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Sample records for planet candidate orbiting

  1. Evidence for at least three planet candidates orbiting HD 20794

    Science.gov (United States)

    Feng, F.; Tuomi, M.; Jones, H. R. A.

    2017-09-01

    Aims: We explore the feasibility of detecting Earth analogs around Sun-like stars using the radial velocity method by investigating one of the largest radial velocities data sets for the one of the most stable radial-velocity stars HD 20794. Methods: We proceed by disentangling the Keplerian signals from correlated noise and activity-induced variability. We diagnose the noise using the differences between radial velocities measured at different wavelength ranges, so-called "differential radial velocities". Results: We apply this method to the radial velocities measured by HARPS, and identify four signals at 18, 89, 147 and 330 d. The two signals at periods of 18 and 89 d are previously reported and are better quantified in this work. The signal at a period of about 147 d is reported for the first time, and corresponds to a super-Earth with a minimum mass of 4.59 Earth mass located 0.51 AU from HD 20794. We also find a significant signal at a period of about 330 d corresponding to a super-Earth or Neptune in the habitable zone. Since this signal is close to the annual sampling period and significant periodogram power in some noise proxies are found close to this signal, further observations and analyses are required to confirm it. The analyses of the eccentricity and consistency of signals provide weak evidence for the existence of the previously reported 43 d signal and a new signal at a period of about 11.9 d with a semi-amplitude of 0.4 m/s. Conclusions: We find that the detection of a number of signals with radial velocity variations around 0.5 m/s that are likely caused by low mass planet candidates demonstrates the important role of noise modeling in searching for Earth analogs. Radial velocity tables are available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/605/A103

  2. Orbital Constraints on the (beta) Pic Inner Planet Candidate with Keck Adaptive Optics

    Energy Technology Data Exchange (ETDEWEB)

    Fitzgerald, M P; Kalas, P G; Graham, J R

    2009-09-23

    A point source observed 8AU in projection from {beta} Pictoris in L{prime} (3.8 {micro}m) imaging in 2003 has been recently presented as a planet candidate. Here we show the results of L{prime}-band adaptive optics imaging obtained at Keck Observatory in 2008. We do not detect {beta} Pic b beyond a limiting radius of 0.29-inch, or 5.5AU in projection, from the star. If {beta} Pic b is an orbiting planet, then it has moved {ge} 0.12-inch (2.4AU in projection) closer to the star in the five years separating the two epochs of observation. We examine the range of orbital parameters consistent with the observations, including likely bounds from the locations of previously inferred planetesimal belts. We find a family of low-eccentricity orbits with semimajor axes {approx} 8-9AU that are completely allowed, as well as a broad region of orbits with e {approx}< 0.2, a {approx}> 10AU that are allowed if the apparent motion of the planet was towards the star in 2003. We compare this allowed space with predictions of the planetary orbital elements from the literature. Additionally, we show how similar observations in the next several years can further constrain the space of allowed orbits. Non-detections of the source through 2013 will exclude the interpretation of the candidate as a planet orbiting between the 6.4 and 16AU planetesimal belts.

  3. KOI-2700b—a planet candidate with dusty effluents on a 22 hr orbit

    Energy Technology Data Exchange (ETDEWEB)

    Rappaport, Saul; Sanchis-Ojeda, Roberto [Department of Physics, and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Barclay, Thomas; Still, Martin [BAER Institute/NASA Ames Research Center, M/S 244-30, Moffett Field, Mountain View, CA 94035 (United States); DeVore, John [Visidyne, Inc., 111 South Bedford St., Suite 103, Burlington, MA 01803 (United States); Rowe, Jason, E-mail: sar@mit.edu, E-mail: rsanchis86@gmail.com, E-mail: thomas.barclay@nasa.gov, E-mail: martin.d.still@nasa.gov, E-mail: devore@visidyne.com, E-mail: jasonfrowe@gmail.com [SETI Institute, 189 Bernardo Ave, Suite 100 Mountain View, CA 94043 (United States)

    2014-03-20

    Kepler planet candidate KOI-2700b (KIC 8639908b), with an orbital period of 21.84 hr, exhibits a distinctly asymmetric transit profile, likely indicative of the emission of dusty effluents, and reminiscent of KIC 1255b. The host star has T {sub eff} = 4435 K, M ≅ 0.63 M {sub ☉}, and R ≅ 0.57 R {sub ☉}, comparable to the parameters ascribed to KIC 12557548. The transit egress can be followed for ∼25% of the orbital period and, if interpreted as extinction from a dusty comet-like tail, indicates a long lifetime for the dust grains of more than a day. We present a semiphysical model for the dust tail attenuation and fit for the physical parameters contained in that expression. The transit is not sufficiently deep to allow for a study of the transit-to-transit variations, as is the case for KIC 1255b; however, it is clear that the transit depth is slowly monotonically decreasing by a factor of ∼2 over the duration of the Kepler mission. We infer a mass-loss rate in dust from the planet of ∼2 lunar masses per Gyr. The existence of a second star hosting a planet with a dusty comet-like tail would help to show that such objects may be more common and less exotic than originally thought. According to current models, only quite small planets with M{sub p} ≲ 0.03 M {sub ⊕} are likely to release a detectable quantity of dust. Thus, any 'normal-looking' transit that is inferred to arise from a rocky planet of radius greater than ∼1/2 R {sub ⊕} should not exhibit any hint of a dusty tail. Conversely, if one detects an asymmetric transit due to a dusty tail, then it will be very difficult to detect the hard body of the planet within the transit because, by necessity, the planet must be quite small (i.e., ≲ 0.3 R {sub ⊕}).

  4. Almost All of Kepler's Multiple Planet Candidates are Planets

    CERN Document Server

    Lissauer, Jack J; Rowe, Jason F; Bryson, Stephen T; Adams, Elisabeth; Buchhave, Lars A; Ciardi, David R; Cochran, William D; Fabrycky, Daniel C; Ford, Eric B; Fressin, Francois; Geary, John; Gilliland, Ronald L; Holman, Matthew J; Howell, Steve B; Jenkins, Jon M; Kinemuchi, Karen; Koch, David G; Morehead, Robert C; Ragozzine, Darin; Seader, Shawn E; Tanenbaum, Peter G; Torres, Guillermo; Twicken, Joseph D

    2012-01-01

    We present a statistical analysis that demonstrates that the overwhelming majority of Kepler candidate multiple transiting systems (multis) indeed represent true, physically-associated transiting planets. Binary stars provide the primary source of false positives among Kepler planet candidates, implying that false positives should be nearly randomly-distributed among Kepler targets. In contrast, true transiting planets would appear clustered around a smaller number of Kepler targets if detectable planets tend to come in systems and/or if the orbital planes of planets encircling the same star are correlated. There are more than one hundred times as many Kepler planet candidates in multi-candidate systems as would be predicted from a random distribution of candidates, implying that the vast majority are true planets. Most of these multis are multiple planet systems orbiting the Kepler target star, but there are likely cases where (a) the planetary system orbits a fainter star, and the planets are thus significa...

  5. A terrestrial planet candidate in a temperate orbit around Proxima Centauri

    CERN Document Server

    Anglada-Escudé, Guillem; Barnes, John; Berdiñas, Zaira M; Butler, R Paul; Coleman, Gavin A L; de la Cueva, Ignacio; Dreizler, Stefan; Endl, Michael; Giesers, Benjamin; Jeffers, Sandra V; Jenkins, James S; Jones, Hugh R A; Kiraga, Marcin; Kürster, Martin; López-González, María J; Marvin, Christopher J; Morales, Nicolás; Morin, Julien; Nelson, Richard P; Ortiz, José L; Ofir, Aviv; Paardekooper, Sijme-Jan; Reiners, Ansgar; Rodríguez, Eloy; Rodríguez-López, Cristina; Sarmiento, Luis F; Strachan, John P; Tsapras, Yiannis; Tuomi, Mikko; Zechmeister, Mathias

    2016-01-01

    At a distance of 1.295 parsecs, the red-dwarf Proxima Centauri ($\\alpha$ Centauri C, GL 551, HIP 70890, or simply Proxima) is the Sun's closest stellar neighbor and one of the best studied low-mass stars. It has an effective temperature of only $\\sim$ 3050 K, a luminosity of $\\sim$0.1 per cent solar, a measured radius of 0.14 R$_\\odot$ and a mass of about 12 per cent the mass of the Sun. Although Proxima is considered a moderately active star, its rotation period is $\\sim$ 83 days, and its quiescent activity levels and X-ray luminosity are comparable to the Sun's. New observations reveal the presence of a small planet orbiting Proxima with a minimum mass of 1.3~Earth masses and an orbital period of $\\sim$11.2 days. Its orbital semi-major axis is $\\sim0.05$ AU, with an equilibrium temperature in the range where water could be liquid on its surface.

  6. A Candidate Young Massive Planet in Orbit around the Classical T Tauri Star CI Tau

    CERN Document Server

    Johns-Krull, Christopher M; Prato, L; Crockett, Christopher J; Jaffe, Daniel T; Hartigan, Patrick M; Beichman, Charles A; Mahmud, Naved I; Chen, Wei; Skiff, B A; Cauley, P Wilson; Jones, Joshua A; Mace, G N

    2016-01-01

    The ~2 Myr old classical T Tauri star CI Tau shows periodic variability in its radial velocity (RV) variations measured at infrared (IR) and optical wavelengths. We find that these observations are consistent with a massive planet in a ~9-day period orbit. These results are based on 71 IR RV measurements of this system obtained over 5 years, and on 26 optical RV measurements obtained over 9 years. CI Tau was also observed photometrically in the optical on 34 nights over ~one month in 2012. The optical RV data alone are inadequate to identify an orbital period, likely the result of star spot and activity induced noise for this relatively small dataset. The infrared RV measurements reveal significant periodicity at ~9 days. In addition, the full set of optical and IR RV measurements taken together phase coherently and with equal amplitudes to the ~9 day period. Periodic radial velocity signals can in principle be produced by cool spots, hot spots, and reflection of the stellar spectrum off the inner disk, in ad...

  7. Exploring plausible formation scenarios for the planet candidate orbiting Proxima Centauri

    CERN Document Server

    Coleman, Gavin A L; Paardekooper, Sijme-Jan; Dreizler, Stefan; Giesers, Benjamin; Anglada-Escude, Guillem

    2016-01-01

    We present a study of 4 different formation scenarios that may explain the origin of the recently announced planet `Proxima b' orbiting the star Proxima Centauri. The aim is to examine how the formation scenarios differ in their predictions for the multiplicity of the Proxima planetary system, the water/volatile content of Proxima b and its eccentricity, so that these can be tested by future observations. A scenario of in situ formation via giant impacts from a locally enhanced disc of planetary embryos and planetesimals, predicts that Proxima b will be a member of a multiplanet system with a measurably finite value of orbital eccentricity. Assuming that the local solid enhancement needed to form a Proxima b analogue with a minimum mass of 1.3 Earth masses arises because of the inwards drift of solids in the form of small planetesimals/boulders, this scenario also likely results in Proxima b analogues that are moderately endowed with water/volatiles, arising from the dynamical diffusion of icy planetesimals f...

  8. Measurements of Stellar Inclinations for Kepler Planet Candidates II: Candidate Spin-Orbit Misalignments in Single and Multiple-Transiting Systems

    CERN Document Server

    Hirano, Teruyuki; Takeda, Yoichi; Winn, Joshua N; Narita, Norio; Takahashi, Yasuhiro H

    2014-01-01

    We present a test for spin-orbit alignment for the host stars of 25 candidate planetary systems detected by the {\\it Kepler} spacecraft. The inclination angle of each star's rotation axis was estimated from its rotation period, rotational line broadening, and radius. The rotation periods were determined using the {\\it Kepler} photometric time series. The rotational line broadening was determined from high-resolution optical spectra with Subaru/HDS. Those same spectra were used to determine the star's photospheric parameters (effective temperature, surface gravity, metallicity) which were then interpreted with stellar-evolutionary models to determine stellar radii. We combine the new sample with the 7 stars from our previous work on this subject, finding that the stars show a statistical tendency to have inclinations near 90$^\\circ$, in alignment with the planetary orbits. Possible spin-orbit misalignments are seen in several systems, including three multiple-planet systems (KOI-304, 988, 2261). Ideally these ...

  9. A terrestrial planet candidate in a temperate orbit around Proxima Centauri.

    Science.gov (United States)

    Anglada-Escudé, Guillem; Amado, Pedro J; Barnes, John; Berdiñas, Zaira M; Butler, R Paul; Coleman, Gavin A L; de la Cueva, Ignacio; Dreizler, Stefan; Endl, Michael; Giesers, Benjamin; Jeffers, Sandra V; Jenkins, James S; Jones, Hugh R A; Kiraga, Marcin; Kürster, Martin; López-González, Marίa J; Marvin, Christopher J; Morales, Nicolás; Morin, Julien; Nelson, Richard P; Ortiz, José L; Ofir, Aviv; Paardekooper, Sijme-Jan; Reiners, Ansgar; Rodríguez, Eloy; Rodrίguez-López, Cristina; Sarmiento, Luis F; Strachan, John P; Tsapras, Yiannis; Tuomi, Mikko; Zechmeister, Mathias

    2016-08-25

    At a distance of 1.295 parsecs, the red dwarf Proxima Centauri (α Centauri C, GL 551, HIP 70890 or simply Proxima) is the Sun's closest stellar neighbour and one of the best-studied low-mass stars. It has an effective temperature of only around 3,050 kelvin, a luminosity of 0.15 per cent of that of the Sun, a measured radius of 14 per cent of the radius of the Sun and a mass of about 12 per cent of the mass of the Sun. Although Proxima is considered a moderately active star, its rotation period is about 83 days (ref. 3) and its quiescent activity levels and X-ray luminosity are comparable to those of the Sun. Here we report observations that reveal the presence of a small planet with a minimum mass of about 1.3 Earth masses orbiting Proxima with a period of approximately 11.2 days at a semi-major-axis distance of around 0.05 astronomical units. Its equilibrium temperature is within the range where water could be liquid on its surface.

  10. A New Way to Confirm Planet Candidates

    Science.gov (United States)

    Kohler, Susanna

    2016-05-01

    What was the big deal behind the Kepler news conference yesterday? Its not just that the number of confirmed planets found by Kepler has more than doubled (though thats certainly exciting news!). Whats especially interesting is the way in which these new planets were confirmed.Number of planet discoveries by year since 1995, including previous non-Kepler discoveries (blue), previous Kepler discoveries (light blue) and the newly validated Kepler planets (orange). [NASA Ames/W. Stenzel; Princeton University/T. Morton]No Need for Follow-UpBefore Kepler, the way we confirmed planet candidates was with follow-up observations. The candidate could be validated either by directly imaging (which is rare) or obtaining a large number radial-velocity measurements of the wobble of the planets host star due to the planets orbit. But once Kepler started producing planet candidates, these approaches to validation became less feasible. A lot of Kepler candidates are small and orbit faint stars, making follow-up observations difficult or impossible.This problem is what inspired the development of whats known as probabilistic validation, an analysis technique that involves assessing the likelihood that the candidates signal is caused by various false-positive scenarios. Using this technique allows astronomers to estimate the likelihood of a candidate signal being a true planet detection; if that likelihood is high enough, the planet candidate can be confirmed without the need for follow-up observations.A breakdown of the catalog of Kepler Objects of Interest. Just over half had previously been identified as false positives or confirmed as candidates. 1284 are newly validated, and another 455 have FPP of1090%. [Morton et al. 2016]Probabilistic validation has been used in the past to confirm individual planet candidates in Kepler data, but now Timothy Morton (Princeton University) and collaborators have taken this to a new level: they developed the first code thats designed to do fully

  11. Planet Hunters VI: The First Kepler Seven Planet Candidate System and 13 Other Planet Candidates from the Kepler Archival Data

    CERN Document Server

    Schmitt, Joseph R; Fischer, Debra A; Jek, Kian J; Moriarty, John C; Boyajian, Tabetha S; Schwamb, Megan E; Lintott, Chris; Smith, Arfon M; Parrish, Michael; Schawinski, Kevin; Lynn, Stuart; Simpson, Robert; Omohundro, Mark; Winarski, Troy; Goodman, Samuel J; Jebson, Tony; Lacourse, Daryll

    2013-01-01

    We report the discovery of 14 new transiting planet candidates in the Kepler field from the Planet Hunters citizen science program. None of these candidates overlap with Kepler Objects of Interest (KOIs), and five of the candidates were missed by the Kepler Transit Planet Search (TPS) algorithm. The new candidates have periods ranging from 124-904 days, eight residing in their host star's habitable zone (HZ) and two (now) in multiple planet systems. We report the discovery of one more addition to the six planet candidate system around KOI-351, marking the first seven planet candidate system from Kepler. Additionally, KOI-351 bears some resemblance to our own solar system, with the inner five planets ranging from Earth to mini-Neptune radii and the outer planets being gas giants; however, this system is very compact, with all seven planet candidates orbiting $\\lesssim 1$ AU from their host star. We perform a numerical integration of the orbits and show that the system remains stable for over 100 million years....

  12. THREE PLANETS ORBITING WOLF 1061

    Energy Technology Data Exchange (ETDEWEB)

    Wright, D. J.; Wittenmyer, R. A.; Tinney, C. G.; Bentley, J. S.; Zhao, Jinglin, E-mail: duncan.wright@unsw.edu.au [Department of Astronomy and Australian Centre for Astrobiology, School of Physics, University of New South Wales, NSW 2052 (Australia)

    2016-02-01

    We use archival HARPS spectra to detect three planets orbiting the M3 dwarf Wolf 1061 (GJ 628). We detect a 1.36 M{sub ⊕} minimum-mass planet with an orbital period P = 4.888 days (Wolf 1061b), a 4.25 M{sub ⊕} minimum-mass planet with orbital period P = 17.867 days (Wolf 1061c), and a likely 5.21 M{sub ⊕} minimum-mass planet with orbital period P = 67.274 days (Wolf 1061d). All of the planets are of sufficiently low mass that they may be rocky in nature. The 17.867 day planet falls within the habitable zone for Wolf 1061 and the 67.274 day planet falls just outside the outer boundary of the habitable zone. There are no signs of activity observed in the bisector spans, cross-correlation FWHMs, calcium H and K indices, NaD indices, or Hα indices near the planetary periods. We use custom methods to generate a cross-correlation template tailored to the star. The resulting velocities do not suffer the strong annual variation observed in the HARPS DRS velocities. This differential technique should deliver better exploitation of the archival HARPS data for the detection of planets at extremely low amplitudes.

  13. Three planets orbiting Wolf 1061

    CERN Document Server

    Wright, D J; Tinney, C G; Bentley, J S; Zhao, Jinglin

    2015-01-01

    We use archival HARPS spectra to detect three planets orbiting the M3 dwarf Wolf1061 (GJ 628). We detect a 1.36 Mearth minimum-mass planet with an orbital period P = 4.888d (Wolf1061b), a 4.25 Mearth minimum-mass planet with orbital period P = 17.867d (Wolf1061c), and a likely 5.21 Mearth minimum-mass planet with orbital period P = 67.274d (Wolf1061d). All of the planets are of sufficiently low mass that they may be rocky in nature. The 17.867d planet falls within the habitable zone for Wolf 1061 and the 67.274d planet falls just outside the outer boundary of the habitable zone. There are no signs of activity observed in the bisector spans, cross-correlation full-width-half-maxima, Calcium H & K indices, NaD indices, or H-alpha indices near the planetary periods. We use custom methods to generate a cross-correlation template tailored to the star. The resulting velocities do not suffer the strong annual variation observed in the HARPS DRS velocities. This differential technique should deliver better exploi...

  14. Planet Hunters: New Kepler planet candidates from analysis of quarter 2

    CERN Document Server

    Lintott, Chris; Sharzer, Charlie; Fisher, Debra A; Barclay, Thomas; Parrish, Michael; Batalha, Natalie; Bryson, Steve; Jenkins, Jon; Ragozzine, Darin; Rowe, Jason F; Schawinski, Kevin; Gagliano, Rovert; Gilardi, Joe; Jek, Kian J; Pääkkönen, Jari-Pekka; Smits, Tjapko

    2012-01-01

    We present new planet candidates identified in NASA Kepler quarter two public release data by volunteers engaged in the Planet Hunters citizen science project. The two candidates presented here survive checks for false-positives, including examination of the pixel offset to constrain the possibility of a background eclipsing binary. The orbital periods of the planet candidates are 97.46 days (KIC 4552729) and 284.03 (KIC 10005758) days and the modeled planet radii are 5.3 and 3.790 R_Earth. The latter star has an additional known planet candidate with a radius of 5.05 R_Earth and a period of 134.49 which was detected by the Kepler pipeline. The discovery of these candidates illustrates the value of massively distributed volunteer review of the Kepler database to recover candidates which were otherwise uncatalogued.

  15. Masses, Radii, and Orbits of Small Kepler Planets: The Transition from Gaseous to Rocky Planets

    NARCIS (Netherlands)

    Marcy, G.W.; et al., [Unknown; Hekker, S.

    2014-01-01

    We report on the masses, sizes, and orbits of the planets orbiting 22 Kepler stars. There are 49 planet candidates around these stars, including 42 detected through transits and 7 revealed by precise Doppler measurements of the host stars. Based on an analysis of the Kepler brightness measurements,

  16. SDSS-III MARVELS Planet Candidate RV Follow-up

    Science.gov (United States)

    Ge, Jian; Thomas, Neil; Ma, Bo; Li, Rui; SIthajan, Sirinrat

    2014-02-01

    Planetary systems, discovered by the radial velocity (RV) surveys, reveal strong correlations between the planet frequency and stellar properties, such as metallicity and mass, and a greater diversity in planets than found in the solar system. However, due to the sample sizes of extant surveys (~100 to a few hundreds of stars) and their heterogeneity, many key questions remained to be addressed: Do metal poor stars obey the same trends for planet occurrence as metal rich stars? What is the distribution of giant planets around intermediate- mass stars and binaries? Is the ``planet desert'' within 0.6 AU in the planet orbital distribution of intermediate-mass stars real? The MARVELS survey has produced the largest homogeneous RV measurements of 3300 V=7.6-12 FGK stars. The latest data pipeline effort at UF has been able to remove long term systematic errors suffered in the earlier data pipeline. 18 high confident giant planet candidates have been identified among newly processed data. We propose to follow up these giant planet candidates with the KPNO EXPERT instrument to confirm the detection and also characterize their orbits. The confirmed planets will be used to measure occurrence rates, distributions and multiplicity of giants planets around F,G,K stars with a broad range of mass (~0.6-2.5 M_⊙) and metallicity ([Fe/H]~-1.5-0.5). The well defined MARVELS survey cadence allows robust determinations of completeness limits for rigorously testing giant planet formation theories and constraining models.

  17. The statistical mechanics of planet orbits

    CERN Document Server

    Tremaine, Scott

    2015-01-01

    The final "giant-impact" phase of terrestrial planet formation is believed to begin with a large number of planetary "embryos" on nearly circular, coplanar orbits. Mutual gravitational interactions gradually excite their eccentricities until their orbits cross and they collide and merge; through this process the number of surviving bodies declines until the system contains a small number of planets on well-separated, stable orbits. In this paper we explore a simple statistical model for the orbit distribution of planets formed by this process, based on the sheared-sheet approximation and the ansatz that the planets explore uniformly all of the stable region of phase space. The model provides analytic predictions for the distribution of eccentricities and semimajor axis differences, correlations between orbital elements of nearby planets, and the complete N-planet distribution function, in terms of a single parameter that is determined by the planetary masses. The predicted properties are generally consistent ...

  18. THE STATISTICAL MECHANICS OF PLANET ORBITS

    Energy Technology Data Exchange (ETDEWEB)

    Tremaine, Scott, E-mail: tremaine@ias.edu [Institute for Advanced Study, Princeton, NJ 08540 (United States)

    2015-07-10

    The final “giant-impact” phase of terrestrial planet formation is believed to begin with a large number of planetary “embryos” on nearly circular, coplanar orbits. Mutual gravitational interactions gradually excite their eccentricities until their orbits cross and they collide and merge; through this process the number of surviving bodies declines until the system contains a small number of planets on well-separated, stable orbits. In this paper we explore a simple statistical model for the orbit distribution of planets formed by this process, based on the sheared-sheet approximation and the ansatz that the planets explore uniformly all of the stable region of phase space. The model provides analytic predictions for the distribution of eccentricities and semimajor axis differences, correlations between orbital elements of nearby planets, and the complete N-planet distribution function, in terms of a single parameter, the “dynamical temperature,” that is determined by the planetary masses. The predicted properties are generally consistent with N-body simulations of the giant-impact phase and with the distribution of semimajor axis differences in the Kepler catalog of extrasolar planets. A similar model may apply to the orbits of giant planets if these orbits are determined mainly by dynamical evolution after the planets have formed and the gas disk has disappeared.

