comparison of these lower temperature spectra over the entire spectral range observed by HST shows that even though the color and spectrum resemble the color and spectrum of the GRS, there is still enough difference to suggest that another component may be needed to adequately fit spectra of the GRS and other red regions of Jupiter's clouds. Regardless, the presence of NH4SH in the atmosphere of Jupiter and other gas giants, combined with this compound's clear alteration via radiolysis, suggests that its contribution to the ultraviolet-visible spectra of any of these object's clouds is significant.

  2. Jupiter's Magnetic Field and Magnetosphere after Juno's First 8 Orbits

    Science.gov (United States)

    Connerney, J. E. P.; Oliversen, R. J.; Espley, J. R.; Gruesbeck, J.; Kotsiaros, S.; DiBraccio, G. A.; Joergensen, J. L.; Joergensen, P. S.; Merayo, J. M. G.; Denver, T.; Benn, M.; Bjarno, J. B.; Malinnikova Bang, A.; Bloxham, J.; Moore, K.; Bolton, S. J.; Levin, S.; Gershman, D. J.

    2017-12-01

    The Juno spacecraft entered polar orbit about Jupiter on July 4, 2016, embarking upon an ambitious mission to map Jupiter's magnetic and gravitational potential fields and probe its deep atmosphere, in search of clues to the planet's formation and evolution. Juno is also instrumented to conduct the first exploration of the polar magnetosphere and to acquire images and spectra of its polar auroras and atmosphere. Juno's 53.5-day orbit trajectory carries her science instruments from pole to pole in approximately 2 hours, with a closest approach to within 1.05 Rj of the center of the planet (one Rj = 71,492 km, Jupiter's equatorial radius), just a few thousand km above the clouds. Repeated periapsis passes will eventually encircle the planet with a dense net of observations equally spaced in longitude (magnetometer sensor suites, located 10 and 12 m from the center of the spacecraft at the end of one of Juno's three solar panel wings. Each contains a vector fluxgate magnetometer (FGM) sensor and a pair of co-located non-magnetic star tracker camera heads, providing accurate attitude determination for the FGM sensors. We present an overview of the magnetometer observations obtained during Juno's first year in orbit in context with prior observations and those acquired by Juno's other science instruments.

  3. Radio Emission from Red-Giant Hot Jupiters

    Science.gov (United States)

    Fujii, Yuka; Spiegel, David S.; Mroczkowski, Tony; Nordhaus, Jason; Zimmerman, Neil T.; Parsons, Aaron R.; Mirbabayi, Mehrdad; Madhusudhan, Nikku

    2016-01-01

    When planet-hosting stars evolve off the main sequence and go through the red-giant branch, the stars become orders of magnitudes more luminous and, at the same time, lose mass at much higher rates than their main sequence counterparts. Accordingly, if planetary companions exist around these stars at orbital distances of a few au, they will be heated up to the level of canonical hot Jupiters and also be subjected to a dense stellar wind. Given that magnetized planets interacting with stellar winds emit radio waves, such "Red-Giant Hot Jupiters" (RGHJs) may also be candidate radio emitters. We estimate the spectral auroral radio intensity of RGHJs based on the empirical relation with the stellar wind as well as a proposed scaling for planetary magnetic fields. RGHJs might be intrinsically as bright as or brighter than canonical hot Jupiters and about 100 times brighter than equivalent objects around main-sequence stars. We examine the capabilities of low-frequency radio observatories to detect this emission and find that the signal from an RGHJ may be detectable at distances up to a few hundred parsecs with the Square Kilometer Array.

  4. Polycyclic aromatic hydrocarbons in the atmospheres of Titan and Jupiter

    Science.gov (United States)

    Sagan, Carl; Khare, B. N.; Thompson, W. R.; Mcdonald, G. D.; Wing, Michael R.; Bada, Jeffrey L.; Vo-Dinh, Tuan; Arakawa, E. T.

    1993-01-01

    PAHs are important components of the interstellar medium and carbonaceous chondrites, but have never been identified in the reducing atmospheres of the outer solar system. Incompletely characterized complex organic solids (tholins) produced by irradiating simulated Titan atmospheres reproduce well the observed UV/visible/IR optical constants of the Titan stratospheric haze. Titan tholin and a tholin generated in a crude simulation of the atmosphere of Jupiter are examined by two-step laser desorption/multiphoton ionization mass spectrometry. A range of two- to four-ring PAHs, some with one to four alkylation sites, are identified, with a net abundance of about 0.0001 g/g (grams per gram) of tholins produced. Synchronous fluorescence techniques confirm this detection. Titan tholins have proportionately more one- and two-ring PAHs than do Jupiter tholins, which in turn have more four-ring and larger PAHs. The four-ringed PAH chrysene, prominent in some discussions of interstellar grains, is found in Jupiter tholins.

  5. ATMOSPHERIC CIRCULATION OF HOT JUPITERS: INSENSITIVITY TO INITIAL CONDITIONS

    International Nuclear Information System (INIS)

    Liu Beibei; Showman, Adam P.

    2013-01-01

    The ongoing characterization of hot Jupiters has motivated a variety of circulation models of their atmospheres. Such models must be integrated starting from an assumed initial state, which is typically taken to be a wind-free, rest state. Here, we investigate the sensitivity of hot-Jupiter atmospheric circulation to initial conditions with shallow-water models and full three-dimensional models. Those models are initialized with zonal jets, and we explore a variety of different initial jet profiles. We demonstrate that, in both classes of models, the final, equilibrated state is independent of initial condition—as long as frictional drag near the bottom of the domain and/or interaction with a specified planetary interior are included so that the atmosphere can adjust angular momentum over time relative to the interior. When such mechanisms are included, otherwise identical models initialized with vastly different initial conditions all converge to the same statistical steady state. In some cases, the models exhibit modest time variability; this variability results in random fluctuations about the statistical steady state, but we emphasize that, even in these cases, the statistical steady state itself does not depend on initial conditions. Although the outcome of hot-Jupiter circulation models depend on details of the radiative forcing and frictional drag, aspects of which remain uncertain, we conclude that the specification of initial conditions is not a source of uncertainty, at least over the parameter range explored in most current models.

  6. Architectural and chemical insights into the origin of hot Jupiters

    Science.gov (United States)

    Schlaufman, Kevin C.

    2015-10-01

    The origin of Jupiter-mass planets with orbital periods of only a few days is still uncertain. This problem has been with us for 20 years, long enough for significant progress to have been made, and also for a great deal of ``lore" to have accumulated about the properties of these planets. Among this lore is the widespread belief that hot Jupiters are less likely to be in multiple giant planet systems than longer-period giant planets. I will show that in this case the lore is not supported by the best data available today: hot Jupiters are not lonely. I will also show that stellar sodium abundance is inversely proportional to the probability that a star hosts a short-period giant planet. This observation is best explained by the effect of decreasing sodium abundance on protoplanetary disk structure and reveals that planetesimal-disk or planet-disk interactions are critical for the existence of short-period giant planets.

  7. Physical conditions for Jupiter-like dynamo models

    Science.gov (United States)

    Duarte, Lúcia D. V.; Wicht, Johannes; Gastine, Thomas

    2018-01-01

    The Juno mission will measure Jupiter's magnetic field with unprecedented precision and provide a wealth of additional data that will allow us to constrain the planet's interior structure and dynamics. Here we analyse 66 different numerical simulations in order to explore the sensitivity of the dynamo-generated magnetic field to the planets interior properties. Jupiter field models based on pre-Juno data and up-to-date interior models based on ab initio simulations serve as benchmarks. Our results suggest that Jupiter-like magnetic fields can be found for a number of different models. These complement the steep density gradients in the outer part of the simulated shell with an electrical conductivity profile that mimics the low conductivity in the molecular hydrogen layer and thus renders the dynamo action in this region largely unimportant. We find that whether we assume an ideal gas or use the more realistic interior model based on ab initio simulations makes no difference. However, two other factors are important. A low Rayleigh number leads to a too strong axial dipole contribution while the axial dipole dominance is lost altogether when the convective driving is too strong. The required intermediate range that yields Jupiter-like magnetic fields depends on the other system properties. The second important factor is the convective magnetic Reynolds number radial profile Rmc(r), basically a product of the non-axisymmetric flow velocity and electrical conductivity. We find that the depth where Rmc exceeds about 50 is a good proxy for the top of the dynamo region. When the dynamo region sits too deep, the axial dipole is once more too dominant due to geometric reasons. Extrapolating our results to Jupiter and the result suggests that the Jovian dynamo extends to 95% of the planetary radius. The zonal flow system in our simulations is dominated by an equatorial jet which remains largely confined to the molecular layer. Where the jet reaches down to higher

  8. GO JUPITER PWS EDITED EDR 10KHZ WAVEFORM RECEIVER V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes wideband waveform measurements from the Galileo plasma wave receiver obtained during Jupiter orbital operations. These data were obtained...

  9. GO JUPITER PWS EDITED EDR 1KHZ WAVEFORM RECEIVER V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes wideband waveform measurements from the Galileo plasma wave receiver obtained during Jupiter orbital operations. These data were obtained...

  10. Kepler and Ground-Based Transits of the exo-Neptune HAT-P-11b

    Science.gov (United States)

    Deming, Drake; Sada, Pedro V.; Jackson, Brian; Peterson, Steven W.; Agol, Eric; Knutson, Heather A.; Jennings, Donald E.; Haase, Plynn; Bays, Kevin

    2011-01-01

    We analyze 26 archival Kepler transits of the exo-Neptune HAT-P-11b, supplemented by ground-based transits observed in the blue (B band) and near-IR (J band). Both the planet and host star are smaller than previously believed; our analysis yields Rp = 4.31 R xor 0.06 R xor and Rs = 0.683 R solar mass 0.009 R solar mass, both about 3 sigma smaller than the discovery values. Our ground-based transit data at wavelengths bracketing the Kepler bandpass serve to check the wavelength dependence of stellar limb darkening, and the J-band transit provides a precise and independent constraint on the transit duration. Both the limb darkening and transit duration from our ground-based data are consistent with the new Kepler values for the system parameters. Our smaller radius for the planet implies that its gaseous envelope can be less extensive than previously believed, being very similar to the H-He envelope of GJ 436b and Kepler-4b. HAT-P-11 is an active star, and signatures of star spot crossings are ubiquitous in the Kepler transit data. We develop and apply a methodology to correct the planetary radius for the presence of both crossed and uncrossed star spots. Star spot crossings are concentrated at phases 0.002 and +0.006. This is consistent with inferences from Rossiter-McLaughlin measurements that the planet transits nearly perpendicular to the stellar equator. We identify the dominant phases of star spot crossings with active latitudes on the star, and infer that the stellar rotational pole is inclined at about 12 deg 5 deg to the plane of the sky. We point out that precise transit measurements over long durations could in principle allow us to construct a stellar Butterfly diagram to probe the cyclic evolution of magnetic activity on this active K-dwarf star.

  11. A High Mass & Low Envelope Fraction for the Warm Neptune K2-55b

    Science.gov (United States)

    Dressing, Courtney; Sinukoff, Evan; Fulton, Benjamin; Lopez, Eric; Beichman, Charles; Howard, Andrew; Knutson, Heather; Werner, Michael; Schlieder, Joshua; Benneke, Björn; Crossfield, Ian; Isaacson, Howard; Krick, Jessica; Gorjian, Varoujan; Livingston, John; Petigura, Erik; Akeson, Rachel; Batygin, Konstantin; Christiansen, Jessie; Ciardi, David; Crepp, Justin; Jasmine Gonzales, Erica; Hardegree-Ullman, Kevin; Hirsch, Lea; Kosiarek, Molly; Weiss, Lauren

    2018-01-01

    The NASA K2 mission is using the Kepler spacecraft to search for transiting planets in multiple fields along the ecliptic plane. One of the planets detected by K2 is K2-55b, a warm Neptune in a short-period orbit (2.8 days) around a late K dwarf. We previously obtained near-infrared spectra from IRTF/SpeX to characterize the system and found that the host star K2-55 has a radius of 0.715 (+0.043/-0.040) solar radii, a mass of 0.668 (+/- 0.069) solar masses, and an effective temperature of 4300K (+100/-107). We then combined our updated stellar properties with new fits to the K2 photometry to estimate a planet radius of 4.38 (+0.29/-0.25) Earth radii, confirmed the transit ephemeris using Spitzer/IRAC (GO 11026, PI Werner), and embarked on radial velocity observations with Keck/HIRES to measure the planet mass. Our RV data suggest that K2-55b is much more massive than expected, indicating that the planet has a high density despite having a relatively high mass. The lack of a significant volatile envelope tests current theories of gas giant formation and indicates that K2-55b may have avoided runaway accretion by migration, delayed formation, or inefficient core accretion. We gratefully acknowledge funding from the NASA Sagan Fellowship Program and the NASA K2 Guest Observer Program. This work is based in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech.

  12. An HST/STIS Optical Transmission Spectrum of Warm Neptune GJ 436b

    Science.gov (United States)

    Lothringer, Joshua D.; Benneke, Björn; Crossfield, Ian J. M.; Henry, Gregory W.; Morley, Caroline; Dragomir, Diana; Barman, Travis; Knutson, Heather; Kempton, Eliza; Fortney, Jonathan; McCullough, Peter; Howard, Andrew W.

    2018-02-01

    GJ 436b is a prime target for understanding warm Neptune exoplanet atmospheres and a target for multiple James Webb Space Telescope (JWST) Guaranteed Time Observation programs. Here, we report the first space-based optical transmission spectrum of the planet using two Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) transit observations from 0.53 to 1.03 μm. We find no evidence for alkali absorption features, nor evidence of a scattering slope longward of 0.53 μm. The spectrum is indicative of moderate to high metallicity (∼100–1000× solar), while moderate-metallicity scenarios (∼100× solar) require aerosol opacity. The optical spectrum also rules out some highly scattering haze models. We find an increase in transit depth around 0.8 μm in the transmission spectra of three different sub-Jovian exoplanets (GJ 436b, HAT-P-26b, and GJ 1214b). While most of the data come from STIS, data from three other instruments may indicate this is not an instrumental effect. Only the transit spectrum of GJ 1214b is well fit by a model with stellar plages on the photosphere of the host star. Our photometric monitoring of the host star reveals a stellar rotation rate of 44.1 days and an activity cycle of 7.4 years. Intriguingly, GJ 436 does not become redder as it gets dimmer, which is expected if star spots were dominating the variability. These insights into the nature of the GJ 436 system help refine our expectations for future observations in the era of JWST, whose higher precision and broader wavelength coverage will shed light on the composition and structure of GJ 436b’s atmosphere.

  13. Summary report of NEPTUN investigations into the steady state thermal hydraulics of the passive decay heat removal

    International Nuclear Information System (INIS)

    Rust, K.; Weinberg, D.; Hoffmann, H.; Frey, H.H.; Baumann, W.; Hain, K.; Leiling, W.; Hayafune, H.; Ohira, H.

    1995-12-01

    During the course of steady state NEPTUN investigations, the effects of different design and operating parameters were studied; in particular: The shell design of the above core sturcture, the core power, the number of decay heat exchangers put in operation, the complete flow path blockage at the primary side of the intermediate heat exchangers, and the fluid level in the primary vessel. The findings of the NEPTUN experiments indicate that the decay heat can be safely removed by natural convection. The interwrapper flow makes an essential contribution to that behavior. The decay heat exchangers installed in the upper plenum cause a thermal stratification associated with a pronounced gradient. The vertical extent of the stratification and the quantity of the gradient are depending on the fact whether a permeable or an impermeable shell covers the above core structure. An increase of the core power or a reduction of the number of decay heat exchangers being in operation leads to a higher temperature level in the primary system but does not alter the global temperature distribution. In the case that no coolant enters the inlet windows at the primary side of the intermediate and decay heat exchangers, the core remains coolable as far as the primary vessel is filled with fluid up to a minimum level. Cold water penetrates from the upper plenum into the core and removes the decay heat. The thermal hydraulic computer code FLUTAN was applied for the three-dimensional numerical simulation of the majority of NEPTUN tests reported here. The comparison of computed against experimental data indicates a qualitatively and quantitatively satisfying agreement of the findings with respect to the field of isotherms as well as the temperature profiles in the upper plenum and within the core region of very complex geometry. (orig./HP) [de

  14. Modeling of Multisize Bubbly Flow and Application to the Simulation of Boiling Flows with the Neptune_CFD Code

    Directory of Open Access Journals (Sweden)

    Christophe Morel

    2009-01-01

    Full Text Available This paper describes the modeling of boiling multisize bubbly flows and its application to the simulation of the DEBORA experiment. We follow the method proposed originally by Kamp, assuming a given mathematical expression for the bubble diameter pdf. The original model is completed by the addition of some new terms for vapor compressibility and phase change. The liquid-to-interface heat transfer term, which essentially determines the bubbles condensation rate in the DEBORA experiment, is also modeled with care. First numerical results realized with the Neptune_CFD code are presented and discussed.

  15. Quasar Host Galaxies/Neptune Rotation/Galaxy Building Blocks/Hubble Deep Field/Saturn Storm

    Science.gov (United States)

    2001-01-01

    Computerized animations simulate a quasar erupting in the core of a normal spiral galaxy, the collision of two interacting galaxies, and the evolution of the universe. Hubble Space Telescope (HST) images show six quasars' host galaxies (including spirals, ellipticals, and colliding galaxies) and six clumps of galaxies approximately 11 billion light years away. A false color time lapse movie of Neptune displays the planet's 16-hour rotation, and the evolution of a storm on Saturn is seen though a video of the planet's rotation. A zoom sequence starts with a ground-based image of the constellation Ursa major and ends with the Hubble Deep Field through progressively narrower and deeper views.

  16. Between history, art and medicine: the Dresden-Friedrichstadt hospital, its Neptune fountain and connections to Vienna.

    Science.gov (United States)

    Wollina, Uwe; Hunger, Sabine; Koch, André; França, Katlein; Lotti, Torello; Fioranelli, Massimo; Roccia, Maria Grazia

    2017-10-01

    The Dresden-Friedrichstadt hospital originated from Marcolini's summer palace. It was founded in 1845 and opened in 1849. It is a place where history and art of European importance mixes with technical and medical innovations. We reflect on the meetings of Napoleon Bonaparte and Metternich in 1812, the creation of the famous Neptune fountain by Longuelune and Matielli and two outstanding physicians of the 19 th  century, the surgeon Eduard Zeis, who coined the medical term "plastic surgery", and Maximilian Nitze, inventor of the first "modern" cystoscope and the father of urology.

  17. Jupiter Trojan's Shallow Subsurface: Direct Observation By Radar Sounding

    Science.gov (United States)

    Herique, A.; Plettemeier, D.; Beck, P.; Michel, P.; Kumamoto, A.; Kofman, W. W.

    2017-12-01

    Most of the Jupiter's Trojan are classified as spectral type P or D from visible and near-IR observations. Still, major question remain regarding theire origin and geological evolution: What ices are present in their interior, and in what amount? What is the abundance and the nature of the organic fraction? Did they experience some level of differentiation powered by 26Al? Answering theses question is the goal of the Solar-Power Sail JAXA mission [1, 2]. This mission plans to study the surface by remote sensing in the optical in IR domain. This probe will carry a large-sized lander with a drill to sample the constitutive material at meter depth in order to complement physical and chemical properties measured by on-board instruments. The sample return is an option under study.Radar sounding of the shallow subsurface would be envisaged in complement to this payload. Sounding radar could provide the structure of the first tens of meters of the Trojan surface. It will allow identifying layering, ice lens, and embedded block. It also will enable to reconnect the surface with the deep interior in order to identify exogenous / pristine material. For the surface package, the drilling and the sample return, radar sounding is a unique opportunity to support the selection of the landing site and to provide the greater geological context of the samples that will be returned to Earth.In this paper, we will detail the objective of this instrument and then we will outline the proposed instrument, which is inheriting from the radar developed for the AIDA/AIM mission.[1] Mori, O. et al., Science experiments on a Jupiter Trojan Asteroid in the solar powerd sail mission. LPSC 2016 - 1822.[2] Okada, T. et al., Science and Exploration of a Jupiter Trojan Asteroid in the solar-power sail mission. LPSC 2017 - 1828.

  18. New Measurements Of Jupiter's Equatorial Region In Visible Wavelengths

    Science.gov (United States)

    Rojas, Jose; Arregi, J.; García-Melendo, E.; Barrado-Izagirre, N.; Hueso, R.; Gómez-Forrellad, J. M.; Pérez-Hoyos, S.; Sanz-Requena, J. F.; Sánchez-Lavega, A.

    2010-10-01

    We have studied the equatorial region of Jupiter, between 15ºS and 15ºN, on Cassini ISS images obtained during the Jupiter flyby at the end of 2000 and on HST images acquired in May and July 2008. We have found significant longitudinal variations in the intensity of the 6ºN eastward jet, up to 60 m s-1 in Cassini and HST observations. In the HST case we found that these longitudinal variations are associated to different cloud morphology. Photometric and radiative transfer analysis of the cloud features used as tracers in HST images shows that there is only a small height difference, no larger than 0.5 - 1 scale heights at most, between the slow ( 100 m s-1) and fast ( 150 m s-1) moving features. This suggests that speed variability at 6ºN is not dominated by vertical wind shears and we propose that Rossby wave activity is the responsible for the zonal variability. After removing this variability we found that Jupiter's equatorial jet is actually symmetric relative to the equator with two peaks of 140 - 150 m s-1 located at latitudes 6ºN and 6ºS and at a similar pressure level. We also studied a large, long-lived feature called the White Spot (WS) located at 6ºS that turns to form and desapear. The internal flow field in the White Spot indicates that it is a weakly rotating quasi-equatorial anticyclone relative to the ambient meridionally sheared flow. Acknowledgements: This work was supported by the Spanish MICIIN AYA2009-10701 with FEDER and Grupos Gobierno Vasco IT-464-07.

  19. DOPPLER SIGNATURES OF THE ATMOSPHERIC CIRCULATION ON HOT JUPITERS

    International Nuclear Information System (INIS)

    Showman, Adam P.; Lewis, Nikole K.; Fortney, Jonathan J.; Shabram, Megan

    2013-01-01

    The meteorology of hot Jupiters has been characterized primarily with thermal measurements, but recent observations suggest the possibility of directly detecting the winds by observing the Doppler shift of spectral lines seen during transit. Motivated by these observations, we show how Doppler measurements can place powerful constraints on the meteorology. We show that the atmospheric circulation—and Doppler signature—of hot Jupiters splits into two regimes. Under weak stellar insolation, the day-night thermal forcing generates fast zonal jet streams from the interaction of atmospheric waves with the mean flow. In this regime, air along the terminator (as seen during transit) flows toward Earth in some regions and away from Earth in others, leading to a Doppler signature exhibiting superposed blueshifted and redshifted components. Under intense stellar insolation, however, the strong thermal forcing damps these planetary-scale waves, inhibiting their ability to generate jets. Strong frictional drag likewise damps these waves and inhibits jet formation. As a result, this second regime exhibits a circulation dominated by high-altitude, day-to-night airflow, leading to a predominantly blueshifted Doppler signature during transit. We present state-of-the-art circulation models including non-gray radiative transfer to quantify this regime shift and the resulting Doppler signatures; these models suggest that cool planets like GJ 436b lie in the first regime, HD 189733b is transitional, while planets hotter than HD 209458b lie in the second regime. Moreover, we show how the amplitude of the Doppler shifts constrains the strength of frictional drag in the upper atmospheres of hot Jupiters. If due to winds, the ∼2 km s –1 blueshift inferred on HD 209458b may require drag time constants as short as 10 4 -10 6 s, possibly the result of Lorentz-force braking on this planet's hot dayside.