  19. Chromosomes Emission of Planet Candidate Host Stars: A Way to Identify False Positives

    Science.gov (United States)

    Karoff, Christoffer; Albrecht, Simon; Bonanno, Alfio; Faurschou Knudsen, Mads

    2016-10-01

    It has been hypothesized that the presence of closely orbiting giant planets is associated with enhanced chromospheric emission of their host stars. The main cause for such a relation would likely be enhanced dynamo action induced by the planet. We present measurements of chromospheric emission in 234 planet candidate systems from the Kepler mission. This ensemble includes 37 systems with giant-planet candidates, which show a clear emission enhancement. The enhancement, however, disappears when systems that are also identified as eclipsing binary candidates are removed from the ensemble. This suggests that a large fraction of the giant-planet candidate systems with chromospheric emission stronger than the Sun are not giant-planet systems, but false positives. Such false-positive systems could be tidally interacting binaries with strong chromospheric emission. This hypothesis is supported by an analysis of 188 eclipsing binary candidates that show increasing chromospheric emission as function of decreasing orbital period.

  20. Early Giant Planet Candidates from the SDSS-III MARVELS Planet Survey

    Science.gov (United States)

    Thomas, Neil; Ge, J.; Li, R.; Sithajan, S.; Chen, Y.; Shi, J.; Ma, B.; Liu, J.

    2014-01-01

    We report the first discoveries of giant planet candidates from the SDSS-III MARVELS survey. These candidates are found using the new MARVELS data pipeline developed at UF from scratch over the past two years. Unlike the old data pipeline, this pipeline carefully corrects most of the instrument effects (such as trace, slant, distortion, drifts and dispersion) and observation condition effects (such as illumination profile). The result is long-term RV precisions that approach the photon limits in many cases and has yielded four giant planet candidates of ~1-6 Jupiter mass from only the initial fraction of data processed with the new techniques. More survey data is being processed which will likely lead to discoveries of additional giant planet candidates that will be verified and characterized with follow-up observations by the MARVELS team. The MARVELS survey has produced the largest homogeneous RV measurements of 3300 V=7.6-12 FGK stars with well defined cadence 27 RV measurements over 2 years). The MARVELS RV data and other follow-up data (photometry, high contrast imaging, high resolution spectroscopy and RV measurements) will explore the diversity of giant planet companion formation and evolution around stars with a broad range in metallicity ([Fe/H -1.5-0.5), mass ( 0.6-2.5M(sun)), and environment (thin disk and thick disk), and will help to address the key scientific questions identified for the MARVELS survey including, but not limited to: Do metal poor stars obey the same trends for planet occurrence as metal rich stars? What is the distribution of giant planets around intermediate-mass stars and binaries? Is the “planet desert” within 0.6 AU in the planet orbital distribution of intermediate-mass stars real?

  1. Planet hunters. VI. An independent characterization of KOI-351 and several long period planet candidates from the Kepler archival data

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, Joseph R.; Wang, Ji; Fischer, Debra A.; Moriarty, John C.; Boyajian, Tabetha S. [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Jek, Kian J.; LaCourse, Daryll; Omohundro, Mark R.; Winarski, Troy; Goodman, Samuel Jon; Jebson, Tony; Schwengeler, Hans Martin; Paterson, David A.; Schwamb, Megan E. [Institute of Astronomy and Astrophysics, Academia Sinica, 11F of Astronomy-Mathematics Building, National Taiwan University. No.1, Sec. 4, Roosevelt Rd, Taipei 10617, Taiwan (China); Lintott, Chris; Simpson, Robert [Oxford Astrophysics, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Lynn, Stuart; Smith, Arfon M.; Parrish, Michael [Adler Planetarium, 1300 S. Lake Shore Drive, Chicago, IL 60605 (United States); Schawinski, Kevin, E-mail: joseph.schmitt@yale.edu [Institute for Astronomy, Department of Physics, ETH Zurich, Wolfgang-Pauli-Strasse 16, CH-8093 Zurich (Switzerland); and others

    2014-08-01

    We report the discovery of 14 new transiting planet candidates in the Kepler field from the Planet Hunters citizen science program. None of these candidates overlapped with Kepler Objects of Interest (KOIs) at the time of submission. We report the discovery of one more addition to the six planet candidate system around KOI-351, making it the only seven planet candidate system from Kepler. Additionally, KOI-351 bears some resemblance to our own solar system, with the inner five planets ranging from Earth to mini-Neptune radii and the outer planets being gas giants; however, this system is very compact, with all seven planet candidates orbiting ≲ 1 AU from their host star. A Hill stability test and an orbital integration of the system shows that the system is stable. Furthermore, we significantly add to the population of long period transiting planets; periods range from 124 to 904 days, eight of them more than one Earth year long. Seven of these 14 candidates reside in their host star's habitable zone.

  2. Chromospheric emission of planet candidate systems - a way to identify false positives

    CERN Document Server

    Karoff, Christoffer; Boxano, Alfio; Knudsen, Mads Faurschou

    2016-01-01

    It has been hypothesized that the presence of closely orbiting giant planets is associated with enhanced chromospheric emission of their host stars. The main cause for such a relation would likely be enhanced dynamo action induced by the planet. We present measurements of chromospheric emission in 234 planet candidate systems from the Kepler mission. This ensemble includes 37 systems with giant planet candidates, which show a clear emission enhancement. The enhancement, however, disappears when systems which are also identified as eclipsing binary candidates are removed from the ensemble. This suggests that a large fraction of the giant planet candidate systems with chromospheric emission stronger than the Sun are not giant planet system, but false positives. Such false-positive systems could be tidally interacting binaries with strong chromospheric emission. This hypotesis is supported by an analysis of 188 eclipsing binary candidates that show increasing chromospheric emission as function of decreasing orbi...

  3. Urey Prize Lecture: Orbital Dynamics of Extrasolar Planets, Large and Small

    Science.gov (United States)

    Ford, Eric B.

    2012-10-01

    For centuries, planet formation theories were fine tuned to explain the details of solar system. Since 1999, the Doppler technique has discovered dozens of multiple planet systems. The diversity of architectures of systems with giant planets challenged previous theories and led to insights into planet formation, orbital migration and the excitation of orbital eccentricities and inclinations. Recently, NASA's Kepler mission has identified over 300 systems with multiple transiting planet candidates, including many potentially rocky planets. Precise measurements of the orbital period and phase constrain the significance of mutual gravitational interactions and potential orbital resonances. For systems that are tightly-packed or near an orbital resonance, measurements of transit timing variations provide a new means for confirming transiting planets and detecting non-transiting planets in multiple planet systems, even around faint target stars. Over the course of the extended mission, Kepler is poised to measure the gravitational effects of mutual planetary perturbations for 200 planets, providing precise (but complex) constraints on planetary masses, densities and orbits. I will survey the systems with multiple transiting planet candidates identified by Kepler and discuss early efforts to translate these observations into new constraints on the formation and orbital evolution of planetary systems with low-mass planets.

  4. Spectroscopic follow up of Kepler planet candidates

    DEFF Research Database (Denmark)

    Latham..[], D. W.; Cochran, W. D.; Marcy, G.W.

    2010-01-01

    Spectroscopic follow-up observations play a crucial role in the confirmation and characterization of transiting planet candidates identified by Kepler. The most challenging part of this work is the determination of radial velocities with a precision approaching 1 m/s in order to derive masses from...... and not planets, our strategy is to start with reconnaissance spectroscopy using smaller telescopes, to sort out and reject as many of the false positives as possible before going to Keck. During the first Kepler observing season in 2009, more than 100 nights of telescope time were allocated for this work, using...... high-resolution spectrometers on the Lick 3.0-m Shane Telescope, the McDonald 2.7-m Reflector, the 2.5-m Nordic Optical Telescope, and the 1.5-m Tillinghast Reflector at the Whipple observatory. In this paper we will summarize the scope and organization of the spectroscopic follow-up observations...

  5. Planet Hunters. V. A Confirmed Jupiter-size Planet in the Habitable Zone and 42 Planet Candidates from the Kepler Archive Data

    Science.gov (United States)

    Wang, Ji; Fischer, Debra A.; Barclay, Thomas; Boyajian, Tabetha S.; Crepp, Justin R.; Schwamb, Megan E.; Lintott, Chris; Jek, Kian J.; Smith, Arfon M.; Parrish, Michael; Schawinski, Kevin; Schmitt, Joseph R.; Giguere, Matthew J.; Brewer, John M.; Lynn, Stuart; Simpson, Robert; Hoekstra, Abe J.; Jacobs, Thomas Lee; LaCourse, Daryll; Schwengeler, Hans Martin; Chopin, Mike; Herszkowicz, Rafal

    2013-10-01

    We report the latest Planet Hunter results, including PH2 b, a Jupiter-size (R PL = 10.12 ± 0.56 R ⊕) planet orbiting in the habitable zone of a solar-type star. PH2 b was elevated from candidate status when a series of false-positive tests yielded a 99.9% confidence level that transit events detected around the star KIC 12735740 had a planetary origin. Planet Hunter volunteers have also discovered 42 new planet candidates in the Kepler public archive data, of which 33 have at least 3 transits recorded. Most of these transit candidates have orbital periods longer than 100 days and 20 are potentially located in the habitable zones of their host stars. Nine candidates were detected with only two transit events and the prospective periods are longer than 400 days. The photometric models suggest that these objects have radii that range between those of Neptune and Jupiter. These detections nearly double the number of gas-giant planet candidates orbiting at habitable-zone distances. We conducted spectroscopic observations for nine of the brighter targets to improve the stellar parameters and we obtained adaptive optics imaging for four of the stars to search for blended background or foreground stars that could confuse our photometric modeling. We present an iterative analysis method to derive the stellar and planet properties and uncertainties by combining the available spectroscopic parameters, stellar evolution models, and transiting light curve parameters, weighted by the measurement errors. Planet Hunters is a citizen science project that crowd sources the assessment of NASA Kepler light curves. The discovery of these 43 planet candidates demonstrates the success of citizen scientists at identifying planet candidates, even in longer period orbits with only two or three transit events. .

  6. PLANET HUNTERS. V. A CONFIRMED JUPITER-SIZE PLANET IN THE HABITABLE ZONE AND 42 PLANET CANDIDATES FROM THE KEPLER ARCHIVE DATA

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ji; Fischer, Debra A.; Boyajian, Tabetha S.; Schmitt, Joseph R.; Giguere, Matthew J.; Brewer, John M. [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Barclay, Thomas [NASA Ames Research Center, M/S 244-30, Moffett Field, CA 94035 (United States); Crepp, Justin R. [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556 (United States); Schwamb, Megan E. [Department of Physics, Yale University, P.O. Box 208121, New Haven, CT 06520 (United States); Lintott, Chris; Simpson, Robert [Oxford Astrophysics, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Jek, Kian J.; Hoekstra, Abe J.; Jacobs, Thomas Lee; LaCourse, Daryll; Schwengeler, Hans Martin; Smith, Arfon M.; Parrish, Michael; Lynn, Stuart [Adler Planetarium, 1300 South Lake Shore Drive, Chicago, IL 60605 (United States); Schawinski, Kevin, E-mail: ji.wang@yale.edu [Institute for Astronomy, Department of Physics, ETH Zurich, Wolfgang-Pauli-Strasse 16, CH-8093 Zurich (Switzerland); and others

    2013-10-10

    We report the latest Planet Hunter results, including PH2 b, a Jupiter-size (R{sub PL} = 10.12 ± 0.56 R{sub ⊕}) planet orbiting in the habitable zone of a solar-type star. PH2 b was elevated from candidate status when a series of false-positive tests yielded a 99.9% confidence level that transit events detected around the star KIC 12735740 had a planetary origin. Planet Hunter volunteers have also discovered 42 new planet candidates in the Kepler public archive data, of which 33 have at least 3 transits recorded. Most of these transit candidates have orbital periods longer than 100 days and 20 are potentially located in the habitable zones of their host stars. Nine candidates were detected with only two transit events and the prospective periods are longer than 400 days. The photometric models suggest that these objects have radii that range between those of Neptune and Jupiter. These detections nearly double the number of gas-giant planet candidates orbiting at habitable-zone distances. We conducted spectroscopic observations for nine of the brighter targets to improve the stellar parameters and we obtained adaptive optics imaging for four of the stars to search for blended background or foreground stars that could confuse our photometric modeling. We present an iterative analysis method to derive the stellar and planet properties and uncertainties by combining the available spectroscopic parameters, stellar evolution models, and transiting light curve parameters, weighted by the measurement errors. Planet Hunters is a citizen science project that crowd sources the assessment of NASA Kepler light curves. The discovery of these 43 planet candidates demonstrates the success of citizen scientists at identifying planet candidates, even in longer period orbits with only two or three transit events.

  7. Masses, Radii, and Orbits of Small Kepler Planets: The Transition from Gaseous to Rocky Planets

    CERN Document Server

    Marcy, Geoffrey W; Howard, Andrew W; Rowe, Jason F; Jenkins, Jon M; Bryson, Stephen T; Latham, David W; Howell, Steve B; Gautier, Thomas N; Batalha, Natalie M; Rogers, Leslie A; Ciardi, David; Fischer, Debra A; Gilliland, Ronald L; Kjeldsen, Hans; Christensen-Dalsgaard, Jørgen; Huber, Daniel; Chaplin, William J; Basu, Sarbani; Buchhave, Lars A; Quinn, Samuel N; Borucki, William J; Koch, David G; Hunter, Roger; Caldwell, Douglas A; Van Cleve, Jeffrey; Kolbl, Rea; Weiss, Lauren M; Petigura, Erik; Seager, Sara; Morton, Timothy; Johnson, John Asher; Ballard, Sarah; Burke, Chris; Cochran, William D; Endl, Michael; MacQueen, Phillip; Everett, Mark E; Lissauer, Jack J; Ford, Eric B; Torres, Guillermo; Fressin, Francois; Brown, Timothy M; Steffen, Jason H; Charbonneau, David; Basri, Gibor S; Sasselov, Dimitar D; Winn, Joshua; Sanchis-Ojeda, Roberto; Christiansen, Jessie; Adams, Elisabeth; Henze, Christopher; Dupree, Andrea; Fabrycky, Daniel C; Fortney, Jonathan J; Tarter, Jill; Holman, Matthew J; Tenenbaum, Peter; Shporer, Avi; Lucas, Philip W; Welsh, William F; Orosz, Jerome A; Bedding, T R; Campante, T L; Davies, G R; Elsworth, Y; Handberg, R; Hekker, S; Karoff, C; Kawaler, S D; Lund, M N; Lundkvist, M; Metcalfe, T S; Miglio, A; Aguirre, V Silva; Stello, D; White, T R; Boss, Alan; Devore, Edna; Gould, Alan; Prsa, Andrej; Agol, Eric; Barclay, Thomas; Coughlin, Jeff; Brugamyer, Erik; Mullally, Fergal; Quintana, Elisa V; Still, Martin; hompson, Susan E; Morrison, David; Twicken, Joseph D; Désert, Jean-Michel; Carter, Josh; Crepp, Justin R; Hébrard, Guillaume; Santerne, Alexandre; Moutou, Claire; Sobeck, Charlie; Hudgins, Douglas; Haas, Michael R; Robertson, Paul; Lillo-Box, Jorge; Barrado, David

    2014-01-01

    We report on the masses, sizes, and orbits of the planets orbiting 22 Kepler stars. There are 49 planet candidates around these stars, including 42 detected through transits and 7 revealed by precise Doppler measurements of the host stars. Based on an analysis of the Kepler brightness measurements, along with high-resolution imaging and spectroscopy, Doppler spectroscopy, and (for 11 stars) asteroseismology, we establish low false-positive probabilities for all of the transiting planets (41 of 42 have a false-positive probability under 1%), and we constrain their sizes and masses. Most of the transiting planets are smaller than 3X the size of Earth. For 16 planets, the Doppler signal was securely detected, providing a direct measurement of the planet's mass. For the other 26 planets we provide either marginal mass measurements or upper limits to their masses and densities; in many cases we can rule out a rocky composition. We identify 6 planets with densities above 5 g/cc, suggesting a mostly rocky interior f...

  8. PLANET HUNTERS. VIII. CHARACTERIZATION OF 41 LONG-PERIOD EXOPLANET CANDIDATES FROM KEPLER ARCHIVAL DATA

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ji; Fischer, Debra A.; Picard, Alyssa; Schmitt, Joseph R.; Boyajian, Tabetha S. [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Barclay, Thomas [NASA Ames Research Center, M/S 244-30, Moffett Field, CA 94035 (United States); Ma, Bo [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611-2055 (United States); Bowler, Brendan P.; Riddle, Reed [California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91101 (United States); Jek, Kian J.; LaCourse, Daryll; Simister, Dean Joseph; Grégoire, Boscher; Babin, Sean P.; Poile, Trevor; Jacobs, Thomas Lee; Baranec, Christoph [Institute for Astronomy, University of Hawai‘i at Mānoa, Hilo, HI 96720-2700 (United States); Law, Nicholas M. [Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3255 (United States); Lintott, Chris [Oxford Astrophysics, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Schawinski, Kevin [Institute for Astronomy, Department of Physics, ETH Zurich, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich (Switzerland); and others

    2015-12-20

    The census of exoplanets is incomplete for orbital distances larger than 1 AU. Here, we present 41 long-period planet candidates in 38 systems identified by Planet Hunters based on Kepler archival data (Q0–Q17). Among them, 17 exhibit only one transit, 14 have two visible transits, and 10 have more than three visible transits. For planet candidates with only one visible transit, we estimate their orbital periods based on transit duration and host star properties. The majority of the planet candidates in this work (75%) have orbital periods that correspond to distances of 1–3 AU from their host stars. We conduct follow-up imaging and spectroscopic observations to validate and characterize planet host stars. In total, we obtain adaptive optics images for 33 stars to search for possible blending sources. Six stars have stellar companions within 4″. We obtain high-resolution spectra for 6 stars to determine their physical properties. Stellar properties for other stars are obtained from the NASA Exoplanet Archive and the Kepler Stellar Catalog by Huber et al. We validate 7 planet candidates that have planet confidence over 0.997 (3σ level). These validated planets include 3 single-transit planets (KIC-3558849b, KIC-5951458b, and KIC-8540376c), 3 planets with double transits (KIC-8540376b, KIC-9663113b, and KIC-10525077b), and 1 planet with four transits (KIC-5437945b). This work provides assessment regarding the existence of planets at wide separations and the associated false positive rate for transiting observation (17%–33%). More than half of the long-period planets with at least three transits in this paper exhibit transit timing variations up to 41 hr, which suggest additional components that dynamically interact with the transiting planet candidates. The nature of these components can be determined by follow-up radial velocity and transit observations.

  9. THE CALIFORNIA PLANET SURVEY IV: A PLANET ORBITING THE GIANT STAR HD 145934 AND UPDATES TO SEVEN SYSTEMS WITH LONG-PERIOD PLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Katherina Feng, Y.; Wright, Jason T.; Nelson, Benjamin; Wang, Sharon X.; Ford, Eric B. [Center for Exoplanets and Habitable Worlds, Department of Astronomy and Astrophysics, 525 Davey Lab, The Pennsylvania State University, University Park, PA 16802 (United States); Marcy, Geoffrey W.; Isaacson, Howard [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Howard, Andrew W., E-mail: astrowright@gmail.com [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)

    2015-02-10

    We present an update to seven stars with long-period planets or planetary candidates using new and archival radial velocities from Keck-HIRES and literature velocities from other telescopes. Our updated analysis better constrains orbital parameters for these planets, four of which are known multi-planet systems. HD 24040 b and HD 183263 c are super-Jupiters with circular orbits and periods longer than 8 yr. We present a previously unseen linear trend in the residuals of HD 66428 indicative of an additional planetary companion. We confirm that GJ 849 is a multi-planet system and find a good orbital solution for the c component: it is a 1 M {sub Jup} planet in a 15 yr orbit (the longest known for a planet orbiting an M dwarf). We update the HD 74156 double-planet system. We also announce the detection of HD 145934 b, a 2 M {sub Jup} planet in a 7.5 yr orbit around a giant star. Two of our stars, HD 187123 and HD 217107, at present host the only known examples of systems comprising a hot Jupiter and a planet with a well constrained period greater than 5 yr, and with no evidence of giant planets in between. Our enlargement and improvement of long-period planet parameters will aid future analysis of origins, diversity, and evolution of planetary systems.

  10. Discovery of Two Jovian Planet Candidates Around AU Mic

    Science.gov (United States)

    Plavchan, Peter; Gao, Peter; Gagne, Jonathan; Tanner, Angelle M.; Furlan, Elise; Brinkworth, Carolyn; von Braun, Kaspar; Ciardi, David R.; Kane, Stephen R.; White, Russel; Johnson, John A.; Hall, Ryan; Giddens, Frank; Zilberman, Perri; Huber, Joe; Nishimoto, America; Cancino, Andrew; Weigand, Denise; Klenke, Christopher

    2017-01-01

    We present a pair of candidate Jovian exoplanets discovered with the radial velocity (RV) technique in the near-infrared (NIR) orbiting the young M dwarf star AU Mic (a ~ 0.3 and 3.5 AU; M_p ~ 1.5 and 6 M_J). Data were obtained at 2.3 microns from 2010-2016 with the R=46,000 CSHELL spectrograph at the NASA Infrared Telescope Facility, and from 2005-2007 with the R=25,000 NIRSPEC spectrograph at the Keck Observatory. AU Mic possesses long-lived BY Draconis type polar starspots with a known rotation period of 4.865 days. No signal in the NIR RVs is identified that is consistent with the rotation period of the star, but stellar activity remains a possible explanation for the observed NIR RV variability. The outer Jovian planet candidate offers a plausible dynamical explanation for the observed debris disk dynamics of moving "clumps" on several year time-scales. It may be possible to directly image the outer planet candidate with the current generation of high contrast imaging instruments. If confirmed, this discovery would demonstrate the utility of RV precursor observations for informing direct imaging surveys and the utility of NIR RV searches for planets around young and/or active stars. These results also point to the promise of future NIR precise RVs, including iSHELL, SPIRou, HPF and CARMENES, which will operate at higher precision and with larger spectral grasp than CSHELL.

  11. Inferring Planet Occurrence Rates With a Q1-Q17 Kepler Planet Candidate Catalog Produced by a Machine Learning Classifier

    Science.gov (United States)

    Catanzarite, Joseph; Jenkins, Jon Michael; McCauliff, Sean D.; Burke, Christopher; Bryson, Steve; Batalha, Natalie; Coughlin, Jeffrey; Rowe, Jason; mullally, fergal; thompson, susan; Seader, Shawn; Twicken, Joseph; Li, Jie; morris, robert; smith, jeffrey; haas, michael; christiansen, jessie; Clarke, Bruce

    2015-08-01

    NASA’s Kepler Space Telescope monitored the photometric variations of over 170,000 stars, at half-hour cadence, over its four-year prime mission. The Kepler pipeline calibrates the pixels of the target apertures for each star, produces light curves with simple aperture photometry, corrects for systematic error, and detects threshold-crossing events (TCEs) that may be due to transiting planets. The pipeline estimates planet parameters for all TCEs and computes diagnostics used by the Threshold Crossing Event Review Team (TCERT) to produce a catalog of objects that are deemed either likely transiting planet candidates or false positives.We created a training set from the Q1-Q12 and Q1-Q16 TCERT catalogs and an ensemble of synthetic transiting planets that were injected at the pixel level into all 17 quarters of data, and used it to train a random forest classifier. The classifier uniformly and consistently applies diagnostics developed by the Transiting Planet Search and Data Validation pipeline components and by TCERT to produce a robust catalog of planet candidates.The characteristics of the planet candidates detected by Kepler (planet radius and period) do not reflect the intrinsic planet population. Detection efficiency is a function of SNR, so the set of detected planet candidates is incomplete. Transit detection preferentially finds close-in planets with nearly edge-on orbits and misses planets whose orbital geometry precludes transits. Reliability of the planet candidates must also be considered, as they may be false positives. Errors in detected planet radius and in assumed star properties can also bias inference of intrinsic planet population characteristics.In this work we infer the intrinsic planet population, starting with the catalog of detected planet candidates produced by our random forest classifier, and accounting for detection biases and reliabilities as well as for radius errors in the detected population.Kepler was selected as the 10th mission

  12. Habitability of Planets Orbiting Cool Stars

    CERN Document Server

    Barnes, Rory; Domagal-Goldman, Shawn D; Heller, Rene; Jackson, Brian; Lopez-Morales, Mercedes; Tanner, Angelle; Gomez-Perez, Natalia; Ruedas, Thomas

    2010-01-01

    Terrestrial planets are more likely to be detected if they orbit M dwarfs due to the favorable planet/star size and mass ratios. However, M dwarf habitable zones are significantly closer to the star than the one around our Sun, which leads to different requirements for planetary habitability and its detection. We review 1) the current limits to detection, 2) the role of M dwarf spectral energy distributions on atmospheric chemistry, 3) tidal effects, stressing that tidal locking is not synonymous with synchronous rotation, 4) the role of atmospheric mass loss and propose that some habitable worlds may be the volatile-rich, evaporated cores of giant planets, and 5) the role of planetary rotation and magnetic field generation, emphasizing that slow rotation does not preclude strong magnetic fields and their shielding of the surface from stellar activity. Finally we present preliminary findings of the NASA Astrobiology Institute's workshop "Revisiting the Habitable Zone." We assess the recently-announced planet ...

  13. Periodic orbits of planets in binary systems

    Science.gov (United States)

    Voyatzis, G.

    2017-03-01

    Periodic solutions of the three body problem are very important for understanding its dynamics either in a theoretical framework or in various applications in celestial mechanics. In this paper we discuss the computation and continuation of periodic orbits for planetary systems. The study is restricted to coplanar motion. Starting from known results of two-planet systems around single stars, we perform continuation of solutions with respect to the mass and approach periodic orbits of single planets in two-star systems. Also, families of periodic solutions can be computed for fixed masses of the primaries. When they are linearly stable, we can conclude about the existence of phase space domains of long-term orbital stability.

  14. 197 Candidates and 104 Validated Planets in K2’s First Five Fields

    Science.gov (United States)

    Crossfield, Ian J. M.; Ciardi, David R.; Petigura, Erik A.; Sinukoff, Evan; Schlieder, Joshua E.; Howard, Andrew W.; Beichman, Charles A.; Isaacson, Howard; Dressing, Courtney D.; Christiansen, Jessie L.; Fulton, Benjamin J.; Lépine, Sébastien; Weiss, Lauren; Hirsch, Lea; Livingston, John; Baranec, Christoph; Law, Nicholas M.; Riddle, Reed; Ziegler, Carl; Howell, Steve B.; Horch, Elliott; Everett, Mark; Teske, Johanna; Martinez, Arturo O.; Obermeier, Christian; Benneke, Björn; Scott, Nic; Deacon, Niall; Aller, Kimberly M.; Hansen, Brad M. S.; Mancini, Luigi; Ciceri, Simona; Brahm, Rafael; Jordán, Andrés; Knutson, Heather A.; Henning, Thomas; Bonnefoy, Michaël; Liu, Michael C.; Crepp, Justin R.; Lothringer, Joshua; Hinz, Phil; Bailey, Vanessa; Skemer, Andrew; Defrere, Denis

    2016-09-01

    We present 197 planet candidates discovered using data from the first year of the NASA K2 mission (Campaigns 0-4), along with the results of an intensive program of photometric analyses, stellar spectroscopy, high-resolution imaging, and statistical validation. We distill these candidates into sets of 104 validated planets (57 in multi-planet systems), 30 false positives, and 63 remaining candidates. Our validated systems span a range of properties, with median values of R P = 2.3 {R}\\oplus , P = 8.6 days, {T}{eff} = 5300 K, and Kp = 12.7 mag. Stellar spectroscopy provides precise stellar and planetary parameters for most of these systems. We show that K2 has increased by 30% the number of small planets known to orbit moderately bright stars (1-4 R ⊕, Kp = 9-13 mag). Of particular interest are 76 planets smaller than 2 R ⊕, 15 orbiting stars brighter than Kp = 11.5 mag, 5 receiving Earth-like irradiation levels, and several multi-planet systems—including 4 planets orbiting the M dwarf K2-72 near mean-motion resonances. By quantifying the likelihood that each candidate is a planet we demonstrate that our candidate sample has an overall false positive rate of 15%-30%, with rates substantially lower for small candidates (\\lt 2{R}\\oplus ) and larger for candidates with radii \\gt 8{R}\\oplus and/or with P\\lt 3 {{days}}. Extrapolation of the current planetary yield suggests that K2 will discover between 500 and 1000 planets in its planned four-year mission, assuming sufficient follow-up resources are available. Efficient observing and analysis, together with an organized and coherent follow-up strategy, are essential for maximizing the efficacy of planet-validation efforts for K2, TESS, and future large-scale surveys.

  15. Giant Planet Candidates, Brown Dwarfs, and Binaries from the SDSS-III MARVELS Planet Survey.

    Science.gov (United States)

    Thomas, Neil; Ge, Jian; Li, Rui; de Lee, Nathan M.; Heslar, Michael; Ma, Bo; SDSS-Iii Marvels Team

    2015-01-01

    We report the discoveries of giant planet candidates, brown dwarfs, and binaries from the SDSS-III MARVELS survey. The finalized 1D pipeline has provided 18 giant planet candidates, 16 brown dwarfs, and over 500 binaries. An additional 96 targets having RV variability indicative of a giant planet companion are also reported for future investigation. These candidates are found using the advanced MARVELS 1D data pipeline developed at UF from scratch over the past three years. This pipeline carefully corrects most of the instrument effects (such as trace, slant, distortion, drifts and dispersion) and observation condition effects (such as illumination profile, fiber degradation, and tracking variations). The result is long-term RV precisions that approach the photon limits in many cases for the ~89,000 individual stellar observations. A 2D version of the pipeline that uses interferometric information is nearing completion and is demonstrating a reduction of errors to half the current levels. The 2D processing will be used to increase the robustness of the detections presented here and to find new candidates in RV regions not confidently detectable with the 1D pipeline. The MARVELS survey has produced the largest homogeneous RV measurements of 3300 V=7.6-12 FGK stars with a well defined cadence of 27 RV measurements over 2 years. The MARVELS RV data and other follow-up data (photometry, high contrast imaging, high resolution spectroscopy and RV measurements) will explore the diversity of giant planet companion formation and evolution around stars with a broad range in metallicity (Fe/H -1.5-0.5), mass ( 0.6-2.5M(sun)), and environment (thin disk and thick disk), and will help to address the key scientific questions identified for the MARVELS survey including, but not limited to: Do metal poor stars obey the same trends for planet occurrence as metal rich stars? What is the distribution of giant planets around intermediate-mass stars and binaries? Is the 'planet desert

  16. Direct Imaging discovery of a second planet candidate around the possibly transiting planet host CVSO 30

    Science.gov (United States)

    Schmidt, T. O. B.; Neuhäuser, R.; Briceño, C.; Vogt, N.; Raetz, St.; Seifahrt, A.; Ginski, C.; Mugrauer, M.; Buder, S.; Adam, C.; Hauschildt, P.; Witte, S.; Helling, Ch.; Schmitt, J. H. M. M.

    2016-09-01

    Context. Direct imaging has developed into a very successful technique for the detection of exoplanets in wide orbits, especially around young stars. Directly imaged planets can be both followed astrometrically on their orbits and observed spectroscopically and thus provide an essential tool for our understanding of the early solar system. Aims: We surveyed the 25 Ori association for direct-imaging companions. This association has an age of only few million years. Among other targets, we observed CVSO 30, which has recently been identified as the first T Tauri star found to host a transiting planet candidate. Methods: We report on photometric and spectroscopic high-contrast observations with the Very Large Telescope, the Keck telescopes, and the Calar Alto observatory. They reveal a directly imaged planet candidate close to the young M3 star CVSO 30. Results: The JHK-band photometry of the newly identified candidate is at better than 1σ consistent with late-type giants, early-T and early-M dwarfs, and free-floating planets. Other hypotheses such as galaxies can be excluded at more than 3.5σ. A lucky imaging z' photometric detection limit z' = 20.5 mag excludes early-M dwarfs and results in less than 10 MJup for CVSO 30 c if bound. We present spectroscopic observations of the wide companion that imply that the only remaining explanation for the object is that it is the first very young (ESO Telescopes at the La Silla Paranal Observatory under programme IDs 090.C-0448(A), 290.C-5018(B), 092.C-0488(A) and at the Centro Astronómico Hispano-Alemán in programme H15-2.2-002.

  17. VizieR Online Data Catalog: Properties of Kepler multi-planet candidate systems (Wang+, 2014)

    Science.gov (United States)

    Wang, J.; Xie, J.-W.; Barclay, T.; Fischer, D. A.

    2016-05-01

    Our sample consists of bright host stars with multi-planet transiting systems from Kepler. Out of 5779 Kepler Objects of Interest (http://exoplanetarchive.ipac.caltech.edu/), we selected all the systems with a Kepler magnitude (KP) brighter than 13.5mag and with at least two planet candidates. The sample includes 343 planet candidates (see Table3) in 138 multi-planet candidate systems (see Table2) from the Kepler mission. For these systems, we used archival data from Kepler to characterize their stellar (see Table2) and orbital properties (see Table3). We used UKIRT images to calculate brightness contrast curves and to detect stellar companions around planet candidate host stars (see Table4). (3 data files).

  18. MEASUREMENTS OF STELLAR INCLINATIONS FOR KEPLER PLANET CANDIDATES

    Energy Technology Data Exchange (ETDEWEB)

    Hirano, Teruyuki; Taruya, Atsushi; Suto, Yasushi [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Sanchis-Ojeda, Roberto; Winn, Joshua N. [Department of Physics, and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Takeda, Yoichi; Narita, Norio, E-mail: hirano@utap.phys.s.u-tokyo.ac.jp [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

    2012-09-01

    We present an investigation of spin-orbit angles for planetary system candidates reported by Kepler. By combining the rotational period P{sub s} inferred from the flux variation due to starspots and the projected rotational velocity Vsin I{sub s} and stellar radius obtained by a high-resolution spectroscopy, we attempt to estimate the inclination I{sub s} of the stellar spin axis with respect to the line of sight. For transiting planetary systems, in which planetary orbits are edge-on seen from us, the stellar inclination I{sub s} can be a useful indicator of a spin-orbit alignment/misalignment. We newly conducted spectroscopic observations with Subaru/HDS for 15 Kepler Object of Interest (KOI) systems, whose light curves show periodic flux variations. Detailed analyses of their light curves and spectra revealed that some of them are binaries, or the flux variations are too coherent to be caused by starspots, and consequently we could constrain stellar inclinations I{sub s} for eight systems. Among them, KOI-262 and 280 are in good agreement with I{sub s} 90 Degree-Sign suggesting a spin-orbit alignment, while at least one system, KOI-261, shows a possible spin-orbit misalignment. We also obtain a small I{sub s} for KOI-1463, but the transiting companion seems to be a star rather than a planet. The results for KOI-257, 269, 367, and 974 are ambiguous and can be explained with either misalignments or moderate differential rotation. Since our method can be applied to any system having starspots regardless of the planet size, future observations will allow for the expansion of the parameter space in which the spin-orbit relations are investigated.

  19. The California Planet Survey IV: A Planet Orbiting the Giant Star HD 145934 and Updates to Seven Systems with Long-Period Planets

    CERN Document Server

    Feng, Y Katherina; Nelson, Benjamin; Wang, Sharon X; Ford, Eric B; Marcy, Geoffrey W; Isaacson, Howard; Howard, Andrew W

    2015-01-01

    We present an update to seven stars with long-period planets or planetary candidates using new and archival radial velocities from Keck-HIRES and literature velocities from other telescopes. Our updated analysis better constrains orbital parameters for these planets, four of which are known multi-planet systems. HD 24040 b and HD 183263 c are super-Jupiters with circular orbits and periods longer than 8 yr. We present a previously unseen linear trend in the residuals of HD 66428 indicative on an additional planetary companion. We confirm that GJ 849 is a multi-planet system and find a good orbital solution for the c component: it is a $1 M_{\\rm Jup}$ planet in a 15 yr orbit (the longest known for a planet orbiting an M dwarf). We update the HD 74156 double-planet system. We also announce the detection of HD 145934 b, a $2 M_{\\rm Jup}$ planet in a 7.5 yr orbit around a giant star. Two of our stars, HD 187123 and HD 217107, at present host the only known examples of systems comprising a hot Jupiter and a planet...

  20. Planet Hunters. V. A Confirmed Jupiter-Size Planet in the Habitable Zone and 42 Planet Candidates from the Kepler Archive Data

    CERN Document Server

    Wang, Ji; Barclay, Thomas; Boyajian, Tabetha S; Crepp, Justin R; Schwamb, Megan E; Lintott, Chris; Jek, Kian J; Smith, Arfon M; Parrish, Michael; Schawinski, Kevin; Schmitt, Joseph; Giguere, Matthew J; Brewer, John M; Lynn, Stuart; Simpson, Robert; Hoekstra, Abe J; Jacobs, Thomas Lee; LaCourse, Daryll; Schwengeler, Hans Martin; Chopin, Mike

    2013-01-01

    We report the latest Planet Hunter results, including PH2 b, a Jupiter-size (R_PL = 10.12 \\pm 0.56 R_E) planet orbiting in the habitable zone of a solar-type star. PH2 b was elevated from candidate status when a series of false positive tests yielded a 99.9% confidence level that transit events detected around the star KIC 12735740 had a planetary origin. Planet Hunter volunteers have also discovered 42 new planet candidates in the Kepler public archive data, of which 33 have at least three transits recorded. Most of these transit candidates have orbital periods longer than 100 days and 20 are potentially located in the habitable zones of their host stars. Nine candidates were detected with only two transit events and the prospective periods are longer than 400 days. The photometric models suggest that these objects have radii that range between Neptune to Jupiter. These detections nearly double the number of gas giant planet candidates orbiting at habitable zone distances. We conducted spectroscopic observat...

  1. 197 Candidates and 104 Validated Planets in K2's First Five Fields

    CERN Document Server

    Crossfield, Ian J M; Petigura, Erik A; Sinukoff, Evan; Schlieder, Joshua E; Howard, Andrew W; Beichman, Charles A; Isaacson, Howard; Dressing, Courtney D; Christiansen, Jessie L; Fulton, Benjamin J; Lépine, Sébastien; Weiss, Lauren; Hirsch, Lea; Livingston, John; Baranec, Christoph; Law, Nicholas M; Riddle, Reed; Ziegler, Carl; Howell, Steve B; Horch, Elliott; Everett, Mark; Teske, Johanna; Martinez, Arturo O; Obermeier, Christian; Benneke, Björn; Scott, Nic; Deacon, Niall; Aller, Kimberly M; Hansen, Brad M S; Mancini, Luigi; Ciceri, Simona; Brahm, Rafael; Jordán, Andrés; Knutson, Heather A; Henning, Thomas; Bonnefoy, Michaël; Liu, Michael C; Crepp, Justin R; Lothringer, Joshua; Hinz, Phil; Bailey, Vanessa; Skemer, Andrew; Defrere, Denis

    2016-01-01

    We present 197 planet candidates discovered using data from the first year of the NASA K2 mission (Campaigns 0-4), along with the results of an intensive program of photometric analyses, stellar spectroscopy, high-resolution imaging, and statistical validation. We distill these candidates into sets of 104 validated planets (57 in multi-planet systems), 30 false positives, and 63 remaining candidates. Our validated systems span a range of properties, with median values of R_P = 2.3 R_E, P=8.6 d, Tef = 5300 K, and Kp=12.7 mag. Stellar spectroscopy provides precise stellar and planetary parameters for most of these systems. We show that K2 has increased by 30% the number of small planets known to orbit moderately bright stars (1-4 R_E, Kp=9-13 mag). Of particular interest are 37 planets smaller than 2 R_E, 15 orbiting stars brighter than Kp=11.5, five receiving Earth-like irradiation levels, and several multi-planet systems -- including four planets orbiting the M dwarf K2-72 near mean-motion resonances. By quan...

  2. A First Comparison of Kepler Planet Candidates in Single and Multiple Systems

    CERN Document Server

    Latham, David W; Quinn, Samuel N; Batalha, Natalie M; Borucki, William J; Brown, Timothy M; Bryson, Stephen T; Buchhave, Lars A; Caldwell, Douglas A; Carter, Joshua A; Christiansen, Jesse L; Ciardi, David R; Cochran, William D; Dunham, Edward W; Fabrycky, Daniel C; Ford, Eric B; Gautier, Thomas N; Gilliland, Ronald L; Holman, Matthew J; Howell, Steve B; Ibrahim, Khadeejah A; Isaacson, Howard; Basri, Gibor; Furesz, Gabor; Geary, John C; Jenkins, Jon M; Koch, David G; Lissauer, Jack J; Marcy, Geoffrey W; Quintana, Elisa V; Ragozzine, Darin; Sasselov, Dimitar D; Shporer, Avi; Steffen, Jason H; Welsh, William F; Wohler, Bill

    2011-01-01

    In this letter we present an overview of the rich population of systems with multiple candidate transiting planets found in the first four months of Kepler data. The census of multiples includes 115 targets that show 2 candidate planets, 45 with 3, 8 with 4, and 1 each with 5 and 6, for a total of 170 systems with 408 candidates. When compared to the 827 systems with only one candidate, the multiples account for 17 percent of the total number of systems, and a third of all the planet candidates. We compare the characteristics of candidates found in multiples with those found in singles. False positives due to eclipsing binaries are much less common for the multiples, as expected. Singles and multiples are both dominated by planets smaller than Neptune; 69 +2/-3 percent for singles and 86 +2/-5 percent for multiples. This result, that systems with multiple transiting planets are less likely to include a transiting giant planet, suggests that close-in giant planets tend to disrupt the orbital inclinations of sm...

  3. Planet Hunters: the first two planet candidates identified by the public using the Kepler public archive data

    Science.gov (United States)

    Fischer, Debra A.; Schwamb, Megan E.; Schawinski, Kevin; Lintott, Chris; Brewer, John; Giguere, Matt; Lynn, Stuart; Parrish, Michael; Sartori, Thibault; Simpson, Robert; Smith, Arfon; Spronck, Julien; Batalha, Natalie; Rowe, Jason; Jenkins, Jon; Bryson, Steve; Prsa, Andrej; Tenenbaum, Peter; Crepp, Justin; Morton, Tim; Howard, Andrew; Beleu, Michele; Kaplan, Zachary; Vannispen, Nick; Sharzer, Charlie; Defouw, Justin; Hajduk, Agnieszka; Neal, Joe P.; Nemec, Adam; Schuepbach, Nadine; Zimmermann, Valerij

    2012-02-01

    Planet Hunters is a new citizen science project designed to engage the public in an exoplanet search using NASA Kepler public release data. In the first month after launch, users identified two new planet candidates which survived our checks for false positives. The follow-up effort included analysis of Keck HIRES spectra of the host stars, analysis of pixel centroid offsets in the Kepler data and adaptive optics imaging at Keck using NIRC2. Spectral synthesis modelling coupled with stellar evolutionary models yields a stellar density distribution, which is used to model the transit orbit. The orbital periods of the planet candidates are 9.8844 ± 0.0087 d (KIC 10905746) and 49.7696 ± 0.000 39 d (KIC 6185331), and the modelled planet radii are 2.65 and 8.05 R⊕. The involvement of citizen scientists as part of Planet Hunters is therefore shown to be a valuable and reliable tool in exoplanet detection. This publication has been made possible by the participation of more than 40 000 volunteers in the Planet Hunters project. Their contributions are individually acknowledged at .

  4. HD15082b, a short-period planet orbiting an A-star

    Directory of Open Access Journals (Sweden)

    Lodieu N.

    2011-02-01

    Full Text Available Most of the known transiting extrasolar planets orbit slowly rotating F, G or K stars. In here we report on the detection of a transiting planet orbiting the bright, rapidly rotating A5 star HD15082, recently made by SuperWASP. Time resolved spectroscopic observations taken during transit show a hump caused by the planet crossing the line profile. From the analysis of the spectra, we derive the radius of the planet and find that it is orbiting retrograde in respect to the spin of the star. Because of its small distance from an A5 star, this planet must be one of the hottest planets known, which makes it relatively easy to detect it in the IR. We thus tried to detect it using the TNG but did not succeed. Using direct imaging, we search for possible companions, and found one candidate.

  5. The impact of red noise in radial velocity planet searches: only three planets orbiting GJ 581?

    Science.gov (United States)

    Baluev, Roman V.

    2013-03-01

    We perform a detailed analysis of the latest HARPS and Keck radial velocity data for the planet-hosting red dwarf GJ 581, which attracted a lot of attention in recent time. We show that these data contain important correlated noise component (`red noise') with the correlation time-scale of the order of 10 d. This red noise imposes a lot of misleading effects while we work in the traditional white-noise model. To eliminate these misleading effects, we propose a maximum-likelihood algorithm equipped by an extended model of the noise structure. We treat the red noise as a Gaussian random process with an exponentially decaying correlation function. Using this method we prove that (i) planets b and c do exist in this system, since they can be independently detected in the HARPS and Keck data, and regardless of the assumed noise models; (ii) planet e can also be confirmed independently by both the data sets, although to reveal it in the Keck data it is mandatory to take the red noise into account; (iii) the recently announced putative planets f and g are likely just illusions of the red noise; (iv) the reality of the planet candidate GJ 581 d is questionable, because it cannot be detected from the Keck data, and its statistical significance in the HARPS data (as well as in the combined data set) drops to a marginal level of ˜2σ, when the red noise is taken into account. Therefore, the current data for GJ 581 really support the existence of no more than four (or maybe even only three) orbiting exoplanets. The planet candidate GJ 581 d requests serious observational verification.

  6. Planet Hunters: The First Two Planet Candidates Identified by the Public using the Kepler Public Archive Data

    CERN Document Server

    Fisher, Debra; Schawinski, Kevin; Lintott, Chris; Brewer, John; Giguere, Matt; Lynn, Stuart; Parrish, Michael; Sartori, Thibault; Simpson, Robert; Smith, Arfon; Spronck, Julien; Batalha, Natalie; Rowe, Jason; Jenkins, Jon; Bryson, Steve; Prsa, Andrej; Tenenbaum, Peter; Crepp, Justin; Morton, Tim; Howard, Andrew; Beleu, Michele; Kaplan, Zachary; vanNispen, Nick; Sharzer, Charlie; DeFouw, Justin; Hajduk, Agnieszka; Neal, Joe; Nemec, Adam; Schuepbach, Nadine; Zimmermann, Valerij

    2011-01-01

    Planet Hunters is a new citizen science project, designed to engage the public in an exoplanet search using NASA Kepler public release data. In the first month after launch, users identified two new planet candidates which survived our checks for false- positives. The follow-up effort included analysis of Keck HIRES spectra of the host stars, analysis of pixel centroid offsets in the Kepler data and adaptive optics imaging at Keck using NIRC2. Spectral synthesis modeling coupled with stellar evolutionary models yields a stellar density distribution, which is used to model the transit orbit. The orbital periods of the planet candidates are 9.8844 ±0.0087 days (KIC 10905746) and 49.7696 ±0.00039 (KIC 6185331) days and the modeled planet radii are 2.65 and 8.05 R⊕. The involvement of citizen scientists as part of Planet Hunters is therefore shown to be a valuable and reliable tool in exoplanet detection.

  7. Identifying False Alarms in the Kepler Planet Candidate Catalog

    Science.gov (United States)

    Mullally, F.; Coughlin, Jeffery L.; Thompson, Susan E.; Christiansen, Jessie; Burke, Christopher; Clarke, Bruce D.; Haas, Michael R.

    2016-07-01

    We present a new automated method to identify instrumental features masquerading as small, long-period planets in the Kepler planet candidate catalog. These systematics, mistakenly identified as planet transits, can have a strong impact on occurrence rate calculations because they cluster in a region of parameter space where Kepler’s sensitivity to planets is poor. We compare individual transit-like events to a variety of models of real transits and systematic events and use a Bayesian information criterion to evaluate the likelihood that each event is real. We describe our technique and test its performance on simulated data. Results from this technique are incorporated in the Kepler Q1-Q17 DR24 planet candidate catalog of Coughlin et al.

  8. Identifying False Alarms in the Kepler Planet Candidate Catalog

    CERN Document Server

    Mullally, F; Thompson, Susan E; Christiansen, Jessie; Burke, Christopher; Clarke, Bruce D; Haas, Michael R

    2016-01-01

    We present a new automated method to identify instrumental features masquerading as small, long period planets in the \\kepler\\ planet candidate catalog. These systematics, mistakenly identified as planet transits, can have a strong impact on occurrence rate calculations because they cluster in a region of parameter space where Kepler's sensitivity to planets is poor. We compare individual transit-like events to a variety of models of real transits and systematic events, and use a Bayesian Information Criterion to evaluate the likelihood that each event is real. We describe our technique and test its performance on simulated data. Results from this technique are incorporated in the \\kepler\\ Q1-17 DR24 planet candidate catalog of \\citet{Coughlin15}.

  9. Planet Hunters. VIII. Characterization of 41 Long-Period Exoplanet Candidates from Kepler Archival Data

    CERN Document Server

    Wang, Ji; Barclay, Thomas; Picard, Alyssa; Ma, Bo; Bowler, Brendan P; Schmitt, Joseph R; Boyajian, Tabetha S; Jek, Kian J; LaCourse, Daryll; Baranec, Christoph; Riddle, Reed; Law, Nicholas M; Lintott, Chris; Schawinski, Kevin; Simister, Dean Joseph; Gregoire, Boscher; Babin, Sean P; Poile, Trevor; Jacobs, Thomas Lee; Jebson, Tony; Omohundro, Mark R; Schwengeler, Hans Martin; Sejpka, Johann; Terentev, Ivan A; Gagliano, Robert; Paakkonen, Jari-Pekka; Berge, Hans Kristian Otnes; Winarski, Troy; Green, Gerald R; Schmitt, Allan R

    2015-01-01

    The census of exoplanets is incomplete for orbital distances larger than 1 AU. Here, we present 41 long-period planet candidates in 38 systems identified by Planet Hunters based on Kepler archival data (Q0-Q17). Among them, 17 exhibit only one transit, 14 have two visible transits and 10 have more than three visible transits. For planet candidates with only one visible transit, we estimate their orbital periods based on transit duration and host star properties. The majority of the planet candidates in this work (75%) have orbital periods that correspond to distances of 1-3 AU from their host stars. We conduct follow-up imaging and spectroscopic observations to validate and characterize planet host stars. In total, we obtain adaptive optics images for 33 stars to search for possible blending sources. Six stars have stellar companions within 4". We obtain high-resolution spectra for 6 stars to determine their physical properties. Stellar properties for other stars are obtained from the NASA Exoplanet Archive a...