  20. Prevalent lightning sferics at 600 megahertz near Jupiter's poles

    Science.gov (United States)

    Brown, Shannon; Janssen, Michael; Adumitroaie, Virgil; Atreya, Sushil; Bolton, Scott; Gulkis, Samuel; Ingersoll, Andrew; Levin, Steven; Li, Cheng; Li, Liming; Lunine, Jonathan; Misra, Sidharth; Orton, Glenn; Steffes, Paul; Tabataba-Vakili, Fachreddin; Kolmašová, Ivana; Imai, Masafumi; Santolík, Ondřej; Kurth, William; Hospodarsky, George; Gurnett, Donald; Connerney, John

    2018-06-01

    Lightning has been detected on Jupiter by all visiting spacecraft through night-side optical imaging and whistler (lightning-generated radio waves) signatures1-6. Jovian lightning is thought to be generated in the mixed-phase (liquid-ice) region of convective water clouds through a charge-separation process between condensed liquid water and water-ice particles, similar to that of terrestrial (cloud-to-cloud) lightning7-9. Unlike terrestrial lightning, which emits broadly over the radio spectrum up to gigahertz frequencies10,11, lightning on Jupiter has been detected only at kilohertz frequencies, despite a search for signals in the megahertz range12. Strong ionospheric attenuation or a lightning discharge much slower than that on Earth have been suggested as possible explanations for this discrepancy13,14. Here we report observations of Jovian lightning sferics (broadband electromagnetic impulses) at 600 megahertz from the Microwave Radiometer15 onboard the Juno spacecraft. These detections imply that Jovian lightning discharges are not distinct from terrestrial lightning, as previously thought. In the first eight orbits of Juno, we detected 377 lightning sferics from pole to pole. We found lightning to be prevalent in the polar regions, absent near the equator, and most frequent in the northern hemisphere, at latitudes higher than 40 degrees north. Because the distribution of lightning is a proxy for moist convective activity, which is thought to be an important source of outward energy transport from the interior of the planet16,17, increased convection towards the poles could indicate an outward internal heat flux that is preferentially weighted towards the poles9,16,18. The distribution of moist convection is important for understanding the composition, general circulation and energy transport on Jupiter.

  1. Tidal formation of Hot Jupiters in binary star systems

    Science.gov (United States)

    Bataille, M.; Libert, A.-S.; Correia, A. C. M.

    2015-10-01

    More than 150 Hot Jupiters with orbital periods less than 10 days have been detected. Their in-situ formation is physically unlikely. We need therefore to understand the migration of these planets from high distance (several AUs). Three main models are currently extensively studied: disk-planet interactions (e.g. [3]), planet-planet scattering (e.g. [4]) and Kozai migration (e.g. [2]). Here we focus on this last mechanism, and aim to understand which dynamical effects are the most active in the accumulation of planetary companions with low orbital periods in binary star systems. To do so, we investigate the secular evolution of Hot Jupiters in binary star systems. Our goal is to study analytically the 3-day pile-up observed in their orbital period. Our framework is the hierarchical three-body problem, with the effects of tides, stellar oblateness, and general relativity. Both the orbital evolution and the spin evolution are considered. Using the averaged equations of motion in a vectorial formalism of [1], we have performed # 100000 numerical simulations of well diversified three-body systems, reproducing and generalizing the numerical results of [2]. Based on a thorough analysis of the initial and final configurations of the systems, we have identified different categories of secular evolutions present in the simulations, and proposed for each one a simplified set of equations reproducing the evolution. Statistics about spin-orbit misalignements and mutual inclinations between the orbital planes of the Hot Jupiter and the star companion are also provided. Finally, we show that the extent of the 3 day pile-up is very dependent on the initial parameters of the simulations.

  2. Observation of L-bursts of Jupiter decameter waves

    International Nuclear Information System (INIS)

    Imai, Kazumasa; Tomisawa, Ichiro

    1978-01-01

    The Jupiter decameter waves are the only information source which can be obtained on the earth for the investigation of dynamics concerning the generation of plasma waves in the magnetosphere of Jupiter. The emission of Jupiter decameter waves is modulated by the satellite Io considerably. It is observed that the emission of decameter waves fluctuated much in course of time. The duration time of bursts is 1 to 10 sec and 1 to 50 msec for L-bursts and S-bursts, respectively. The simultaneous observations were conducted at two locations from August, 1977, and at three locations from December, 1977, for searching the source of L-bursts. The relation between the appearance frequency of L-bursts and S-bursts and Io phase and system 3 longitude is explained. The observation points were Sugadaira, Chofu and Toyokawa, The minimum detectable flux density by the wave receiving network is 10 -21 W/m 2 .Hz. Concerning the observed results, the locations of observed events on the Io phase and the system 3 longitude are shown. The analytical results on the L-bursts of the main source and the early source are explained, taking ten events. The analysed dynamic cross-correlation and the spectrum analysis of the decameter intensity are shown. The relation between the origin and the emission mechanism was investigated, considering the observed data and the evaluation mentioned above for the main source and early source, and the clue was obtained to solve the riddle of emission mechanism. (Nakai, Y.)

  3. Solar wind control of stratospheric temperatures in Jupiter's auroral regions?

    Science.gov (United States)

    Sinclair, James Andrew; Orton, Glenn; Kasaba, Yasumasa; Sato, Takao M.; Tao, Chihiro; Waite, J. Hunter; Cravens, Thomas; Houston, Stephen; Fletcher, Leigh; Irwin, Patrick; Greathouse, Thomas K.

    2017-10-01

    Auroral emissions are the process through which the interaction of a planet’s atmosphere and its external magnetosphere can be studied. Jupiter exhibits auroral emission at a multitude of wavelengths including the X-ray, ultraviolet and near-infrared. Enhanced emission of CH4 and other stratospheric hydrocarbons is also observed coincident with Jupiter’s shorter-wavelength auroral emission (e.g. Caldwell et al., 1980, Icarus 44, 667-675, Kostiuk et al., 1993, JGR 98, 18823). This indicates that auroral processes modify the thermal structure and composition of the auroral stratosphere. The exact mechanism responsible for this auroral-related heating of the stratosphere has however remained elusive (Sinclair et al., 2017a, Icarus 292, 182-207, Sinclair et al., 2017b, GRL, 44, 5345-5354). We will present an analysis of 7.8-μm images of Jupiter measured by COMICS (Cooled Mid-Infrared Camera and Spectrograph, Kataza et al., 2000, Proc. SPIE(4008), 1144-1152) on the Subaru telescope. These images were acquired on January 11th, 12th, 13th, 14th, February 4, 5th and May 17th, 18th, 19th and 20th in 2017, allowing the daily variability of Jupiter’s auroral-related stratospheric heating to be tracked. Preliminary results suggest lower stratospheric temperatures are directly forced by the solar wind dynamical pressure. The southern auroral hotspot exhibited a significant increase in brightness temperature over a 24-hour period. Over the same time period, a solar wind propagation model (Tao et al. 2005, JGR 110, A11208) predicts a strong increase in the solar wind dynamical pressure at Jupiter.

  4. JUPITER-3実験解析(4)

    OpenAIRE

    三田 敏男

    1990-01-01

    本報告書は、技術開発部プラント工学室で組識しているJUPITERサブワーキングGrの平成元年度の成果をまとめたものである。JUPITERサブワーキングGrは、動燃事業団が米国エネルギー省(DOE)との共同研究としてアルゴンヌ国立研究所(ANL-W)の大型臨界実験装置ZPPRで実施した大型高速炉臨界実験(JUPITER-III)の計画、実験解析を行うためのワーキンググループである。JUPITER-IIIは電気出力65万kW級の軸方向非均質炉心模擬実験(ZPPR-17シリーズ)と100万kW級の均質炉心模擬実験(ZPPR-18シリーズ)からなる。JUPITER-III実験解析は本年度で終了し、その成果を過去のJUPITER-I,II(電気出力60万sim80万kW級の均質、径方向非均質炉心模擬実験)の解析結果と比較してJUPITER実験解析を総合評価した。本年度の主な成果は下記の通りである。(1) JUPITER実験解析法をセル計算を中心に検討して現状の最新解析法をまとめると共に、これらに基づく炉心設計法を設定した。...

  5. Lyapunov Orbits in the Jupiter System Using Electrodynamic Tethers

    Science.gov (United States)

    Bokelmann, Kevin; Russell, Ryan P.; Lantoine, Gregory

    2013-01-01

    Various researchers have proposed the use of electrodynamic tethers for power generation and capture from interplanetary transfers. The effect of tether forces on periodic orbits in Jupiter-satellite systems are investigated. A perturbation force is added to the restricted three-body problem model and a series of simplifications allows development of a conservative system that retains the Jacobi integral. Expressions are developed to find modified locations of equilibrium positions. Modified families of Lyapunov orbits are generated as functions of tether size and Jacobi integral. Zero velocity curves and stability analyses are used to evaluate the dynamical properties of tether-modified orbits.

  6. JESTR: Jupiter Exploration Science in the Time Regime

    Science.gov (United States)

    Noll, Keith S.; Simon-Miller, A. A.; Wong, M. H.; Choi, D. S.

    2012-01-01

    Solar system objects are inherently time-varying with changes that occur on timescales ranging from seconds to years. For all planets other than the Earth, temporal coverage of atmospheric phenomena is limited and sparse. Many important atmospheric phenomena, especially those related to atmospheric dynamics, can be studied in only very limited ways with current data. JESTR is a mission concept that would remedy this gap in our exploration of the solar system by ncar-continuous imaging and spectral monitoring of Jupiter over a multi-year mission lifetime.

  7. JUICE: A European Mission to Jupiter and its Icy Moons

    Science.gov (United States)

    Grasset, Olivier; Witasse, Olivier; Barabash, Stas; Brandt, Pontus; Bruzzone, Lorenzo; Bunce, Emma; Cecconi, Baptiste; Cavalié, Thibault; Cimo, Giuseppe; Coustenis, Athena; Cremonese, Gabriele; Dougherty, Michele; Fletcher, Leigh N.; Gladstone, Randy; Gurvits, Leonid; Hartogh, Paul; Hoffmann, Holger; Hussmann, Hauke; Iess, Luciano; Jaumann, Ralf; Kasaba, Yasumasa; Kaspi, Yohai; Krupp, Norbert; Langevin, Yves; Mueller-Wodarg, Ingo; Palumbo, Pasquale; Piccioni, Giuseppe; Plaut, Jeffrey; Poulet, Francois; Roatsch, Thomas; Retherford, Kurt D.; Rothkaehl, Hanna; Stevenson, David J.; Tosi, Federico; Van Hoolst, Tim; Wahlund, Jan-Erik; Wurz, Peter; Altobelli, Nicolas; Accomazzo, A.; Boutonnet, Arnaud; Erd, Christian; Vallat, Claire

    2016-10-01

    JUICE - JUpiter ICy moons Explorer - is the first large mission in the ESA Cosmic Vision programme [1]. The implementation phase started in July 2015. JUICE will arrive at Jupiter in October 2029, and will spend 3 years characterizing the Jovian system, the planet itself, its giant magnetosphere, and the giant icy moons: Ganymede, Callisto and Europa. JUICE will then orbit Ganymede.The first goal of JUICE is to explore the habitable zone around Jupiter [2]. Ganymede is a high-priority target because it provides a unique laboratory for analyzing the nature, evolution and habitability of icy worlds, including the characteristics of subsurface oceans, and because it possesses unique magnetic fields and plasma interactions with the environment. On Europa, the focus will be on recently active zones, where the composition, surface and subsurface features (including putative water reservoirs) will be characterized. Callisto will be explored as a witness of the early Solar System.JUICE will also explore the Jupiter system as an archetype of gas giants. The circulation, meteorology, chemistry and structure of the Jovian atmosphere will be studied from the cloud tops to the thermosphere and ionosphere. JUICE will investigate the 3D properties of the magnetodisc, and study the coupling processes within the magnetosphere, ionosphere and thermosphere. The mission also focuses on characterizing the processes that influence surface and space environments of the moons.The payload consists of 10 instruments plus a ground-based experiment (PRIDE) to better constrain the S/C position. A remote sensing package includes imaging (JANUS) and spectral-imaging capabilities from UV to sub-mm wavelengths (UVS, MAJIS, SWI). A geophysical package consists of a laser altimeter (GALA) and a radar sounder (RIME) for exploring the moons, and a radio science experiment (3GM) to probe the atmospheres and to determine the gravity fields. The in situ package comprises a suite to study plasma and

  8. Vorticity and energy diagnostics from the 2000 Cassini Jupiter flyby

    Science.gov (United States)

    Young, R. M. B.; Read, P. L.; Armstrong, D.; Lancaster, A.

    2011-10-01

    The Cassini spacecraft flew by Jupiter in December 2000, returning hundreds of images near closest approach [1]. We have been analysing the images spanning four Jupiter rotation periods at closest approach using automated cloud tracking software to obtain horizontal velocity fields. Our method has some advantages over other methods used for this purpose in that it accounts for both cloud deformation and rotation in addition to the standard translation. We shall present detailed horizontal velocity vectors and related vorticity and energy fields over four Jupiter rotation periods. We also intend to produce derived energy and turbulence diagnostics that will help us to understand the interplay between processes acting on different length scales. It may also be possible to relate these diagnostics to 'zonostrophic' jets and small-scale turbulence studied in the laboratory using the Coriolis rotating tank, work itself motivated by jets in giant planet atmospheres [2]. In the future we intend to combine velocity fields with temperature data to produce fully-3D velocity and potential vorticity fields for Jupiter's troposphere and stratosphere. The cloud tracking method is based on correlation image velocimetry (CIV) and was originally developed by the Coriolis facility team at LEGI, Université de Grenoble [3], where it is used to extract velocity fields from data obtained in their 13m diameter rotating tank experiment. The method has two stages. First, velocity vectors are calculated using translation only, where the velocity is defined by the highest correlation between two images taken 63 minutes apart of a small pixel patch moving within a larger search box. In the second stage the correlation analysis is repeated, but instead of just translation of the pixel patch, rotation and deformation (shearing, stretching) are taken into account. We use the first stage velocity field as an estimate of the velocity vector and search within a small window around this, including

  9. Photochemistry, mixing and transport in Jupiter's stratosphere constrained by Cassini

    Science.gov (United States)

    Hue, V.; Hersant, F.; Cavalié, T.; Dobrijevic, M.; Sinclair, J. A.

    2018-06-01

    In this work, we aim at constraining the diffusive and advective transport processes in Jupiter's stratosphere, using Cassini/CIRS observations published by Nixon et al. (2007,2010). The Cassini-Huygens flyby of Jupiter on December 2000 provided the highest spatially resolved IR observations of Jupiter so far, with the CIRS instrument. The IR spectrum contains the fingerprints of several atmospheric constituents and allows probing the tropospheric and stratospheric composition. In particular, the abundances of C2H2 and C2H6, the main compounds produced by methane photochemistry, can be retrieved as a function of latitude in the pressure range at which CIRS is sensitive to. CIRS observations suggest a very different meridional distribution for these two species. This is difficult to reconcile with their photochemical histories, which are thought to be tightly coupled to the methane photolysis. While the overall abundance of C2H2 decreases with latitude, C2H6 becomes more abundant at high latitudes. In this work, a new 2D (latitude-altitude) seasonal photochemical model of Jupiter is developed. The model is used to investigate whether the addition of stratospheric transport processes, such as meridional diffusion and advection, are able to explain the latitudinal behavior of C2H2 and C2H6. We find that the C2H2 observations are fairly well reproduced without meridional diffusion. Adding meridional diffusion to the model provides an improved agreement with the C2H6 observations by flattening its meridional distribution, at the cost of a degradation of the fit to the C2H2 distribution. However, meridional diffusion alone cannot produce the observed increase with latitude of the C2H6 abundance. When adding 2D advective transport between roughly 30 mbar and 0.01 mbar, with upwelling winds at the equator and downwelling winds at high latitudes, we can, for the first time, reproduce the C2H6 abundance increase with latitude. In parallel, the fit to the C2H2 distribution is

  10. Clinical implications of JUPITER in a contemporary European population: the EPIC-Norfolk prospective population study

    NARCIS (Netherlands)

    Sondermeijer, Brigitte M.; Boekholdt, S. Matthijs; Rana, Jamal S.; Kastelein, John J. P.; Wareham, Nicholas J.; Khaw, Kay-Tee

    2013-01-01

    Justification for the Use of statins in Prevention: an Intervention Trial Evaluating Rosuvastatin (JUPITER) has raised several points of debate. We quantified the proportion of individuals meeting the JUPITER criteria, determined their risk profile, and their risk of coronary heart disease (CHD)

  11. Jupiter Icy Moons Explorer (JUICE) : Science Objectives, Mission and Instruments (abstract)

    NARCIS (Netherlands)

    Gurvits, L.; Plaut, J.J.; Barabash, S.; Bruzzone, L.; Dougherty, M.; Erd, C.; Fletcher, L.; Gladstone, R.; Grasset, O.; Hartogh, P.; Hussmann, H.; Iess, L.; Jaumann, R.; Langevin, Y.; Palumbo, P.; Piccioni, G.; Titov, D.; Wahlund, J.E.

    2014-01-01

    The JUpiter ICy Moons Explorer (JUICE) is a European Space Agency mission that will fly by and observe the Galilean satellites Europa, Ganymede and Callisto, characterize the Jovian system in a lengthy Jupiter-orbit phase, and ultimately orbit Ganymede for in-depth studies of habitability, evolution

  12. Periodic Comet Shoemaker-Levy 9 Collides with Jupiter. Background Material for Science Teachers.

    Science.gov (United States)

    Jet Propulsion Lab., Pasadena, CA.

    In July of 1994, fragments of Comet Shoemaker-Levy collided with Jupiter. This document has been provided to better inform students of the work that will be done by scientists and others involved in the study of this event. This document offers some background material on Jupiter, comets, what has and possibly will happen, and how scientists…

  13. 78 FR 32696 - Jupiter Enterprises, Inc., Order of Suspension of Trading

    Science.gov (United States)

    2013-05-31

    ... SECURITIES AND EXCHANGE COMMISSION [File No. 500-1] Jupiter Enterprises, Inc., Order of Suspension of Trading May 29, 2013. It appears to the Securities and Exchange Commission that there is a lack of current and accurate information concerning the securities of Jupiter Enterprises, Inc. because it has not...

  14. Forming Hot Jupiters: Observational Constraints on Gas Giant Formation and migration

    Science.gov (United States)

    Becker, Juliette; Vanderburg, Andrew; Adams, Fred C.; Khain, Tali; Bryan, Marta

    2018-04-01

    Since the first extrasolar planets were detected, the existence of hot Jupiters has challenged prevailing theories of planet formation. The three commonly considered pathways for hot Jupiter formation are in situ formation, runaway accretion in the outer disk followed by disk migration, and tidal migration (occurring after the disk has dissipated). None of these explains the entire observed sample of hot Jupiters, suggesting that different selections of systems form via different pathways. The way forward is to use observational data to constrain the migration pathways of particular classes of systems, and subsequently assemble these results into a coherent picture of hot Jupiter formation. We present constraints on the migratory pathway for one particular type of system: hot Jupiters orbiting cool stars (T< 6200 K). Using the full observational sample, we find that the orbits of most wide planetary companions to hot Jupiters around these cool stars must be well aligned with the orbits of the hot Jupiters and the spins of the host stars. The population of systems containing both a hot Jupiter and an exterior companion around a cool star thus generally exist in roughly coplanar configurations, consistent with the idea that disk-driven migratory mechanisms have assembled most of this class of systems. We then discuss the overall applicability of this result to a wider range of systems and the broader implications on planet formation.

  15. Secular chaos and its application to Mercury, hot Jupiters, and the organization of planetary systems.

    Science.gov (United States)

    Lithwick, Yoram; Wu, Yanqin

    2014-09-02

    In the inner solar system, the planets' orbits evolve chaotically, driven primarily by secular chaos. Mercury has a particularly chaotic orbit and is in danger of being lost within a few billion years. Just as secular chaos is reorganizing the solar system today, so it has likely helped organize it in the past. We suggest that extrasolar planetary systems are also organized to a large extent by secular chaos. A hot Jupiter could be the end state of a secularly chaotic planetary system reminiscent of the solar system. However, in the case of the hot Jupiter, the innermost planet was Jupiter (rather than Mercury) sized, and its chaotic evolution was terminated when it was tidally captured by its star. In this contribution, we review our recent work elucidating the physics of secular chaos and applying it to Mercury and to hot Jupiters. We also present results comparing the inclinations of hot Jupiters thus produced with observations.

  16. Secular chaos and its application to Mercury, hot Jupiters, and the organization of planetary systems

    Science.gov (United States)

    Lithwick, Yoram; Wu, Yanqin

    2014-01-01

    In the inner solar system, the planets’ orbits evolve chaotically, driven primarily by secular chaos. Mercury has a particularly chaotic orbit and is in danger of being lost within a few billion years. Just as secular chaos is reorganizing the solar system today, so it has likely helped organize it in the past. We suggest that extrasolar planetary systems are also organized to a large extent by secular chaos. A hot Jupiter could be the end state of a secularly chaotic planetary system reminiscent of the solar system. However, in the case of the hot Jupiter, the innermost planet was Jupiter (rather than Mercury) sized, and its chaotic evolution was terminated when it was tidally captured by its star. In this contribution, we review our recent work elucidating the physics of secular chaos and applying it to Mercury and to hot Jupiters. We also present results comparing the inclinations of hot Jupiters thus produced with observations. PMID:24367108

  17. Ulysses radio and plasma wave observations in the jupiter environment.

    Science.gov (United States)

    Stone, R G; Pedersen, B M; Harvey, C C; Canu, P; Cornilleau-Wehrlin, N; Desch, M D; de Villedary, C; Fainberg, J; Farrell, W M; Goetz, K; Hess, R A; Hoang, S; Kaiser, M L; Kellogg, P J; Lecacheux, A; Lin, N; Macdowall, R J; Manning, R; Meetre, C A; Meyer-Vernet, N; Moncuquet, M; Osherovich, V; Reiner, M J; Tekle, A; Thiessen, J; Zarka, P

    1992-09-11

    The Unified Radio and Plasma Wave (URAP) experiment has produced new observations of the Jupiter environment, owing to the unique capabilities of the instrument and the traversal of high Jovian latitudes. Broad-band continuum radio emission from Jupiter and in situ plasma waves have proved valuable in delineating the magnetospheric boundaries. Simultaneous measurements of electric and magnetic wave fields have yielded new evidence of whistler-mode radiation within the magnetosphere. Observations of aurorallike hiss provided evidence of a Jovian cusp. The source direction and polarization capabilities of URAP have demonstrated that the outer region of the lo plasma torus supported at least five separate radio sources that reoccurred during successive rotations with a measurable corotation lag. Thermal noise measurements of the lo torus densities yielded values in the densest portion that are similar to models suggested on the basis of Voyager observations of 13 years ago. The URAP measurements also suggest complex beaming and polarization characteristics of Jovian radio components. In addition, a new class of kilometer-wavelength striated Jovian bursts has been observed.