  10. Vetting Kepler Planet Candidates in the Sub-Jovian Desert with Multi-Band Photometry

    CERN Document Server

    Colón, Knicole D; Ford, Eric B

    2015-01-01

    We present new multi-band transit photometry of three small (R$_{p}$ < 6 R$_{\\oplus}$), short-period (P < 6 days) Kepler planet candidates acquired with the Gran Telescopio Canarias. These observations supplement the results presented in Col\\'on & Ford (2011) and Col\\'on et al. (2012), where we used multicolor transit photometry of five Kepler planet candidates to search for wavelength-dependent transit depths and either validate planet candidates or identify eclipsing binary false positives within our sample. In those previous studies, we provided evidence that three targets were false positives and two targets were planets. Here, we present observations that provide evidence supporting a planetary nature for KOI 439.01 and KOI 732.01, and we find that KOI 531.01, a 6 R$_{\\oplus}$ planet candidate around an M dwarf, is likely a false positive. We also present a discussion of the purported "sub-Jovian desert" in the orbital period-planet radius plane, which cannot be easily explained by observationa...

  11. Speckle Imaging of Kepler Exo-planet Transit Candidate Stars

    Science.gov (United States)

    Howell, Steve B.; Horch, Elliott; Sherry, William

    2009-08-01

    The NASA Kepler mission was successfully launched on 6 March 2009 and will begin science operations near 1 May. At the present time, commissioning tests are being performed and all spacecraft and science instruments are nominal. Kepler's main science focus is to discover Earth-like exo-planets via photometric transit detection. ``Hot Jupiters" will be found by the hundreds (using current ground-based statistics) but Earth-sized planets (up to 2.5 Earth radii) will be more difficult, yet are the holy grail of the mission. To take the list of candidate transiting planets found by Kepler and move them to probable or certain exo-planet detections, a decision tree of false positive elimination will occur. While earth-sized exo-planets can not currently be confirmed from the ground, many of the false positive eliminations steps can be performed. This proposal aims to obtain high resolution speckle imaging to 1) finish the characterization of ~500 comparison sample stars in the Kepler field of view prior to any transit information as a sample to place planet host stars in context with and to 2) observe Kepler exo-planet transit candidates in order to eliminate the largest false positive contributor in any transit search - background eclipsing binary stars or faint companion stars.

  12. A Resolved Debris Disk Around the Candidate Planet-hosting Star HD 95086

    Science.gov (United States)

    Moor, A.; Abraham, P.; Kospal, A.; Szabo, Gy. M.; Apai, D.; Balog, Z.; Csengeri, T.; Grady, C.; Henning, Th.; Juhasz, J.; Kiss, Cs.; Pasucci, I.; Szulagyi, J.; Vavrek, R.

    2013-01-01

    Recently, a new planet candidate was discovered on direct images around the young (10-17 Myr) A-type star HD 95086. The strong infrared excess of the system indicates that, similar to HR8799, Beta Pic, and Fomalhaut, the star harbors a circumstellar disk. Aiming to study the structure and gas content of the HD 95086 disk, and to investigate its possible interaction with the newly discovered planet, here we present new optical, infrared, and millimeter observations. We detected no CO emission, excluding the possibility of an evolved gaseous primordial disk. Simple blackbody modeling of the spectral energy distribution suggests the presence of two spatially separate dust belts at radial distances of 6 and 64 AU. Our resolved images obtained with the Herschel Space Observatory reveal a characteristic disk size of approx. 6.0 × 5.4 (540 × 490 AU) and disk inclination of approx 25 deg. Assuming the same inclination for the planet candidate's orbit, its reprojected radial distance from the star is 62 AU, very close to the blackbody radius of the outer cold dust ring. The structure of the planetary system at HD 95086 resembles the one around HR8799. Both systems harbor a warm inner dust belt and a broad colder outer disk and giant planet(s) between the two dusty regions. Modeling implies that the candidate planet can dynamically excite the motion of planetesimals even out to 270 AU via their secular perturbation if its orbital eccentricity is larger than about 0.4. Our analysis adds a new example to the three known systems where directly imaged planet(s) and debris disks coexist.

  13. Planet Mars from Viking Orbiter 1

    Science.gov (United States)

    1976-01-01

    This color picture of Mars was made from three frames shuttered nine seconds apart by the Viking 1 Orbiter on June 18. Each of the three pictures was taken through a different filter - red, green and violet. Color reconstruction was done at the Image Processing Facility of the U. S. Geological Survey in Flagstaff, Arizona. Just below the center of the picture and near the morning terminator is the large impact basin Argyre. Interior of the basin is bright, suggesting ground frost or a ground haze. Bright area south of Argyre probably is an area of discontinuous frost cover near the south pole. The pole, itself, is in the dark at lower left. North of Argyre, the 'Grand Canyon' of Mars, called Vallis Marineris, can be seen near the terminator. Markings elsewhere on the planet are mostly due to differences in brightness; however, color differences are present, suggesting compositional differences. Area at the top is the eastern side of the Tharsis volcanic region and is bright because of cloud activity. Photograph and caption published in Winds of Change, 75th Anniversary NASA publication (page 107), by James Schultz.

  14. The Pan-Pacific Planet Search III: Five companions orbiting giant stars

    CERN Document Server

    Wittenmyer, R A; Wang, L; Bergmann, C; Salter, G S; Tinney, C G; Johnson, John Asher

    2015-01-01

    We report a new giant planet orbiting the K giant HD 155233, as well as four stellar-mass companions from the Pan-Pacific Planet Search, a southern hemisphere radial velocity survey for planets orbiting nearby giants and subgiants. We also present updated velocities and a refined orbit for HD 47205b (7 CMa b), the first planet discovered by this survey. HD 155233b has a period of 885$\\pm$63 days, eccentricity e=0.03$\\pm$0.20, and m sin i=2.0$\\pm$0.5 M_jup. The stellar-mass companions range in m sin i from 0.066 M_sun to 0.33 M_sun. Whilst HD 104358B falls slightly below the traditional 0.08 M_sun hydrogen-burning mass limit, and is hence a brown dwarf candidate, we estimate only a 50% a priori probability of a truly substellar mass.

  15. Evolution and Magnitudes of Candidate Planet Nine

    CERN Document Server

    Linder, Esther F

    2016-01-01

    Context. Given the recently renewed interest in a possible additional major body in the outer Solar System, the thermodynamic evolution of such an object was studied, assuming that it is a smaller version of Uranus and Neptune. Aims. We have modeled the temporal evolution of the radius, temperature, intrinsic luminosity, and the black body spectrum of distant ice giants. The aim is to provide also estimates of the magnitudes in different bands to assess the object's detectability. Methods. Simulations of the cooling and contraction were conducted for ice giants with masses of 5, 10, 20, and 50 Mearth containing 10, 14, 21, and 37 % H/He in mass that are located at 280, 700, and 1120 AU from the Sun. The core composition was varied from purely rocky to purely icy as well as 50% rock and 50% ice. The atmospheric opacity was set to 1, 50, and 100 times solar metallicity. Results. We find for the nominal 10 Mearth planet at 700 AU at the current age of the Solar System an effective temperature of 47 K, much more ...

  16. Radial Velocities of Stars with Multiple Co-orbital Planets

    CERN Document Server

    Dobrovolskis, Anthony R

    2014-01-01

    To date, well over a thousand planets have been discovered orbiting other stars, hundreds of them in multi-planet systems. Most of these exoplanets have been detected by either the transit method or the radial velocity method, rather than by other methods such as astrometry or direct imaging. Both the radial velocity and astrometric methods rely upon the reflex motion of the parent star induced by the gravitational attraction of its planets. However, this reflex motion is subject to misinterpretation when a star has two or more planets with the same orbital period. Such co-orbital planets may effectively "hide" from detection by current algorithms. In principle, any number of planets can share the same orbit; the case where they all have the same mass has been studied most. Salo and Yoder (A & A 205, 309--327, 1988) have shown that more than 8 planets of equal mass sharing a circular orbit must be equally spaced for dynamical stability, while fewer than 7 equal-mass planets are stable only in a configurat...

  17. Speckle Imaging and Spectroscopy of Kepler Exo-planet Transit Candidate Stars

    Science.gov (United States)

    Howell, Steve B.; Sherry, William; Horch, Elliott; Doyle, Laurance

    2010-02-01

    The NASA Kepler mission was successfully launched on 6 March 2009 and has begun science operations. Commissioning tests done early on in the mission have shown that for the bright sources, 10-15 ppm relative photometry can be achieved. This level assures we will detect Earth- like transits if they are present. ``Hot Jupiter" and similar large planet candidates have already been discovered and will be discussed at the Jan. AAS meeting as well as in a special issue of Science magazine to appear near years end. The plethora of variability observed is astounding and includes a number of eclipsing binaries which appear to have Jupiter and smaller size objects as an orbiting their body. Our proposal consists of three highly related objectives: 1) To continue our highly successful speckle imaging program which is a major component of defense to weed out false positive candidate transiting planets found by Kepler and move the rest to probable or certain exo-planet detections; 2) To obtain low resolution ``discovery" type spectra for planet candidate stars in order to provide spectral type and luminosity class indicators as well as a first look triage to eliminate binaries and rapid rotators; and 3) to obtain ~1Aresolution time ordered spectra of eclipsing binaries that are exo-planet candidates in order to obtain the velocity solution for the binary star, allowing its signal to be modeled and removed from the Keck or HET exo-planet velocity search. As of this writing, Kepler has produced a list of 227 exo-planet candidates which require false positive decision tree observations. Our proposed effort performs much of the first line of defense for the mission.

  18. On the Low False Positive Probabilities of Kepler Planet Candidates

    CERN Document Server

    Morton, Timothy D

    2011-01-01

    We present a framework to conservatively estimate the probability that any particular planet-like transit signal observed by the Kepler mission is in fact a planet, prior to any ground-based follow-up efforts. We use Monte Carlo methods based on stellar population synthesis and Galactic structure models, and we provide empirical analytic fits to our results that may be applied to the as-yet-unconfirmed Kepler candidates. We find that the false positive probability for candidates that pass preliminary Kepler vetting procedures is generally 20% to < 2%, assuming a continuous power law for the planet mass function with index alpha = -1.5. Since Kepler will detect many more planetary signals than can be positively confirmed with ground-based follow-up efforts in the near term, these calculations will be crucial to using the ensemble of Kepler data to determine population characteristic s of planetary systems.

  19. Direct imaging of multiple planets orbiting the star HR 8799

    Energy Technology Data Exchange (ETDEWEB)

    Marois, C; Macintosh, B; Barman, T; Zuckerman, B; Song, I; Patience, J; Lafreniere, D; Doyon, R

    2008-10-14

    Direct imaging of exoplanetary systems is a powerful technique that can reveal Jupiter-like planets in wide orbits, can enable detailed characterization of planetary atmospheres, and is a key step towards imaging Earth-like planets. Imaging detections are challenging due to the combined effect of small angular separation and large luminosity contrast between a planet and its host star. High-contrast observations with the Keck and Gemini telescopes have revealed three planets orbiting the star HR 8799, with projected separations of 24, 38, and 68 astronomical units. Multi-epoch data show counter-clockwise orbital motion for all three imaged planets. The low luminosity of the companions and the estimated age of the system imply planetary masses between 5 and 13 times that of Jupiter. This system resembles a scaled-up version of the outer portion of our Solar System.

  20. The Search for other Earths: limits on the giant planet orbits that allow habitable terrestrial planets to form

    OpenAIRE

    Raymond, Sean N.

    2006-01-01

    Gas giant planets are far easier than terrestrial planets to detect around other stars, and are thought to form much more quickly than terrestrial planets. Thus, in systems with giant planets, the late stages of terrestrial planet formation are strongly affected by the giant planets' dynamical presence. Observations of giant planet orbits may therefore constrain the systems that can harbor potentially habitable, Earth-like planets. We present results of 460 N-body simulations of terrestrial a...

  1. Direct Imaging of Extra-Solar Planets – Homogeneous Comparison of Detected Planets and Candidates

    OpenAIRE

    Neuhäuser, Ralph; Schmidt, Tobias

    2012-01-01

    Searching the literature, we found 25 stars with directly imaged planets and candidates. We gathered photometric and spectral information for all these objects to derive their luminosities in a homogeneous way, taking a bolometric correction into account. Using theoretical evolutionary models, one can then estimate the mass from luminosity, temperature, and age. According to our mass estimates, all of them can have a mass below 25 Jup masses, so that they are considered as planets.

  2. Transit Lightcurves of Extrasolar Planets Orbiting Rapidly-Rotating Stars

    CERN Document Server

    Barnes, Jason W

    2009-01-01

    Main-sequence stars earlier than spectral type ~F6 or so are expected to rotate rapidly due to their radiative exteriors. This rapid rotation leads to an oblate stellar figure. It also induces the photosphere to be hotter (by up to several thousand Kelvin) at the pole than at the equator as a result of a process called gravity darkening that was first predicted by von Zeipel (1924). Transits of extrasolar planets across such a non-uniform, oblate disk yield unusual and distinctive lightcurves that can be used to determine the relative alignment of the stellar rotation pole and the planet orbit normal. This spin-orbit alignment can be used to constrain models of planet formation and evolution. Orderly planet formation and migration within a disk that is coplanar with the stellar equator will result in spin-orbit alignment. More violent planet-planet scattering events should yield spin-orbit misaligned planets. Rossiter-McLaughlin measurements of transits of lower-mass stars show that some planets are spin-orbi...

  3. Interaction between massive planets on inclined orbits and circumstellar discs

    CERN Document Server

    Xiang-Gruess, Meng

    2013-01-01

    We study the interaction between massive planets and a gas disc with a mass in the range expected for protoplanetary discs. We use SPH simulations to study the orbital evolution of a massive planet as well as the dynamical response of the disc for planet masses between 1 and $6\\ \\rmn{M_J}$ and the full range of initial relative orbital inclinations. Gap formation can occur for planets in inclined orbits. For given planet mass, a threshold relative orbital inclination exists under which a gap forms. At high relative inclinations, the inclination decay rate increases for increasing planet mass and decreasing initial relative inclination. For an initial semi-major axis of 5 AU and relative inclination of $i_0=80^\\circ,$ the times required for the inclination to decay by $10^\\circ$ is $\\sim10^{6}\\ \\rmn{yr}$ and $\\sim10^{5}\\ \\rmn{yr}$ for $1\\ \\rmn{M_J}$ and $6\\ \\rmn{M_J}$. Planets on inclined orbits warp the disc by an extent that is negligible for $1\\ \\rmn{M_J}$ but increases with increasing mass becoming quite s...

  4. The (Historical) Search for Planets Orbiting Proxima Centauri

    Science.gov (United States)

    Kohler, Susanna

    2016-08-01

    The European Southern Observatory (ESO) is widely expected to address the reportsofthe discovery of a planet orbiting our nearest stellar neighbor, Proxima Centauri, today. Due to its proximity 4.25 light-years away this red dwarf star has been a prime target for exoplanet searches throughout the last couple decades.Hubble image of Proxima Centauri, our nearest stellar neighbor. [ESA/Hubble]In anticipation of ESOspress conference this afternoon, lets take a look at someof the past work in the search for planetary companions around Proxima Centauri.The Early Years of Exploring Proxima CentauriProxima Centauri was discovered by astronomer Robert Innes in 1915. Studies of this star over the next eighty years primarily focused on better understanding its orbital motion (is it part of the Alpha Centauri star system?) and its flaring nature. But in the 1990s, after the detection of the first exoplanets, Proxima Centauri became a target for its potential to host planet-mass companions.Top: Images of Proxima Centauri on two different days from Hubbles FOS instrument. The bar across the center is an occulter that partially blocks the light from Proxima Centauri. Middle: Reconstructed images allowing a closer look at a moving feature identified by the authors as a possible companion. Bottom: diagram of the position of the planet candidate (box) relative to Proxima Centauri (star) in the two frames. [Schultz et al. 1998]1990s: A Possible Planet Detected With Hubble?In January 1998, a paper led by A.B. Schultz (STScI) reported the possible visual detection of a planetary companion to Proxima Centauri. Observations from Hubbles Faint Object Spectrograph, which was being used as a coronagraphic camera, revealed excess light that could be interpreted as a substellar object located ~0.5 AU from Proxima Centauri, a small separation that could imply either a short (~1 yr) period or a highly eccentric orbit.But follow-up observations led by David Golimowski (Johns Hopkins University

  5. Orbital migration of giant planets induced by gravitationally unstable gaps: the effect of planet mass

    CERN Document Server

    Cloutier, Ryan

    2013-01-01

    It has been suggested that long-period giant planets, such as HD 95086b and HR 8799bcde, may have formed through gravitational instability of protoplanetary discs. However, self-gravitating disc-satellite interaction can lead to the formation of a gravitationally unstable gap. Such an instability significantly affects the orbital migration of gap-opening perturbers in massive discs. We use 2D hydrodynamical simulations to examine the role of planet mass on the gravitational stability of gaps and its impact on orbital migration. We consider giant planets with planet-to-star mass ratio q=0.0003 to q=0.003, in a self-gravitating disc with disc-to-star mass ratio M_d/M_*=0.08, aspect ratio h=0.05, and Keplerian Toomre parameter Q = 1.5 at 2.5 times the planet's initial orbital radius. Fixed-orbit simulations show that all planet masses we consider open gravitationally unstable gaps, but the instability is stronger and develops sooner with increasing planet mass. The disc-on-planet torques typically become more po...

  6. An Earth-mass planet orbiting α Centauri B.

    Science.gov (United States)

    Dumusque, Xavier; Pepe, Francesco; Lovis, Christophe; Ségransan, Damien; Sahlmann, Johannes; Benz, Willy; Bouchy, François; Mayor, Michel; Queloz, Didier; Santos, Nuno; Udry, Stéphane

    2012-11-08

    Exoplanets down to the size of Earth have been found, but not in the habitable zone--that is, at a distance from the parent star at which water, if present, would be liquid. There are planets in the habitable zone of stars cooler than our Sun, but for reasons such as tidal locking and strong stellar activity, they are unlikely to harbour water-carbon life as we know it. The detection of a habitable Earth-mass planet orbiting a star similar to our Sun is extremely difficult, because such a signal is overwhelmed by stellar perturbations. Here we report the detection of an Earth-mass planet orbiting our neighbour star α Centauri B, a member of the closest stellar system to the Sun. The planet has an orbital period of 3.236 days and is about 0.04 astronomical units from the star (one astronomical unit is the Earth-Sun distance).

  7. The Frequency of Habitable Planets Around Small Stars and the Characterization of Planets Orbiting Bright Kepler Targets

    Science.gov (United States)

    Dressing, Courtney D.

    2015-01-01

    My thesis focuses on the frequency, detectability, and composition of small planets. I revised the parameters of the smallest Kepler main-sequence dwarf stars using Dartmouth Stellar Models and wrote a pipeline to search for planets in the full four-year Kepler data set. I characterized the completeness of my pipeline by injecting transiting planets and recording the fraction recovered. I refined the planet candidate sample by inspecting follow-up observations of planet host stars and correcting for transit depth dilution due to nearby stars. Accounting for possible false positive contamination, I estimated an occurrence rate of 0.2-0.8 potentially habitable planets per M dwarf; the variation in this estimated is dominated by the choice of habitable zone boundaries. For orbital periods conducted an adaptive optics imaging survey of 87 bright Kepler target stars with ARIES at the MMT to search for nearby stars that might be diluting the depths of the planetary transits. I identified visual companions within 1' for 5 targets, between 1' and 2' for 7 targets, and between 2' and 4' for 15 stars. For all stars observed, we placed limits on the presence of undetected nearby stars.Finally, I collaborated with the HARPS-N consortium to conduct an intensive observing campaign with the HARPS-N spectrograph at the Telescopio Nazionale Galileo in La Palma, Spain. We studied the Kepler-93 system, which contains a 1.4-Earth-radius planet in a 4.7-day orbit. Kepler-93b is a valuable addition to the exoplanet mass-radius diagram, as the physical parameters of the star have been accurately determined from asteroseismology. As a result, the size of the 1.4-Earth-radius transiting planet has been measured to an unprecedented precision of 120km (1.3%).

  8. Orbital evolution of eccentric planets in radiative discs

    Science.gov (United States)

    Bitsch, B.; Kley, W.

    2010-11-01

    Context. With an average eccentricity of about 0.29, the eccentricity distribution of extrasolar planets is markedly different from the solar system. Among other scenarios considered, it has been proposed that eccentricity may grow through planet-disc interaction. Recently, it has been noticed that the thermodynamical state of the disc can significantly influence the migration properties of growing protoplanets. However, the evolution of planetary eccentricity in radiative discs has not been considered yet. Aims: In this paper we study the evolution of planets on eccentric orbits that are embedded in a three-dimensional viscous disc and analyse the disc's effect on the orbital evolution of the planet. Methods: We use the three-dimensional hydrodynamical code NIRVANA that includes full tensor viscosity and implicit radiation transport in the flux-limited diffusion approximation. The code uses the FARGO-algorithm to speed up the simulations. First we measure the torque and power exerted on the planet by the disc for fixed orbits, and then we let the planet start with initial eccentricity and evolve it in the disc. Results: For locally isothermal discs we confirm previous results and find eccentricity damping and inward migration for planetary cores. For low eccentricity (e ⪉ 2 H/r) the damping is exponential, while for higher e it follows dot{e} ∝ e-2. In the case of radiative discs, the planets experience an inward migration as long as its eccentricity lies above a certain threshold. After the damping of eccentricity cores with masses below 33 MEarth begin to migrate outward in radiative discs, while higher mass cores always migrate inward. For all planetary masses studied (up to 200 MEarth) we find eccentricity damping. Conclusions: In viscous discs the orbital eccentricity of embedded planets is damped during the evolution independent of the mass. Hence, planet-disc interaction does not seem to be a viable mechanism to explain the observed high eccentricity of

  9. Libration of arguments of circumbinary-planet orbits at resonance

    Science.gov (United States)

    Schubart, Joachim

    2017-02-01

    The paper refers to fictitious resonant orbits of planet type that surround both components of a binary system. In case of 16 studied examples a suitable choice of the starting values leads to a process of libration of special angular arguments and to an evolution with an at least temporary stay of the planet in the resonant orbit. The ratio of the periods of revolution of the binary and a planet is equal to 1:5. Eight orbits depend on the ratio 1:5 of the masses of the binary components, but two other ratios appear as well. The basis of this study is the planar, elliptic or circular restricted problem of three bodies, but remarks at the end of the text refer to a four-body problem.

  10. The Pan-Pacific Planet Search. VI. Giant Planets Orbiting HD 86950 and HD 222076

    Science.gov (United States)

    Wittenmyer, Robert A.; Jones, M. I.; Zhao, Jinglin; Marshall, J. P.; Butler, R. P.; Tinney, C. G.; Wang, Liang; Johnson, John Asher

    2017-02-01

    We report the detection of two new planets orbiting the K giants HD 86950 and HD 222076, based on precise radial velocities obtained with three instruments: AAT/UCLES, FEROS, and CHIRON. HD 86950b has a period of 1270 ± 57 days at a=2.72+/- 0.08 au, and m sin i=3.6+/- 0.7 {M}{Jup}. HD 222076b has P=871+/- 19 days at a=1.83+/- 0.03 au, and m sin i=1.56+/- 0.11 {M}{Jup}. These two giant planets are typical of the population of planets known to orbit evolved stars. In addition, we find a high-amplitude periodic velocity signal (K∼ 50 m s‑1) in HD 29399 and show that it is due to stellar variability rather than Keplerian reflex motion. We also investigate the relation between planet occurrence and host-star metallicity for the 164-star Pan-Pacific Planet Search (PPPS) sample of evolved stars. In spite of the small sample of PPPS detections, we confirm the trend of increasing planet occurrence as a function of metallicity found by other studies of planets orbiting evolved stars.

  11. The Pan-Pacific Planet Search VI: Giant planets orbiting HD 86950 and HD 222076

    CERN Document Server

    Wittenmyer, Robert A; Zhao, Jinglin; Marshall, J P; Butler, R P; Tinney, C G; Wang, Liang; Johnson, John Asher

    2016-01-01

    We report the detection of two new planets orbiting the K giants HD 86950 and HD 222076, based on precise radial velocities obtained with three instruments: AAT/UCLES, FEROS, and CHIRON. HD 86950b has a period of 1270$\\pm$57 days at $a=2.72\\pm$0.08 AU, and m sin $i=3.6\\pm$0.7 Mjup. HD 222076b has $P=871\\pm$19 days at $a=1.83\\pm$0.03 AU, and m sin $i=1.56\\pm$0.11 Mjup. These two giant planets are typical of the population of planets known to orbit evolved stars. In addition, we find a high-amplitude periodic velocity signal ($K\\sim$50 m/s) in HD 29399, and show that it is due to stellar variability rather than Keplerian reflex motion. We also investigate the relation between planet occurrence and host-star metallicity for the 164-star Pan-Pacific Planet Search sample of evolved stars. In spite of the small sample of PPPS detections, we confirm the trend of increasing planet occurrence as a function of metallicity found by other studies of planets orbiting evolved stars.

  12. A Six-Planet System Orbiting HD 219134

    CERN Document Server

    Vogt, Steven S; Meschiari, Stefano; Butler, R Paul; Henry, Gregory W; Wang, Songhu; Holden, Brad; Gapp, Cyril; Hanson, Russell; Arriagada, Pamela; Keiser, Sandy; Teske, Johanna; Laughlin, Gregory

    2015-01-01

    We present new, high-precision Doppler radial velocity (RV) data sets for the nearby K3V star HD 219134. The data include 175 velocities obtained with the HIRES Spectrograph at the Keck I Telescope, and 101 velocities obtained with the Levy Spectrograph at the Automated Planet Finder Telescope (APF) at Lick Observatory. Our observations reveal six new planetary candidates, with orbital periods of P=3.1, 6.8, 22.8, 46.7, 94.2 and 2247 days, spanning masses of msini=3.8, 3.5, 8.9, 21.3, 10.8 and 108 M_earth respectively. Our analysis indicates that the outermost signal is unlikely to be an artifact induced by stellar activity. In addition, several years of precision photometry with the T10 0.8~m automatic photometric telescope (APT) at Fairborn Observatory demonstrated a lack of brightness variability to a limit of ~0.0002 mag, providing strong support for planetary-reflex motion as the source of the radial velocity variations. The HD 219134 system, with its bright (V=5.6) primary provides an excellent opportun...

  13. Limits to the planet candidate GJ 436c

    CERN Document Server

    Alonso, R; Rabus, M; Deeg, H J; Belmonte, J A; Almenara, J M

    2008-01-01

    We report on H-band ground-based observations of a transit of the hot Neptune GJ 436b. Once combined to achieve an equivalent sampling as archived observations taken with Spitzer, our measurements reach comparable precision levels. We analyze both sets of observations in a consistent way, and measure the rate of orbital inclination change to be of 0.02+/-0.04 degrees in the time span between the two observations (253.8 d, corresponding to 0.03+/-0.05 degrees/yr if extrapolated). By performing simulations of planetary systems including a second planet GJ 436c which has been recently suggested (Ribas et al. 2008), this rate allows to put limits to the relative inclination between the two planets. The allowed inclinations for a 5 M_E super-Earth GJ 436c in a 5.2 d orbit are within ~7 degrees of the one of GJ 436b; for larger differences the observed inclination change can be reproduced only during short sections (<50%) of the orbital evolution of the system. The measured times of three transit centers of the ...

  14. Star-planet interactions: I. Stellar rotation and planetary orbits

    CERN Document Server

    Privitera, Giovanni; Eggenberger, Patrick; Vidotto, Aline A; Villaver, Eva; Bianda, Michele

    2016-01-01

    Context. As a star evolves, the planet orbits change with time due to tidal interactions, stellar mass losses, friction and gravitational drag forces, mass accretion and evaporation on/by the planet. Stellar rotation modifies the structure of the star and therefore the way these different processes occur. Changes of the orbits, at their turn, have an impact on the rotation of the star. Aims. Models accounting in a consistent way for these interactions between the orbital evolution of the planet and the evolution of the rotation of the star are still missing. The present work is a first attempt to fill this gap. Methods. We compute the evolution of stellar models including a comprehensive treatment of rotational effects together with the evolution of planetary orbits, so that the exchanges of angular momentum between the star and the planetary orbit are treated in a self-consistent way. The evolution of the rotation of the star accounts for the angular momentum exchange with the planet and also follows the eff...

  15. Sensitivity of Saturn's orbit to a hypothetical distant planet

    Science.gov (United States)

    Folkner, William; Jacobson, Robert A.; Park, Ryan; Williams, James G.

    2016-10-01

    Several distant scattered Kuiper belt objects have similar perihelion directions that might be aligned due to the influence an unknown planet well outside the orbit of Neptune (Batygin & Brown, 2016 Astronomical J. 151:22). Such a planet, with a mass up to an order of magnitude larger than the Earth, would affect the rest of the solar system. Saturn, which is well observed from radio range and VLBI observations of the Cassini spacecraft, provides an opportunity to look for these perturbations. An unknown large planet would be expected to affect the orbit of Saturn, but the effect might be partially absorbed in the estimation of parameters used to fit the planetary ephemerides. Ephemeris parameters include the planetary orbital elements, the mass of the Sun and the masses of asteroids that perturb the orbit of Mars. Earlier analysis of the Cassini data showed no effect as suggested by the Modified Newtonian Dynamics theory (Hees et al., 2014 Phys. Rev. D 89:102002). We present an updated Cassini data set, with the accuracy of ranges to Saturn improved through updated estimates of the Cassini spacecraft orbit, and an analysis of the largest possible perturbing distant planet mass consistent with the ranging data.

  16. The Final Kepler Planet Candidate Catalog (DR25)

    Science.gov (United States)

    Coughlin, Jeffrey; Thompson, Susan E.; Kepler Team

    2017-06-01

    We present Kepler's final planet candidate catalog, which is based on the Q1--Q17 DR25 data release and was created to allow for accurate calculations of planetary occurrence rates. We discuss improvements made to our fully automated candidate vetting procedure, which yields specific categories of false positives and a disposition score value to indicate decision confidence. We present the use of light curve inversion and scrambling, in addition to our continued use of pixel-level transit injection, to produce artificial planet candidates and false positives. Since these simulated data sets were subjected to the same automated vetting procedure as the real data set, we are able to measure both the completeness and reliability of the catalog. The DR25 catalog, source code, and a multitude of completeness and reliability data products are available at the Exoplanet Archive (http://exoplanetarchive.ipac.caltech.edu). The DR25 light curves and pixel-level data are available at MAST (http://archive.stsci.edu/kepler).

  17. VALFAST: Secure Probabilistic Validation of Hundreds of Kepler Planet Candidates

    Science.gov (United States)

    Morton, Tim; Petigura, E.; Johnson, J. A.; Howard, A.; Marcy, G. W.; Baranec, C.; Law, N. M.; Riddle, R. L.; Ciardi, D. R.; Robo-AO Team

    2014-01-01

    The scope, scale, and tremendous success of the Kepler mission has necessitated the rapid development of probabilistic validation as a new conceptual framework for analyzing transiting planet candidate signals. While several planet validation methods have been independently developed and presented in the literature, none has yet come close to addressing the entire Kepler survey. I present the results of applying VALFAST---a planet validation code based on the methodology described in Morton (2012)---to every Kepler Object of Interest. VALFAST is unique in its combination of detail, completeness, and speed. Using the transit light curve shape, realistic population simulations, and (optionally) diverse follow-up observations, it calculates the probability that a transit candidate signal is the result of a true transiting planet or any of a number of astrophysical false positive scenarios, all in just a few minutes on a laptop computer. In addition to efficiently validating the planetary nature of hundreds of new KOIs, this broad application of VALFAST also demonstrates its ability to reliably identify likely false positives. This extensive validation effort is also the first to incorporate data from all of the largest Kepler follow-up observing efforts: the CKS survey of ~1000 KOIs with Keck/HIRES, the Robo-AO survey of >1700 KOIs, and high-resolution images obtained through the Kepler Follow-up Observing Program. In addition to enabling the core science that the Kepler mission was designed for, this methodology will be critical to obtain statistical results from future surveys such as TESS and PLATO.

  18. Validation of transting planet candidates: a Bayesian view

    Science.gov (United States)

    Díaz, Rodrigo Fernando; Almenara, Jose Manuel; Santerne, Alexandre

    2015-08-01

    Transiting candidate validation is essentially a Bayesian model comparison problem: different models, all explaining the observations comparably well, compete for the support of the available data. It has, however, two particularities that render it very complex and difficult to tackle: i) the relevant data sets are of diverse nature (transit light curves, broad band photometry, high angular resolution images, radial velocity observations, etc.), and ii) the models representing each hypothesis are highly non-linear and in some cases make the computation of the likelihood very time consuming.Despite its clear Bayesian nature, the planet validation problem has received in the past mainly a frequentist treatment (BLENDER). Other techniques exist, but they employ unrealistic models that increase speed but only partially exploit the available datasets (ValFast).The Planet Analysis and Small Transit Investigation Software (PASTIS) was developped keeping these issues and the characteristics of the problem in mind. It aims at computing the Bayesian evidence for a full set of false positive scenarios and the planet hypothesis, modelling in all cases the available data self-consistently, thus producing robust and rigorous Bayes factor for all models of interest. Its object-oriented architecture also permits constructing a vast set of false positive models easily.I will review some key results of the planet validation technique, showing the limitations and dangers of some approaches and of the validation technique in general. I will also describe the PASTIS tool and present out results on CoRoT-22 b, Kepler-22 b, and other transiting candidates.

  19. Exo-Mercury Analogues and the Roche Limit for Close-Orbiting Rocky Planets

    Science.gov (United States)

    Rogers, Leslie A.; Price, Ellen

    2015-12-01

    The origin of Mercury's enhanced iron content is a matter of ongoing debate. The characterization of rocky exoplanets promises to provide new independent insights on this topic, by constraining the occurrence rate and physical and orbital properties of iron-enhanced planets orbiting distant stars. The ultra-short-period transiting planet candidate KOI-1843.03 (0.6 Earth-radius, 4.245 hour orbital period, 0.46 Solar-mass host star) represents the first exo-Mercury planet candidate ever identified. For KOI-1843.03 to have avoided tidal disruption on such a short orbit, Rappaport et al. (2013) estimate that it must have a mean density of at least 7g/cc and be at least as iron rich as Mercury. This density lower-limit, however, relies upon interpolating the Roche limits of single-component polytrope models, which do not accurately capture the density profiles of >1000 km differentiated rocky bodies. A more exact calculation of the Roche limit for the case of rocky planets of arbitrary composition and central concentration is needed. We present 3D interior structure simulations of ultra-short-period tidally distorted rocky exoplanets, calculated using a modified version of Hachisu’s self-consistent field method and realistic equations of state for silicates and iron. We derive the Roche limits of rocky planets as a function of mass and composition, and refine the composition constraints on KOI-1843.03. We conclude by discussing the implications of our simulations for the eventual characterization of short-period transiting planets discovered by K2, TESS, CHEOPS and PLATO.

  20. Transiting planet candidates with ASTEP 400 at Dome C, Antarctica

    Science.gov (United States)

    Mékarnia, D.; Guillot, T.; Rivet, J.-P.; Schmider, F.-X.; Abe, L.; Gonçalves, I.; Agabi, A.; Crouzet, N.; Fruth, T.; Barbieri, M.; Bayliss, D. D. R.; Zhou, G.; Aristidi, E.; Szulagyi, J.; Daban, J.-B.; Fanteï-Caujolle, Y.; Gouvret, C.; Erikson, A.; Rauer, H.; Bouchy, F.; Gerakis, J.; Bouchez, G.

    2016-11-01

    ASTEP 400, the main instrument of the ASTEP (Antarctica Search for Transiting ExoPlanets) programme, is a 40 cm telescope, designed to withstand the harsh conditions in Antarctica, achieving a photometric accuracy of a fraction of millimagnitude on hourly time-scales for planet-hosting southern bright (R ˜ 12 mag) stars. We review the performances of this instrument, describe its operating conditions, and present results from the analysis of observations obtained during its first three years (2010-2012) of operation, before its repatriation in 2014. During this time, we observed a total of 22 stellar fields (1° × 1° field of view). Each field, in which we measured stars up to magnitude R = 18 mag, was observed continuously during ˜7 to ˜30 d. More than 200 000 frames were recorded and 310 000 stars processed, using an implementation of the optimal image subtraction photometry algorithm. We found 43 planetary transit candidates. 20 of these candidates were observed using spectroscopic follow-ups including four targets classified as good planet candidates. Our results demonstrate that accurate near-continuous photometric observations are achievable from the Concordia station at Dome C in Antarctica, even if we were not able to reach the nominal photometric precision of the instrument. We conducted a correlation analysis between the rms noise and a large number of external parameters and found that source of the ˜1 mmag correlated noise is not obvious and does not depend on a single parameter. However, our analysis provided some hints and guidance to increase the photometric accuracy of the instrument. These improvements should equip any future telescope operating in Antarctica.

  1. Direct Imaging discovery of a second planet candidate around the possibly transiting planet host CVSO 30

    CERN Document Server

    Schmidt, T O B; Briceño, C; Vogt, N; Raetz, St; Seifahrt, A; Ginski, C; Mugrauer, M; Buder, S; Adam, C; Hauschildt, P H; Witte, S; Helling, Ch; Schmitt, J H M M

    2016-01-01

    We surveyed the 25 Ori association for direct-imaging companions. This association has an age of only few million years. Among other targets, we observed CVSO 30, which has recently been identified as the first T Tauri star found to host a transiting planet candidate. We report on photometric and spectroscopic high-contrast observations with the Very Large Telescope, the Keck telescopes, and the Calar Alto observatory. They reveal a directly imaged planet candidate close to the young M3 star CVSO 30. The JHK-band photometry of the newly identified candidate is at better than 1 sigma consistent with late-type giants, early-T and early-M dwarfs, and free-floating planets. Other hypotheses such as galaxies can be excluded at more than 3.5 sigma. A lucky imaging z' photometric detection limit z'= 20.5 mag excludes early-M dwarfs and results in less than 10 MJup for CVSO 30 c if bound. We present spectroscopic observations of the wide companion that imply that the only remaining explanation for the object is that ...

  2. Herschel Observations of Debris Discs Orbiting Planet-hosting Subgiants

    CERN Document Server

    Bonsor, Amy; Wyatt, Mark C; Johnson, John A; Sibthorpe, Bruce

    2013-01-01

    Debris discs are commonly detected orbiting main-sequence stars, yet little is known regarding their fate as the star evolves to become a giant. Recent observations of radial velocity detected planets orbiting giant stars highlight this population and its importance for probing, for example, the population of planetary systems orbiting intermediate mass stars. Our Herschel survey observed a subset of the Johnson et al program subgiants, finding that 4/36 exhibit excess emission thought to indicate debris, of which 3/19 are planet-hosting stars and 1/17 are stars with no current planet detections. Given the small numbers involved, there is no evidence that the disc detection rate around stars with planets is different to that around stars without planets. Our detections provide a clear indication that large quantities of dusty material can survive the stars' main-sequence lifetime and be detected on the subgiant branch, with important implications for the evolution of planetary systems and observations of poll...

  3. The Habitability of Planets Orbiting M-dwarf Stars

    CERN Document Server

    Shields, Aomawa L; Johnson, John A

    2016-01-01

    The prospects for the habitability of M-dwarf planets have long been debated, due to key differences between the unique stellar and planetary environments around these low-mass stars, as compared to hotter, more luminous Sun-like stars. Over the past decade, significant progress has been made by both space- and ground-based observatories to measure the likelihood of small planets to orbit in the habitable zones of M-dwarf stars. We now know that most M dwarfs are hosts to closely-packed planetary systems characterized by a paucity of Jupiter-mass planets and the presence of multiple rocky planets, with roughly a third of these rocky M-dwarf planets orbiting within the habitable zone, where they have the potential to support liquid water on their surfaces. Theoretical studies have also quantified the effect on climate and habitability of the interaction between the spectral energy distribution of M-dwarf stars and the atmospheres and surfaces of their planets. These and other recent results fill in knowledge g...

  4. Secular Orbital Dynamics of Hierarchical Two Planet Systems

    CERN Document Server

    Veras, Dimitri

    2010-01-01

    The discovery of multi-planet extrasolar systems has kindled interest in using their orbital evolution as a probe of planet formation. Accurate descriptions of planetary orbits identify systems which could hide additional planets or be in a special dynamical state, and inform targeted follow-up observations. We combine published radial velocity data with Markov Chain Monte Carlo analyses in order to obtain an ensemble of masses, semimajor axes, eccentricities and orbital angles for each of 5 dynamically active multi-planet systems: HD 11964, HD 38529, HD 108874, HD 168443, and HD 190360. We dynamically evolve these systems using 52,000 long-term N-body integrations that sample the full range of possible line-of-sight and relative inclinations, and we report on the system stability, secular evolution and the extent of the resonant interactions. We find that planetary orbits in hierarchical systems exhibit complex dynamics and can become highly eccentric and maybe significantly inclined. Additionally we incorpo...

  5. Humans Need Not Apply: Robotization of Kepler Planet Candidate Vetting

    Science.gov (United States)

    Coughlin, Jeffrey; Mullally, Fergal; Thompson, Susan E.; Kepler Team

    2015-01-01

    Until now, the vast majority of Kepler planet candidate vetting has been performed by a dedicated team of humans. While human expertise has been invaluable in understanding the nuances of Kepler data, human vetting is very time-consuming and can be inconsistent. Over 20,000 threshold crossing events have been produced by the latest pipeline run on all 17 quarters of Kepler mission data, and many more artificial planet transits have been injected to estimate completeness. Given these large numbers, human vetting is no longer feasible on a reasonable time-scale, and would be difficult to characterize. We have created automated vetting programs known as "robovetters" that are specifically designed to mimic the decision-making process employed by the humans. They analyze both the light curve and pixel-level data in order to produce specific reasons for identifying false positives. We present benchmark tests on the Q1-Q16 Kepler planet catalog, which was vetted by humans, and present preliminary robovetter results based on a recent transit-search of the newly reprocessed Q1-Q17 data set.

  6. A Venus-Mass Planet Orbiting a Brown Dwarf: Missing Link between Planets and Moons

    CERN Document Server

    Udalski, A; Han, C; Gould, A; Kozlowski, S; Skowron, J; Poleski, R; Soszyński, I; Pietrukowicz, P; Mróz, P; Szymański, M K; Wyrzykowski, Ł; Ulaczyk, K; Pietrzyński, G; Shvartzvald, Y; Maoz, D; Kaspi, S; Gaudi, B S; Hwang, K -H; Choi, J -Y; Shin, I -G; Park, H; Bozza, V

    2015-01-01

    The co-planarity of solar-system planets led Kant to suggest that they formed from an accretion disk, and the discovery of hundreds of such disks around young stars as well as hundreds of co-planar planetary systems by the {\\it Kepler} satellite demonstrate that this formation mechanism is extremely widespread. Many moons in the solar system, such as the Galilean moons of Jupiter, also formed out of the accretion disks that coalesced into the giant planets. We report here the discovery of an intermediate system OGLE-2013-BLG-0723LB/Bb composed of a Venus-mass planet orbiting a brown dwarf, which may be viewed either as a scaled down version of a planet plus star or as a scaled up version of a moon plus planet orbiting a star. The latter analogy can be further extended since they orbit in the potential of a larger, stellar body. For ice-rock companions formed in the outer parts of accretion disks, like Uranus and Callisto, the scaled masses and separations of the three types of systems are similar, leading us ...

  7. The Dynamics of Orbit-Clearing for Planets on Eccentric Orbits

    Science.gov (United States)

    Hastings, Danielle; Margot, Jean-Luc

    2016-10-01

    The third requirement in the 2006 International Astronomical Union (IAU) definition of a planet is that the object has cleared the neighborhood around its orbit. Margot (2015) proposed a metric that quantitatively determines if an object has enough mass to clear an orbital zone of a specific extent within a defined time interval. In this metric, the size of the zone to be cleared is given by CRH, where C is a constant and RH is the Hill Radius. Margot (2015) adopts C=2*31/2 to describe the minimum extent of orbital clearing on the basis of the planet's feeding zone. However, this value of C may only apply for eccentricities up to about 0.3 (Quillen & Faber 2006). Here, we explore the timescales and boundaries of orbital clearing for planets over a range of orbital eccentricities and planet-star mass ratios using the MERCURY integration package (Chambers 1999). The basic setup for the integrations includes a single planet orbiting a star and a uniform distribution of massless particles extending beyond CRH. The system is integrated for at least 106 revolutions and the massless particles are tracked in order to quantify the timescale and extent of the clearing.

  8. Utilizing Astrometric Orbits to Obtain Coronagraphic Images of Extrasolar Planets

    Science.gov (United States)

    Davidson, John M.

    2011-08-01

    We present an approach for utilizing astrometric orbit information to improve the yield of planetary images and spectra from a follow-on direct-detection mission. This approach is based on the notion—strictly hypothetical—that if a particular star could be observed continuously, the instrument would in time observe all portions of the habitable zone so that no planet residing therein could be missed. This strategy could not be implemented in any realistic mission scenario. But if an exoplanet’s orbit is known from astrometric observation, then it may be possible to plan and schedule a sequence of imaging observations that is the equivalent of continuous observation. A series of images—optimally spaced in time—could be recorded to examine contiguous segments of the orbit. In time, all segments would be examined, leading to the inevitable detection of the planet. In this article, we show how astrometric orbit information can be used to construct such a sequence. We apply this methodology to seven stars taken from the target lists of proposed astrometric and direct-detection missions. In addition, we construct this sequence for the Sun-Earth system as it would appear from a distance of 10 pc. In constructing these sequences, we have assumed that the imaging instrument has an inner working angle (IWA) of 75 mas and that the planets are visible whenever they are separated from their host stars by ≥IWA and are in quarter-phase or greater. In addition, we have assumed that the planets orbit at a distance of 1 AU scaled to luminosity and that the inclination of the orbit plane is 60°. For the individual stars in this target pool, we find that the number of observations in this sequence ranges from two to seven, representing the maximum number of observations required to find the planet. The probable number of observations ranges from 1.5 to 3.1. These results suggest that a direct-detection mission using astrometric orbits would find all eight exoplanets in

  9. Two Earth-sized planets orbiting Kepler-20.

    Science.gov (United States)

    Fressin, Francois; Torres, Guillermo; Rowe, Jason F; Charbonneau, David; Rogers, Leslie A; Ballard, Sarah; Batalha, Natalie M; Borucki, William J; Bryson, Stephen T; Buchhave, Lars A; Ciardi, David R; Désert, Jean-Michel; Dressing, Courtney D; Fabrycky, Daniel C; Ford, Eric B; Gautier, Thomas N; Henze, Christopher E; Holman, Matthew J; Howard, Andrew; Howell, Steve B; Jenkins, Jon M; Koch, David G; Latham, David W; Lissauer, Jack J; Marcy, Geoffrey W; Quinn, Samuel N; Ragozzine, Darin; Sasselov, Dimitar D; Seager, Sara; Barclay, Thomas; Mullally, Fergal; Seader, Shawn E; Still, Martin; Twicken, Joseph D; Thompson, Susan E; Uddin, Kamal

    2011-12-20

    Since the discovery of the first extrasolar giant planets around Sun-like stars, evolving observational capabilities have brought us closer to the detection of true Earth analogues. The size of an exoplanet can be determined when it periodically passes in front of (transits) its parent star, causing a decrease in starlight proportional to its radius. The smallest exoplanet hitherto discovered has a radius 1.42 times that of the Earth's radius (R(⊕)), and hence has 2.9 times its volume. Here we report the discovery of two planets, one Earth-sized (1.03R(⊕)) and the other smaller than the Earth (0.87R(⊕)), orbiting the star Kepler-20, which is already known to host three other, larger, transiting planets. The gravitational pull of the new planets on the parent star is too small to measure with current instrumentation. We apply a statistical method to show that the likelihood of the planetary interpretation of the transit signals is more than three orders of magnitude larger than that of the alternative hypothesis that the signals result from an eclipsing binary star. Theoretical considerations imply that these planets are rocky, with a composition of iron and silicate. The outer planet could have developed a thick water vapour atmosphere.

  10. Dynamics of two planets in co-orbital motion

    CERN Document Server

    Giuppone, C A; Michtchenko, T A; Ferraz-Mello, S

    2010-01-01

    We study the stability regions and families of periodic orbits of two planets locked in a co-orbital configuration. We consider different ratios of planetary masses and orbital eccentricities, also we assume that both planets share the same orbital plane. Initially we perform numerical simulations over a grid of osculating initial conditions to map the regions of stable/chaotic motion and identify equilibrium solutions. These results are later analyzed in more detail using a semi-analytical model. Apart from the well known quasi-satellite (QS) orbits and the classical equilibrium Lagrangian points L4 and L5, we also find a new regime of asymmetric periodic solutions. For low eccentricities these are located at $(\\sigma,\\Delta\\omega) = (\\pm 60\\deg, \\mp 120\\deg)$, where \\sigma is the difference in mean longitudes and \\Delta\\omega is the difference in longitudes of pericenter. The position of these Anti-Lagrangian solutions changes with the mass ratio and the orbital eccentricities, and are found for eccentricit...

  11. Pre-Spectroscopic False Positive Elimination of Kepler Planet Candidates

    CERN Document Server

    Batalha, N M; Gilliland, R L; Jenkins, J J; Caldwell, D A; Borucki, W J; Koch, D G; Lissauer, J J; Dunham, E W; Gautier, T N; Howell, S B; Latham, D W; Marcy, G W; Prsa, A

    2010-01-01

    Ten days of commissioning data (Quarter 0) and thirty-three days of science data (Quarter 1) yield instrumental flux timeseries of ~150,000 stars that were combed for transit events, termed Threshold Crossing Events (TCE), each having a total detection statistic above 7.1-sigma. TCE light curves are modeled as star+planet systems. Those returning a companion radius smaller than 2R_J are assigned a KOI (Kepler Object of Interest) number. The raw flux, pixel flux, and flux-weighted centroids of every KOI are scrutinized to assess the likelihood of being an astrophysical false-positive versus the likelihood of a being a planetary companion. This vetting using Kepler data is referred to as data validation. Herein, we describe the data validation metrics and graphics used to identify viable planet candidates amongst the KOIs. Light curve modeling tests for a) the difference in depth of the odd- versus even-numbered transits, b) evidence of ellipsoidal variations, and c) evidence of a secondary eclipse event at pha...