  18. Magnetotail Reconnection and Flux Circulation: Jupiter and Saturn Compared

    Science.gov (United States)

    Jackman, C. M.; Vogt, M. F.; Slavin, J. A.; Cowley, S. W. H.; Boardsen, S. A.

    2011-01-01

    The Jovian magnetosphere has been visited by eight spacecraft, and the magnetometer data have been used to identify dozens of plasmoids and 250 field dipolarizations associated with magnetic reconnection in the tail [e.g. Vogt et al., 2010]. Since the arrival of the Cassini spacecraft at Saturn in 2004, the magnetometer instrument has also been used to identify reconnection signatures. The deepest magnetotail orbits were in 2006, and during this time 34 signatures of plasmoids were identified. In this study we compare the statistical properties of plasmoids at Jupiter and Saturn such as duration, size, location, and recurrence period. Such parameters can be influenced by many factors, including the different Dungey cycle timescales and cross-magnetospheric potential drops at the two planets. We present superposed epoch analyses of plasmoids at the two planets to determine their average properties and to infer their role in the reconfiguration of the nightside of the magnetosphere. We examine the contributions of plasmoids to the magnetic flux transfer cycle at both planets. At Jupiter, there is evidence of an extended interval after reconnection where the field remains northward (analogous to the terrestrial post-plasmoid plasma sheet). At Saturn we see a similar feature, and calculate the amount of flux closed on average in reconnection events, leading us to an estimation of the recurrence rate of plasmoid release.

  19. A retrograde co-orbital asteroid of Jupiter.

    Science.gov (United States)

    Wiegert, Paul; Connors, Martin; Veillet, Christian

    2017-03-29

    Recent theoretical work in celestial mechanics has revealed that an asteroid may orbit stably in the same region as a planet, despite revolving around the Sun in the sense opposite to that of the planet itself. Asteroid 2015 BZ 509 was discovered in 2015, but with too much uncertainty in its measured orbit to establish whether it was such a retrograde co-orbital body. Here we report observations and analysis that demonstrates that asteroid 2015 BZ 509 is indeed a retrograde co-orbital asteroid of the planet Jupiter. We find that 2015 BZ 509 has long-term stability, having been in its current, resonant state for around a million years. This is long enough to preclude precise calculation of the time or mechanism of its injection to its present state, but it may be a Halley-family comet that entered the resonance through an interaction with Saturn. Retrograde co-orbital asteroids of Jupiter and other planets may be more common than previously expected.

  20. Modeling of Jupiter's electron an ion radiation belts

    International Nuclear Information System (INIS)

    Sicard, Angelica

    2004-01-01

    In the Fifties, James Van Allen showed the existence of regions of the terrestrial magnetosphere consisted of energetic particles, trapped by the magnetic field: the radiation belts. The radiation belts of the Earth were the subject of many modeling works and are studied since several years at the Departement Environnement Spatial (DESP) of ONERA. In 1998, the DESP decided to adapt the radiation belts model of the Earth, Salammbo, to radiation environment of Jupiter. A first thesis was thus carried out on the subject and a first radiation belts model of electrons of Jupiter was developed [Santos-Costa, 2001]. The aim of this second thesis is to develop a radiation belts model for protons and heavy ions. In order to validate the developed model, the comparisons between Salammbo results and observations are essential. However, the validation is difficult in the case of protons and heavy ions because in-situ measurements of the probes are very few and most of the time contaminated by very energetic electrons. To solve this problem, a very good model of electrons radiation belts is essential to confirm or cancel the contamination of protons and heavy ions measurements. Thus, in parallel to the development of the protons and heavy ions radiation belts model, the electrons models, already existing, has been improved. Then Salammbo results have been compared to the different observations available (in-situ measurements, radio-astronomical observations). The different comparisons show a very good agreement between Salammbo results and observations. (author) [fr

  1. RADIO EMISSION FROM RED-GIANT HOT JUPITERS

    International Nuclear Information System (INIS)

    Fujii, Yuka; Spiegel, David S.; Mroczkowski, Tony; Nordhaus, Jason; Zimmerman, Neil T.; Parsons, Aaron R.; Mirbabayi, Mehrdad; Madhusudhan, Nikku

    2016-01-01

    When planet-hosting stars evolve off the main sequence and go through the red-giant branch, the stars become orders of magnitudes more luminous and, at the same time, lose mass at much higher rates than their main-sequence counterparts. Accordingly, if planetary companions exist around these stars at orbital distances of a few au, they will be heated up to the level of canonical hot Jupiters and also be subjected to a dense stellar wind. Given that magnetized planets interacting with stellar winds emit radio waves, such “Red-Giant Hot Jupiters” (RGHJs) may also be candidate radio emitters. We estimate the spectral auroral radio intensity of RGHJs based on the empirical relation with the stellar wind as well as a proposed scaling for planetary magnetic fields. RGHJs might be intrinsically as bright as or brighter than canonical hot Jupiters and about 100 times brighter than equivalent objects around main-sequence stars. We examine the capabilities of low-frequency radio observatories to detect this emission and find that the signal from an RGHJ may be detectable at distances up to a few hundred parsecs with the Square Kilometer Array

  2. NUMERICAL MODELING OF THE 2009 IMPACT EVENT ON JUPITER

    Energy Technology Data Exchange (ETDEWEB)

    Pond, Jarrad W. T.; Palotai, Csaba; Gabriel, Travis; Harrington, Joseph; Rebeli, Noemi [Planetary Sciences Group, Department of Physics, University of Central Florida, Orlando, FL 32816-2385 (United States); Korycansky, Donald G., E-mail: jarradpond@gmail.com [Department of Earth and Planetary Science, University of California, Santa Cruz, CA 95064 (United States)

    2012-02-01

    We have investigated the 2009 July impact event on Jupiter using the ZEUS-MP 2 three-dimensional hydrodynamics code. We studied the impact itself and the following plume development. Eight impactors were considered: 0.5 km and 1 km porous ({rho} = 1.760 g cm{sup -3}) and non-porous ({rho} = 2.700 g cm{sup -3}) basalt impactors, and 0.5 km and 1 km porous ({rho} = 0.600 g cm{sup -3}) and non-porous ({rho} = 0.917 g cm{sup -3}) ice impactors. The simulations consisted of these bolides colliding with Jupiter at an incident angle of {theta} = 69 Degree-Sign from the vertical and with an impact velocity of v = 61.4 km s{sup -1}. Our simulations show the development of relatively larger, faster plumes created after impacts involving 1 km diameter bodies. Comparing simulations of the 2009 event with simulations of the Shoemaker-Levy 9 (SL9) events reveals a difference in plume development, with the higher incident angle of the 2009 impact leading to a shallower terminal depth and a smaller and slower plume. We also studied the amount of dynamical chaos present in the simulations conducted at the 2009 incident angle. Compared to the chaos of the SL9 simulations, where {theta} Almost-Equal-To 45 Degree-Sign , we find no significant difference in chaos at the higher 2009 incident angle.

  3. The size of Jupiter's electrically conducting fluid core

    International Nuclear Information System (INIS)

    Hide, R.; Malin, S.R.C.

    1979-01-01

    When the magnetic field of a planet is due to hydromagnetic dynamo action in an electrically conducting fluid core surrounded by a poorly conducting mantle it is possible in principle to determine the radius rsub(c) of the core from determinations of secular changes in the magnetic field B in the accessible region above the surface of the planet, mean radius rsub(s) (> = rsub(c)). A preliminary study is described in which the magnetic field measurements made in December 1973 and December 1974 when the Pioneer 10 and 11 fly-by space probes encountered Jupiter have been analysed. It was expected that over such a short time interval any true secular changes would be masked by errors and the corresponding estimates of rsub(c)/rsub(s) highly implausible or even physically impossible, but this turns out not to be the case. Taken at their face value the apparent secular changes in the dipole and quadrupole components of Jupiter's magnetic field imply that rsub(c)/rsub(s) is close to 0.7. Somewhat higher values of rsub(c)/rsub(s) are found when contributions from the octupole component are also included. (UK)

  4. RADIO EMISSION FROM RED-GIANT HOT JUPITERS

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Yuka [Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, 152-8550 (Japan); Spiegel, David S. [Analytics and Algorithms, Stitch Fix, San Francisco, CA 94103 (United States); Mroczkowski, Tony [Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 (United States); Nordhaus, Jason [Department of Science and Mathematics, National Technical Institute for the Deaf, Rochester Institute of Technology, Rochester, NY 14623 (United States); Zimmerman, Neil T. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Parsons, Aaron R. [Astronomy Department, University of California, Berkeley, CA (United States); Mirbabayi, Mehrdad [Astrophysics Department, Institute for Advanced Study, Princeton, NJ 08540 (United States); Madhusudhan, Nikku, E-mail: yuka.fujii@elsi.jp [Astronomy Department, University of Cambridge (United Kingdom)

    2016-04-01

    When planet-hosting stars evolve off the main sequence and go through the red-giant branch, the stars become orders of magnitudes more luminous and, at the same time, lose mass at much higher rates than their main-sequence counterparts. Accordingly, if planetary companions exist around these stars at orbital distances of a few au, they will be heated up to the level of canonical hot Jupiters and also be subjected to a dense stellar wind. Given that magnetized planets interacting with stellar winds emit radio waves, such “Red-Giant Hot Jupiters” (RGHJs) may also be candidate radio emitters. We estimate the spectral auroral radio intensity of RGHJs based on the empirical relation with the stellar wind as well as a proposed scaling for planetary magnetic fields. RGHJs might be intrinsically as bright as or brighter than canonical hot Jupiters and about 100 times brighter than equivalent objects around main-sequence stars. We examine the capabilities of low-frequency radio observatories to detect this emission and find that the signal from an RGHJ may be detectable at distances up to a few hundred parsecs with the Square Kilometer Array.

  5. Family Portrait of the Small Inner Satellites of Jupiter

    Science.gov (United States)

    1997-01-01

    These images, taken by Galileo's solid state imaging system between November 1996 and June 1997, provide the first ever 'family portrait' of the four small, irregularly shaped moons that orbit Jupiter in the zone between the planet's ring and the larger Galilean satellites. The moons are shown in their correct relative sizes, with north approximately up in all cases. From left to right, arranged in order of increasing distance from Jupiter, are Metis (longest dimension is approximately 60 kilometers or 37 miles across), Adrastea (20 kilometers or 12 miles across), Amalthea (247 kilometers or 154 miles across), and Thebe (116 kilometers or 72 miles across). While Amalthea, the largest of these four tiny moons, was imaged by NASA's two Voyager spacecraft in 1979 with a resolution comparable to what is shown here, the new Galileo observations represent the first time that Metis, Adrastea, and Thebe have been seen as more than points of light.The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://www.jpl.nasa.gov/ galileo.

  6. Some features of Jupiter decametric radiation and its temporary variations

    International Nuclear Information System (INIS)

    Levitskij, L.S.

    1977-01-01

    The following parameters of Jupiter decametric radiation are considered: duration of the storms, the distribution of the storms over Jupiter's longitudes and Io's position, the distribution along frequency range, burstness. It is shown that probability W of revealing decametric emission does not depend on solar activity level. The relative probability (W 3 /W) of appearing noise storms of large intensity changes according to variations of solar activity indexes for all frequencies (10-35 MHz). The duration of noise storms, its frequency range, intensity and L-burst number increase systematically with the storm's power. There is a tendency to the expansion of the sources of the emission along the longitude if the observer (the Earth) changes his position from the boundary to center of emission cone. Io effects in decametric emission are appreciable for the largest storms only. For small storms these effects may be revealed only in years of minimum solar activity. A part of storms with large number of L-bursts is correlated with the Asub(p)-index

  7. Discovery of a Jupiter/Saturn analog with gravitational microlensing.

    Science.gov (United States)

    Gaudi, B S; Bennett, D P; Udalski, A; Gould, A; Christie, G W; Maoz, D; Dong, S; McCormick, J; Szymanski, M K; Tristram, P J; Nikolaev, S; Paczynski, B; Kubiak, M; Pietrzynski, G; Soszynski, I; Szewczyk, O; Ulaczyk, K; Wyrzykowski, L; Depoy, D L; Han, C; Kaspi, S; Lee, C-U; Mallia, F; Natusch, T; Pogge, R W; Park, B-G; Abe, F; Bond, I A; Botzler, C S; Fukui, A; Hearnshaw, J B; Itow, Y; Kamiya, K; Korpela, A V; Kilmartin, P M; Lin, W; Masuda, K; Matsubara, Y; Motomura, M; Muraki, Y; Nakamura, S; Okumura, T; Ohnishi, K; Rattenbury, N J; Sako, T; Saito, To; Sato, S; Skuljan, L; Sullivan, D J; Sumi, T; Sweatman, W L; Yock, P C M; Albrow, M D; Allan, A; Beaulieu, J-P; Burgdorf, M J; Cook, K H; Coutures, C; Dominik, M; Dieters, S; Fouqué, P; Greenhill, J; Horne, K; Steele, I; Tsapras, Y; Chaboyer, B; Crocker, A; Frank, S; Macintosh, B

    2008-02-15

    Searches for extrasolar planets have uncovered an astonishing diversity of planetary systems, yet the frequency of solar system analogs remains unknown. The gravitational microlensing planet search method is potentially sensitive to multiple-planet systems containing analogs of all the solar system planets except Mercury. We report the detection of a multiple-planet system with microlensing. We identify two planets with masses of approximately 0.71 and approximately 0.27 times the mass of Jupiter and orbital separations of approximately 2.3 and approximately 4.6 astronomical units orbiting a primary star of mass approximately 0.50 solar mass at a distance of approximately 1.5 kiloparsecs. This system resembles a scaled version of our solar system in that the mass ratio, separation ratio, and equilibrium temperatures of the planets are similar to those of Jupiter and Saturn. These planets could not have been detected with other techniques; their discovery from only six confirmed microlensing planet detections suggests that solar system analogs may be common.

  8. Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 574: Neptune, Nevada National Security Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environmental Restoration

    2011-08-31

    This Streamlined Approach for Environmental Restoration (SAFER) Plan identifies the activities required for closure of Corrective Action Unit (CAU) 574, Neptune. CAU 574 is included in the Federal Facility Agreement and Consent Order (FFACO) (1996 [as amended March 2010]) and consists of the following two Corrective Action Sites (CASs) located in Area 12 of the Nevada National Security Site: (1) CAS 12-23-10, U12c.03 Crater (Neptune); (2) CAS 12-45-01, U12e.05 Crater (Blanca). This plan provides the methodology for the field activities that will be performed to gather the necessary information for closure of the two CASs. There is sufficient information and process knowledge regarding the expected nature and extent of potential contaminants to recommend closure of CAU 574 using the SAFER process. Based on historical documentation, personnel interviews, site process knowledge, site visits, photographs, field screening, analytical results, the results of the data quality objective (DQO) process (Section 3.0), and an evaluation of corrective action alternatives (Appendix B), closure in place with administrative controls is the expected closure strategy for CAU 574. Additional information will be obtained by conducting a field investigation to verify and support the expected closure strategy and provide a defensible recommendation that no further corrective action is necessary. This will be presented in a Closure Report that will be prepared and submitted to the Nevada Division of Environmental Protection (NDEP) for review and approval.

  9. Contribution to the qualification of the Neptune system. Application to the follow-up of the Tihange reactor

    International Nuclear Information System (INIS)

    Tournier, Dominique.

    1980-08-01

    For the calculations of light water reactors the modular system Neptune has been developed. It includes transport, diffusion, thermohydraulic and kinetic codes and so allows the treatment of the various problems of core physics. The first part of this thesis is devoted to a comparison of the most usually used modulus of the neutron transport code (APOLLO). Two examples are considered: a PWR lattice and a BWR U-Pu mixed assembly. The consequences of the different hypotheses made to solve the Boltzmann's equation by a collision probability method can be appreciated on these practical cases. The second part is a check of the complete calculation scheme against experimental results obtained during the first cycle of Tihange (900 MWe PWR). The core calculation is a 3D-diffusion calculation taking into account the thermohydraulic feedbacks; the macroscopic cross-sections needed by the neutron calculation are obtained by the transport code and tabulated versus the burn-up, the fuel temperature and the water density. The results prove that Neptune can now be considered as a precise and reliable tool [fr

  10. New vision solar system exploration missions study: Analysis of the use of biomodal space nuclear power systems to support outer solar system exploration missions. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-08

    This report presents the results of an analysis of the capability of nuclear bimodal systems to perform outer solar system exploration missions. Missions of interest include orbiter mission s to Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. An initial technology baseline consisting of a NEBA 10 kWe, 1000 N thrust, 850 s, 1500 kg bimodal system was selected, and its performance examined against a data base for trajectories to outer solar system planetary destinations to select optimal direct and gravity assisted trajectories for study. A conceptual design for a common bimodal spacecraft capable of performing missions to all the planetary destinations was developed and made the basis of end to end mission designs for orbiter missions to Jupiter, Saturn, and Neptune. Concepts for microspacecraft capable of probing Jupiter`s atmosphere and exploring Titan were also developed. All mission designs considered use the Atlas 2AS for launch. It is shown that the bimodal nuclear power and propulsion system offers many attractive option for planetary missions, including both conventional planetary missions in which all instruments are carried by a single primary orbiting spacecraft, and unconventional missions in which the primary spacecraft acts as a carrier, relay, and mother ship for a fleet of micro spacecraft deployed at the planetary destination.

  11. Pan-Planets: Searching for hot Jupiters around cool dwarfs

    Science.gov (United States)

    Obermeier, C.; Koppenhoefer, J.; Saglia, R. P.; Henning, Th.; Bender, R.; Kodric, M.; Deacon, N.; Riffeser, A.; Burgett, W.; Chambers, K. C.; Draper, P. W.; Flewelling, H.; Hodapp, K. W.; Kaiser, N.; Kudritzki, R.-P.; Magnier, E. A.; Metcalfe, N.; Price, P. A.; Sweeney, W.; Wainscoat, R. J.; Waters, C.

    2016-03-01

    The Pan-Planets survey observed an area of 42 sq deg. in the galactic disk for about 165 h. The main scientific goal of the project is the detection of transiting planets around M dwarfs. We establish an efficient procedure for determining the stellar parameters Teff and log g of all sources using a method based on SED fitting, utilizing a three-dimensional dust map and proper motion information. In this way we identify more than 60 000 M dwarfs, which is by far the largest sample of low-mass stars observed in a transit survey to date. We present several planet candidates around M dwarfs and hotter stars that are currently being followed up. Using Monte Carlo simulations we calculate the detection efficiency of the Pan-Planets survey for different stellar and planetary populations. We expect to find 3.0+3.3-1.6 hot Jupiters around F, G, and K dwarfs with periods lower than 10 days based on the planet occurrence rates derived in previous surveys. For M dwarfs, the percentage of stars with a hot Jupiter is under debate. Theoretical models expect a lower occurrence rate than for larger main sequence stars. However, radial velocity surveys find upper limits of about 1% due to their small sample, while the Kepler survey finds a occurrence rate that we estimate to be at least 0.17b(+0.67-0.04) %, making it even higher than the determined fraction from OGLE-III for F, G and K stellar types, 0.14 (+0.15-0.076) %. With the large sample size of Pan-Planets, we are able to determine an occurrence rate of 0.11 (+0.37-0.02) % in case one of our candidates turns out to be a real detection. If, however, none of our candidates turn out to be true planets, we are able to put an upper limit of 0.34% with a 95% confidence on the hot Jupiter occurrence rate of M dwarfs. This limit is a significant improvement over previous estimates where the lowest limit published so far is 1.1% found in the WFCAM Transit Survey. Therefore we cannot yet confirm the theoretical prediction of a lower

  12. Research in space physics at the University of Iowa, 1982

    International Nuclear Information System (INIS)

    Vanallen, J.A.; Frank, L.A.; Gurnett, D.A.; Shawhan, S.; Robison, E.D.; Robertson, T.D.

    1983-07-01

    The energetic particles and the electric, magnetic, and electromagnetic fields associated with the Earth, the Sun, the Moon, the planets, comets, and the interplanetary medium are examined. Matters under current investigation are following: energetic particles trapped in the Earth's magnetic field, origin and propagation of very low frequency radio waves and electrostatic, the magnetospheres of Jupiter, Saturn and prospectively Uranus and Neptune, diffusion of energetic particles in Saturn's magnetosphere, radio emissions from Jupiter and Saturn, solar modulation and the heliocentric radial dependence of the intensity of galactic cosmic rays, interplanetary propagation and acceleration of energetic particles, the theory of wave phenomena in turbulent plasmas, and basic wave-particle-chemical processes in the ionospheric plasma

  13. Planck intermediate results - LII. Planet flux densities

    DEFF Research Database (Denmark)

    Akrami, Y.; Ashdown, M.; Aumont, J.

    2017-01-01

    Measurements of flux density are described for five planets, Mars, Jupiter, Saturn, Uranus, and Neptune, across the six Planck High Frequency Instrument frequency bands (100–857 GHz) and these are then compared with models and existing data. In our analysis, we have also included estimates...... of the brightness of Jupiter and Saturn at the three frequencies of the Planck Low Frequency Instrument (30, 44, and 70 GHz). The results provide constraints on the intrinsic brightness and the brightness time-variability of these planets. The majority of the planet flux density estimates are limited by systematic...... errors, but still yield better than 1% measurements in many cases. Applying data from Planck HFI, the Wilkinson Microwave Anisotropy Probe (WMAP), and the Atacama Cosmology Telescope (ACT) to a model that incorporates contributions from Saturn’s rings to the planet’s total flux density suggests a best...

  14. Chairmanship of the Neptune/Pluto outer planets science working group

    Science.gov (United States)

    Stern, S. Alan

    1993-11-01

    The Outer Planets Science Working Group (OPSWG) is the NASA Solar System Exploration Division (SSED) scientific steering committee for the Outer Solar System missions. OPSWG consists of 19 members and is chaired by Dr. S. Alan Stern. This proposal summarizes the FY93 activities of OPSWG, describes a set of objectives for OPSWG in FY94, and outlines the SWG's activities for FY95. As chair of OPSWG, Dr. Stern will be responsible for: organizing priorities, setting agendas, conducting meetings of the Outer Planets SWG; reporting the results of OPSWG's work to SSED; supporting those activities relating to OPSWG work, such as briefings to the SSES, COMPLEX, and OSS; supporting the JPL/SAIC Pluto study team; and other tasks requested by SSED. As the Scientific Working Group (SWG) for Jupiter and the planets beyond, OPSWG is the SSED SWG chartered to study and develop mission plans for all missions to the giant planets, Pluto, and other distant objects in the remote outer solar system. In that role, OPSWG is responsible for: defining and prioritizing scientific objectives for missions to these bodies; defining and documenting the scientific goals and rationale behind such missions; defining and prioritizing the datasets to be obtained in these missions; defining and prioritizing measurement objectives for these missions; defining and documenting the scientific rationale for strawman instrument payloads; defining and prioritizing the scientific requirements for orbital tour and flyby encounter trajectories; defining cruise science opportunities plan; providing technical feedback to JPL and SSED on the scientific capabilities of engineering studies for these missions; providing documentation to SSED concerning the scientific goals, objectives, and rationale for the mission; interfacing with other SSED and OSS committees at the request of SSED's Director or those committee chairs; providing input to SSED concerning the structure and content of the Announcement of Opportunity

  15. Gas flow in the solar nebula leading to the formation of Jupiter

    International Nuclear Information System (INIS)

    Sekiya, Minoru; Miyama, Shoken M.; Hayashi, Chushiro.