  12. Kepler-36: A Pair of Planets with Neighboring Orbits and Dissimilar Densities

    CERN Document Server

    Carter, Joshua A; Chaplin, William J; Basu, Sarbani; Bedding, Timothy R; Buchhave, Lars A; Christensen-Dalsgaard, Jørgen; Deck, Katherine M; Elsworth, Yvonne; Fabrycky, Daniel C; Ford, Eric B; Fortney, Jonathan J; Hale, Steven J; Handberg, Rasmus; Hekker, Saskia; Holman, Matthew J; Huber, Daniel; Karoff, Christopher; Kawaler, Steven D; Kjeldsen, Hans; Lissauer, Jack J; Lopez, Eric D; Lund, Mikkel N; Lundkvist, Mia; Metcalfe, Travis S; Miglio, Andrea; Rogers, Leslie A; Stello, Dennis; Borucki, William J; Bryson, Steve; Christiansen, Jessie L; Cochran, William D; Geary, John C; Gilliland, Ronald L; Haas, Michael R; Hall, Jennifer; Howard, Andrew W; Jenkins, Jon M; Klaus, Todd; Koch, David G; Latham, David W; MacQueen, Phillip J; Sasselov, Dimitar; Steffen, Jason H; Twicken, Joseph D; Winn, Joshua N

    2012-01-01

    In the Solar system the planets' compositions vary with orbital distance, with rocky planets in close orbits and lower-density gas giants in wider orbits. The detection of close-in giant planets around other stars was the first clue that this pattern is not universal, and that planets' orbits can change substantially after their formation. Here we report another violation of the orbit-composition pattern: two planets orbiting the same star with orbital distances differing by only 10%, and densities differing by a factor of 8. One planet is likely a rocky `super-Earth', whereas the other is more akin to Neptune. These planets are thirty times more closely spaced--and have a larger density contrast--than any adjacent pair of planets in the Solar system.

  13. Kepler-36: a pair of planets with neighboring orbits and dissimilar densities.

    Science.gov (United States)

    Carter, Joshua A; Agol, Eric; Chaplin, William J; Basu, Sarbani; Bedding, Timothy R; Buchhave, Lars A; Christensen-Dalsgaard, Jørgen; Deck, Katherine M; Elsworth, Yvonne; Fabrycky, Daniel C; Ford, Eric B; Fortney, Jonathan J; Hale, Steven J; Handberg, Rasmus; Hekker, Saskia; Holman, Matthew J; Huber, Daniel; Karoff, Christopher; Kawaler, Steven D; Kjeldsen, Hans; Lissauer, Jack J; Lopez, Eric D; Lund, Mikkel N; Lundkvist, Mia; Metcalfe, Travis S; Miglio, Andrea; Rogers, Leslie A; Stello, Dennis; Borucki, William J; Bryson, Steve; Christiansen, Jessie L; Cochran, William D; Geary, John C; Gilliland, Ronald L; Haas, Michael R; Hall, Jennifer; Howard, Andrew W; Jenkins, Jon M; Klaus, Todd; Koch, David G; Latham, David W; MacQueen, Phillip J; Sasselov, Dimitar; Steffen, Jason H; Twicken, Joseph D; Winn, Joshua N

    2012-08-03

    In the solar system, the planets' compositions vary with orbital distance, with rocky planets in close orbits and lower-density gas giants in wider orbits. The detection of close-in giant planets around other stars was the first clue that this pattern is not universal and that planets' orbits can change substantially after their formation. Here, we report another violation of the orbit-composition pattern: two planets orbiting the same star with orbital distances differing by only 10% and densities differing by a factor of 8. One planet is likely a rocky "super-Earth," whereas the other is more akin to Neptune. These planets are 20 times more closely spaced and have a larger density contrast than any adjacent pair of planets in the solar system.

  14. Extrasolar Giant Planet in Earth-like Orbit

    Science.gov (United States)

    1999-07-01

    Discovery from a Long-term Project at La Silla A new extrasolar planet has been found at the ESO La Silla Observatory as a companion to iota Horologii (iota Hor) . This 5.4-mag solar-type star is located at a distance of 56 light-years and is just visible to the unaided eye in the southern constellation Horologium (The Pendulum Clock). The discovery is the result of a long-term survey of forty solar-type stars that was begun in November 1992. It is based on highly accurate measurements of stellar radial velocities, i.e. the speed with which a star moves along the line of sight. The presence of a planet in orbit around a star is inferred from observed, regular changes of this velocity, as the host star and its planet revolve around a common center of gravity. Since in all cases the star is much heavier than the planet, the resulting velocity variations of the star are always quite small. The team that found the new planet, now designated iota Hor b , consists of Martin Kürster , Michael Endl and Sebastian Els (ESO-Chile), Artie P. Hatzes and William D. Cochran (University of Texas, Austin, USA), and Stefan Döbereiner and Konrad Dennerl (Max-Planck-Institut für extraterrestrische Physik, Garching, Germany). Iodine cell provides very accurate velocity measurements iota Hor b represents the first discovery of an extrasolar planet with an ESO instrument [1]. The finding is based on data obtained with ESO's highest-resolution spectrograph, the Coudé Echelle Spectrometer (CES) at the 1.4-m Coudé Auxiliary Telescope (CAT). While this telescope has recently been decommissioned, the CES instrument is now coupled via an optical fiber link to the larger ESO 3.6-m telescope, thus permitting the continuation of this survey. The high precision radial velocity measurements that are necessary for a study of this type were achieved by means of a special calibration technique. It incorporates an iodine gas absorption cell and sophisticated data modelling. The cell is used like

  15. ON THE ORIGIN OF PLANETS AT VERY WIDE ORBITS FROM THE RECAPTURE OF FREE FLOATING PLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Perets, Hagai B. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Kouwenhoven, M. B. N., E-mail: hperets@physics.cfa.harvard.edu, E-mail: thijskouwenhoven@gmail.com [Kavli Institute for Astronomy and Astrophysics at Peking University, Yi He Yuan Lu 5, Hai Dian District, Beijing 100871 (China)

    2012-05-01

    In recent years, several planets have been discovered at wide orbits (>100 AU) around their host stars. Theoretical studies encounter difficulties in explaining their formation and origin. Here we propose a novel scenario for the production of planetary systems at such orbits, through the dynamical recapture of free floating planets (FFPs) in dispersing stellar clusters and stellar associations. This process is a natural extension of the recently suggested scenario for the formation of wide stellar binaries. We use N-body simulations of dispersing clusters with 10-1000 stars and comparable numbers of FFPs to study this process. We find that planets are captured into wide orbits in the typical range {approx}few Multiplication-Sign 100-10{sup 6} AU and have a wide range of eccentricities (thermal distribution). Typically, 3-6 Multiplication-Sign (f{sub FFP}/1)% of all stars capture a planetary companion with such properties (where f{sub FFP} is the number of FFP per star in the birth clusters). The planetary capture efficiency is comparable to that of capture-formed stellar binaries, and shows a similar dependence on the cluster size and structure. It is almost independent of the specific planetary mass; planets as well as substellar companions of any mass can be captured. The capture efficiency decreases with increasing cluster size, and for a given cluster size it increases with the host/primary mass. We also find that more than one planet can be captured around the same host through independent consecutive captures; similarly, planets can be captured into binary systems, both in circumstellar and circumbinary orbits. We also expect planets to be captured into pre-existing planetary (and protoplanetary systems) as well as into orbits around black holes and massive white dwarfs, if these formed early enough before the cluster dispersal. In particular, stellar black holes have a high capture efficiency (>50% and 5-10 Multiplication-Sign (f{sub FFP}/1)% for capture of

  16. Shock formation around planets orbiting M-dwarf stars

    CERN Document Server

    Vidotto, A A; Jardine, M; Helling, Ch; Wood, K

    2011-01-01

    Bow shocks can be formed around planets due to their interaction with the coronal medium of the host stars. The net velocity of the particles impacting on the planet determines the orientation of the shock. At the Earth's orbit, the (mainly radial) solar wind is primarily responsible for the formation of a shock facing towards the Sun. However, for close-in planets that possess high Keplerian velocities and are frequently located at regions where the host star's wind is still accelerating, a shock may develop ahead of the planet. If the compressed material is able to absorb stellar radiation, then the signature of bow shocks may be observed during transits. Bow-shock models have been investigated in a series of papers (Vidotto et al. 2010, 2011,a,b; Llama et al. 2011) for known transiting systems. Once the signature of a bow-shock is observed, one can infer the magnetic field intensity of the transiting planet. Here, we investigate the potential to use this model to detect magnetic fields of (hypothetical) pl...

  17. Measurements of Stellar Inclinations for Kepler Planet Candidates

    CERN Document Server

    Hirano, Teruyuki; Takeda, Yoichi; Narita, Norio; Winn, Joshua N; Taruya, Atsushi; Suto, Yasushi

    2012-01-01

    We present an investigation of spin-orbit angles for planetary system candidates reported by Kepler. By combining the rotational period $P_s$ inferred from the flux variation due to starspots and the projected rotational velocity $V\\sin I_s$ and stellar radius obtained by a high resolution spectroscopy, we attempt to estimate the inclination $I_s$ of the stellar spin axis with respect to the line-of-sight. For transiting planetary systems, in which planetary orbits are edge-on seen from us, the stellar inclination $I_s$ can be a useful indicator of a spin-orbit alignment/misalignment. We newly conducted spectroscopic observations with Subaru/HDS for 15 KOI systems, whose lightcurves show periodic flux variations. After detailed analyses of their lightcurves and spectra, it turned out that some of them are binaries, or the flux variations are too coherent to be caused by starspots, probably representing ellipsoidal variations, and consequently we could constrain stellar inclinations $I_s$ for eight systems. Am...

  18. Kepler-36: a pair of planets with neighboring orbits and dissimilar densities

    NARCIS (Netherlands)

    Carter, J.A.; Agol, E.; Chaplin, W.J.; Basu, S.; Bedding, T.R.; Buchhave, L.A.; Christensen-Dalsgaard, J.; Deck, K.M.; Elsworth, Y.; Fabrycky, D.C.; Ford, E.B.; Fortney, J.J.; Hale, S.J.; Handberg, R.; Hekker, S.; Holman, M.J.; Huber, D.; Karoff, C.; Kawaler, S.D.; Kjeldsen, H.; Lissauer, J.J.; Lopez, E.D.; Lund, M.N.; Lundkvist, M.; Metcalfe, T.S.; Miglio, A.; Rogers, L.A.; Stello, D.; Borucki, W.J.; Bryson, S.; Christiansen, J.L.; Cochran, W.D.; Geary, J.C.; Gilliland, R.L.; Haas, M.R.; Hall, J.; Howard, A.W.; Jenkins, J.M.; Klaus, T.; Koch, D.G.; Latham, D.W.; MacQueen, P.J.; Sasselov, D.; Steffen, J.H.; Twicken, J.D.; Winn, J.N.

    2012-01-01

    In the solar system, the planets’ compositions vary with orbital distance, with rocky planets in close orbits and lower-density gas giants in wider orbits. The detection of close-in giant planets around other stars was the first clue that this pattern is not universal and that planets’ orbits can ch

  19. Orbital Eccentricity and the Stability of Planets in the Alpha Centauri System

    Science.gov (United States)

    Lissauer, Jack

    2016-01-01

    Planets on initially circular orbits are typically more dynamically stable than planets initially having nonzero eccentricities. However, the presence of a major perturber that forces periodic oscillations of planetary eccentricity can alter this situation. We investigate the dependance of system lifetime on initial eccentricity for planets orbiting one star within the alpha Centauri system. Our results show that initial conditions chosen to minimize free eccentricity can substantially increase stability compared to planets on circular orbits.

  20. How planet-planet scattering can create high-inclination as well as long-period orbits

    CERN Document Server

    Chatterjee, Sourav; Rasio, Frederic A

    2010-01-01

    Recent observations have revealed two new classes of planetary orbits. Rossiter- Mclaughlin (RM) measurements have revealed hot Jupiters in high-obliquity orbits. In addition, direct-imaging has discovered giant planets at large (~ 100 AU) separations via direct-imaging technique. Simple-minded disk-migration scenarios are inconsistent with the high-inclination (and even retrograde) orbits as seen in recent RM measurements. Furthermore, forming giant planets at large semi-major axis (a) may be challenging in the core-accretion paradigm. We perform many N-body simulations to explore the two above-mentioned orbital architectures. Planet-planet scattering in a multi-planet system can naturally excite orbital inclinations. Planets can also get scattered to large distances. Large-a planetary orbits created from planet-planet scattering are expected to have high eccentricities (e). Theoretical models predict that the observed long-period planets, such as Fomalhaut-b have moderate e \\approx 0.3. Interestingly, these...

  1. Planetary Candidates Observed by Kepler VI: Planet Sample from Q1-Q16 (47 Months)

    CERN Document Server

    Mullally, F; Thompson, Susan E; Rowe, Jason; Burke, Christopher; Latham, David W; Batalha, Natalie M; Bryson, Stephen T; Christiansen, Jessie; Henze, Christopher E; Ofir, Aviv; Quarles, Billy; Shporer, Avi; Van Eylen, Vincent; Van Laerhoven, Christa; Shah, Yash; Wolfgang, Angie; Chaplin, W J; Xie, Ji-Wei; Akeson, Rachel; Argabright, Vic; Bachtell, Eric; Borucki, Thomas Barclay William J; Caldwell, Douglas A; Campbell, Jennifer R; Catanzarite, Joseph H; Cochran, William D; Duren, Riley M; Fleming, Scott W; Fraquelli, Dorothy; Girouard, Forrest R; Haas, Michael R; Hełminiak, Krzysztof G; Howell, Steve B; Huber, Daniel; Larson, Kipp; Gautier, Thomas N; Jenkins, Jon; Li, Jie; Lissauer, Jack J; McArthur, Scot; Miller, Chris; Morris, Robert L; Patil-Sabale, Anima; Plavchan, Peter; Putnam, Dustin; Quintana, Elisa V; Ramirez, Solange; Aguirre, V Silva; Seader, Shawn; Smith, Jeffrey C; Steffen, Jason H; Stewart, Chris; Stober, Jeremy; Still, Martin; Tenenbaum, Peter; Troeltzsch, John; Twicken, Joseph D; Zamudio, Khadeejah A

    2015-01-01

    \\We present the sixth catalog of Kepler candidate planets based on nearly 4 years of high precision photometry. This catalog builds on the legacy of previous catalogs released by the Kepler project and includes 1493 new Kepler Objects of Interest (KOIs) of which 554 are planet candidates, and 131 of these candidates have best fit radii 50 days to provide a consistently vetted sample that can be used to improve planet occurrence rate calculations. We discuss the performance of our planet detection algorithms, and the consistency of our vetting products. The full catalog is publicly available at the NASA Exoplanet Archive.

  2. Two Earth-sized planets orbiting Kepler-20

    CERN Document Server

    Fressin, Francois; Rowe, Jason F; Charbonneau, David; Rogers, Leslie A; Ballard, Sarah; Batalha, Natalie M; Borucki, William J; Bryson, Stephen T; Buchhave, Lars A; Ciardi, David R; Desert, Jean-Michel; Dressing, Courtney D; Fabrycky, Daniel C; Ford, Eric B; Gautier, Thomas N; Henze, Christopher E; Holman, Matthew J; Howard, Andrew W; Howell, Steve B; Jenkins, Jon M; Koch, David G; Latham, David W; Lissauer, Jack J; Marcy, Geoffrey W; Quinn, Samuel N; Ragozzine, Darin; Sasselov, Dimitar D; Seager, Sara; Barclay, Thomas; Mullally, Fergal; Seader, Shawn E; Still, Martin; Twicken, Joseph D; Thompson, Susan E; Uddin, Kamal

    2011-01-01

    Since the discovery of the first extrasolar giant planets around Sun-like stars, evolving observational capabilities have brought us closer to the detection of true Earth analogues. The size of an exoplanet can be determined when it periodically passes in front of (transits) its parent star, causing a decrease in starlight proportional to its radius. The smallest exoplanet hitherto discovered has a radius 1.42 times that of the Earth's radius (R Earth), and hence has 2.9 times its volume. Here we report the discovery of two planets, one Earth-sized (1.03R Earth) and the other smaller than the Earth (0.87R Earth), orbiting the star Kepler-20, which is already known to host three other, larger, transiting planets. The gravitational pull of the new planets on the parent star is too small to measure with current instrumentation. We apply a statistical method to show that the likelihood of the planetary interpretation of the transit signals is more than three orders of magnitude larger than that of the alternative...

  3. Refined Parameters of the Planet Orbiting HD 189733

    Science.gov (United States)

    Bakos, G. Á.; Knutson, H.; Pont, F.; Moutou, C.; Charbonneau, D.; Shporer, A.; Bouchy, F.; Everett, M.; Hergenrother, C.; Latham, D. W.; Mayor, M.; Mazeh, T.; Noyes, R. W.; Queloz, D.; Pál, A.; Udry, S.

    2006-10-01

    We report on the BVRI multiband follow-up photometry of the transiting extrasolar planet HD 189733b. We revise the transit parameters and find a planetary radius of RP=1.154+/-0.033RJ and an inclination of iP=85.79d+/-0.24d. The new density (~1 g cm-3) is significantly higher than the former estimate (~0.75 g cm-3) this shows that from the current sample of nine transiting planets, only HD 209458 (and possibly OGLE-10b) have anomalously large radii and low densities. We note that due to the proximity of its parent star, HD 189733b currently has one of the most precise radius determinations among extrasolar planets. We calculate new ephemerides, P=2.218573+/-0.000020 days and T0=2453629.39420+/-0.00024 (HJD), and estimate the timing offsets of the 11 distinct transits with respect to the predictions of a constant orbital period, which can be used to reveal the presence of additional planets in the system.

  4. The effect of J{sub 2} on equatorial and halo orbits around a magnetic planet

    Energy Technology Data Exchange (ETDEWEB)

    Inarrea, Manuel [Universidad de la Rioja, Area de Fisica, 26006 Logrono (Spain); Lanchares, Victor [Dpto. de Matematicas y Computacion, CIEMUR: Centro de Investigacion en Informatica, Estadistica y Matematicas, Universidad de la Rioja, 26004 Logrono (Spain)], E-mail: vlancha@unirioja.es; Palacian, Jesus F. [Universidad Publica de Navarra, Departamento de Ingenieria Matematica e Informatica, 31006 Pamplona (Spain); Pascual, Ana I. [Dpto. de Matematicas y Computacion, CIEMUR: Centro de Investigacion en Informatica, Estadistica y Matematicas, Universidad de la Rioja, 26004 Logrono (Spain); Pablo Salas, J. [Universidad de la Rioja, Area de Fisica, 26006 Logrono (Spain); Yanguas, Patricia [Universidad Publica de Navarra, Departamento de Ingenieria Matematica e Informatica, 31006 Pamplona (Spain)

    2009-10-15

    We calculate equatorial and halo orbits around a non-spherical (both oblate and prolate) magnetic planet. It is known that circular equatorial and halo orbits exist for a dust grain orbiting a spherical magnetic planet. However, the frequency of the orbit is constrained by the charge-mass ratio of the particle. If the non-sphericity of the planet is taken into account this constraint is modified or, in some cases, it disappears.

  5. Orbital obliquities of transiting planets from starspot occultations

    CERN Document Server

    Southworth, John

    2016-01-01

    When a planet passes in front of a starspot during a transit of its host star, it causes a small upward blip in the light curve. Modelling the transit with the starspot allows the size, brightness and position of the spot to be measured. If the same spot can be observed in two different transits, it is possible to track the motion of the spot due to the rotation of the star. The rotation period and velocity of the star (Prot and Vsini) and the sky-projected orbital obliquity of the system (lambda) can then be determined. If one has three or more observations of the same spot, the true orbital obliquity (psi) can be measured. We are performing this analysis for a number of cool stars orbited by transiting planets. We present our results so far and compile a catalogue of lambda and psi measurements from spot crossing events. The method is particularly useful for cool stars, and is therefore complementary to studies of the Rossiter-McLaughlin effect, which perform better on hotter and faster-rotating stars.

  6. Impact of Orbital Eccentricity on the Detection of Transiting Extrasolar Planets

    CERN Document Server

    Burke, Christopher J

    2008-01-01

    For extrasolar planets with orbital periods, P>10 days, radial velocity surveys find non-circular orbital eccentricities are common, ~0.3. Future surveys for extrasolar planets using the transit technique will also have sensitivity to detect these longer period planets. Orbital eccentricity affects the detection of extrasolar planets using the transit technique in two opposing ways: an enhancement in the probability for the planet to transit near pericenter and a reduction in the detectability of the transit due to a shorter transit duration. For an eccentricity distribution matching the currently known extrasolar planets with P>10 day, the probability for the planet to transit is ~1.25 times higher than the equivalent circular orbit and the average transit duration is ~0.88 times shorter than the equivalent circular orbit. These two opposing effects nearly cancel for an idealized field transit survey with independent photometric measurements that are dominated by Poisson noise. The net effect is a modest ~4%...

  7. On the co-orbital motion of two planets in quasi-circular orbits

    CERN Document Server

    Robutel, Philippe

    2013-01-01

    We develop an analytical Hamiltonian formalism adapted to the study of the motion of two planets in co-orbital resonance. The Hamiltonian, averaged over one of the planetary mean longitude, is expanded in power series of eccentricities and inclinations. The model, which is valid in the entire co-orbital region, possesses an integrable approximation modeling the planar and quasi-circular motions. First, focusing on the fixed points of this approximation, we highlight relations linking the eigenvectors of the associated linearized differential system and the existence of certain remarkable orbits like the elliptic Eulerian Lagrangian configurations, the Anti-Lagrange (Giuppone et al., 2010) orbits and some second sort orbits discovered by Poincar\\'e. Then, the variational equation is studied in the vicinity of any quasi-circular periodic solution. The fundamental frequencies of the trajectory are deduced and possible occurrence of low order resonances are discussed. Finally, with the help of the construction of...

  8. Conditions of Passage and Entrapment of Terrestrial Planets in Spin-Orbit Resonances

    Science.gov (United States)

    2012-06-10

    May 25 ABSTRACT The dynamical evolution of terrestrial planets resembling Mercury in the vicinity of spin-orbit resonances is investigated using... planet and assuming a zero obliquity. We find that a Mercury -like planet with a current value of orbital eccentricity (0.2056) is always captured in... Mercury rarely fails to align itself into this state of unstable equilibrium before it traverses 2:1 resonance. Key words: celestial mechanics – planets

  9. TRANSITING PLANETS WITH LSST. II. PERIOD DETECTION OF PLANETS ORBITING 1 M{sub ⊙} HOSTS

    Energy Technology Data Exchange (ETDEWEB)

    Jacklin, Savannah [Department of Astrophysics and Planetary Science, Villanova University, Villanova, PA 19085 (United States); Lund, Michael B.; Stassun, Keivan G. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Pepper, Joshua [Department of Physics, Lehigh University, Bethlehem, PA 18015 (United States)

    2015-07-15

    The Large Synoptic Survey Telescope (LSST) will photometrically monitor ∼10{sup 9} stars for 10 years. The resulting light curves can be used to detect transiting exoplanets. In particular, as demonstrated by Lund et al., LSST will probe stellar populations currently undersampled in most exoplanet transit surveys, including out to extragalactic distances. In this paper we test the efficiency of the box-fitting least-squares (BLS) algorithm for accurately recovering the periods of transiting exoplanets using simulated LSST data. We model planets with a range of radii orbiting a solar-mass star at a distance of 7 kpc, with orbital periods ranging from 0.5 to 20 days. We find that standard-cadence LSST observations will be able to reliably recover the periods of Hot Jupiters with periods shorter than ∼3 days; however, it will remain a challenge to confidently distinguish these transiting planets from false positives. At the same time, we find that the LSST deep-drilling cadence is extremely powerful: the BLS algorithm successfully recovers at least 30% of sub-Saturn-size exoplanets with orbital periods as long as 20 days, and a simple BLS power criterion robustly distinguishes ∼98% of these from photometric (i.e., statistical) false positives.

  10. HATNet Field G205: Follow-Up Observations of 28 Transiting-Planet candidates and Confirmation of the Planet HAT-P-8b

    CERN Document Server

    Latham, David W; Torres, Guillermo; Stefanik, Robert P; Noyes, Robert W; Kovács, Géza; Pál, András; Marcy, Geoffrey W; Fischer, Debra A; Butler, R Paul; Sip\\H{o)cz, Brigitta; Sasselov, Dimitar D; Esquerdo, Gilbert A; Vogt, Steven S; Hartman, Joel D; Kovács, Gábor; Lázár, József; Papp, István; Sári, Pál

    2008-01-01

    We report the identification of 32 transiting-planet candidates in HATNet field G205. We describe the procedures that we have used to follow up these candidates with spectroscopic and photometric observations, and we present a status report on our interpretation of the 28 candidates for which we have follow-up observations. Eight are eclipsing binaries with orbital solutions whose periods are consistent with their photometric ephemerides; two of these spectroscopic orbits are singled-lined and six are double-lined. For one of the candidates, a nearby but fainter eclipsing binary proved to be the source for the HATNet light curve, due to blending in the HATNet images. Four of the candidates were found to be rotating more rapidly than vsini = 50 km/s and were not pursued further. Thirteen of the candidates showed no significant velocity variation at the level of 0.5 to 1.0 km/s . Seven of these were eventually withdrawn as photometric false alarms based on an independent reanalysis using more sophisticated tool...