    1987-01-01

    The three-dimensional gas flow in the solar nebula, which is subject to the gravity of the Sun and proto-Jupiter, is numerically calculated using a three-dimensional hydrodynamic code i.e., the so-called smoothed-particle method. The flow is circulating around the Sun as well as falling into the potential well of proto-Jupiter. The results for various masses of proto-Jupiter show that the e-folding growth time of proto-Jupiter by accretion of the nebular gas is as short as about 300 years in stages where the mass of proto-Jupiter is 0.2 ∼ 0.5 times the present Jovian mass and that proto-Jupiter begins to push away the nebular gas from the orbit of proto-Jupiter and form a gap around the orbit, when its mass is about 0.7 times the present Jovian mass. It is possible that this pushing-away process determined the present Jovian mass

  16. Clinical implications of JUPITER in a contemporary European population: the EPIC-Norfolk prospective population study.

    Science.gov (United States)

    Sondermeijer, Brigitte M; Boekholdt, S Matthijs; Rana, Jamal S; Kastelein, John J P; Wareham, Nicholas J; Khaw, Kay-Tee

    2013-05-01

    Justification for the Use of statins in Prevention: an Intervention Trial Evaluating Rosuvastatin (JUPITER) has raised several points of debate. We quantified the proportion of individuals meeting the JUPITER criteria, determined their risk profile, and their risk of coronary heart disease (CHD) events during a long-term follow-up in a contemporary European cohort. A total of 25 639 participants aged between 45 and 79 years were followed for 11.4 ± 2.8 years in EPIC-Norfolk population cohort. A total of 8397 individuals with complete data available were considered potentially eligible for primary prevention. A total of 846 (10.1%) individuals fulfilled the JUPITER criteria [low-density lipoprotein cholesterol-C (LDL-C) JUPITER criteria had significantly higher CHD risk compared with those with LDL-C ≥ 3.4 mmol/L and C-reactive protein JUPITER criteria. In this European cohort, JUPITER-eligible individuals had significantly higher event rates compared with those with LDL-C JUPITER criteria qualified almost one-fifth of the population for statin therapy that otherwise would not have qualified based on SCORE or ATP III criteria.

  17. Comet Shoemaker-Levy 9/Jupiter collision observed with a high resolution speckle imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Gravel, D. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    During the week of July 16, 1994, comet Shoemaker-Levy 9, broken into 20 plus pieces by tidal forces on its last orbit, smashed into the planet Jupiter, releasing the explosive energy of 500 thousand megatons. A team of observers from LLNL used the LLNL Speckle Imaging Camera mounted on the University of California`s Lick Observatory 3 Meter Telescope to capture continuous sequences of planet images during the comet encounter. Post processing with the bispectral phase reconstruction algorithm improves the resolution by removing much of the blurring due to atmospheric turbulence. High resolution images of the planet surface showing the aftermath of the impact are probably the best that were obtained from any ground-based telescope. We have been looking at the regions of the fragment impacts to try to discern any dynamic behavior of the spots left on Jupiter`s cloud tops. Such information can lead to conclusions about the nature of the comet and of Jupiter`s atmosphere. So far, the Hubble Space Telescope has observed expanding waves from the G impact whose mechanism is enigmatic since they appear to be too slow to be sound waves and too fast to be gravity waves, given the present knowledge of Jupiter`s atmosphere. Some of our data on the G and L impact region complements the Hubble observations but, so far, is inconclusive about spot dynamics.

  18. Near equality of ion phase space densities at earth, Jupiter, and Saturn

    Science.gov (United States)

    Cheng, A. F.; Krimigis, S. M.; Armstrong, T. P.

    1985-01-01

    Energetic-ion phase-space density profiles are strikingly similar in the inner magnetospheres of earth, Jupiter, and Saturn for ions of first adiabatic invariant near 100 MeV/G and small mirror latitudes. Losses occur inside L approximately equal to 7 for Jupiter and Saturn and inside L approximately equal to 5 at earth. At these L values there exist steep plasma-density gradients at all three planets, associated with the Io plasma torus at Jupiter, the Rhea-Dione-Tethys torus at Saturn, and the plasmasphere at earth. Measurements of ion flux-tube contents at Jupiter and Saturn by the low-energy charged-particle experiment show that these are similar (for O ions at L = 5-9) to those at earth (for protons at L = 2-6). Furthermore, the thermal-ion flux-tube contents from Voyager plasma-science data at Jupiter and Saturn are also very nearly equal, and again similar to those at earth, differing by less than a factor of 3 at the respective L values. The near equality of energetic and thermal ion flux-tube contents at earth, Jupiter, and Saturn suggests the possibility of strong physical analogies in the interaction between plasma and energetic particles at the plasma tori/plasma sheets of Jupiter and Saturn and the plasmasphere of earth.

  19. Design, Observing and Data Systems, and Final Installation of the NEPTUNE Canada Regional Cabled Ocean Observatory

    Science.gov (United States)

    Barnes, C. R.; Best, M. M.; Johnson, F. R.; Phibbs, P.; Pirenne, B.

    2009-05-01

    NEPTUNE Canada (NC; www.neptunecanada.ca) will complete most of the installation of the world's first regional cabled ocean observatory in late 2009 off Canada's west coast. It will comprise five main observatory nodes (100-2700m water depths) linked by an 800km backbone cable delivering 10kVDC power and 10Gbps communications bandwidth to hundreds of sensors, with a 25-year design life. Infrastructure (100M) and initial operational funding (20M) is secured. University of Victoria (UVic) leads a consortium of 12 Canadian universities, hosts the coastal VENUS cabled observatory, with Ocean Networks Canada (ONC) providing management oversight. Observatory architecture has a trunk and branch topology. Installed in late 2007, the backbone cable loops from/to UVic's Port Alberni shore station. The wet plant's design, manufacture and installation was contracted to Alcatel-Lucent. Each node provides six interface ports for connection of science instrument arrays or extensions. Each port provides dual optical Ethernet links and up to 9kW of electrical power at 400VDC. Junction boxes, designed and built by OceanWorks support up to 10 instruments each and can be daisy- chained. They accommodate both serial and 10/100 Ethernet instruments, and provide a variety of voltages (400V, 48V, 24V, 15V). Backbone equipment has all been qualified and installed; shore station re-equipping is complete; junction boxes are manufactured. A major marine program will deploy nodes and instruments in July-September 2009; instruments to one node will probably be deferred until 2010. Observatory instruments will be deployed in subsurface (boreholes), on seabed, and buoyed through the water column. Over 130 instruments (over 40 different types) will host several hundred sensors; mobile assets include a tethered crawler and a 400m vertical profiler. Experiments will address: earthquake dynamics and tsunami hazards; fluid fluxes in both ocean crust and sediments, including gas hydrates; ocean

  20. The interplanetary magnetic field observed by Juno enroute to Jupiter

    Science.gov (United States)

    Gruesbeck, Jacob R.; Gershman, Daniel J.; Espley, Jared R.; Connerney, John E. P.

    2017-06-01

    The Juno spacecraft was launched on 5 August 2011 and spent nearly 5 years traveling through the inner heliosphere on its way to Jupiter. The Magnetic Field Investigation was powered on shortly after launch and obtained vector measurements of the interplanetary magnetic field (IMF) at sample rates from 1 to 64 samples/second. The evolution of the magnetic field with radial distance from the Sun is compared to similar observations obtained by Voyager 1 and 2 and the Ulysses spacecraft, allowing a comparison of the radial evolution between prior solar cycles and the current depressed one. During the current solar cycle, the strength of the IMF has decreased throughout the inner heliosphere. A comparison of the variance of the normal component of the magnetic field shows that near Earth the variability of the IMF is similar during all three solar cycles but may be less at greater radial distances.

  1. High resolution LBT imaging of Io and Jupiter

    Science.gov (United States)

    Conrad, A.; de Kleer, K.; Leisenring, J.; La Camera, A.; Arcidiacono, C.; Bertero, M.; Boccacci, P.; Defrère, D.; de Pater, I.; Hinz, P.; Hoffman, K.-H.; Kürster, M.; Rathbun, J.; Schertl, D.; Skemer, A.; Skrutskie, M.; Spencer, J.; Veillet, C.; Weigelt, G.; Woodward, C.

    2015-10-01

    We report here results from observing Io at high angular resolution, ˜32 mas at 4.8 μm, with LBT at two favorable oppositions as described in our report given at the 2011 EPSC [1]. Analysis of datasets acquired during the last two oppositions has yielded spatially resolved M-band emission at Loki Patera [2], L-band fringes at an eruption site, an occultation of Loki and Pele by Europa, and sufficient sub-earth longitude (SEL) and parallactic angle coverage to produce a full disk map.We summarize completed results for the first of these, and give brief progress reports for the latter three. Finally, we provide plans for imaging the full disk of Jupiter using the MCAO system which is in its commissioning phase at LBT.

  2. KARL GOOSS AND A TEMPLE OF JUPITER IN APULUM

    Directory of Open Access Journals (Sweden)

    Csaba Szabó

    2015-12-01

    Full Text Available Karl Gooss (1844-1881 was one of the few intellectuals of his time who witnessed personally the building of the railway and the ditch of Alba Iulia between 1865 and 1868. The construction was the biggest project of the city since the building of the Vauban fort and destroyed the most significant part of the Colonia Aurelia Apulensis, one of the biggest urban centers of the province. During these works, Gooss witnessed the discovery and destruction of the first Jupiter temple attested in Dacia, the biggest silver deposit ever found in Transylvania and the first coin hoard of Apulum. His German publication was ignored by the later historiography, although it is the first and only detailed account of the archaeological finds discovered in the Partoș in the end of August, 1867. His detailed account helps us to identify the context of some well known artifacts and to reconsider the topography of the Colonia Aurelia Apulensis.

  3. The Interplanetary Magnetic Field Observed by Juno Enroute to Jupiter

    Science.gov (United States)

    Gruesbeck, Jacob R.; Gershman, Daniel J.; Espley, Jared R.; Connerney, John E. P.

    2017-01-01

    The Juno spacecraft was launched on 5 August 2011 and spent nearly 5 years traveling through the inner heliosphere on its way to Jupiter. The Magnetic Field Investigation was powered on shortly after launch and obtained vector measurements of the interplanetary magnetic field (IMF) at sample rates from 1 to 64 samples/second. The evolution of the magnetic field with radial distance from the Sun is compared to similar observations obtained by Voyager 1 and 2 and the Ulysses spacecraft, allowing a comparison of the radial evolution between prior solar cycles and the current depressed one. During the current solar cycle, the strength of the IMF has decreased throughout the inner heliosphere. A comparison of the variance of the normal component of the magnetic field shows that near Earth the variability of the IMF is similar during all three solar cycles but may be less at greater radial distances.

  4. An interstellar origin for Jupiter's retrograde co-orbital asteroid

    Science.gov (United States)

    Namouni, F.; Morais, M. H. M.

    2018-06-01

    Asteroid (514107) 2015 BZ509 was discovered recently in Jupiter's co-orbital region with a retrograde motion around the Sun. The known chaotic dynamics of the outer Solar system have so far precluded the identification of its origin. Here, we perform a high-resolution statistical search for stable orbits and show that asteroid (514107) 2015 BZ509 has been in its current orbital state since the formation of the Solar system. This result indicates that (514107) 2015 BZ509 was captured from the interstellar medium 4.5 billion years in the past as planet formation models cannot produce such a primordial large-inclination orbit with the planets on nearly coplanar orbits interacting with a coplanar debris disc that must produce the low-inclination small-body reservoirs of the Solar system such as the asteroid and Kuiper belts. This result also implies that more extrasolar asteroids are currently present in the Solar system on nearly polar orbits.

  5. Survey of Galileo Plasma Observations in Jupiter's Plasma Sheet

    Science.gov (United States)

    Bagenal, Fran; Wilson, Robert J.; Siler, Scott; Paterson, William R.; Kurth, William S.

    2016-01-01

    The plasma science (PLS) Instrument on the Galileo spacecraft (orbiting Jupiter from December 1995 to September 2003) measured properties of the ions that were trapped in the magnetic field. The PLS data provide a survey of the plasma properties between approx. 5 and 30 Jupiter radii [R(sub J)] in the equatorial region. We present plasma properties derived via two analysis methods: numerical moments and forward modeling. We find that the density decreases with radial distance by nearly 5 orders of magnitude from approx. 2 to 3000 cm(exp.-3) at 6R(sub j) to approx. 0.05cm(sub -3) at 30 R(sub j). The density profile did not show major changes from orbit to orbit, suggesting that the plasma production and transport remained constant within about a factor of 2. The radial profile of ion temperature increased with distance which implied that contrary to the concept of adiabatic cooling on expansion, the plasma heats up as it expands out from Io's orbit (where TI is approx.60-80 eV) at approx. 6R(sub j) to a few keV at 30R(sub j).There does not seem to be a long-term, systematic variation in ion temperature with either local time or longitude. This latter finding differs from earlier analysis of Galileo PLS data from a selection of orbits. Further examination of all data from all Galileo orbits suggests that System Ill variations are transitory on timescales of weeks, consistent with the modeling of Cassini Ultraviolet Imaging Spectrograph observations. The plasma flow is dominated by azimuthal flow that is between 80% and 100% of corotation out to 25 R(sub j).

  6. Formation of Silicate and Titanium Clouds on Hot Jupiters

    Science.gov (United States)

    Powell, Diana; Zhang, Xi; Gao, Peter; Parmentier, Vivien

    2018-06-01

    We present the first application of a bin-scheme microphysical and vertical transport model to determine the size distribution of titanium and silicate cloud particles in the atmospheres of hot Jupiters. We predict particle size distributions from first principles for a grid of planets at four representative equatorial longitudes, and investigate how observed cloud properties depend on the atmospheric thermal structure and vertical mixing. The predicted size distributions are frequently bimodal and irregular in shape. There is a negative correlation between the total cloud mass and equilibrium temperature as well as a positive correlation between the total cloud mass and atmospheric mixing. The cloud properties on the east and west limbs show distinct differences that increase with increasing equilibrium temperature. Cloud opacities are roughly constant across a broad wavelength range, with the exception of features in the mid-infrared. Forward-scattering is found to be important across the same wavelength range. Using the fully resolved size distribution of cloud particles as opposed to a mean particle size has a distinct impact on the resultant cloud opacities. The particle size that contributes the most to the cloud opacity depends strongly on the cloud particle size distribution. We predict that it is unlikely that silicate or titanium clouds are responsible for the optical Rayleigh scattering slope seen in many hot Jupiters. We suggest that cloud opacities in emission may serve as sensitive tracers of the thermal state of a planet’s deep interior through the existence or lack of a cold trap in the deep atmosphere.

  7. Main magnetic field of Jupiter and its implications for future orbiter missions

    Science.gov (United States)

    Acuna, M. H.; Ness, N. F.

    1975-01-01

    A very strong planetary magnetic field and an enormous magnetosphere with extremely intense radiation belts exist at Jupiter. Pioneer 10 and 11 fly-bys confirmed and extended the earlier ground based estimates of many of these characteristics but left unanswered or added to the list of several important and poorly understood features: the source mechanism and location of decametric emissions, and the absorption effects by the natural satellites Amalthea, Io, Europa and Ganymede. High inclination orbits (exceeding 60 deg) with low periapses (less than 2 Jupiter radii) are required to map the radiation belts and main magnetic field of Jupiter accurately so as to permit full investigation of these and associated phenomena.

  8. Jupiter's interior and deep atmosphere: The initial pole-to-pole passes with the Juno spacecraft

    DEFF Research Database (Denmark)

    Bolton, S. J.; Adriani, Alberto; Adumitroaie, V.

    2017-01-01

    On 27 August 2016, the Juno spacecraft acquired science observations of Jupiter, passing less than 5000 kilometers above the equatorial cloud tops. Images of Jupiter's poles show a chaotic scene, unlike Saturn's poles. Microwave sounding reveals weather features at pressures deeper than 100 bars,...... of magnitude more precise. This has implications for the distribution of heavy elements in the interior, including the existence and mass of Jupiter's core. The observed magnetic field exhibits smaller spatial variations than expected, indicative of a rich harmonic content....

  9. THE PHOTOECCENTRIC EFFECT AND PROTO-HOT JUPITERS. III. A PAUCITY OF PROTO-HOT JUPITERS ON SUPER-ECCENTRIC ORBITS

    International Nuclear Information System (INIS)

    Dawson, Rebekah I.; Murray-Clay, Ruth A.; Johnson, John Asher

    2015-01-01

    Gas giant planets orbiting within 0.1 AU of their host stars are unlikely to have formed in situ and are evidence for planetary migration. It is debated whether the typical hot Jupiter smoothly migrated inward from its formation location through the proto-planetary disk, or was perturbed by another body onto a highly eccentric orbit, which tidal dissipation subsequently shrank and circularized during close stellar passages. Socrates and collaborators predicted that the latter model should produce a population of super-eccentric proto-hot Jupiters readily observable by Kepler. We find a paucity of such planets in the Kepler sample, which is inconsistent with the theoretical prediction with 96.9% confidence. Observational effects are unlikely to explain this discrepancy. We find that the fraction of hot Jupiters with an orbital period P > 3 days produced by the star-planet Kozai mechanism does not exceed (at two-sigma) 44%. Our results may indicate that disk migration is the dominant channel for producing hot Jupiters with P > 3 days. Alternatively, the typical hot Jupiter may have been perturbed to a high eccentricity by interactions with a planetary rather than stellar companion, and began tidal circularization much interior to 1 AU after multiple scatterings. A final alternative is that early in the tidal circularization process at high eccentricities tidal circularization occurs much more rapidly than later in the process at low eccentricities, although this is contrary to current tidal theories

  10. HAT-P-26b: A Neptune-mass exoplanet with a well-constrained heavy element abundance.

    Science.gov (United States)

    Wakeford, Hannah R; Sing, David K; Kataria, Tiffany; Deming, Drake; Nikolov, Nikolay; Lopez, Eric D; Tremblin, Pascal; Amundsen, David S; Lewis, Nikole K; Mandell, Avi M; Fortney, Jonathan J; Knutson, Heather; Benneke, Björn; Evans, Thomas M

    2017-05-12

    A correlation between giant-planet mass and atmospheric heavy elemental abundance was first noted in the past century from observations of planets in our own Solar System and has served as a cornerstone of planet-formation theory. Using data from the Hubble and Spitzer Space Telescopes from 0.5 to 5 micrometers, we conducted a detailed atmospheric study of the transiting Neptune-mass exoplanet HAT-P-26b. We detected prominent H 2 O absorption bands with a maximum base-to-peak amplitude of 525 parts per million in the transmission spectrum. Using the water abundance as a proxy for metallicity, we measured HAT-P-26b's atmospheric heavy element content ([Formula: see text] times solar). This likely indicates that HAT-P-26b's atmosphere is primordial and obtained its gaseous envelope late in its disk lifetime, with little contamination from metal-rich planetesimals. Copyright © 2017, American Association for the Advancement of Science.

  11. Advanced Representation Technologies Applied to the Temple of Neptune, the Sphinx and the Metope in the Archaeological Park of Paestum

    Science.gov (United States)

    Cardinale, T.; Valva, R.; Lucarelli, M.

    2013-02-01

    The Summer School of Surveying and 3D modelling in Paestum was an opportunity to explore the use of innovative tools and advanced techniques in the design, implementation and management of surveys of historic and artistic complexes. In general such methods are used specifically for the development and management of vulnerability maps of existing heritage and so for the preventive conservation and valorisation of the built environment. The accurate detection of risk situations and the systematic promotion of highly selected and minimally invasive maintenance practices means that restoration and the efficiency of cycles of intervention can be optimized, with clear benefits from economic and cultural points of view. The group worked on the survey and 3D modelling of the Temple of Neptune, the Sphinx and the Metope of the Archaeological Park in Paestum.

  12. The constructive solution of the Greifswald linear accelerator 'Neptun 10 p' project from the point of view of radiation protection

    International Nuclear Information System (INIS)

    Schmidt, W.; Waag, V.; Nadrowitz, R.; Wendorff, W.

    1981-01-01

    In 1981 the linear accelerator 'Neptun 10 p' will be mounted at the Radiological Clinic of the University of Greifswald. Its place will be an irradiation room which is equipped for a radiation of 1.33 MeV. The strengthening of walls and celling, which is necessary for 9 MeV bremsstrahlung and 10 MeV electron radiation, can only be realized by a self-supporting lead-steel construction for reasons of the distance to the neighbouring house and of the connected conditions of foundation as well as of the load capacity of the existing construction of the roof. As in the eighties similar problems are to be expected in other radiological hospitals of the GDR the constructive solution of the Greifswald linear accelerator project and connected problems of the radiation protection are represented. (author)

  13. Discovery of a Transiting Adolescent Sub-Neptune Exoplanet in the Cas-Tau Association With K2

    Science.gov (United States)

    Mamajek, Eric; David, Trevor; Bieryla, Allyson; Bristow, Makennah; Ciardi, David; Cody, Ann Marie; Crossfield, Ian; Fulton, Benjamin; Jasmine Gonzales, Erica; Hillenbrand, Lynne; Hirsch, Lea; Howard, Andrew; Isaacson, Howard; Latham, David W.; Petigura, Erik; Rebull, Luisa; Schlieder, Joshua; Stauffer, John; Vanderburg, Andrew; Vasisht, Gautam

    2018-01-01

    The role of stellar age in the measured properties and occurrence rates of exoplanets is not well understood. This is in part due to a paucity of young planets and the uncertainties in age-dating for most exoplanet host stars. Exoplanets belonging to coeval stellar populations, young or old, are particularly useful as benchmarks for studies aiming to constrain the evolutionary timescales relevant for planets. Such timescales may concern orbital migration, gravitational contraction, or photo-evaporation, among other mechanisms. Here we report the serendipitous discovery of a transiting sub-Neptune from K2 photometry of a K-type star that is a new candidate member of the nearby young Cas-Tau association. The size of the planet (3.0 +/- 0.5 Earth radii) and its age (~50-90 Myr) make it an intriguing test case for photo-evaporation models, which predict enhanced atmospheric mass loss during early evolutionary stages.