  11. A possible giant planet orbiting the cataclysmic variable LX Ser

    CERN Document Server

    Li, K; Zhou, J -L; Wu, D -H; Guo, D -F; Jiang, Y -G; Gao, D -Y; Chen, X; Wang, X -Y

    2016-01-01

    LX Ser is a deeply eclipsing cataclysmic variable with an orbital period of $0.^d 1584325$. Sixty two new eclipse times were determined by our observations and the AAVSO International Data base. Combining all available eclipse times, we analyzed the O-C behavior of LX Ser. We found that the O-C diagram of LX Ser shows a sinusoidal oscillation with a period of 22.8 yr and an amplitude of 0.00035 days. Two mechanisms (i.e., the Applegate mechanism and the light travel time effect) are applied to explain the cyclic modulation. We found that the Applegate mechanism is difficult to explain the cyclic oscillation in the orbital period. Therefore, the cyclic period change is most likely to be caused by the light travel time effect due to the presence of a third body. The mass of the tertiary component was determined to be $M_3\\sim7.5 M_{Jup}$. We supposed that the tertiary companion is plausible a giant planet. The stability of the giant planet was checked, and we found that the multiple system is stable.

  12. A possible giant planet orbiting the cataclysmic variable LX Ser

    Science.gov (United States)

    Li, Kai; Hu, Shaoming; Zhou, Jilin; Wu, Donghong; Guo, Difu; Jiang, Yunguo; Gao, Dongyang; Chen, Xu; Wang, Xianyu

    2017-02-01

    LX Ser is a deeply eclipsing cataclysmic variable with an orbital period of 0.1584325 d. 62 new eclipse times were determined by our observations and the AAVSO International Data base. Combining all available eclipse times, we analyzed the O - C behavior of LX Ser. We found that the O - C diagram of LX Ser shows a sinusoidal oscillation with a period of 22.8 yr and an amplitude of 0.00035 d. Two mechanisms (i.e., the Applegate mechanism and the light-travel time effect) are applied to explain the cyclic modulation. We found that it is difficult to apply the Applegate mechanism to explain the cyclic oscillation in the orbital period. Therefore, the cyclic period change is most likely to be caused by the light-travel time effect due to the presence of a third body. The mass of the tertiary component was determined to be M3 ∼ 7.5 MJup. We supposed that the tertiary companion is plausibly a giant planet. The stability of the giant planet was checked, and we found that the multiple system is stable.

  13. 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 D.; Chen, Ying-Tung; Delsanti, Audrey; Fraser, Wesley C.; Gladman, Brett J.; Granvik, Mikael; Grundy, Will M.; Guilbert-Lepoutre, Aurélie; Gwyn, Stephen D. J.; Ip, Wing-Huen; Jakubik, Marian; Jones, R. Lynne; Kaib, Nathan; Kavelaars, J. J.; Lacerda, Pedro; Lawler, Samantha; Lehner, Matthew J.; Lin, Hsing Wen; Lykawka, Patryk Sofia; Marsset, Michael; Murray-Clay, Ruth; Noll, Keith S.; Parker, Alex; Petit, Jean-Marc; Pike, Rosemary E.; Rousselot, Philippe; Schwamb, Megan E.; Shankman, Cory; Veres, Peter; Vernazza, Pierre; Volk, Kathryn; Wang, Shiang-Yu; Weryk, Robert

    2016-12-01

    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 {H}r=3.6+/- 0.1; for an assumed albedo of p V = 12%, the object has a diameter of ∼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) identified 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.

  14. OSSOS: IV. Discovery of a dwarf planet candidate in the 9:2 resonance

    CERN Document Server

    Bannister, Michele T; Benecchi, Susan D; Chen, Ying-Tung; Delsanti, Audrey; Fraser, Wesley C; Gladman, Brett J; Granvik, Mikael; Grundy, Will M; Guilbert-Lepoutre, Aurelie; Gwyn, Stephen D J; Ip, Wing-Huen; Jakubik, Marian; Jones, R Lynne; Kaib, Nathan; Kavelaars, J J; Lacerda, Pedro; Lawler, Samantha; Lehner, Matthew J; Lin, Hsing Wen; Lykawka, Patryk Sofia; Marsset, Michael; Murray-Clay, Ruth; Noll, Keith S; Parker, Alex; Petit, Jean-Marc; Pike, Rosemary E; Rousselot, Philippe; Schwamb, Megan E; Shankman, Cory; Veres, Peter; Vernazza, Pierre; Volk, Kathryn; Wang, Shiang-Yu; Weryk, Robert

    2016-01-01

    We report the discovery and orbit of a new dwarf planet candidate, 2015 RR$_{245}$, by the Outer Solar System Origins Survey (OSSOS). 2015 RR$_{245}$'s orbit is eccentric ($e=0.586$), with a semi-major axis near 82 au, yielding a perihelion distance of 34 au. 2015 RR$_{245}$ has $g-r = 0.59 \\pm 0.11$ and absolute magnitude $H_{r} = 3.6 \\pm 0.1$; for an assumed albedo of $p_V = 12$% the object has a diameter of $\\sim670$ km. Based on astrometric measurements from OSSOS and Pan-STARRS1, we find that 2015 RR$_{245}$ is securely trapped in the 9:2 mean-motion resonance with Neptune. It is the first TNO identified in this resonance. On hundred-Myr timescales, particles in 2015 RR$_{245}$-like orbits depart and sometimes return to the resonance, indicating that 2015 RR$_{245}$ 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 t...

  15. 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.

  16. The Weihai Observatory search for close-in planets orbiting giant stars

    CERN Document Server

    Wittenmyer, Robert A; Hu, Shao Ming; Villaver, Eva; Endl, Michael; Wright, Duncan

    2015-01-01

    Planets are known to orbit giant stars, yet there is a shortage of planets orbiting within ~0.5 AU (P<100 days). First-ascent giants have not expanded enough to engulf such planets, but tidal forces can bring planets to the surface of the star far beyond the stellar radius. So the question remains: are tidal forces strong enough in these stars to engulf all the missing planets? We describe a high-cadence observational program to obtain precise radial velocities of bright giants from Weihai Observatory of Shandong University. We present data on the planet host Beta Gem (HD 62509), confirming our ability to derive accurate and precise velocities; our data achieve an rms of 7.3 m/s about the Keplerian orbit fit. This planet-search programme currently receives ~100 nights per year, allowing us to aggressively pursue short-period planets to determine whether they are truly absent.

  17. YETI observations of the young transiting planet candidate CVSO 30 b

    CERN Document Server

    Raetz, St; Czesla, S; Klocová, T; Holmes, L; Errmann, R; Kitze, M; Fernández, M; Sota, A; Briceño, C; Hernández, J; Downes, J J; Dimitrov, D P; Kjurkchieva, D; Radeva, V; Wu, Z -Y; Zhou, X; Takahashi, H; Henych, T; Seeliger, M; Mugrauer, M; Adam, Ch; Marka, C; Schmidt, J G; Hohle, M M; Ginski, Ch; Pribulla, T; Trepl, L; Moualla, M; Pawellek, N; Gelszinnis, J; Buder, S; Masda, S; Maciejewski, G; Neuhäuser, R

    2016-01-01

    CVSO 30 is a unique young low-mass system, because, for the first time, a close-in transiting and a wide directly imaged planet candidates are found around a common host star. The inner companion, CVSO 30 b, is the first possible young transiting planet orbiting a previously known weak-lined T-Tauri star. With five telescopes of the 'Young Exoplanet Transit Initiative' (YETI) located in Asia, Europe and South America we monitored CVSO 30 over three years in a total of 144 nights and detected 33 fading events. In two more seasons we carried out follow-up observations with three telescopes. We can confirm that there is a change in the shape of the fading event between different observations and that the fading event even disappears and reappears. A total of 38 fading event light curves were simultaneously modelled. We derived the planetary, stellar, and geometrical properties of the system and found them slightly smaller but in agreement with the values from the discovery paper. The period of the fading event w...

  18. Fundamental Properties of Kepler Planet-candidate Host Stars using Asteroseismology

    NARCIS (Netherlands)

    Huber, D.; Chaplin, W.J.; Christensen-Dalsgaard, J.; Gilliland, R.L.; Kjeldsen, H.; Buchhave, L.A.; Fischer, D.A.; Lissauer, J.J.; Rowe, J.F.; Sanchis-Ojeda, R.; Basu, S.; Handberg, R.; Hekker, S.; Howard, A.W.; Isaacson, H.; Karoff, C.; Latham, D.W.; Lund, M.N.; Lundkvist, M.; Marcy, G.W.; Miglio, A.; Silva Aguirre, V.; Stello, D.; Arentoft, T.; Barclay, T.; Bedding, T.R.; Burke, C.J.; Christiansen, J.L.; Elsworth, Y.P.; Haas, M.R.; Kawaler, S.D.; Metcalfe, T.S.; Mullally, F.; Thompson, S.E.

    2013-01-01

    We have used asteroseismology to determine fundamental properties for 66 Kepler planet-candidate host stars, with typical uncertainties of 3% and 7% in radius and mass, respectively. The results include new asteroseismic solutions for four host stars with confirmed planets (Kepler-4, Kepler-14,

  19. Mapping Earth-analogs from Photometric Variability: Spin-Orbit Tomography for Planets in Inclined Orbits

    CERN Document Server

    Fujii, Yuka

    2012-01-01

    Aiming at obtaining detailed information of surface environment of Earth-analogs, Kawahara & Fujii 2011 proposed an inversion technique of annual scattered light curves named the spin-orbit tomography (SOT), which enables one to sketch a 2-dimensional albedo map from annual variation of the disk-integrated scattered light, and demonstrated the method with a planet in a face-on orbit. We extend it to be applicable to general geometric configurations, including low-obliquity planets like the Earth in inclined orbits. We simulate light curves of the Earth in an inclined orbit in three photometric bands (0.4-0.5um, 0.6-0.7um, and 0.8-0.9um) and show that the distribution of clouds, snow, and continents are retrieved with the aid of the SOT. We also demonstrate the SOT by applying it to an upright Earth, a tidally-locked Earth, and Earth-analogs with ancient continental configurations. The inversion is model-independent in the sense that we do not assume specific albedo models when mapping the surface, and hen...

  20. Color Difference Makes a Difference: Four Planet Candidates around τ Ceti

    Science.gov (United States)

    Feng, F.; Tuomi, M.; Jones, H. R. A.; Barnes, J.; Anglada-Escudé, G.; Vogt, S. S.; Butler, R. P.

    2017-10-01

    The removal of noise typically correlated in time and wavelength is one of the main challenges for using the radial-velocity (RV) method to detect Earth analogues. We analyze τ Ceti RV data and find robust evidence for wavelength-dependent noise. We find that this noise can be modeled by a combination of moving average models and the so-called “differential radial velocities.” We apply this noise model to various RV data sets for τ Ceti, and find four periodic signals at 20.0, 49.3, 160, and 642 days, which we interpret as planets. We identify two new signals with orbital periods of 20.0 and 49.3 days while the other two previously suspected signals around 160 and 600 days are quantified to a higher precision. The 20.0 days candidate is independently detected in Keck data. All planets detected in this work have minimum masses less than 4{M}\\oplus with the two long-period ones located around the inner and outer edges of the habitable zone, respectively. We find that the instrumental noise gives rise to a precision limit of the High Accuracy Radial Velocity Planet Searcher (HARPS) around 0.2 m s‑1. We also find correlation between the HARPS data and the central moments of the spectral line profile at around 0.5 m s‑1 level, although these central moments may contain both noise and signals. The signals detected in this work have semi-amplitudes as low as 0.3 m s‑1, demonstrating the ability of the RV technique to detect relatively weak signals.

  1. ARCHITECTURE AND DYNAMICS OF KEPLER'S CANDIDATE MULTIPLE TRANSITING PLANET SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Lissauer, Jack J.; Jenkins, Jon M.; Borucki, William J.; Bryson, Stephen T.; Howell, Steve B. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Ragozzine, Darin; Holman, Matthew J.; Carter, Joshua A. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Fabrycky, Daniel C.; Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Steffen, Jason H. [Fermilab Center for Particle Astrophysics, Batavia, IL 60510 (United States); Ford, Eric B. [211 Bryant Space Science Center, University of Florida, Gainesville, FL 32611 (United States); Shporer, Avi [Las Cumbres Observatory Global Telescope Network, Santa Barbara, CA 93117 (United States); Rowe, Jason F.; Quintana, Elisa V.; Caldwell, Douglas A. [SETI Institute/NASA Ames Research Center, Moffett Field, CA 94035 (United States); Batalha, Natalie M. [Department of Physics and Astronomy, San Jose State University, San Jose, CA 95192 (United States); Ciardi, David [Exoplanet Science Institute/Caltech, Pasadena, CA 91125 (United States); Dunham, Edward W. [Lowell Observatory, Flagstaff, AZ 86001 (United States); Gautier, Thomas N. III, E-mail: Jack.Lissauer@nasa.gov [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); and others

    2011-11-01

    About one-third of the {approx}1200 transiting planet candidates detected in the first four months of Kepler data are members of multiple candidate systems. There are 115 target stars with two candidate transiting planets, 45 with three, 8 with four, and 1 each with five and six. We characterize the dynamical properties of these candidate multi-planet systems. The distribution of observed period ratios shows that the vast majority of candidate pairs are neither in nor near low-order mean-motion resonances. Nonetheless, there are small but statistically significant excesses of candidate pairs both in resonance and spaced slightly too far apart to be in resonance, particularly near the 2:1 resonance. We find that virtually all candidate systems are stable, as tested by numerical integrations that assume a nominal mass-radius relationship. Several considerations strongly suggest that the vast majority of these multi-candidate systems are true planetary systems. Using the observed multiplicity frequencies, we find that a single population of planetary systems that matches the higher multiplicities underpredicts the number of singly transiting systems. We provide constraints on the true multiplicity and mutual inclination distribution of the multi-candidate systems, revealing a population of systems with multiple super-Earth-size and Neptune-size planets with low to moderate mutual inclinations.

  2. Observational constraints on the orbit and location of Planet Nine in the outer solar system

    CERN Document Server

    Brown, Michael E

    2016-01-01

    We use an extensive suite of numerical simulations to constrain the mass and orbit of Planet Nine, the recently proposed perturber in a distant eccentric orbit in the outer solar system. We compare our simulations to the observed population of aligned eccentric high semimajor axis Kuiper belt objects and determine which simulation parameters are statistically compatible with the observations. We find that only a narrow range of orbital elements can reproduce the observations. In particular, the combination of semimajor axis, eccentricity, and mass of Planet Nine strongly dictates the semimajor axis range of the orbital confinement of the distant eccentric Kuiper belt objects. Allowed orbits, which confine Kuiper belt objects with semimajor axis beyond 230 AU, have perihelia roughly between 200 and 350 AU, semimajor axes between 300 and 900 AU, and masses of approximately 10 Earth masses. Orbitally confined objects also generally have orbital planes similar to that of the planet, suggesting that the planet is ...

  3. Transiting Planets with LSST II. Period Detection of Planets Orbiting 1 Solar Mass Hosts

    CERN Document Server

    Jacklin, Savannah R; Pepper, Joshua; Stassun, Keivan G

    2015-01-01

    The Large Synoptic Survey Telescope (LSST) will photometrically monitor ~1 billion stars for ten years. The resulting light curves can be used to detect transiting exoplanets. In particular, as demonstrated by Lund et al. (2015), LSST will probe stellar populations currently undersampled in most exoplanet transit surveys, including out to extragalactic distances. In this paper we test the efficiency of the box-fitting least-squares (BLS) algorithm for accurately recovering the periods of transiting exoplanets using simulated LSST data. We model planets with a range of radii orbiting a solar-mass star at a distance of 7 kpc, with orbital periods ranging from 0.5 to 20 d. We find that typical LSST observations will be able to reliably detect Hot Jupiters with periods shorter than ~3 d. At the same time, we find that the LSST deep drilling cadence is extremely powerful: the BLS algorithm successfully recovers at least 30% of sub-Saturn-size exoplanets with orbital periods as long as 20 d.

  4. A giant planet orbiting the 'extreme horizontal branch' star V 391 Pegasi.

    Science.gov (United States)

    Silvotti, R; Schuh, S; Janulis, R; Solheim, J-E; Bernabei, S; Østensen, R; Oswalt, T D; Bruni, I; Gualandi, R; Bonanno, A; Vauclair, G; Reed, M; Chen, C-W; Leibowitz, E; Paparo, M; Baran, A; Charpinet, S; Dolez, N; Kawaler, S; Kurtz, D; Moskalik, P; Riddle, R; Zola, S

    2007-09-13

    After the initial discoveries fifteen years ago, over 200 extrasolar planets have now been detected. Most of them orbit main-sequence stars similar to our Sun, although a few planets orbiting red giant stars have been recently found. When the hydrogen in their cores runs out, main-sequence stars undergo an expansion into red-giant stars. This expansion can modify the orbits of planets and can easily reach and engulf the inner planets. The same will happen to the planets of our Solar System in about five billion years and the fate of the Earth is matter of debate. Here we report the discovery of a planetary-mass body (Msini = 3.2M(Jupiter)) orbiting the star V 391 Pegasi at a distance of about 1.7 astronomical units (au), with a period of 3.2 years. This star is on the extreme horizontal branch of the Hertzsprung-Russell diagram, burning helium in its core and pulsating. The maximum radius of the red-giant precursor of V 391 Pegasi may have reached 0.7 au, while the orbital distance of the planet during the stellar main-sequence phase is estimated to be about 1 au. This detection of a planet orbiting a post-red-giant star demonstrates that planets with orbital distances of less than 2 au can survive the red-giant expansion of their parent stars.

  5. Transit Timing Observations from Kepler: VII. Confirmation of 27 planets in 13 multiplanet systems via Transit Timing Variations and orbital stability

    CERN Document Server

    Steffen, Jason H; Agol, Eric; Ford, Eric B; Morehead, Robert C; Cochran, William D; Lissauer, Jack J; Adams, Elisabeth R; Borucki, William J; Bryson, Steve; Caldwell, Douglas A; Dupree, Andrea; Jenkins, Jon M; Robertson, Paul; Rowe, Jason F; Seader, Shawn; Thompson, Susan; Twicken, Joseph D

    2012-01-01

    We confirm 27 planets in 13 planetary systems by showing the existence of statistically significant anti-correlated transit timing variations (TTVs), which demonstrates that the planet candidates are in the same system, and long-term dynamical stability, which places limits on the masses of the candidates---showing that they are planetary. %This overall method of planet confirmation was first applied to \\kepler systems 23 through 32. All of these newly confirmed planetary systems have orbital periods that place them near first-order mean motion resonances (MMRs), including 6 systems near the 2:1 MMR, 5 near 3:2, and one each near 4:3, 5:4, and 6:5. In addition, several unconfirmed planet candidates exist in some systems (that cannot be confirmed with this method at this time). A few of these candidates would also be near first order MMRs with either the confirmed planets or with other candidates. One system of particular interest, Kepler-56 (KOI-1241), is a pair of planets orbiting a 12th magnitude, giant sta...

  6. Planets in Spin-Orbit Misalignment and the Search for Stellar Companions

    CERN Document Server

    Addison, Brett C; Wright, Duncan J; Salter, Graeme; Bayliss, Daniel; Zhou, George

    2014-01-01

    The discovery of giant planets orbiting close to their host stars was one of the most unexpected results of early exoplanetary science. Astronomers have since found that a significant fraction of these 'Hot Jupiters' move on orbits substantially misaligned with the rotation axis of their host star. We recently reported the measurement of the spin-orbit misalignment for WASP-79b by using data from the 3.9 m Anglo-Australian Telescope. Contemporary models of planetary formation produce planets on nearly coplanar orbits with respect to their host star's equator. We discuss the mechanisms which could drive planets into spin-orbit misalignment. The most commonly proposed being the Kozai mechanism, which requires the presence of a distant, massive companion to the star-planet system. We therefore describe a volume-limited direct-imaging survey of Hot Jupiter systems with measured spin-orbit angles, to search for the presence of stellar companions and test the Kozai hypothesis.

  7. Exploring the Planet Mercury: One Year of MESSENGER Orbital Observations

    Science.gov (United States)

    Solomon, Sean C.

    2012-05-01

    Launched in 2004, MESSENGER flew by Mercury three times in 2008-2009 en route to becoming the first spacecraft to orbit the solar system’s innermost planet in March 2011. MESSENGER’s chemical remote sensing measurements of Mercury’s surface indicate that the planet’s bulk silicate fraction, low in Fe and high in Mg, differs from those of the other inner planets. Moreover, surface materials are richer in the moderately volatile constituents S and K than predicted by most current models for inner planet formation. Global image mosaics and targeted high-resolution images reveal that Mercury experienced globally extensive volcanism, including large expanses of plains emplaced as flood lavas and widespread examples of pyroclastic deposits likely emplaced during explosive eruptions of volatile-bearing magmas. Bright deposits within impact craters host fresh-appearing, rimless depressions or hollows, often with high-reflectance interiors and halos and likely formed through processes involving the geologically recent loss of volatiles. The large-scale deformational history of Mercury, although dominated by near-global contractional deformation as first seen by Mariner 10, is more complex than first appreciated, with numerous examples of extensional deformation that accompanied impact crater and basin modification. Mercury’s magnetic field is dominantly dipolar, but the field is axially symmetric and equatorially asymmetric, a geometry that poses challenges to dynamo models for field generation. The interaction between the solar wind and Mercury’s magnetosphere, among the most dynamic in the solar system, serves both to replenish the exosphere and space weather the planet’s surface. Plasma ions of planetary origin are seen throughout the sampled volume of Mercury’s magnetosphere, with maxima in heavy-ion fluxes in the planet’s magnetic-cusp regions. Bursts of energetic electrons, seen at most local times, point to an efficient acceleration mechanism

  8. Disruption of planetary orbits through evection resonance with an external companion: circumbinary planets and multiplanet systems

    Science.gov (United States)

    Xu, Wenrui; Lai, Dong

    2016-07-01

    Planets around binary stars and those in multiplanet systems may experience resonant eccentricity excitation and disruption due to perturbations from a distant stellar companion. This `evection resonance' occurs when the apsidal precession frequency of the planet, driven by the quadrupole associated with the inner binary or the other planets, matches the orbital frequency of the external companion. We develop an analytic theory to study the effects of evection resonance on circumbinary planets and multiplanet systems. We derive the general conditions for effective eccentricity excitation or resonance capture of the planet as the system undergoes long-term evolution. Applying to circumbinary planets, we show that inward planet migration may lead to eccentricity growth due to evection resonance with an external perturber, and planets around shrinking binaries may not survive the resonant eccentricity growth. On the other hand, significant eccentricity excitation in multiplanet systems occurs in limited parameter space of planet and binary semimajor axes, and requires the planetary migration to be sufficiently slow.

  9. A planet in a polar orbit of 1.4 solar-mass star

    Directory of Open Access Journals (Sweden)

    Guenther E.W.

    2015-01-01

    Full Text Available Although more than a thousand transiting extrasolar planets have been discovered, only very few of them orbit stars that are more massive than the Sun. The discovery of such planets is interesting, because they have formed in disks that are more massive but had a shorter life time than those of solar-like stars. Studies of planets more massive than the Sun thus tell us how the properties of the proto-planetary disks effect the formation of planets. Another aspect that makes these planets interesting is that they have kept their original orbital inclinations. By studying them we can thus find out whether the orbital axes planets are initially aligned to the stars rotational axes, or not. Here we report on the discovery of a planet of a 1.4 solar-mass star with a period of 5.6 days in a polar orbit made by CoRoT. This new planet thus is one of the few known close-in planets orbiting a star that is substantially more massive than the Sun.