  14. FORMATION OF CLOSE IN SUPER-EARTHS AND MINI-NEPTUNES: REQUIRED DISK MASSES AND THEIR IMPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Schlichting, Hilke E., E-mail: hilke@mit.edu [Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139-4307 (United States)

    2014-11-01

    Recent observations by the Kepler space telescope have led to the discovery of more than 4000 exoplanet candidates consisting of many systems with Earth- to Neptune-sized objects that reside well inside the orbit of Mercury around their respective host stars. How and where these close-in planets formed is one of the major unanswered questions in planet formation. Here, we calculate the required disk masses for in situ formation of the Kepler planets. We find that if close-in planets formed as isolation masses, then standard gas-to-dust ratios yield corresponding gas disks that are gravitationally unstable for a significant fraction of systems, ruling out such a scenario. We show that the maximum width of a planet's accretion region in the absence of any migration is 2v {sub esc}/Ω, where v {sub esc} is the escape velocity of the planet and Ω is the Keplerian frequency, and we use it to calculate the required disk masses for in situ formation with giant impacts. Even with giant impacts, formation without migration requires disk surface densities in solids at semi-major axes of less than 0.1 AU of 10{sup 3}-10{sup 5} g cm{sup –2}, implying typical enhancements above the minimum-mass solar nebular (MMSN) by at least a factor of 20. Corresponding gas disks are below but not far from the gravitational stability limit. In contrast, formation beyond a few AU is consistent with MMSN disk masses. This suggests that the migration of either solids or fully assembled planets is likely to have played a major role in the formation of close-in super-Earths and mini-Neptunes.

  15. Periodicity in changes of Jupiter's hemispheres activity factor is continues to recover in 2018

    Science.gov (United States)

    Vidmachenko, A. P.

    2018-05-01

    From the mid-1990s to 2013 that there was a maximum mismatch between the time of Jupiter's passage at orbit at perihelion and aphelion, and the moments of minima and maxima of Solar activity. In 1963-1995 the correlation between the changes in factor AJ, Solar activity and the moments of passage of perihelion and aphelion of the orbit - was high, and the nature of the changes was synchronized. After 1995, inconsistency in the supply of Solar energy to northern and southern hemispheres of Jupiter and its movement in orbit - has become significant. But after 2014, the periodicity in the change of photometric characteristics of the northern and southern hemispheres of Jupiter, again becomes coordinated. And the data for 2017 and 2018 confirm the improvement of the matching of the course of the Aj(T) dependence, SA index and the regime irradiation by the Sun of Jupiter at it moves along the orbit.

  16. BUILDING MODEL ANALYSIS APPLICATIONS WITH THE JOINT UNIVERSAL PARAMETER IDENTIFICATION AND EVALUATION OF RELIABILITY (JUPITER) API

    Science.gov (United States)

    The open-source, public domain JUPITER (Joint Universal Parameter IdenTification and Evaluation of Reliability) API (Application Programming Interface) provides conventions and Fortran-90 modules to develop applications (computer programs) for analyzing process models. The input ...

  17. GO JUP POS MOONS TRAJ JUPITER CENTERED COORDINATES V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains the System III (1965.0) trajectory and Sun and Earth phase angles of Galileo and selected Jovian moons when Galileo was inside 30 Jupiter...

  18. VOYAGER 1&2 JUPITER BRIGHTNESS NORTH/SOUTH MAP SET V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains Voyager 1 and 2 measurements of the brightness of Jupiter at H Lyman alpha and in the H2 Lyman and Werner bands shortward of H Lyman alpha....

  19. MSSSO CASPIR STAR CALS BEFORE SL9 IMPACTS WITH JUPITER V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This archive contains star images used as calibrations in preparation for the collision of Comet Shoemaker-Levy 9 with Jupiter obtained with CASPIR on the Australian...

  20. JUPOS : Amateur analysis of Jupiter images with specialized measurement software

    Science.gov (United States)

    Jacquesson, M.; Mettig, H.-J.

    2008-09-01

    Introduction - Beginning of JUPOS in 1989, H.J. Mettig and Grischa Hahn in Dresden - 350.000 positional measures on electronic images of almost 180 observers have been gathered since 1998 - What do we mean by "electronic images": o digitized hi-res chemical photographs o traditional CCD technique o webcam images - 2002 started the implementation of WinJUPOS by Grischa, now finished - Cooperation with the Jupiter Section of the BAA for many years - At present, JUPOS has four active measurers: o Gianluigi Adamoli and Marco Vedovato (Italy) o H.J. Mettig (Germany) o Michel Jacquesson (France) How we work together - Each member of the team measures images of several observers (useful to detect and avoid systematic errors) - When necessary, exchange of problems and ideas by e-mail - During the period of visibility of Jupiter, team leader H.J. Mettig: o collects all recent measurements about once a month o produces drift charts - Once a year or two, the JUPOS team helds an informal meeting Criteria for image selection 1) Validity of time and date: Origins of time errors: 1. local zonal times are wrongly (or, not at all) converted to UT. This is still easy to find out: Either "only" the full hour is erroneous, or/and the date (problem of observers with UTC+10) 2. the computer clock has not been synchronised over a longer period 3. exposure of the final image exceeds the recommended two minutes or observers communicate begin or end of the total period of image recording instead of its middle How to test the validity of the time? - Position of a galilean satellite visible on or near Jupiter - Position of a satellite shadow - Measuring the longitude of permanent or long lived objects whose positions are known from former measurements 2) Avoid measuring the same object on different images taken at about the same time. One image every 1 ½ hours is sufficient 3) Duration of exposure: not more than 2-3 minutes because of the rapid rotation of Jupiter 4) Spectral range: Visual

  1. Eligibility for statin therapy by the JUPITER trial criteria and subsequent mortality.

    Science.gov (United States)

    Cushman, Mary; McClure, Leslie A; Lakoski, Susan G; Jenny, Nancy S

    2010-01-01

    Justification for the Use of Statins in Primary Prevention: An Intervention Trial Using Rosuvastatin (JUPITER) reported reduced cardiovascular and all-cause mortality with statin treatment in patients with elevated C-reactive protein (CRP) and average cholesterol levels who were not eligible for lipid-lowering treatment on the basis of existing guidelines. The aim of this study was to determine the prevalence of eligibility and mortality in a general population sample on the basis of eligibility for statin treatment using the JUPITER criteria. The study group consisted of 30,229 participants in the REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort, an observational study of US African American and white participants aged > or =45 years, enrolled in their homes from 2003 to 2007 and followed biannually by telephone. Among 11,339 participants age eligible for JUPITER and without vascular diagnoses or using lipid-lowering treatment, 21% (n = 2,342) met JUPITER entry criteria. Compared with JUPITER participants, they had similar low-density lipoprotein cholesterol and CRP levels, were more often women, were more often black, had metabolic syndrome, and used aspirin for cardioprotection. Over 3.5 years of follow-up, the mortality rate in REGARDS participants eligible for JUPITER was 1.17 per 100 patient-years (95% confidence interval 0.94 to 1.42). Compared with those otherwise JUPITER eligible who had CRP levels or =2 mg/L had a multivariate-adjusted relative risk of 1.5 (95% confidence interval 1.1 to 2.2) for total mortality. In conclusion, 21% not otherwise eligible would be newly eligible for lipid lowering treatment on the basis of JUPITER trial eligibility.

  2. Dekametric and hectometric observations of Jupiter from the RAE-1 satellite

    Science.gov (United States)

    Desch, M. D.; Carr, T. D.

    1974-01-01

    Analysis of RAE-1 satellite data has revealed the presence of radio bursts from Jupiter in the frequency range from 4700 kHz to 450 kHz. Variations in the activity with respect to the planet's system III longitude are presented at seven frequencies. A merge of ground-based and satellite-acquired data indicates that the long-sought-for peak in Jupiter's low-frequency flux spectrum occurs at about 8 MHz.

  3. NEBULAR WATER DEPLETION AS THE CAUSE OF JUPITER'S LOW OXYGEN ABUNDANCE

    International Nuclear Information System (INIS)

    Mousis, Olivier; Lunine, Jonathan I.; Madhusudhan, Nikku; Johnson, Torrence V.

    2012-01-01

    Motivated by recent spectroscopic observations suggesting that atmospheres of some extrasolar giant planets are carbon-rich, i.e., carbon/oxygen ratio (C/O) ≥ 1, we find that the whole set of compositional data for Jupiter is consistent with the hypothesis that it should be a carbon-rich giant planet. We show that the formation of Jupiter in the cold outer part of an oxygen-depleted disk (C/O ∼ 1) reproduces the measured Jovian elemental abundances at least as well as the hitherto canonical model of Jupiter formed in a disk of solar composition (C/O 0.54). The resulting O abundance in Jupiter's envelope is then moderately enriched by a factor of ∼2 × solar (instead of ∼7 × solar) and is found to be consistent with values predicted by thermochemical models of the atmosphere. That Jupiter formed in a disk with C/O ∼ 1 implies that water ice was heterogeneously distributed over several AU beyond the snow line in the primordial nebula and that the fraction of water contained in icy planetesimals was a strong function of their formation location and time. The Jovian oxygen abundance to be measured by NASA's Juno mission en route to Jupiter will provide a direct and strict test of our predictions.

  4. NEBULAR WATER DEPLETION AS THE CAUSE OF JUPITER'S LOW OXYGEN ABUNDANCE

    Energy Technology Data Exchange (ETDEWEB)

    Mousis, Olivier [Universite de Franche-Comte, Institut UTINAM, CNRS/INSU, UMR 6213, Observatoire des Sciences de l' Univers de Besancon (France); Lunine, Jonathan I. [Center for Radiophysics and Space Research, Space Sciences Building, Cornell University, Ithaca, NY 14853 (United States); Madhusudhan, Nikku [Yale Center for Astronomy and Astrophysics, Department of Physics, Yale University, New Haven, CT 06511 (United States); Johnson, Torrence V., E-mail: olivier.mousis@obs-besancon.fr [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)

    2012-05-20

    Motivated by recent spectroscopic observations suggesting that atmospheres of some extrasolar giant planets are carbon-rich, i.e., carbon/oxygen ratio (C/O) {>=} 1, we find that the whole set of compositional data for Jupiter is consistent with the hypothesis that it should be a carbon-rich giant planet. We show that the formation of Jupiter in the cold outer part of an oxygen-depleted disk (C/O {approx} 1) reproduces the measured Jovian elemental abundances at least as well as the hitherto canonical model of Jupiter formed in a disk of solar composition (C/O 0.54). The resulting O abundance in Jupiter's envelope is then moderately enriched by a factor of {approx}2 Multiplication-Sign solar (instead of {approx}7 Multiplication-Sign solar) and is found to be consistent with values predicted by thermochemical models of the atmosphere. That Jupiter formed in a disk with C/O {approx} 1 implies that water ice was heterogeneously distributed over several AU beyond the snow line in the primordial nebula and that the fraction of water contained in icy planetesimals was a strong function of their formation location and time. The Jovian oxygen abundance to be measured by NASA's Juno mission en route to Jupiter will provide a direct and strict test of our predictions.

  5. Coupled rotational dynamics of Jupiter's thermosphere and magnetosphere

    Directory of Open Access Journals (Sweden)

    C. G. A. Smith

    2009-01-01

    Full Text Available We describe an axisymmetric model of the coupled rotational dynamics of the thermosphere and magnetosphere of Jupiter that incorporates self-consistent physical descriptions of angular momentum transfer in both systems. The thermospheric component of the model is a numerical general circulation model. The middle magnetosphere is described by a simple physical model of angular momentum transfer that incorporates self-consistently the effects of variations in the ionospheric conductivity. The outer magnetosphere is described by a model that assumes the existence of a Dungey cycle type interaction with the solar wind, producing at the planet a largely stagnant plasma flow poleward of the main auroral oval. We neglect any decoupling between the plasma flows in the magnetosphere and ionosphere due to the formation of parallel electric fields in the magnetosphere. The model shows that the principle mechanism by which angular momentum is supplied to the polar thermosphere is meridional advection and that mean-field Joule heating and ion drag at high latitudes are not responsible for the high thermospheric temperatures at low latitudes on Jupiter. The rotational dynamics of the magnetosphere at radial distances beyond ~30 RJ in the equatorial plane are qualitatively unaffected by including the detailed dynamics of the thermosphere, but within this radial distance the rotation of the magnetosphere is very sensitive to the rotation velocity of the thermosphere and the value of the Pedersen conductivity. In particular, the thermosphere connected to the inner magnetosphere is found to super-corotate, such that true Pedersen conductivities smaller than previously predicted are required to enforce the observed rotation of the magnetosphere within ~30 RJ. We find that increasing the Joule heating at high latitudes by adding a component due to rapidly fluctuating electric fields is unable to explain the high equatorial temperatures. Adding a component of Joule

  6. Jupiter's Magnetosphere: Plasma Description from the Ulysses Flyby.

    Science.gov (United States)

    Bame, S J; Barraclough, B L; Feldman, W C; Gisler, G R; Gosling, J T; McComas, D J; Phillips, J L; Thomsen, M F; Goldstein, B E; Neugebauer, M

    1992-09-11

    Plasma observations at Jupiter show that the outer regions of the Jovian magnetosphere are remarkably similar to those of Earth. Bow-shock precursor electrons and ions were detected in the upstream solar wind, as at Earth. Plasma changes across the bow shock and properties of the magnetosheath electrons were much like those at Earth, indicating that similar processes are operating. A boundary layer populated by a varying mixture of solar wind and magnetospheric plasmas was found inside the magnetopause, again as at Earth. In the middle magnetosphere, large electron density excursions were detected with a 10-hour periodicity as planetary rotation carried the tilted plasma sheet past Ulysses. Deep in the magnetosphere, Ulysses crossed a region, tentatively described as magnetically connected to the Jovian polar cap on one end and to the interplanetary magnetic field on the other. In the inner magnetosphere and lo torus, where corotation plays a dominant role, measurements could not be made because of extreme background rates from penetrating radiation belt particles.

  7. A possible flyby anomaly for Juno at Jupiter

    Science.gov (United States)

    Acedo, L.; Piqueras, P.; Moraño, J. A.

    2018-05-01

    In the last decades there have been an increasing interest in improving the accuracy of spacecraft navigation and trajectory data. In the course of this plan some anomalies have been found that cannot, in principle, be explained in the context of the most accurate orbital models including all known effects from classical dynamics and general relativity. Of particular interest for its puzzling nature, and the lack of any accepted explanation for the moment, is the flyby anomaly discovered in some spacecraft flybys of the Earth over the course of twenty years. This anomaly manifest itself as the impossibility of matching the pre and post-encounter Doppler tracking and ranging data within a single orbit but, on the contrary, a difference of a few mm/s in the asymptotic velocities is required to perform the fitting. Nevertheless, no dedicated missions have been carried out to elucidate the origin of this phenomenon with the objective either of revising our understanding of gravity or to improve the accuracy of spacecraft Doppler tracking by revealing a conventional origin. With the occasion of the Juno mission arrival at Jupiter and the close flybys of this planet, that are currently been performed, we have developed an orbital model suited to the time window close to the perijove. This model shows that an anomalous acceleration of a few mm/s2 is also present in this case. The chance for overlooked conventional or possible unconventional explanations is discussed.

  8. First results from the Hubble OPAL Program: Jupiter in 2015

    Science.gov (United States)

    Simon, Amy A.; Wong, Michael H.; Orton, Glenn S.

    2015-11-01

    The Hubble 2020: Outer Planet Atmospheres Legacy (OPAL) program is a Director's Discretionary program designed to generate two yearly global maps for each of the outer planets to enable long term studies of atmospheric color, structure and two-dimensional wind fields. This presentation focuses on Jupiter results from the first year of the campaign. Data were acqured January 19, 2015 with the WFC3/UVIS camera and the F275W, F343N, F395N, F467M, F502N, F547M, F631N, F658N, and F889N filters. Global maps were generated and are publicly available through the High Level Science Products archive: https://archive.stsci.edu/prepds/opal/Using cross-correlation on the global maps, the zonal wind profile was measured between +/- 50 degrees latitude and is in family with Voyager and Cassini era profiles. There are some variations in mid to high latitude wind jet magnitudes, particularly at +40°and -35° planetographic latitude. The Great Red Spot continues to maintain an intense orange coloration, as it did in 2014. However, the interior shows changed structure, including a reduced core and new filamentary features. Finally, a wave not previously seen in Hubble images was also observed and is interpreted as a baroclinic instability with associated cyclone formation near 16° N latitude. A similar feature was observed faintly in Voyager 2 images, and is consistent with the Hubble feature in location and scale.

  9. A catalog of observed nuclear magnitudes of Jupiter family comets

    Science.gov (United States)

    Tancredi, G.; Fernández, J. A.; Rickman, H.; Licandro, J.

    2000-10-01

    A catalog of a sample of 105 Jupiter family (JF) comets (defined as those with Tisserand constants T > 2 and orbital periods P International Comet Quarterly Archive of Cometary Photometric Data, the Minor Planet Center (MPC) data base, IAU Circulars, International Comet Quarterly, and a few papers devoted to some particular comets, together with our own observations. Photometric data previous to 1990 have mainly been taken from the Comet Light Curve Catalogue (CLICC) compiled by Kamél (\\cite{kamel}). We discuss the reliability of the reported nuclear magnitudes in relation to the inherent sources of errors and uncertainties, in particular the coma contamination often present even at large heliocentric distances. A large fraction of the JF comets of our sample indeed shows various degrees of activity at large heliocentric distances, which is correlated with recent downward jumps in their perihelion distances. The reliability of coma subtraction methods to compute the nuclear magnitude is also discussed. Most absolute nuclear magnitudes are found in the range 15 - 18, with no magnitudes fainter than H_N ~ 19.5. The catalog can be found at: http://www.fisica.edu.uy/ ~ gonzalo/catalog/. Table 2 and Appendix B are only available in electronic form at http://www.edpsciences.org Table 5 is also available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html

  10. Constraining planetary migration and tidal dissipation with coeval hot Jupiters

    Science.gov (United States)

    O'Connor, Christopher E.; Hansen, Bradley M. S.

    2018-06-01

    We investigate the constraints on the formation of, and tidal dissipation processes in, hot Jupiters (HJs) that can be inferred based on reliable knowledge of the age of a system or population. Particular attention is paid to the role of young systems (such as those in open clusters or star-forming regions) in such studies. For an ensemble of coeval HJ (or proto-HJ) systems, we quantify the effect of age on the distribution of orbital eccentricities with respect to orbital periods as well as the location of the observed `pile-up' feature. We expect the effects of pre-main-sequence stellar evolution to be important only if a substantial fraction of HJs approach their current orbits early in protostellar contraction (ages ≲ 10 Myr). Application to the HJs presently known in the cluster M 67 yields constraints on the dissipation roughly consistent with those gleaned from planets in the field; for those in the Hyades and Praesepe, our results suggest a higher degree of dissipation at early times than that inferred from other populations.

  11. Dramatic Change in Jupiter's Great Red Spot from Spacecraft Observations

    Science.gov (United States)

    Simon, Amy A.; Wong, Michael H.; Rogers, John H.; Orton, Glenn S.; de Pater, Imke; Asay-Davis, Xylar; Carlson, Robert W.; Marcus, Philip S.

    2015-01-01

    Jupiter's Great Red Spot (GRS) is one of its most distinct and enduring features. Since the advent of modern telescopes, keen observers have noted its appearance and documented a change in shape from very oblong to oval, confirmed in measurements from spacecraft data. It currently spans the smallest latitude and longitude size ever recorded. Here we show that this change has been accompanied by an increase in cloud/haze reflectance as sensed in methane gas absorption bands, increased absorption at wavelengths shorter than 500 nanometers, and increased spectral slope between 500 and 630 nanometers. These changes occurred between 2012 and 2014, without a significant change in internal tangential wind speeds; the decreased size results in a 3.2 day horizontal cloud circulation period, shorter than previously observed. As the GRS has narrowed in latitude, it interacts less with the jets flanking its north and south edges, perhaps allowing for less cloud mixing and longer UV irradiation of cloud and aerosol particles. Given its long life and observational record, we expect that future modeling of the GRS's changes, in concert with laboratory flow experiments, will drive our understanding of vortex evolution and stability in a confined flow field crucial for comparison with other planetary atmospheres.

  12. Spectral Comparison and Stability of Red Regions on Jupiter

    Science.gov (United States)

    Simon, A. A.; Carlson, R. W.; Sanchez-Lavega, A.

    2013-01-01

    A study of absolute color on Jupiter from Hubble Space Telescope imaging data shows that the Great Red Spot (GRS) is not the reddest region of the planet. Rather, a transient red cyclone visible in 1995 and the North Equatorial Belt both show redder spectra than the GRS (i.e., more absorption at blue and green wavelengths). This cyclone is unique among vortices in that it is intensely colored yet low altitude, unlike the GRS. Temporal analysis shows that the darkest regions of the NEB are relative constant in color from 1995 to 2008, while the slope of the GRS core may vary slightly. Principal component analysis shows several spectral components are needed, in agreement with past work, and further highlights the differences between regions. These color differences may be indicative of the same chromophore(s) under different conditions, such as mixing with white clouds, longer UV irradiation at higher altitude, and thermal processing, or may indicate abundance variations in colored compounds. A single compound does not fit the spectrum of any region well and mixes of multiple compounds including NH4SH, photolyzed NH3, hydrocarbons, and possibly P4, are likely needed to fully match each spectrum.

  13. Dust arcs in the region of Jupiter's Trojan asteroids

    Science.gov (United States)

    Liu, Xiaodong; Schmidt, Jürgen

    2018-01-01

    Aims: The surfaces of the Trojan asteroids are steadily bombarded by interplanetary micrometeoroids, which releases ejecta of small dust particles. These particles form the faint dust arcs that are associated with asteroid clouds. Here we analyze the particle dynamics and structure of the arc in the region of the L4 Trojan asteroids. Methods: We calculate the total cross section of the L4 Trojan asteroids and the production rate of dust particles. The motion of the particles is perturbed by a variety of forces. We simulate the dynamical evolution of the dust particles, and explore the overall features of the Trojan dust arc. Results: The simulations show that the arc is mainly composed of grains in the size range 4-10 microns. Compared to the L4 Trojan asteroids, the dust arc is distributed more widely in the azimuthal direction, extending to a range of [30, 120] degrees relative to Jupiter. The peak number density does not develop at L4. There exist two peaks that are azimuthally displaced from L4.

  14. THE LUPUS TRANSIT SURVEY FOR HOT JUPITERS: RESULTS AND LESSONS

    International Nuclear Information System (INIS)

    Bayliss, Daniel D. R.; Sackett, Penny D.; Weldrake, David T. F.; Tingley, Brandon W.; Lewis, Karen M.

    2009-01-01

    We present the results of a deep, wide-field transit survey targeting 'Hot Jupiter' planets in the Lupus region of the Galactic plane conducted over 53 nights concentrated in two epochs separated by a year. Using the Australian National University 40-inch telescope at Siding Spring Observatory (SSO), the survey covered a 0.66 deg 2 region close to the Galactic plane (b = 11 0 ) and monitored a total of 110,372 stars (15.0 ≤ V ≤ 22.0). Using difference imaging photometry, 16,134 light curves with a photometric precision of σ < 0.025 mag were obtained. These light curves were searched for transits, and four candidates were detected that displayed low-amplitude variability consistent with a transiting giant planet. Further investigations, including spectral typing and radial velocity measurements for some candidates, revealed that of the four, one is a true planetary companion (Lupus-TR-3), two are blended systems (Lupus-TR-1 and 4), and one is a binary (Lupus-TR-2). The results of this successful survey are instructive for optimizing the observational strategy and follow-up procedure for deep searches for transiting planets, including an upcoming survey using the SkyMapper telescope at SSO.

  15. Parameterization of ionization rate by auroral electron precipitation in Jupiter

    Directory of Open Access Journals (Sweden)

    Y. Hiraki

    2008-02-01

    Full Text Available We simulate auroral electron precipitation into the Jovian atmosphere in which electron multi-directional scattering and energy degradation processes are treated exactly with a Monte Carlo technique. We make a parameterization of the calculated ionization rate of the neutral gas by electron impact in a similar way as used for the Earth's aurora. Our method allows the altitude distribution of the ionization rate to be obtained as a function of an arbitrary initial energy spectrum in the range of 1–200 keV. It also includes incident angle dependence and an arbitrary density distribution of molecular hydrogen. We show that there is little dependence of the estimated ionospheric conductance on atomic species such as H and He. We compare our results with those of recent studies with different electron transport schemes by adapting our parameterization to their atmospheric conditions. We discuss the intrinsic problem of their simplified assumption. The ionospheric conductance, which is important for Jupiter's magnetosphere-ionosphere coupling system, is estimated to vary by a factor depending on the electron energy spectrum based on recent observation and modeling. We discuss this difference through the relation with field-aligned current and electron spectrum.

  16. Parameterization of ionization rate by auroral electron precipitation in Jupiter

    Directory of Open Access Journals (Sweden)

    Y. Hiraki

    2008-02-01

    Full Text Available We simulate auroral electron precipitation into the Jovian atmosphere in which electron multi-directional scattering and energy degradation processes are treated exactly with a Monte Carlo technique. We make a parameterization of the calculated ionization rate of the neutral gas by electron impact in a similar way as used for the Earth's aurora. Our method allows the altitude distribution of the ionization rate to be obtained as a function of an arbitrary initial energy spectrum in the range of 1–200 keV. It also includes incident angle dependence and an arbitrary density distribution of molecular hydrogen. We show that there is little dependence of the estimated ionospheric conductance on atomic species such as H and He. We compare our results with those of recent studies with different electron transport schemes by adapting our parameterization to their atmospheric conditions. We discuss the intrinsic problem of their simplified assumption. The ionospheric conductance, which is important for Jupiter's magnetosphere-ionosphere coupling system, is estimated to vary by a factor depending on the electron energy spectrum based on recent observation and modeling. We discuss this difference through the relation with field-aligned current and electron spectrum.

  17. Jupiter: Peer-to-Peer Networking Platform over Heterogeneous Networks

    Directory of Open Access Journals (Sweden)

    Norihiro Ishikawa

    2006-10-01

    Full Text Available Peer-to-peer has entered the public limelight over the last few years. Several research projects are underway on peer-to-peer technologies, but no definitive conclusion is currently available. Compared with traditional Internet technologies, peer-to-peer has the potential to realize highly scalable, extensible, and efficient distributed applications. This is because its basic functions realize resource discovery, resource sharing, and load balancing in a highly distributed manner. An easy prediction is the emergence of an environment in which many sensors, people, and many different kinds of objects exist, move, and communicate with one another. Peer-to-peer is one of the most important and suitable technologies for such networking since it supports discovery mechanisms, simple one-to-one communication between devices, free and extensible distribution of resources, and distributed search to handle the enormous number of resources. The purpose of this study is to explore a universal peer-to-peer network architecture that will allow various devices to communicate with one another across various networks. We have been designing architecture and protocols for realizing peer-to-peer networking among various devices. We are currently designing APIs that are available for various peer-to-peer applications and are implementing a prototype called "Jupiter" as a peer-to-peer networking platform over heterogeneous networks.

  18. Latitudinal beaming of Jupiter's low frequency radio emissions

    International Nuclear Information System (INIS)

    Alexander, J.K.; Desch, M.D.; Kaiser, M.L.; Thieman, J.R.

    1979-01-01

    By comparing Rae 1 and Imp 6 satelite measurements of Jupiter's radio emissions near 1 MHz with recent Voyager 1 and 2 observations in the same frequency range it is now possible to study the properties of the low frequency radiation pattern over a 10 0 range of latitudes with respect to the Jovian rotation equator. These observations, which cover a wider latitudinal range than is possible from the earth, are consistent with many aspect of earlier ground-based measurements that have been used to infer a sharp beaming pattern for the decameter wavelength emissions. We find marked, systematic changes in the statistical occurrence probability distributions with system III central meridian longitude as the Jovigraphic latitude of the observer changes over this range. Moreover, simultaneous observations by the two Voyager spacecraft, which are separated by up to 3 0 in Jovigraphic latitude, suggest that the instantaneous beam width may be no more than a few degrees at times. The new hectometer wave results can be interpreted in terms of a narrow, curved sheet at a fixed magnetic latitude into which the emission is beamed to escape the planet

  19. Mid-infrared spectroscopy of Uranus from the Spitzer Infrared Spectrometer: 1. Determination of the mean temperature structure of the upper troposphere and stratosphere

    Science.gov (United States)

    Orton, Glenn S.; Fletcher, Leigh N.; Moses, Julianne I.; Mainzer, Amy K.; Hines, Dean; Hammel, Heidi B.; Martin-Torres, F. Javier; Burgdorf, Martin; Merlet, Cecile; Line, Michael R.

    2014-11-01

    On 2007 December 16-17, spectra were acquired of the disk of Uranus by the Spitzer Infrared Spectrometer (IRS), ten days after the planet's equinox, when its equator was close to the sub-Earth point. This spectrum provides the highest-resolution broad-band spectrum ever obtained for Uranus from space, allowing a determination of the disk-averaged temperature and molecule composition to a greater degree of accuracy than ever before. The temperature profiles derived from the Voyager radio occultation experiment by Lindal et al. (Lindal, G.F., Lyons, J.R., Sweetnam, D.N., Eshleman, V.R., Hinson, D.P. [1987]. J. Geophys. Res. 92, 14987-15001) and revisions suggested by Sromovsky et al. (Sromovsky, L.A., Fry, P.A., Kim, J.H. [2011]. Icarus 215, 292-312) that match these data best are those that assume a high abundance of methane in the deep atmosphere. However, none of these model profiles provides a satisfactory fit over the full spectral range sampled. This result could be the result of spatial differences between global and low-latitudinal regions, changes in time, missing continuum opacity sources such as stratospheric hazes or unknown tropospheric constituents, or undiagnosed systematic problems with either the Voyager radio-occultation or the Spitzer IRS data sets. The spectrum is compatible with the stratospheric temperatures derived from the Voyager ultraviolet occultations measurements by Herbert et al. (Herbert, F. et al. [1987]. J. Geophys. Res. 92, 15093-15109), but it is incompatible with the hot stratospheric temperatures derived from the same data by Stevens et al. (Stevens, M.H., Strobel, D.F., Herbert, F.H. [1993]. Icarus 101, 45-63). Thermospheric temperatures determined from the analysis of the observed H2 quadrupole emission features are colder than those derived by Herbert et al. at pressures less than ∼1 μbar. Extrapolation of the nominal model spectrum to far-infrared through millimeter wavelengths shows that the spectrum arising solely from H2

  20. Long-term safety and efficacy of single-tablet combinations of solifenacin and tamsulosin oral controlled absorption system in men with storage and voiding lower urinary tract symptoms: results from the NEPTUNE Study and NEPTUNE II open-label extension.

    Science.gov (United States)

    Drake, Marcus J; Chapple, Christopher; Sokol, Roman; Oelke, Matthias; Traudtner, Klaudia; Klaver, Monique; Drogendijk, Ted; Van Kerrebroeck, Philip

    2015-02-01

    Short-term trials have demonstrated the efficacy and safety of combination therapy using antimuscarinics and α-blockers in men with lower urinary tract symptoms (LUTS). The Study of Solifenacin Succinate and Tamsulosin Hydrochloride OCAS (oral controlled absorption system) in Males with Lower Urinary Tract Symptoms (NEPTUNE) II is the first long-term study using solifenacin (Soli) and the oral controlled absorption system formulation of tamsulosin (TOCAS). To evaluate long-term (up to 52 wk) safety and efficacy of flexible dosing of two fixed-dose combinations (FDC) of Soli plus TOCAS in men with moderate to severe storage symptoms and voiding symptoms. Patients with both storage and voiding LUTS, maximum urinary flow rate of 4.0-12.0 ml/s, prostate size storage and voiding subscores, micturition diary variables, and quality of life parameters. In all, 1066 men completed NEPTUNE and received one dose or more of study medication in NEPTUNE II. Treatment-emergent adverse events were reported in 499 (46.8%) patients who participated in NEPTUNE II; most were mild or moderate. Urinary retention occurred in 13 of 1208 (1.1%) patients receiving one or more FDCs in NEPTUNE and/or NEPTUNE II; 8 (0.7%) required catheterisation (acute urinary retention [AUR]). Reductions in total IPSS and TUFS during NEPTUNE were maintained for up to 52 wk of FDC treatment, with mean reductions of 9.0 (standard deviation [SD]: 5.7) and 10.1 (SD: 9.2), respectively, from baseline to end of treatment. Clinically relevant improvements were also observed for secondary efficacy end points. Long-term treatment with FDC Soli plus TOCAS was well tolerated and efficacious in men with storage and voiding LUTS, with a low incidence of AUR. Treatment with solifenacin plus tamsulosin in a fixed-dose combination tablet was well tolerated by men with lower urinary tract symptoms. Improvements in symptoms were achieved after 4 wk of treatment, with further improvements at week 16 maintained for up to 52 wk

  1. An Evaluation of NEPTUNE - A Program for Estimating Life-Cycle Cost of Oily Waste/Waste Oil Collection, Transportation and Treatment Systems.

    Science.gov (United States)

    1981-04-01

    are listed in Appendix B. There was a significant problem with the formal auditing of the NEPTUNE predictions since a complete manual checking effort...WRSE R. Z. ien BROKLY ! ACcA BSTON SATH CROTON SAT VALJLJO OUZ~A 5.3. NW AD AX A’s AMS AOFT AG! AZ AOSS AD "’s A AS& ASI AT! A’S AVM cc C"~ Cv DC OD963

  2. A hot Jupiter orbiting a 2-million-year-old solar-mass T Tauri star.

    Science.gov (United States)

    Donati, J F; Moutou, C; Malo, L; Baruteau, C; Yu, L; Hébrard, E; Hussain, G; Alencar, S; Ménard, F; Bouvier, J; Petit, P; Takami, M; Doyon, R; Collier Cameron, A

    2016-06-30

    Hot Jupiters are giant Jupiter-like exoplanets that orbit their host stars 100 times more closely than Jupiter orbits the Sun. These planets presumably form in the outer part of the primordial disk from which both the central star and surrounding planets are born, then migrate inwards and yet avoid falling into their host star. It is, however, unclear whether this occurs early in the lives of hot Jupiters, when they are still embedded within protoplanetary disks, or later, once multiple planets are formed and interact. Although numerous hot Jupiters have been detected around mature Sun-like stars, their existence has not yet been firmly demonstrated for young stars, whose magnetic activity is so intense that it overshadows the radial velocity signal that close-in giant planets can induce. Here we report that the radial velocities of the young star V830 Tau exhibit a sine wave of period 4.93 days and semi-amplitude 75 metres per second, detected with a false-alarm probability of less than 0.03 per cent, after filtering out the magnetic activity plaguing the spectra. We find that this signal is unrelated to the 2.741-day rotation period of V830 Tau and we attribute it to the presence of a planet of mass 0.77 times that of Jupiter, orbiting at a distance of 0.057 astronomical units from the host star. Our result demonstrates that hot Jupiters can migrate inwards in less than two million years, probably as a result of planet–disk interactions.

  3. Extreme all-cause mortality in JUPITER requires reexamination of vital records.

    Science.gov (United States)

    Serebruany, Victor L

    2011-01-01

    To compare all-cause mortality in JUPITER with other statin trials at 21 months of follow-up. Outcome advantages including all-cause mortality reduction yielded from the JUPITER trial support aggressive use of rosuvastatin and, perhaps by extension, other statins for primary prevention. Despite enrolling apparently healthy subjects and early trial termination at 21 months of mean follow-up, JUPITER revealed very high all-cause mortality in both the placebo (2.8%) and rosuvastatin (2.2%) arms. Comparison of all-cause mortality prorated for 21 months in 10 primary prevention studies and 1 acute coronary syndromes statin trial. The all-cause mortality in JUPITER was more than twice that of the average of primary prevention studies, matching well only with specific trials designed in diabetics (ASPEN or CARDS), early hypertension studies (ALLHAT-LLT) or a trial in patients with acute coronary syndromes (PROVE IT). Since the 'play of chance' is unlikely to explain these discrepancies due to excellent baseline match, excess death rates and all-cause mortality rates in both JUPITER arms must be questioned. It may be important that the study sponsor self-monitored sites. Excess all-cause mortality rates in the apparently relatively healthy JUPITER population are alarming and require independent verification. If, indeed, the surprising outcomes in JUPITER are successfully challenged, and considering established harm of statins with regard to rhabdomyolysis as well as, potentially, diabetes, millions of patients may find better and safer options for primary prevention of vascular events. Copyright © 2011 S. Karger AG, Basel.

  4. Laboratory Simulations of Haze Formation in the Atmospheres of Super-Earths and Mini-Neptunes: Particle Color and Size Distribution

    Science.gov (United States)

    He, Chao; Hörst, Sarah M.; Lewis, Nikole K.; Yu, Xinting; Moses, Julianne I.; Kempton, Eliza M.-R.; McGuiggan, Patricia; Morley, Caroline V.; Valenti, Jeff A.; Vuitton, Véronique

    2018-03-01

    Super-Earths and mini-Neptunes are the most abundant types of planets among the ∼3500 confirmed exoplanets, and are expected to exhibit a wide variety of atmospheric compositions. Recent transmission spectra of super-Earths and mini-Neptunes have demonstrated the possibility that exoplanets have haze/cloud layers at high altitudes in their atmospheres. However, the compositions, size distributions, and optical properties of these particles in exoplanet atmospheres are poorly understood. Here, we present the results of experimental laboratory investigations of photochemical haze formation within a range of planetary atmospheric conditions, as well as observations of the color and size of produced haze particles. We find that atmospheric temperature and metallicity strongly affect particle color and size, thus altering the particles’ optical properties (e.g., absorptivity, scattering, etc.); on a larger scale, this affects the atmospheric and surface temperature of the exoplanets, and their potential habitability. Our results provide constraints on haze formation and particle properties that can serve as critical inputs for exoplanet atmosphere modeling, and guide future observations of super-Earths and mini-Neptunes with the Transiting Exoplanet Survey Satellite, the James Webb Space Telescope, and the Wide-Field Infrared Survey Telescope.

  5. SEVEN-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE (WMAP ) OBSERVATIONS: PLANETS AND CELESTIAL CALIBRATION SOURCES

    International Nuclear Information System (INIS)

    Weiland, J. L.; Odegard, N.; Hill, R. S.; Greason, M. R.; Wollack, E.; Hinshaw, G.; Kogut, A.; Jarosik, N.; Page, L.; Bennett, C. L.; Gold, B.; Larson, D.; Dunkley, J.; Halpern, M.; Komatsu, E.; Limon, M.; Meyer, S. S.; Nolta, M. R.; Smith, K. M.; Spergel, D. N.

    2011-01-01

    We present WMAP seven-year observations of bright sources which are often used as calibrators at microwave frequencies. Ten objects are studied in five frequency bands (23-94 GHz): the outer planets (Mars, Jupiter, Saturn, Uranus, and Neptune) and five fixed celestial sources (Cas A, Tau A, Cyg A, 3C274, and 3C58). The seven-year analysis of Jupiter provides temperatures which are within 1σ of the previously published WMAP five-year values, with slightly tighter constraints on variability with orbital phase (0.2% ± 0.4%), and limits (but no detections) on linear polarization. Observed temperatures for both Mars and Saturn vary significantly with viewing geometry. Scaling factors are provided which, when multiplied by the Wright Mars thermal model predictions at 350 μm, reproduce WMAP seasonally averaged observations of Mars within ∼2%. An empirical model is described which fits brightness variations of Saturn due to geometrical effects and can be used to predict the WMAP observations to within 3%. Seven-year mean temperatures for Uranus and Neptune are also tabulated. Uncertainties in Uranus temperatures are 3%-4% in the 41, 61, and 94 GHz bands; the smallest uncertainty for Neptune is 8% for the 94 GHz band. Intriguingly, the spectrum of Uranus appears to show a dip at ∼30 GHz of unidentified origin, although the feature is not of high statistical significance. Flux densities for the five selected fixed celestial sources are derived from the seven-year WMAP sky maps and are tabulated for Stokes I, Q, and U, along with polarization fraction and position angle. Fractional uncertainties for the Stokes I fluxes are typically 1% to 3%. Source variability over the seven-year baseline is also estimated. Significant secular decrease is seen for Cas A and Tau A: our results are consistent with a frequency-independent decrease of about 0.53% per year for Cas A and 0.22% per year for Tau A. We present WMAP polarization data with uncertainties of a few percent for Tau

  6. Seven-year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Planets and Celestial Calibration Sources

    Science.gov (United States)

    Weiland, J. L.; Odegard, N.; Hill, R. S.; Wollack, E.; Hinshaw, G.; Greason, M. R.; Jarosik, N.; Page, L.; Bennett, C. L.; Dunkley, J.; Gold, B.; Halpern, M.; Kogut, A.; Komatsu, E.; Larson, D.; Limon, M.; Meyer, S. S.; Nolta, M. R.; Smith, K. M.; Spergel, D. N.; Tucker, G. S.; Wright, E. L.

    2011-02-01

    We present WMAP seven-year observations of bright sources which are often used as calibrators at microwave frequencies. Ten objects are studied in five frequency bands (23-94 GHz): the outer planets (Mars, Jupiter, Saturn, Uranus, and Neptune) and five fixed celestial sources (Cas A, Tau A, Cyg A, 3C274, and 3C58). The seven-year analysis of Jupiter provides temperatures which are within 1σ of the previously published WMAP five-year values, with slightly tighter constraints on variability with orbital phase (0.2% ± 0.4%), and limits (but no detections) on linear polarization. Observed temperatures for both Mars and Saturn vary significantly with viewing geometry. Scaling factors are provided which, when multiplied by the Wright Mars thermal model predictions at 350 μm, reproduce WMAP seasonally averaged observations of Mars within ~2%. An empirical model is described which fits brightness variations of Saturn due to geometrical effects and can be used to predict the WMAP observations to within 3%. Seven-year mean temperatures for Uranus and Neptune are also tabulated. Uncertainties in Uranus temperatures are 3%-4% in the 41, 61, and 94 GHz bands; the smallest uncertainty for Neptune is 8% for the 94 GHz band. Intriguingly, the spectrum of Uranus appears to show a dip at ~30 GHz of unidentified origin, although the feature is not of high statistical significance. Flux densities for the five selected fixed celestial sources are derived from the seven-year WMAP sky maps and are tabulated for Stokes I, Q, and U, along with polarization fraction and position angle. Fractional uncertainties for the Stokes I fluxes are typically 1% to 3%. Source variability over the seven-year baseline is also estimated. Significant secular decrease is seen for Cas A and Tau A: our results are consistent with a frequency-independent decrease of about 0.53% per year for Cas A and 0.22% per year for Tau A. We present WMAP polarization data with uncertainties of a few percent for Tau A

  7. Teetering Stars: Resonant Excitation of Stellar Obliquities by Hot and Warm Jupiters with External Companions

    Science.gov (United States)

    Anderson, Kassandra; Lai, Dong

    2018-04-01

    Stellar spin-orbit misalignments (obliquities) in hot Jupiter systems have been extensively probed in recent years thanks to Rossiter-McLaughlin observations. Such obliquities may reveal clues about hot Jupiter dynamical and migration histories. Common explanations for generating stellar obliquities include high-eccentricity migration, or primordial disk misalignment. This talk investigates another mechanism for producing stellar spin-orbit misalignments in systems hosting a close-in giant planet with an external, inclined planetary companion. Spin-orbit misalignment may be excited due to a secular resonance, occurring when the precession rate of the stellar spin axis (due to the inner orbit) becomes comparable to the precession rate of the inner orbital axis (due to the outer companion). Due to the spin-down of the host star via magnetic braking, this resonance may be achieved at some point during the star's main sequence lifetime for a wide range of giant planet masses and orbital architectures. We focus on both hot Jupiters (with orbital periods less than ten days) and warm Jupiters (with orbital periods around tens of days), and identify the outer perburber properties needed to generate substantial obliquities via resonant excitation, in terms of mass, separation, and inclination. For hot Jupiters, the stellar spin axis is strongly coupled to the orbital axis, and resonant excitation of obliquity requires a close perturber, located within 1-2 AU. For warm Jupiters, the spin and orbital axes are more weakly coupled, and the resonance may be achieved for more distant perturbers (at several to tens of AU). Resonant excitation of the stellar obliquity is accompanied by a decrease in the planets' mutual orbital inclination, and can thus erase high mutual inclinations in two-planet systems. Since many warm Jupiters are known to have outer planetary companions at several AU or beyond, stellar obliquities in warm Jupiter systems may be common, regardless of the

  8. TRANSMISSION SPECTRA OF THREE-DIMENSIONAL HOT JUPITER MODEL ATMOSPHERES

    International Nuclear Information System (INIS)

    Fortney, J. J.; Shabram, M.; Showman, A. P.; Lian, Y.; Lewis, N. K.; Freedman, R. S.; Marley, M. S.

    2010-01-01

    We compute models of the transmission spectra of planets HD 209458b, HD 189733b, and generic hot Jupiters. We examine the effects of temperature, surface gravity, and metallicity for the generic planets as a guide to understanding transmission spectra in general. We find that carbon dioxide absorption at 4.4 and 15 μm is prominent at high metallicity, and is a clear metallicity indicator. For HD 209458b and HD 189733b, we compute spectra for both one-dimensional and three-dimensional model atmospheres and examine the differences between them. The differences are usually small, but can be large if atmospheric temperatures are near important chemical abundance boundaries. The calculations for the three-dimensional atmospheres, and their comparison with data, serve as constraints on these dynamical models that complement the secondary eclipse and light curve data sets. For HD 209458b, even if TiO and VO gases are abundant on the dayside, their abundances can be considerably reduced on the cooler planetary limb. However, given the predicted limb temperatures and TiO abundances, the model's optical opacity is too high. For HD 189733b we find a good match with some infrared data sets and constrain the altitude of a postulated haze layer. For this planet, substantial differences can exist between the transmission spectra of the leading and trailing hemispheres, which are an excellent probe of carbon chemistry. In thermochemical equilibrium, the cooler leading hemisphere is methane-dominated, and the hotter trailing hemisphere is CO-dominated, but these differences may be eliminated by non-equilibrium chemistry due to vertical mixing. It may be possible to constrain the carbon chemistry of this planet, and its spatial variation, with James Webb Space Telescope.

  9. Analysis Of The 2009 July Impact Debris In Jupiter'S Atmosphere

    Science.gov (United States)

    Sanchez-Lavega, Agustin; Hueso, R.; Legarreta, J.; Pérez-Hoyos, S.; García-Melendo, E.; Gómez, J. M.; Rojas, J. F.; Orton, G. S.; Wesley, A.; IOPW International Outer Planet Watch Team

    2009-09-01

    We report the analysis of images obtained by the contributors to the International Outer Planet Watch (IOPW) of the debris left in the atmosphere of Jupiter by the object that impacted the planet between 18 and 19 July 2009. The discovery images by Anthony Wesley in July 19.625 and the first two days of its tracking, shows a dark debris spot (continuum wavelength) located at planetocentric latitude -55.1 deg and 304.5 deg System III longitude. The imaging survey indicates that the spot was not present in July 18.375, so the impact occurred during a window between both dates. The main spot had a size of about 4,500 km and to its Northwest a thin debris halo of similar size was initially observed. Methane band images at a wavelength of 890 nm shows the spot to be bright indicating that the debris aerosols are highly placed in the atmosphere relative to surrounding clouds. At the central latitude of the impact, the Jovian flow has nearly zero speed but anticyclonic vorticity bounded by jets at -51.5 deg (directed westward with velocity -10 m/s) and at -57.5 deg (directed eastward with velocity 25 m/s). The morphology in the continuum and the spot brightness in the methane band strongly suggest that the feature was caused by a cometary or asteroidal impact, similar in behaviour to the SL9 impacts of 1994. This work has been funded by Spanish MEC AYA2006-07735 with FEDER support and Grupos Gobierno Vasco IT-464-07. RH acknowledges a "Ramón y Cajal” contract from MEC.

  10. Solar Flux Deposition And Heating Rates In Jupiter's Atmosphere

    Science.gov (United States)

    Perez-Hoyos, Santiago; Sánchez-Lavega, A.

    2009-09-01

    We discuss here the solar downward net flux in the 0.25 - 2.5 µm range in the atmosphere of Jupiter and the associated heating rates under a number of vertical cloud structure scenarios focusing in the effect of clouds and hazes. Our numerical model is based in the doubling-adding technique to solve the radiative transfer equation and it includes gas absorption by CH4, NH3 and H2, in addition to Rayleigh scattering by a mixture of H2 plus He. Four paradigmatic Jovian regions have been considered (hot-spots, belts, zones and Polar Regions). The hot-spots are the most transparent regions with downward net fluxes of 2.5±0.5 Wm-2 at the 6 bar level. The maximum solar heating is 0.04±0.01 K/day and occurs above 1 bar. Belts and zones characterization result in a maximum net downward flux of 0.5 Wm-2 at 2 bar and 0.015 Wm-2 at 6 bar. Heating is concentrated in the stratospheric and tropospheric hazes. Finally, Polar Regions are also explored and the results point to a considerable stratospheric heating of 0.04±0.02 K/day. In all, these calculations suggest that the role of the direct solar forcing in the Jovian atmospheric dynamics is limited to the upper 1 - 2 bar of the atmosphere except in the hot-spot areas. Acknowledgments: This work has been funded by Spanish MEC AYA2006-07735 with FEDER support and Grupos Gobierno Vasco IT-464-07.

  11. A HYPOTHESIS FOR THE COLOR BIMODALITY OF JUPITER TROJANS

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Ian; Brown, Michael E., E-mail: iwong@caltech.edu [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States)

    2016-10-01

    One of the most enigmatic and hitherto unexplained properties of Jupiter Trojans is their bimodal color distribution. This bimodality is indicative of two sub-populations within the Trojans, which have distinct size distributions. In this paper, we present a simple, plausible hypothesis for the origin and evolution of the two Trojan color sub-populations. In the framework of dynamical instability models of early solar system evolution, which suggest a common primordial progenitor population for both Trojans and Kuiper Belt objects, we use observational constraints to assert that the color bimodalities evident in both minor body populations developed within the primordial population prior to the onset of instability. We show that, beginning with an initial composition of rock and ices, location-dependent volatile loss through sublimation in this primordial population could have led to sharp changes in the surface composition with heliocentric distance. We propose that the depletion or retention of H{sub 2}S ice on the surface of these objects was the key factor in creating an initial color bimodality. Objects that retained H{sub 2}S on their surfaces developed characteristically redder colors upon irradiation than those that did not. After the bodies from the primordial population were scattered and emplaced into their current positions, they preserved this primordial color bimodality to the present day. We explore predictions of the volatile loss model—in particular, the effect of collisions within the Trojan population on the size distributions of the two sub-populations—and propose further experimental and observational tests of our hypothesis.

  12. Variability of Jupiter's Five-Micron Hot Spot Inventory

    Science.gov (United States)

    Yanamandra-Fisher, Padma A.; Orton, G. S.; Wakefield, L.; Rogers, J. H.; Simon-Miller, A. A.; Boydstun, K.

    2012-01-01

    Global upheavals on Jupiter involve changes in the albedo of entire axisymmetric regions, lasting several years, with the last two occurring in 1989 and 2006. Against this backdrop of planetary-scale changes, discrete features such as the Great Red Spot (GRS), and other vortices exhibit changes on shorter spatial- and time-scales. We track the variability of the discrete equatorial 5-micron hot spots, semi-evenly spaced in longitude and confined to a narrow latitude band centered at 6.5degN (southern edge of the North Equatorial Belt, NEB), abundant in Voyager images. Tantalizingly similar patterns were observed in the visible (bright plumes and blue-gray regions), where reflectivity in the red is anti-correlated with 5-microns thermal radiance. Ortiz et al. (1998, GRL, 103) characterized the latitude and drift rates of the hot spots, including the descent of the Galileo probe at the southern edge of a 5-micron hot spot, as the superposition of equatorial Rossby waves, with phase speeds between 99 - 103m/s, relative to System III. We note that the high 5-micron radiances correlate well but not perfectly with high 8.57-micron radiances. Because the latter are modulated primarily by changes in the upper ammonia (NH3) ice cloud opacity, this correlation implies that changes in the ammonia ice cloud field may be responsible for the variability seen in the 5-m maps. During the NEB fade (2011 - early 2012), however, these otherwise ubiquitous features were absent, an atmospheric state not seen in decades. The ongoing NEB revival indicates nascent 5-m hot spots as early as April 2012, with corresponding visible dark spots. Their continuing growth through July 2012 indicates the possit.le re-establishment of Rossby waves. The South Equatorial Belt (SEB) and NEB revivals began similarly with an instability that developed into a major outbreak, and many similarities in the observed propagation of clear regions.

  13. Meteorology of Jupiter's Equatorial Hot Spots and Plumes from Cassini

    Science.gov (United States)

    Choi, David Sanghun; Showman, Adam P.; Vasavada, Ashwin R.; Simon-Miller, Amy A.

    2013-01-01

    We present an updated analysis of Jupiter's equatorial meteorology from Cassini observations. For two months preceding the spacecraft's closest approach, the Imaging Science Subsystem (ISS) onboard regularly imaged the atmosphere. We created time-lapse movies from this period in order to analyze the dynamics of equatorial hot spots and their interactions with adjacent latitudes. Hot spots are relatively cloud-free regions that emit strongly at 5 lm; improved knowledge of these features is crucial for fully understanding Galileo probe measurements taken during its descent through one. Hot spots are quasistable, rectangular dark areas on visible-wavelength images, with defined eastern edges that sharply contrast with surrounding clouds, but diffuse western edges serving as nebulous boundaries with adjacent equatorial plumes. Hot spots exhibit significant variations in size and shape over timescales of days and weeks. Some of these changes correspond with passing vortex systems from adjacent latitudes interacting with hot spots. Strong anticyclonic gyres present to the south and southeast of the dark areas appear to circulate into hot spots. Impressive, bright white plumes occupy spaces in between hot spots. Compact cirrus-like 'scooter' clouds flow rapidly through the plumes before disappearing within the dark areas. These clouds travel at 150-200 m/s, much faster than the 100 m/s hot spot and plume drift speed. This raises the possibility that the scooter clouds may be more illustrative of the actual jet stream speed at these latitudes. Most previously published zonal wind profiles represent the drift speed of the hot spots at their latitude from pattern matching of the entire longitudinal image strip. If a downward branch of an equatorially-trapped Rossby wave controls the overall appearance of hot spots, however, the westward phase velocity of the wave leads to underestimates of the true jet stream speed.

  14. A HYPOTHESIS FOR THE COLOR BIMODALITY OF JUPITER TROJANS

    International Nuclear Information System (INIS)

    Wong, Ian; Brown, Michael E.

    2016-01-01

    One of the most enigmatic and hitherto unexplained properties of Jupiter Trojans is their bimodal color distribution. This bimodality is indicative of two sub-populations within the Trojans, which have distinct size distributions. In this paper, we present a simple, plausible hypothesis for the origin and evolution of the two Trojan color sub-populations. In the framework of dynamical instability models of early solar system evolution, which suggest a common primordial progenitor population for both Trojans and Kuiper Belt objects, we use observational constraints to assert that the color bimodalities evident in both minor body populations developed within the primordial population prior to the onset of instability. We show that, beginning with an initial composition of rock and ices, location-dependent volatile loss through sublimation in this primordial population could have led to sharp changes in the surface composition with heliocentric distance. We propose that the depletion or retention of H 2 S ice on the surface of these objects was the key factor in creating an initial color bimodality. Objects that retained H 2 S on their surfaces developed characteristically redder colors upon irradiation than those that did not. After the bodies from the primordial population were scattered and emplaced into their current positions, they preserved this primordial color bimodality to the present day. We explore predictions of the volatile loss model—in particular, the effect of collisions within the Trojan population on the size distributions of the two sub-populations—and propose further experimental and observational tests of our hypothesis.

  15. Phase Offsets and the Energy Budgets of Hot Jupiters

    Science.gov (United States)

    Schwartz, Joel C.; Kashner, Zane; Jovmir, Diana; Cowan, Nicolas B.

    2017-12-01

    Thermal phase curves of short-period planets on circular orbits provide joint constraints on the fraction of incoming energy that is reflected (Bond albedo) and the fraction of absorbed energy radiated by the night hemisphere (heat recirculation efficiency). Many empirical studies of hot Jupiters have implicitly assumed that the dayside is the hottest hemisphere and the nightside is the coldest hemisphere. For a given eclipse depth and phase amplitude, an orbital lag between a planet’s peak brightness and its eclipse—a phase offset—implies that planet’s nightside emits greater flux. To quantify how phase offsets impact the energy budgets of short-period planets, we compile all infrared observations of the nine planets with multi-band eclipse depths and phase curves. Accounting for phase offsets shifts planets to lower Bond albedo and greater day-night heat transport, usually by ≲1σ. For WASP-12b, the published phase variations have been analyzed in two different ways, and the inferred energy budget depends sensitively on which analysis one adopts. Our fiducial scenario supports a Bond albedo of {0.27}-0.13+0.12, significantly higher than the published optical geometric albedo, and a recirculation efficiency of {0.03}-0.02+0.07, following the trend of larger day-night temperature contrast with greater stellar irradiation. If instead we adopt the alternative analysis, then WASP-12b has a Bond albedo consistent with zero and a much higher recirculation efficiency. To definitively determine the energy budget of WASP-12b, new observational analyses will be necessary.

  16. Temporal and spatial distribution of high energy electrons at Jupiter

    Science.gov (United States)

    Jun, I.; Garrett, H. B.; Ratliff, J. M.

    2003-04-01

    Measurements of the high energy, omni-directional electron environment by the Galileo spacecraft Energetic Particle Detector (EPD) were used to study the high energy electron environment in the Jovian magnetosphere, especially in the region between 8 to 18 Rj (1 Rj = 1 Jovian radius = 71,400 km). 10-minute averages of the EPD data collected between Jupiter orbit insertion (JOI) in 1995 and the orbit number 33 (I33) in 2002 form an extensive dataset, which has been extremely useful to observe temporal and spatial variability of the Jovian high energy electron environment. The count rates of the EPD electron channels (0.174, 0.304, 0.527, 1.5, 2.0, and 11 MeV) were grouped into 0.5 Rj or 0.5 L bins and analyzed statistically. The results indicate that: (1) a log-normal Gaussian distribution well describes the statistics of the high energy electron environment (for example, electron differential fluxes) in the Jovian magnetosphere, in the region studied here; (2) the high energy electron environments inferred by the Galileo EPD measurements are in a close agreement with the data obtained using the Divine model, which was developed more than 30 years ago from Pioneer 10, 11 and Voyager 1, 2 data; (3) the data are better organized when plotted against magnetic radial parameter L than Rj; (4) the standard deviations of the 0.174, 0.304, 0.527 MeV channel count rates are larger than those of the 1.5, 2.0, 11 MeV count rates in 12 Rj. These observations are very helpful to understand short- and long-term, and local variability of the Jovian high energy electron environment, and are discussed in detail.

  17. UV Reflectance of Jupiter's Moon Europa and Asteroid (16) Psyche

    Science.gov (United States)

    Becker, T. M.; Retherford, K. D.; Roth, L.; Hendrix, A.; McGrath, M. A.; Cunningham, N.; Feaga, L. M.; Saur, J.; Elkins-Tanton, L. T.; Walhund, J. E.; Molyneux, P.

    2017-12-01

    Surface reflectance observations of solar system objects in the UV are not only complimentary to longer wavelength observations for identifying surface composition, but can also reveal new and meaningful information about the surfaces of those bodies. On Europa, far-UV (FUV) spectral observations made by the Hubble Space Telescope (HST) show that the surface lacks a strong water ice absorption edge near 165 nm, which is intriguing because such a band has been detected on most icy satellites. This may suggest that radiolytic processing by Jupiter's magnetosphere has altered the surface, causing absorption at wavelengths longward of the H2O edge, masking this feature. Additionally, the FUV spectra are blue (increasing albedo with shorter wavelengths), and regions that are observed to be dark in the visible appear bright in the FUV. This spectral inversion, also observed on the Moon and some asteroids, may provide insight into the properties of the surface material and how they are processed.We also explore the UV reflectance spectra of the main belt asteroid (16) Psyche. This asteroid is believed to be the metallic remnant core of a differentiated asteroid, stripped of its mantle through collisions. However, there is speculation that the asteroid could have formed as-is from highly reduced metal-rich material near the Sun early in the formation of the solar system. Further, spectral observations in the infrared have revealed pyroxene and hydroxyl on the asteroid's surface, complicating the interpretation that (16) Psyche is a pure metallic object. Laboratory studies indicate that there are diagnostic spectral features in the UV that could be useful for determining the surface composition. We obtained HST observations of Psyche from 160 - 300 nm. Preliminary results show a featureless, red-sloped spectrum, inconsistent with significant amounts of pyroxene on the surface. We will present the spectra of Europa and the asteroid (16) Psyche and discuss the unique details

  18. Cassini ISS Observations of Jupiter: An Exoplanet Perspective

    Science.gov (United States)

    West, Robert A.; Knowles, Benjamin

    2017-10-01

    Understanding the optical and physical properties of planets in our solar system can guide our approach to the interpretation of observations of exoplanets. Although some work has already been done along these lines, there remain low-hanging fruit. During the Cassini Jupiter encounter, the Imaging Science Subsystem (ISS) obtained an extensive set of images over a large range of phase angles (near-zero to 140 degrees) and in filters from near-UV to near-IR, including three methane bands and nearby continuum. The ISS also obtained images using polarizers. Much later in the mission we also obtained distant images while in orbit around Saturn. Some of these data have already been studied to reveal phase behavior (Dyudina et al., Astrophys. J.822, DOI: 10.3847/0004-637X/822/2/76; Mayorga et al., 2016, Astron. J. 152, DOI: 10.3847/0004-6256/152/6/209). Here we examine rotational modulation to determine wavelength and phase angle dependence, and how these may depend on cloud and haze vertical structure and optical properties. The existence of an optically thin forward-scattering and longitudinally-homogeneous haze overlying photometrically-variable cloud fields tends to suppress rotational modulation as phase angle increases, although in the strong 890-nm methane band cloud vertical structure is important. Cloud particles (non-spherical ammonia ice, mostly) have very small polarization signatures at intermediate phase angles and rotational modulation is not apparent above the noise level of our instrument. Part of this work was performed by the Jet Propulsion Lab, Cal. Inst. Of Technology.

  19. A HOT GAP AROUND JUPITER'S ORBIT IN THE SOLAR NEBULA

    Energy Technology Data Exchange (ETDEWEB)

    Turner, N. J.; Choukroun, M.; Castillo-Rogez, J.; Bryden, G., E-mail: neal.turner@jpl.nasa.gov [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2012-04-01

    The Sun was an order of magnitude more luminous during the first few hundred thousand years of its existence, due in part to the gravitational energy released by material accreting from the solar nebula. If Jupiter was already near its present mass, the planet's tides opened an optically thin gap in the nebula. Using Monte Carlo radiative transfer calculations, we show that sunlight absorbed by the nebula and re-radiated into the gap raised temperatures well above the sublimation threshold for water ice, with potentially drastic consequences for the icy bodies in Jupiter's feeding zone. Bodies up to a meter in size were vaporized within a single orbit if the planet was near its present location during this early epoch. Dust particles lost their ice mantles, and planetesimals were partially to fully devolatilized, depending on their size. Scenarios in which Jupiter formed promptly, such as those involving a gravitational instability of the massive early nebula, must cope with the high temperatures. Enriching Jupiter in the noble gases through delivery trapped in clathrate hydrates will be more difficult, but might be achieved by either forming the planet much farther from the star or capturing planetesimals at later epochs. The hot gap resulting from an early origin for Jupiter also would affect the surface compositions of any primordial Trojan asteroids.

  20. The number of Jupiter family comets as a constraint on the transneptunian population

    Science.gov (United States)

    Tancredi, G.; et al.

    Several duynamical studies point out that the comets of the Jupiter family were originated in a flat belt in the transneptunian region. The Jupiter family is a transient dynamical state between the injection from the outer region and i) the ejection out of the Solar System, ii) the collision against one of its members or iii) the desintegration into a meteor stream. It has been generally assumed that the Jupiter family (JF) is in a steady state; i.e. the injection is balanced by the ejection+collision+ desintegration. Knowing the duration of a typical visit into the Jupiter family and the number of JF comets we could infer the injection rate. The rate of escapes from the transneptunian region and the fraction that reach the Jupiter family can be computed from massive integrations of particles starting in the outer region. An estimate of the required population of transneptunian objects can then be inferred from these numbers. There have been published several estimates of the dynamical parameters mentioned above but the total number of JF comets has been difficult to estimate. Based on a compilation of all the reported nuclear magnitudes of JF comets, we derive the total number of objects in the cometary population. The observed population (~ 200) is a tiny fraction of the total population (several thousands). Compiling all these numbers, we then derive the required trasneptunian population.

  1. Kepler-424 b: A 'lonely' hot Jupiter that found A companion

    International Nuclear Information System (INIS)

    Endl, Michael; Caldwell, Douglas A.; Barclay, Thomas; Huber, Daniel; Havel, Mathieu; Howell, Steve B.; Quintana, Elisa; Isaacson, Howard; Buchhave, Lars A.; Brugamyer, Erik; Robertson, Paul; Cochran, William D.; MacQueen, Phillip J.; Lucas, Phillip; Fischer, Debra; Ciardi, David R.

    2014-01-01

    Hot Jupiter systems provide unique observational constraints for migration models in multiple systems and binaries. We report on the discovery of the Kepler-424 (KOI-214) two-planet system, which consists of a transiting hot Jupiter (Kepler-424b) in a 3.31 day orbit accompanied by a more massive outer companion in an eccentric (e = 0.3) 223 day orbit. The outer giant planet, Kepler-424c, is not detected transiting the host star. The masses of both planets and the orbital parameters for the second planet were determined using precise radial velocity (RV) measurements from the Hobby-Eberly Telescope (HET) and its High Resolution Spectrograph (HRS). In stark contrast to smaller planets, hot Jupiters are predominantly found to be lacking any nearby additional planets; they appear to be l onely . This might be a consequence of these systems having a highly dynamical past. The Kepler-424 planetary system has a hot Jupiter in a multiple system, similar to υ Andromedae. We also present our results for Kepler-422 (KOI-22), Kepler-77 (KOI-127), Kepler-43 (KOI-135), and Kepler-423 (KOI-183). These results are based on spectroscopic data collected with the Nordic Optical Telescope (NOT), the Keck 1 telescope, and HET. For all systems, we rule out false positives based on various follow-up observations, confirming the planetary nature of these companions. We performed a comparison with planetary evolutionary models which indicate that these five hot Jupiters have heavy element contents between 20 and 120 M ⊕ .

  2. Raman scattering in the atmospheres of the major planets

    International Nuclear Information System (INIS)

    Cochran, W.D.; Trafton, L.M.

    1978-01-01

    A method is developed for calculating the rate at which photons are Raman scattered as a function of frequency and depth in an inhomogeneous anisotropically scattering atmosphere. This method is used to determine the effects of Raman scattering by H 2 in the atmospheres of the major planets. Raman scattering causes an insufficient decrease in the blue and ultraviolet to explain the albedos of all of the planets; an additional source of extinction is necessary in this spectral region. Approximately 0.5-2.0% of the blue continuum photons have undergone Raman scattering in the shallow atmospheres of Jupiter and Saturn, while in the deep atmospheres of Uranus and Neptune Raman scattering accounts for abount 10-15% of the blue continuum intensity. The filling in of the cores of solar lines and the production of Raman-shifted ghosts of the Fraunhofer spectrum will be detectable effects in all of the major planets. Raman scattering has a significant influence on the formation and profiles of the strong red and near-infrared CH 4 bands on Uranus and Neptune. The residual intensity in the cores of these bands may be fully explained as a result of Raman scattering by H 2 . This scattering of photons into the cores of saturated absorption bands will cause an underestimate of the abundance of the absorber unless the effects of Raman scattering by H 2 in an inhomogeneous atmosphere are properly included in the analysis

  3. FROM DOCUMENTATION IMAGES TO RESTAURATION SUPPORT TOOLS: A PATH FOLLOWING THE NEPTUNE FOUNTAIN IN BOLOGNA DESIGN PROCESS

    Directory of Open Access Journals (Sweden)

    F. I. Apollonio

    2017-05-01

    Full Text Available The sixteenth-century Fountain of Neptune is one of Bologna’s most renowned landmarks. During the recent restoration activities of the monumental sculpture group, consisting in precious marbles and highly refined bronzes with water jets, a photographic campaign has been carried out exclusively for documentation purposes of the current state of preservation of the complex. Nevertheless, the highquality imagery was used for a different use, namely to create a 3D digital model accurate in shape and color by means of automated photogrammetric techniques and a robust customized pipeline. This 3D model was used as basic tool to support many and different activities of the restoration site. The paper describes the 3D model construction technique used and the most important applications in which it was used as support tool for restoration: (i reliable documentation of the actual state; (ii surface cleaning analysis; (iii new water system and jets; (iv new lighting design simulation; (v support for preliminary analysis and projectual studies related to hardly accessible areas; (vi structural analysis; (vii base for filling gaps or missing elements through 3D printing; (viii high-quality visualization and rendering and (ix support for data modelling and semantic-based diagrams.

  4. Orbital misalignment of the Neptune-mass exoplanet GJ 436b with the spin of its cool star

    Science.gov (United States)

    Bourrier, Vincent; Lovis, Christophe; Beust, Hervé; Ehrenreich, David; Henry, Gregory W.; Astudillo-Defru, Nicola; Allart, Romain; Bonfils, Xavier; Ségransan, Damien; Delfosse, Xavier; Cegla, Heather M.; Wyttenbach, Aurélien; Heng, Kevin; Lavie, Baptiste; Pepe, Francesco

    2018-01-01

    The angle between the spin of a star and the orbital planes of its planets traces the history of the planetary system. Exoplanets orbiting close to cool stars are expected to be on circular, aligned orbits because of strong tidal interactions with the stellar convective envelope. Spin–orbit alignment can be measured when the planet transits its star, but such ground-based spectroscopic measurements are challenging for cool, slowly rotating stars. Here we report the three-dimensional characterization of the trajectory of an exoplanet around an M dwarf star, derived by mapping the spectrum of the stellar photosphere along the chord transited by the planet. We find that the eccentric orbit of the Neptune-mass exoplanet GJ 436b is nearly perpendicular to the stellar equator. Both eccentricity and misalignment, surprising around a cool star, can result from dynamical interactions (via Kozai migration) with a yet-undetected outer companion. This inward migration of GJ 436b could have triggered the atmospheric escape that now sustains its giant exosphere.

  5. Precise VLA positions and flux-density measurements of the Jupiter system

    International Nuclear Information System (INIS)

    Muhleman, D.O.; Berge, G.L.; Rudy, D.; Niell, A.E.

    1986-01-01

    VLA C array configuration observations at 2 and 6 cm are presented for Europa, Ganymede, and Callisto at eastern and western elongations with respect to Jupiter, which allowed measurements in right ascension and declination of the satellites with an rms precision of about + or - 0.03 arcsec. The transfer of the mean offsets of Ganymede to Jupiter yields offsets of -0.185 + or - 0.03 arcsec and -0.06 + or - 0.03 arcsec, with respect to JPL-DE-200, at the mean epoch of April 28, 1983; the large offset in right ascension is a combination of the Jupiter ephemeris error and the error in the frame tie of the Jovian planets with the VLBI system of precise positions which was used as the absolute reference frame for the observations. A significant error is noted in the orbital position of Callisto with respect to Ganymede. 12 references

  6. Aerosol influence on energy balance of the middle atmosphere of Jupiter.

    Science.gov (United States)

    Zhang, Xi; West, Robert A; Irwin, Patrick G J; Nixon, Conor A; Yung, Yuk L

    2015-12-22

    Aerosols are ubiquitous in planetary atmospheres in the Solar System. However, radiative forcing on Jupiter has traditionally been attributed to solar heating and infrared cooling of gaseous constituents only, while the significance of aerosol radiative effects has been a long-standing controversy. Here we show, based on observations from the NASA spacecraft Voyager and Cassini, that gases alone cannot maintain the global energy balance in the middle atmosphere of Jupiter. Instead, a thick aerosol layer consisting of fluffy, fractal aggregate particles produced by photochemistry and auroral chemistry dominates the stratospheric radiative heating at middle and high latitudes, exceeding the local gas heating rate by a factor of 5-10. On a global average, aerosol heating is comparable to the gas contribution and aerosol cooling is more important than previously thought. We argue that fractal aggregate particles may also have a significant role in controlling the atmospheric radiative energy balance on other planets, as on Jupiter.

  7. Jupiter cloud composition, stratification, convection, and wave motion: a view from new horizons.

    Science.gov (United States)

    Reuter, D C; Simon-Miller, A A; Lunsford, A; Baines, K H; Cheng, A F; Jennings, D E; Olkin, C B; Spencer, J R; Stern, S A; Weaver, H A; Young, L A

    2007-10-12

    Several observations of Jupiter's atmosphere made by instruments on the New Horizons spacecraft have implications for the stability and dynamics of Jupiter's weather layer. Mesoscale waves, first seen by Voyager, have been observed at a spatial resolution of 11 to 45 kilometers. These waves have a 300-kilometer wavelength and phase velocities greater than the local zonal flow by 100 meters per second, much higher than predicted by models. Additionally, infrared spectral measurements over five successive Jupiter rotations at spatial resolutions of 200 to 140 kilometers have shown the development of transient ammonia ice clouds (lifetimes of 40 hours or less) in regions of strong atmospheric upwelling. Both of these phenomena serve as probes of atmospheric dynamics below the visible cloud tops.

  8. OCCURRENCE OF ACCELERATING FIELD, FORMATION AND DYNAMICS OF RELATIVISTIC ELECTRON BEAM NEAR JUPITER

    Directory of Open Access Journals (Sweden)

    V. I. Maslov

    2018-06-01

    Full Text Available The possible dynamics of the electron beam, formed in the vicinity of Io, the natural satellite of Jupiter, and injected toward Jupiter, has been investigated analytically. When a beam penetrates the Jupiter plasma to a certain depth, the beam-plasma instability can be developed. In this case, the distribution function of electrons is expanded additionally by excited oscillations. These electrons, when their energy is of order of a required certain value, cause UV polar light. For closing of a current, the formation of a double electric layer is necessary. The necessary parameters and conditions for the formation of a double layer with a large jump of an electric potential at a certain height have been formulated, its properties, stability, behavior over time and beam reflection in its field for closing of a current have been described. Reflection of the beam can lead to its vortex dynamics.

  9. A New Model of Jupiter's Magnetic Field from Juno's First Nine Orbits

    DEFF Research Database (Denmark)

    Connerney, J. E. P.; Kotsiaros, S.; Oliversen, R. J.

    2018-01-01

    A spherical harmonic model of the magnetic field of Jupiter is obtained from vector magnetic field observations acquired by the Juno spacecraft during its first nine polar orbits about the planet. Observations acquired during eight of these orbits provide the first truly global coverage of Jupiter......'s magnetic field with a coarse longitudinal separation of ~45° between perijoves. The magnetic field is represented with a degree 20 spherical harmonic model for the planetary (“internal”) field, combined with a simple model of the magnetodisc for the field (“external”) due to distributed magnetospheric...... currents. Partial solution of the underdetermined inverse problem using generalized inverse techniques yields a model (“Juno Reference Model through Perijove 9”) of the planetary magnetic field with spherical harmonic coefficients well determined through degree and order 10, providing the first detailed...

  10. WARM SPITZER PHOTOMETRY OF THREE HOT JUPITERS: HAT-P-3b, HAT-P-4b AND HAT-P-12b

    Energy Technology Data Exchange (ETDEWEB)

    Todorov, Kamen O. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Deming, Drake [Department of Astronomy, University of Maryland at College Park, College Park, MD 20742 (United States); Knutson, Heather A. [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Burrows, Adam [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Fortney, Jonathan J.; Laughlin, Gregory [Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); Lewis, Nikole K. [Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Cowan, Nicolas B. [Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States); Agol, Eric [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Desert, Jean-Michel [Astronomy Department, California Institute of Technology, Pasadena, CA 91125 (United States); Sada, Pedro V. [Department of Physics and Mathematics, University of Monterrey, Monterrey (Mexico); Charbonneau, David [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Langton, Jonathan [Department of Physics, Principia College, Elsah, IL 62028 (United States); Showman, Adam P. [Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States)

    2013-06-20

    We present Warm Spitzer/IRAC secondary eclipse time series photometry of three short-period transiting exoplanets, HAT-P-3b, HAT-P-4b and HAT-P-12b, in both the available 3.6 and 4.5 {mu}m bands. HAT-P-3b and HAT-P-4b are Jupiter-mass objects orbiting an early K and an early G dwarf star, respectively. For HAT-P-3b we find eclipse depths of 0.112%+0.015%-0.030% (3.6 micron) and 0.094%+0.016%-0.009% (4.5 {mu}m). The HAT-P-4b values are 0.142%+0.014%-0.016% (3.6 micron) and 0.122%+0.012%-0.014% 4.5 {mu}m). The two planets' photometry is consistent with inefficient heat redistribution from their day to night sides (and low albedos), but it is inconclusive about possible temperature inversions in their atmospheres. HAT-P-12b is a Saturn-mass planet and is one of the coolest planets ever observed during secondary eclipse, along with the hot Neptune GJ 436b and the hot Saturn WASP-29b. We are able to place 3{sigma} upper limits on the secondary eclipse depth of HAT-P-12b in both wavelengths: <0.042% (3.6 {mu}m) and <0.085% (4.5 {mu}m). We discuss these results in the context of the Spitzer secondary eclipse measurements of GJ 436b and WASP-29b. It is possible that we do not detect the eclipses of HAT-P-12b due to high eccentricity, but find that weak planetary emission in these wavelengths is a more likely explanation. We place 3{sigma} upper limits on the |e cos {omega}| quantity (where e is eccentricity and {omega} is the argument of periapsis) for HAT-P-3b (<0.0081) and HAT-P-4b (<0.0042), based on the secondary eclipse timings.

  11. THE PHOTOECCENTRIC EFFECT AND PROTO-HOT JUPITERS. I. MEASURING PHOTOMETRIC ECCENTRICITIES OF INDIVIDUAL TRANSITING PLANETS

    International Nuclear Information System (INIS)

    Dawson, Rebekah I.; Johnson, John Asher

    2012-01-01

    Exoplanet orbital eccentricities offer valuable clues about the history of planetary systems. Eccentric, Jupiter-sized planets are particularly interesting: they may link the 'cold' Jupiters beyond the ice line to close-in hot Jupiters, which are unlikely to have formed in situ. To date, eccentricities of individual transiting planets primarily come from radial-velocity measurements. Kepler has discovered hundreds of transiting Jupiters spanning a range of periods, but the faintness of the host stars precludes radial-velocity follow-up of most. Here, we demonstrate a Bayesian method of measuring an individual planet's eccentricity solely from its transit light curve using prior knowledge of its host star's density. We show that eccentric Jupiters are readily identified by their short ingress/egress/total transit durations—part of the 'photoeccentric' light curve signature of a planet's eccentricity—even with long-cadence Kepler photometry and loosely constrained stellar parameters. A Markov Chain Monte Carlo exploration of parameter posteriors naturally marginalizes over the periapse angle and automatically accounts for the transit probability. To demonstrate, we use three published transit light curves of HD 17156 b to measure an eccentricity of e = 0.71 +0.16 –0.09 , in good agreement with the discovery value e = 0.67 ± 0.08 based on 33 radial-velocity measurements. We present two additional tests using Kepler data. In each case, the technique proves to be a viable method of measuring exoplanet eccentricities and their confidence intervals. Finally, we argue that this method is the most efficient, effective means of identifying the extremely eccentric, proto-hot Jupiters predicted by Socrates et al.

  12. An Overview of the Jupiter Icy Moons Orbiter (JIMO) Mission, Environments, and Materials Challenges

    Science.gov (United States)

    Edwards, Dave

    2012-01-01

    Congress authorized NASA's Prometheus Project in February 2003, with the first Prometheus mission slated to explore the icy moons of Jupiter with the following main objectives: (1) Develop a nuclear reactor that would provide unprecedented levels of power and show that it could be processed safely and operated reliably in space for long-duration. (2) Explore the three icy moons of Jupiter -- Callisto, Ganymede, and Europa -- and return science data that would meet the scientific goals as set forth in the Decadal Survey Report of the National Academy of Sciences.

  13. Development of advanced blanket performance under irradiation and system integration through JUPITER-II project

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Katsunori; Kohyama, Akira; Tanaka, Satoru; Namba, C.; Terai, T.; Kunugi, T.; Muroga, Takeo; Hasegawa, Akira; Sagara, A.; Berk, S.; Zinkle, Steven J.; Sze, Dai Kai; Petti, D. A.; Abdou, Mohamed A.; Morley, Neil B.; Kurtz, Richard J.; Snead, Lance L.; Ghoniem, Nasr M.

    2008-12-01

    This report describes an outline of the activities of the JUPITER-II collaboration (japan-USA program of Irradiation/Integration test for Fusion Research-II), Which has bee carried out through six years (2001-2006) under Phase 4 of the collabroation implemented by Amendment 4 of Annex 1 to the DOE (United States Department of Energy)-MEXT (Ministry of Education ,Culture,Sports,Science and Technology) Cooperation. This program followed the RTNS-II Program (Phase1:1982-4986), the FFTF/MOTA Program (Phase2:1987-1994) and the JUPITER Program (Phase 3: 1995-2000) [1].

  14. Discovery of Diffuse Hard X-ray Emission associated with Jupiter

    Science.gov (United States)

    Ezoe, Y.; Miyoshi, Y.; Ishikawa, K.; Ohashi, T.; Terada, N.; Uchiyama, Y.; Negoro, H.

    2009-12-01

    Our discovery of diffuse hard (1-5 keV) X-ray emission around Jupiter is reported. Recent Chandra and XMM-Newton observations revealed several types of X-rays in the vicinity of Jupiter such as auroral and disk emission from Jupiter and faint diffuse X-rays from the Io Plasma Torus (see Bhardwaj et al. 2007 for review). To investigate possible diffuse hard X-ray emission around Jupiter with the highest sensitivity, we conducted data analysis of Suzaku XIS observations of Jupiter on Feb 2006. After removing satellite and planetary orbital motions, we detected a significant diffuse X-ray emission extending to ~6 x 3 arcmin with the 1-5 keV X-ray luminosity of ~3e15 erg/s. The emitting region very well coincided with the Jupiter's radiation belts. The 1-5 keV X-ray spectrum was represented by a simple power law model with a photon index of 1.4. Such a flat continuum strongly suggests non-thermal origin. Although such an emission can be originated from multiple background point sources, its possibility is quite low. We hence examined three mechanisms, assuming that the emission is truly diffuse: bremsstrahlung by keV electrons, synchrotron emission by TeV electrons, and inverse Compton scattering of solar photons by MeV electrons. The former two can be rejected because of the X-ray spectral shape and implausible existence of TeV electrons around Jupiter, respectively. The last possibility was found to be possible because tens MeV electrons, which have been confirmed in inner radiation belts (Bolton et al. 2002), can kick solar photons to the keV energy range and provide a simple power-law continuum. We estimated an average electron density from the X-ray luminosity assuming the oblate spheroid shaped emitting region with 8 x 8 x 4 Jovian radii. The necessary density was 0.02 1/cm3 for 50 MeV electrons. Hence, our results may suggest a new particle acceleration phenomenon around Jupiter.

  15. A New Model of Jupiter's Magnetic Field from Juno's First Nine Orbits

    DEFF Research Database (Denmark)

    Connerney, J. E. P.; Kotsiaros, S.; Oliversen, R. J.

    2018-01-01

    A spherical harmonic model of the magnetic field of Jupiter is obtained from vector magnetic field observations acquired by the Juno spacecraft during its first nine polar orbits about the planet. Observations acquired during eight of these orbits provide the first truly global coverage of Jupiter...... currents. Partial solution of the underdetermined inverse problem using generalized inverse techniques yields a model (“Juno Reference Model through Perijove 9”) of the planetary magnetic field with spherical harmonic coefficients well determined through degree and order 10, providing the first detailed...

  16. Rosuvastatin and the JUPITER trial: critical appraisal of a lifeless planet in the galaxy of primary prevention.

    Science.gov (United States)

    López, Antonio; Wright, James M

    2012-01-01

    In November 2008, the JUPITER trial was published in the New England Journal of Medicine. JUPITER is an acronym for Justification for the Use of Statins in Prevention: an Intervention Trial Evaluating Rosuvastatin. It was an AstraZeneca sponsored randomized double-blind trial comparing rosuvastatin 20 mg with placebo in 17,802 apparently healthy men and women with LDL cholesterol JUPITER trial have been widely publicized, and based on the trial, the main regulatory agencies have approved rosuvastatin for the indication of primary prevention of vascular events. However, the interpretation and clinical implications of the JUPITER trial have been questioned and remain controversial. The objective of this commentary is to evaluate the relevance, design, results, and conclusions of the JUPITER study.

  17. FRIENDS OF HOT JUPITERS. II. NO CORRESPONDENCE BETWEEN HOT-JUPITER SPIN-ORBIT MISALIGNMENT AND THE INCIDENCE OF DIRECTLY IMAGED STELLAR COMPANIONS

    Energy Technology Data Exchange (ETDEWEB)

    Ngo, Henry; Knutson, Heather A.; Hinkley, Sasha; Batygin, Konstantin [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA (United States); Crepp, Justin R.; Bechter, Eric B. [Department of Physics, University of Notre Dame, Notre Dame, IN (United States); Howard, Andrew W. [Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI (United States); Johnson, John A. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Morton, Timothy D. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA (United States); Muirhead, Philip S., E-mail: hngo@caltech.edu [Department of Astronomy, Boston University, Boston, MA (United States)

    2015-02-20

    Multi-star systems are common, yet little is known about a stellar companion's influence on the formation and evolution of planetary systems. For instance, stellar companions may have facilitated the inward migration of hot Jupiters toward to their present day positions. Many observed short-period gas giant planets also have orbits that are misaligned with respect to their star's spin axis, which has also been attributed to the presence of a massive outer companion on a non-coplanar orbit. We present the results of a multi-band direct imaging survey using Keck NIRC2 to measure the fraction of short-period gas giant planets found in multi-star systems. Over three years, we completed a survey of 50 targets ('Friends of Hot Jupiters') with 27 targets showing some signature of multi-body interaction (misaligned or eccentric orbits) and 23 targets in a control sample (well-aligned and circular orbits). We report the masses, projected separations, and confirmed common proper motion for the 19 stellar companions found around 17 stars. Correcting for survey incompleteness, we report companion fractions of 48% ± 9%, 47% ± 12%, and 51% ± 13% in our total, misaligned/eccentric, and control samples, respectively. This total stellar companion fraction is 2.8σ larger than the fraction of field stars with companions approximately 50-2000 AU. We observe no correlation between misaligned/eccentric hot Jupiter systems and the incidence of stellar companions. Combining this result with our previous radial velocity survey, we determine that 72% ± 16% of hot Jupiters are part of multi-planet and/or multi-star systems.

  18. Stellar by Day, Planetary by Night: Atmospheres of Ultra-Hot Jupiters

    Science.gov (United States)

    Hensley, Kerry

    2018-06-01

    Move over, hot Jupiters theres an even stranger kind of giant planet in the universe! Ultra-hot Jupiters are so strongly irradiated that the molecules in their atmospheres split apart. What does this mean for heat transport on these planets?Atmospheres of Exotic PlanetsA diagram showing the orbit of an ultra-hot Jupiter and the longitudes at which dissociation and recombination occur. [Bell Cowan 2018]Similar to hot Jupiters, ultra-hot Jupiters are gas giants with atmospheres dominated by molecular hydrogen. What makes them interesting is that their dayside atmospheres are so hot that the molecules dissociate into individual hydrogen atoms more like the atmospheres of stars than planets.Because of the intense stellar irradiation, there is also an extreme temperature difference between the day and night sides of these planets potentially more than 1,000 K! As the stellar irradiation increases, the dayside atmosphere becomes hotter and hotter and the temperature difference between the day and night sides increases.When hot atomic hydrogen is transported into cooler regions (by winds, for instance), it recombines to form H2 molecules and heats the gas, effectively transporting heat from one location to another. This is similar to how the condensation of water redistributes heat in Earths atmosphere but what effect does this phenomenon have on the atmospheres of ultra-hot Jupiters?Maps of atmospheric temperature of molecular hydrogen dissociation fraction for three wind speeds. Click to enlarge. [Bell Cowan 2018]Modeling Heat RedistributionTaylor Bell and Nicolas Cowan (McGill University) used an energy-balance model to estimate the effects of H2 dissociation and recombination on heat transport in ultra-hot Jupiter atmospheres. In particular, they explored the redistribution of heat and how it affects the resultant phase curve the curve that describes the combination of reflected and thermally emitted light from the planet, observed as a function of its phase angle

  19. Habitability potential of satellites around Jupiter and Saturn

    Science.gov (United States)

    Coustenis, Athena; Raulin, Francois; Encrenaz, Therese; Grasset, Olivier; Solomonidou, Anezina

    2016-07-01

    biomarkers. Currently, for Titan and Enceladus, geophysical models try to explain the possible existence of an oceanic layer that decouples the mantle from the icy crust. Titan has further been suggested to be a possible cryovolcanic world due to the presence of local complex volcanic-like geomorphology and the indications of surface albedo changes with time [7,8]. Such dynamic activity that would most probably include tidal heating, possible internal convection, and ice tectonics, is believed to be a pre-requisite of a habitable planetary body as it allows the recycling of minerals and potential nutrients and provides localized energy sources. In one of our geophysical studies [4], we have showed that tidal forces are a constant and significant source of internal deformation on Titan and the interior liquid water ocean can be relatively warm for reasonable amounts of ammonia concentrations, thus completing the set of parameters needed for a truly habitable planetary body. If the silicate mantles of Europa and Ganymede and the liquid sources of Titan and Enceladus are geologically active as on Earth, giving rise to the equivalent of hydrothermal systems, the simultaneous presence of water, geodynamic interactions, chemical energy sources and a diversity of key chemical elements may fulfill the basic conditions for habitability. Such habitability indications from bodies at distances of 10 AU, are essential discoveries brought to us by space exploration and which have recently revolutionized our perception of habitability in the solar system. In the solar system's neighborhood, such potential habitats can only be investigated with appropriate designed space missions, like JUICE (JUpiter ICy moon Explorer) for Ganymede and Europa [9]. JUICE is an ESA mission to Jupiter and its icy moons, recently selected to launch in 2022. Other future mission concepts are being studied for exploring the moons around Saturn. References: [1] Coustenis, A., Encrenaz, Th., in "Life Beyond Earth

  20. K2-231 b: A Sub-Neptune Exoplanet Transiting a Solar Twin in Ruprecht 147

    Science.gov (United States)

    Curtis, Jason Lee; Vanderburg, Andrew; Torres, Guillermo; Kraus, Adam L.; Huber, Daniel; Mann, Andrew W.; Rizzuto, Aaron C.; Isaacson, Howard; Howard, Andrew W.; Henze, Christopher E.; Fulton, Benjamin J.; Wright, Jason T.

    2018-04-01

    We identify a sub-Neptune exoplanet (R p = 2.5 ± 0.2 {R}\\oplus ) transiting a solar twin in the Ruprecht 147 star cluster (3 Gyr, 300 pc, [Fe/H] = +0.1 dex). The ∼81 day light curve for EPIC 219800881 (V = 12.71) from K2 Campaign 7 shows six transits with a period of 13.84 days, a depth of ∼0.06%, and a duration of ∼4 hr. Based on our analysis of high-resolution MIKE spectra, broadband optical and NIR photometry, the cluster parallax and interstellar reddening, and isochrone models from PARSEC, Dartmouth, and MIST, we estimate the following properties for the host star: M ⋆ = 1.01 ± 0.03 {M}ȯ , R ⋆ = 0.95 ± 0.03 {R}ȯ , and {T}{{eff}} = 5695 ± 50 K. This star appears to be single based on our modeling of the photometry, the low radial velocity (RV) variability measured over nearly 10 yr, and Keck/NIRC2 adaptive optics imaging and aperture-masking interferometry. Applying a probabilistic mass–radius relation, we estimate that the mass of this planet is M p = 7 + 5 – 3 {M}\\oplus , which would cause an RV semi-amplitude of K = 2 ± 1 {\\text{m s}}-1 that may be measurable with existing precise RV facilities. After statistically validating this planet with BLENDER, we now designate it K2-231b, making it the second substellar object to be discovered in Ruprecht 147 and the first planet; it joins the small but growing ranks of 22 other planets and three candidates found in open clusters.