  10. M2K. II. A TRIPLE-PLANET SYSTEM ORBITING HIP 57274

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Debra A.; Giguere, Matthew J.; Moriarty, John; Brewer, John; Spronck, Julien F. P.; Schwab, Christian; Szymkowiak, Andrew [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Gaidos, Eric [Department of Geology and Geophysics, University of Hawaii, Honolulu, HI 96822 (United States); Howard, Andrew W.; Marcy, Geoffrey W. [Department of Astronomy, University of California at Berkeley, Berkeley, CA 94720 (United States); Johnson, John A. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Wright, Jason T. [Center for Exoplanets and Habitable Worlds, 525 Davey Lab, The Pennsylvania State University, University Park, PA 16803 (United States); Valenti, Jeff A. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Piskunov, Nikolai [Department of Astronomy and Space Physics, Uppsala University, Box 515, 751 20 Uppsala (Sweden); Clubb, Kelsey I.; Isaacson, Howard [Pufendorf Institute for Advanced Studies, Lund University, Lund (Sweden); Apps, Kevin [75B Cheyne Walk, Surrey RH6 7LR (United Kingdom); Lepine, Sebastien [American Museum of Natural History, New York, NY 10023 (United States); Mann, Andrew, E-mail: debra.fischer@yale.edu [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States)

    2012-01-20

    Doppler observations from Keck Observatory have revealed a triple-planet system orbiting the nearby K4V star, HIP 57274. The inner planet, HIP 57274b, is a super-Earth with Msin i = 11.6 M{sub Circled-Plus} (0.036 M{sub Jup}), an orbital period of 8.135 {+-} 0.004 days, and slightly eccentric orbit e = 0.19 {+-} 0.1. We calculate a transit probability of 6.5% for the inner planet. The second planet has Msin i = 0.4 M{sub Jup} with an orbital period of 32.0 {+-} 0.02 days in a nearly circular orbit (e = 0.05 {+-} 0.03). The third planet has Msin i = 0.53 M{sub Jup} with an orbital period of 432 {+-} 8 days (1.18 years) and an eccentricity e = 0.23 {+-} 0.03. This discovery adds to the number of super-Earth mass planets with M sin i < 12 M{sub Circled-Plus} that have been detected with Doppler surveys. We find that 56% {+-} 18% of super-Earths are members of multi-planet systems. This is certainly a lower limit because of observational detectability limits, yet significantly higher than the fraction of Jupiter mass exoplanets, 20% {+-} 8%, that are members of Doppler-detected, multi-planet systems.

  11. Prevalence of Earth-size Planets Orbiting Sun-like Stars

    Science.gov (United States)

    Petigura, Erik Ardeshir

    2015-04-01

    In this thesis, I explore two topics in exoplanet science. The first is the prevalence of Earth-size planets in the Milky Way Galaxy. To determine the occurrence of planets having different sizes, orbital periods, and other properties, I conducted a survey of extrasolar planets using data collected by NASA's Kepler Space Telescope. This project involved writing new algorithms to analyze Kepler data, finding planets, and conducting follow-up work using ground-based telescopes. I found that most stars have at least one planet at or within Earth's orbit and that 26% of Sun-like stars have an Earth-size planet with an orbital period of 100 days or less. The second topic is the connection between the properties of planets and their host stars. The precise characterization of exoplanet hosts helps to bring planet properties like mass, size, and equilibrium temperature into sharper focus and probes the physical processes that form planets. I studied the abundance of carbon and oxygen in over 1000 nearby stars using optical spectra taken by the California Planet Search. I found a large range in the relative abundance of carbon and oxygen in this sample, including a handful of carbon-rich stars. I also developed a new technique called SpecMatch for extracting fundamental stellar parameters from optical spectra. SpecMatch is particularly applicable to the relatively faint planet-hosting stars discovered by Kepler.

  12. On Orbital Elements of Extrasolar Planetary Candidates and Spectroscopic Binaries

    Science.gov (United States)

    Stepinski, T. F.; Black, D. C.

    2001-01-01

    We estimate probability densities of orbital elements, periods, and eccentricities, for the population of extrasolar planetary candidates (EPC) and, separately, for the population of spectroscopic binaries (SB) with solar-type primaries. We construct empirical cumulative distribution functions (CDFs) in order to infer probability distribution functions (PDFs) for orbital periods and eccentricities. We also derive a joint probability density for period-eccentricity pairs in each population. Comparison of respective distributions reveals that in all cases EPC and SB populations are, in the context of orbital elements, indistinguishable from each other to a high degree of statistical significance. Probability densities of orbital periods in both populations have P(exp -1) functional form, whereas the PDFs of eccentricities can he best characterized as a Gaussian with a mean of about 0.35 and standard deviation of about 0.2 turning into a flat distribution at small values of eccentricity. These remarkable similarities between EPC and SB must be taken into account by theories aimed at explaining the origin of extrasolar planetary candidates, and constitute an important clue us to their ultimate nature.

  13. Search for circum-planetary material and orbital period variations of short-period Kepler exoplanet candidates

    Science.gov (United States)

    Garai, Z.; Zhou, G.; Budaj, J.; Stellingwerf, R. F.

    2014-12-01

    A unique short-period ({P = 0.65356(1)} d) Mercury-size Kepler exoplanet candidate KIC012557548b has been discovered recently by {Rappaport et al. (2012)}. This object is a transiting disintegrating exoplanet with a circum-planetary material-comet-like tail. Close-in exoplanets, like KIC012557548b, are subjected to the greatest planet-star interactions. This interaction may have various forms. In certain cases it may cause formation of the comet-like tail. Strong interaction with the host star, and/or presence of an additional planet may lead to variations in the orbital period of the planet. Our main aim is to search for comet-like tails similar to KIC012557548b and for long-term orbital period variations. We are curious about frequency of comet-like tail formation among short-period Kepler exoplanet candidates. We concentrate on a sample of 20 close-in candidates with a period similar to KIC012557548b from the Kepler mission. We first improved the preliminary orbital periods and obtained the transit light curves. Subsequently we searched for the signatures of a circum-planetary material in these light curves. For this purpose the final transit light curve of each planet was fitted with a theoretical light curve, and the residuals were examined for abnormalities. We then searched for possible long-term changes of the orbital periods using the method of phase dispersion minimization. In 8 cases out of 20 we found some interesting peculiarities, but none of the exoplanet candidates showed signs of a comet-like tail. It seems that the frequency of comet-like tail formation among short-period Kepler exoplanet candidates is very low. We searched for comet-like tails based on the period criterion. Based on our results we can conclude that the short-period criterion is not enough to cause comet-like tail formation. This result is in agreement with the theory of the thermal wind and planet evaporation (Perez-Becker & Chiang 2013). We also found 3 cases of candidates which

  14. LGS-AO Imaging of Every Kepler Planet Candidate: the Robo-AO KOI Survey

    Science.gov (United States)

    Baranec, Christoph; Law, Nicholas; Morton, Timothy; Ziegler, Carl; Nofi, Larissa; Atkinson, Dani; Riddle, Reed

    2015-12-01

    The Robo-AO Kepler Planetary Candidate Survey is observing every Kepler planet candidate host star with laser adaptive optics imaging, to search for blended nearby stars which may be physically associated companions and/or responsible for transit false positives. We will present the results from searching for companions around over 3,000 Kepler planet hosts in 2012-2015. We will describe our first data release covering 715 planet candidate hosts, and give a preview of ongoing results including improved statistics on the likelihood of false positive planet detections in the Kepler dataset, many new planets in multiple star systems, and new exotic multiple star systems containing Kepler planets. We will also describe the automated Robo-AO survey data reduction methods, including a method of using the large ensemble of target observations as mutual point-spread-function references, along with a new automated companion-detection algorithm designed for extremely large adaptive optics surveys. Our first data release covered 715 objects, searching for companions from 0.15” to 2.5” separation with contrast up to 6 magnitudes. We measured the overall nearby-star-probability for Kepler planet candidates to be 7.4+/-1.0%, and we will detail the variations in this number with stellar host parameters. We will also discuss plans to extend the survey to other transiting planet missions such as K2 and TESS as Robo-AO is in the process of being re-deployed to the 2.1-m telescope at Kitt Peak for 3 years and a higher-contrast Robo-AO system is being developed for the 2.2-m UH telescope on Maunakea.

  15. Disruption of Planetary Orbits Through Evection Resonance with an External Companion: Circumbinary Planets and Multiplanet Systems

    CERN Document Server

    Xu, Wenrui

    2016-01-01

    Planets around binary stars and those in multiplanet systems may experience resonant eccentricity excitation and disruption due to perturbations from a distant stellar companion. This "evection resonance" occurs when the apsidal precession frequency of the planet, driven by the quadrupole associated with the inner binary or the other planets, matches the orbital frequency of the external companion. We develop an analytic theory to study the effects of evection resonance on circumbinary planets and multiplanet systems. We derive the general conditions for effective eccentricity excitation or resonance capture of the planet as the system undergoes long-term evolution. Applying to circumbinary planets, we show that inward planet migration may lead to eccentricity growth due to evection resonance with an external perturber, and planets around shrinking binaries may not survive the resonant eccentricity growth. On the other hand, significant eccentricity excitation in multiplanet systems occurs in limited paramete...

  16. The formation of giant planets in wide orbits by photoevaporation-synchronized migration

    Science.gov (United States)

    Guilera, O. M.; Miller Bertolami, M. M.; Ronco, M. P.

    2017-10-01

    The discovery of giant planets in wide orbits represents a major challenge for planet formation theory. In the standard core accretion paradigm, planets are expected to form at radial distances ≲20 au in order to form massive cores (with masses ≳10 M⊕) able to trigger the gaseous runaway growth before the dissipation of the disc. This has encouraged authors to find modifications of the standard scenario as well as alternative theories like the formation of planets by gravitational instabilities in the disc to explain the existence of giant planets in wide orbits. However, there is not yet consensus on how these systems are formed. In this Letter, we present a new natural mechanism for the formation of giant planets in wide orbits within the core accretion paradigm. If photoevaporation is considered, after a few Myr of viscous evolution a gap in the gaseous disc is opened. We found that, under particular circumstances planet migration becomes synchronized with the evolution of the gap, which results in an efficient outward planet migration. This mechanism is found to allow the formation of giant planets with masses Mp ≲ 1MJup in wide stable orbits as large as ˜130 au from the central star.

  17. Planetary Candidates Observed by Kepler IV: Planet Sample From Q1-Q8 (22 Months)

    CERN Document Server

    Burke, Christopher J; Mullally, F; Rowe, Jason F; Christiansen, Jessie L; Thompson, Susan E; Coughlin, Jeffrey L; Haas, Michael R; Batalha, Natalie M; Caldwell, Douglas A; Jenkins, Jon M; Still, Martin; Barclay, Thomas; Borucki, William J; Chaplin, William J; Ciardi, David R; Clarke, Bruce D; Cochran, William D; Demory, Brice-Olivier; Esquerdo, Gilbert A; Gautier, Thomas N; Gilliland, Ronald L; Girouard, Forrest R; Havel, Mathieu; Henze, Christopher E; Howell, Steve B; Huber, Daniel; Latham, David W; Li, Jie; Morehead, Robert C; Morton, Timothy D; Pepper, Joshua; Quintana, Elisa; Ragozzine, Darin; Seader, Shawn E; Shah, Yash; Shporer, Avi; Tenenbaum, Peter; Twicken, Joseph D; Wolfgang, Angie

    2013-01-01

    We provide updates to the Kepler planet candidate sample based upon nearly two years of high-precision photometry (i.e., Q1-Q8). From an initial list of nearly 13,400 Threshold Crossing Events (TCEs), 480 new host stars are identified from their flux time series as consistent with hosting transiting planets. Potential transit signals are subjected to further analysis using the pixel-level data, which allows background eclipsing binaries to be identified through small image position shifts during transit. We also re-evaluate Kepler Objects of Interest (KOI) 1-1609, which were identified early in the mission, using substantially more data to test for background false positives and to find additional multiple systems. Combining the new and previous KOI samples, we provide updated parameters for 2,738 Kepler planet candidates distributed across 2,017 host stars. From the combined Kepler planet candidates, 472 are new from the Q1-Q8 data examined in this study. The new Kepler planet candidates represent ~40% of th...

  18. Masses, Radii, and Orbits of Small Kepler Planets: The Transition from Gaseous to Rocky Planets

    DEFF Research Database (Denmark)

    Marcy, Geoffrey W.; Isaacson, Howard; Howard, Andrew W.

    2014-01-01

    a rocky composition. We identify six planets with densities above 5 g cm–3, suggesting a mostly rocky interior for them. Indeed, the only planets that are compatible with a purely rocky composition are smaller than ~2 R ⊕. Larger planets evidently contain a larger fraction of low-density material (H, He...

  19. THE HABITABILITY AND DETECTION OF EARTH-LIKE PLANETS ORBITING COOL WHITE DWARFS

    Energy Technology Data Exchange (ETDEWEB)

    Fossati, L.; Haswell, C. A.; Patel, M. R.; Busuttil, R. [Department of Physical Sciences, Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Bagnulo, S. [Armagh Observatory, College Hill, Armagh BT61 9DG (United Kingdom); Kowalski, P. M. [GFZ German Research Centre for Geosciences, Telegrafenberg, D-14473 Potsdam (Germany); Shulyak, D. V. [Institute of Astrophysics, Georg-August-University, Friedrich-Hund-Platz 1, D-37077 Goettingen (Germany); Sterzik, M. F., E-mail: l.fossati@open.ac.uk, E-mail: C.A.Haswell@open.ac.uk, E-mail: M.R.Patel@open.ac.uk, E-mail: r.busuttil@open.ac.uk, E-mail: sba@arm.ac.uk, E-mail: kowalski@gfz-potsdam.de, E-mail: denis.shulyak@gmail.com, E-mail: msterzik@eso.org [European Southern Observatory, Casilla 19001, Santiago 19 (Chile)

    2012-09-20

    Since there are several ways planets can survive the giant phase of the host star, we examine the habitability and detection of planets orbiting white dwarfs. As a white dwarf cools from 6000 K to 4000 K, a planet orbiting at 0.01 AU would remain in the continuous habitable zone (CHZ) for {approx}8 Gyr. We show that photosynthetic processes can be sustained on such planets. The DNA-weighted UV radiation dose for an Earth-like planet in the CHZ is less than the maxima encountered on Earth, and hence non-magnetic white dwarfs are compatible with the persistence of complex life. Polarization due to a terrestrial planet in the CHZ of a cool white dwarf (CWD) is 10{sup 2} (10{sup 4}) times larger than it would be in the habitable zone of a typical M-dwarf (Sun-like star). Polarimetry is thus a viable way to detect close-in rocky planets around white dwarfs. Multi-band polarimetry would also allow us to reveal the presence of a planet atmosphere, providing a first characterization. Planets in the CHZ of a 0.6 M{sub Sun} white dwarf will be distorted by Roche geometry, and a Kepler-11d analog would overfill its Roche lobe. With current facilities a super-Earth-sized atmosphereless planet is detectable with polarimetry around the brightest known CWD. Planned future facilities render smaller planets detectable, in particular by increasing the instrumental sensitivity in the blue.

  20. Finding Mars-Sized Planets in Inner Orbits of Other Stars by Photometry

    Science.gov (United States)

    Borucki, W.; Cullers, K.; Dunham, E.; Koch, D.; Mena-Werth, J.; Cuzzi, Jeffrey N. (Technical Monitor)

    1995-01-01

    High precision photometry from a spaceborne telescope has the potential of discovering sub-earth sized inner planets. Model calculations by Wetherill indicate that Mars-sized planets can be expected to form throughout the range of orbits from that of Mercury to Mars. While a transit of an Earth-sized planet causes a 0.084% decrease in brightness from a solar-like star, a transit of a planet as small as Mars causes a flux decrease of only 0.023%. Stellar variability will be the limiting factor for transit measurements. Recent analysis of solar variability from the SOLSTICE experiment shows that much of the variability is in the UV at planet as small as Mars should be reliably detectable. If Wetherill's models are correct in postulating that Mars-like planets are present in Mercury-like orbits, then a six year search should be able to find them.

  1. High-resolution imaging of $Kepler$ planet host candidates. A comprehensive comparison of different techniques

    CERN Document Server

    Lillo-Box, J; Bouy, H

    2014-01-01

    The Kepler mission has discovered thousands of planet candidates. Currently, some of them have already been discarded; more than 200 have been confirmed by follow-up observations, and several hundreds have been validated. However, most of them are still awaiting for confirmation. Thus, priorities (in terms of the probability of the candidate being a real planet) must be established for subsequent observations. The motivation of this work is to provide a set of isolated (good) host candidates to be further tested by other techniques. We identify close companions of the candidates that could have contaminated the light curve of the planet host. We used the AstraLux North instrument located at the 2.2 m telescope in the Calar Alto Observatory to obtain diffraction-limited images of 174 Kepler objects of interest. The lucky-imaging technique used in this work is compared to other AO and speckle imaging observations of Kepler planet host candidates. We define a new parameter, the blended source confidence level (B...

  2. Masses, Radii, and Orbits of Small Kepler Planets: The Transition from Gaseous to Rocky Planets

    DEFF Research Database (Denmark)

    Marcy, Geoffrey W.; Isaacson, Howard; Howard, Andrew W.

    2014-01-01

    a rocky composition. We identify six planets with densities above 5 g cm–3, suggesting a mostly rocky interior for them. Indeed, the only planets that are compatible with a purely rocky composition are smaller than ~2 R ⊕. Larger planets evidently contain a larger fraction of low-density material (H, He......, along with high-resolution imaging and spectroscopy, Doppler spectroscopy, and (for 11 stars) asteroseismology, we establish low false-positive probabilities (FPPs) for all of the transiting planets (41 of 42 have an FPP under 1%), and we constrain their sizes and masses. Most of the transiting planets...

  3. SOPHIE velocimetry of Kepler transit candidates. XV. KOI-614b, KOI-206b, and KOI-680b: a massive warm Jupiter orbiting a G0 metallic dwarf and two highly inflated planets with a distant companion around evolved F-type stars

    Science.gov (United States)

    Almenara, J. M.; Damiani, C.; Bouchy, F.; Havel, M.; Bruno, G.; Hébrard, G.; Diaz, R. F.; Deleuil, M.; Barros, S. C. C.; Boisse, I.; Bonomo, A. S.; Montagnier, G.; Santerne, A.

    2015-03-01

    We report the validation and characterization of three new transiting exoplanets using SOPHIE radial velocities: KOI-614b, KOI-206b, and KOI-680b. KOI-614b has a mass of 2.86 ± 0.35 MJup and a radius of 1.13 +0.26-0.18 RJup, and it orbits a G0, metallic ([ Fe/H ] = 0.35 ± 0.15) dwarf in 12.9 days. Its mass and radius are familiar and compatible with standard planetary evolution models, so it is one of the few known transiting planets in this mass range to have an orbital period over ten days. With an equilibrium temperature of Teq = 1000 ± 45 K, this places KOI-614b at the transition between what is usually referred to as "hot" and "warm" Jupiters. KOI-206b has a mass of 2.82 ± 0.52 MJup and a radius of 1.45 ± 0.16 RJup, and it orbits a slightly evolved F7-type star in a 5.3-day orbit. It is a massive inflated hot Jupiter that is particularly challenging for planetary models because it requires unusually large amounts of additional dissipated energy in the planet. On the other hand, KOI-680b has a much lower mass of 0.84 ± 0.15 MJup and requires less extra-dissipation to explain its uncommonly large radius of 1.99 ± 0.18 RJup. It is one of the biggest transiting planets characterized so far, and it orbits a subgiant F9-star well on its way to the red giant stage, with an orbital period of 8.6 days. With host stars of masses of 1.46 ± 0.17 M⊙ and 1.54 ± 0.09 M⊙, respectively, KOI-206b, and KOI-680b are interesting objects for theories of formation and survival of short-period planets around stars more massive than the Sun. For those two targets, we also find signs of a possible distant additional companion in the system. Based on observations made with SOPHIE on the 1.93-m telescope at the Observatoire de Haute-Provence (CNRS), France.Figures 11-14 are available in electronic form at http://www.aanda.org

  4. The Equation Based on the Rotational and Orbital Motion of the Planets

    Directory of Open Access Journals (Sweden)

    G.A. Korablev

    2017-03-01

    Full Text Available Equations of dependence of rotational and orbital motions of planets are given, their rotation angles are calculated. Wave principles of direct and reverse rotation of planets are established. The established dependencies are demonstrated at different scale levels of structural interactions, in biosystems as well. The accuracy of calculations corresponds to the accuracy of experimental data.

  5. Prevalence of Earth-size Planets Orbiting Sun-like Stars

    CERN Document Server

    Petigura, Erik Ardeshir

    2015-01-01

    In this thesis, I explore two topics in exoplanet science. The first is the prevalence of Earth-size planets in the Milky Way Galaxy. To determine the occurrence of planets having different sizes, orbital periods, and other properties, I conducted a survey of extrasolar planets using data collected by NASA's Kepler Space Telescope. This project involved writing new algorithms to analyze Kepler data, finding planets, and conducting follow-up work using ground-based telescopes. I found that most stars have at least one planet at or within Earth's orbit and that 26% of Sun-like stars have an Earth-size planet with an orbital period of 100 days or less. The second topic is the connection between the properties of planets and their host stars. The precise characterization of exoplanet hosts helps to bring planet properties like mass, size, and equilibrium temperature into sharper focus and probes the physical processes that form planets. I studied the abundance of carbon and oxygen in over 1000 nearby stars using ...

  6. Two Transiting Earth-size Planets Near Resonance Orbiting a Nearby Cool Star

    CERN Document Server

    Petigura, Erik A; Crossfield, Ian J M; Howard, Andrew W; Deck, Katherine M; Ciardi, David R; Sinukoff, Evan; Allers, Katelyn N; Best, William M J; Liu, Michael C; Beichman, Charles A; Isaacson, Howard; Hansen, Brad M S; Lépine, Sébastien

    2015-01-01

    Discoveries from the prime Kepler mission demonstrated that small planets (< 3 Earth-radii) are common outcomes of planet formation. While Kepler detected many such planets, all but a handful orbit faint, distant stars and are not amenable to precise follow up measurements. Here, we report the discovery of two small planets transiting EPIC-206011691, a bright (K = 9.4) M0 dwarf located 65$\\pm$6 pc from Earth. We detected the transiting planets in photometry collected during Campaign 3 of NASA's K2 mission. Analysis of transit light curves reveals that the planets have small radii compared to their host star, 2.60 $\\pm$ 0.14% and 3.15 $\\pm$ 0.20%, respectively. We obtained follow up NIR spectroscopy of \\epic to constrain host star properties, which imply planet sizes of 1.59 $\\pm$ 0.43 Earth-radii and 1.92 $\\pm$ 0.53 Earth-radii, respectively, straddling the boundary between high-density, rocky planets and low-density planets with thick gaseous envelopes. The planets have orbital periods of 9.32414 days and...

  7. Fundamental Properties of Kepler Planet-Candidate Host Stars using Asteroseismology

    CERN Document Server

    Huber, Daniel; Christensen-Dalsgaard, Jørgen; Gilliland, Ronald L; Kjeldsen, Hans; Buchhave, Lars A; Fischer, Debra A; Lissauer, Jack J; Rowe, Jason F; Sanchis-Ojeda, Roberto; Basu, Sarbani; Handberg, Rasmus; Hekker, Saskia; Howard, Andrew W; Isaacson, Howard; Karoff, Christoffer; Latham, David W; Lund, Mikkel N; Lundkvist, Mia; Marcy, Geoffrey W; Miglio, Andrea; Aguirre, Victor Silva; Stello, Dennis; Arentoft, Torben; Barclay, Thomas; Bedding, Timothy R; Burke, Christopher J; Christiansen, Jessie L; Elsworth, Yvonne P; Haas, Michael R; Kawaler, Steven D; Metcalfe, Travis S; Mullally, Fergal; Thompson, Susan E

    2013-01-01

    We have used asteroseismology to determine fundamental properties for 66 Kepler planet-candidate host stars, with typical uncertainties of 3% and 7% in radius and mass, respectively. The results include new asteroseismic solutions for four host stars with confirmed planets (Kepler-4, Kepler-14, Kepler-23 and Kepler-25) and increase the total number of Kepler host stars with asteroseismic solutions to 77. A comparison with stellar properties in the planet-candidate catalog by Batalha et al. shows that radii for subgiants and giants obtained from spectroscopic follow-up are systematically too low by up to a factor of 1.5, while the properties for unevolved stars are in good agreement. We furthermore apply asteroseismology to confirm that a large majority of cool main-sequence hosts are indeed dwarfs and not misclassified giants. Using the revised stellar properties, we recalculate the radii for 107 planet candidates in our sample, and comment on candidates for which the radii change from a previously giant-plan...

  8. Habitability of planets on eccentric orbits: Limits of the mean flux approximation

    Science.gov (United States)

    Bolmont, Emeline; Libert, Anne-Sophie; Leconte, Jeremy; Selsis, Franck

    2016-06-01

    Unlike the Earth, which has a small orbital eccentricity, some exoplanets discovered in the insolation habitable zone (HZ) have high orbital eccentricities (e.g., up to an eccentricity of ~0.97 for HD 20782 b). This raises the question of whether these planets have surface conditions favorable to liquid water. In order to assess the habitability of an eccentric planet, the mean flux approximation is often used. It states that a planet on an eccentric orbit is called habitable if it receives on average a flux compatible with the presence of surface liquid water. However, because the planets experience important insolation variations over one orbit and even spend some time outside the HZ for high eccentricities, the question of their habitability might not be as straightforward. We performed a set of simulations using the global climate model LMDZ to explore the limits of the mean flux approximation when varying the luminosity of the host star and the eccentricity of the planet. We computed the climate of tidally locked ocean covered planets with orbital eccentricity from 0 to 0.9 receiving a mean flux equal to Earth's. These planets are found around stars of luminosity ranging from 1 L⊙ to 10-4L⊙. We use a definition of habitability based on the presence of surface liquid water, and find that most of the planets considered can sustain surface liquid water on the dayside with an ice cap on the nightside. However, for high eccentricity and high luminosity, planets cannot sustain surface liquid water during the whole orbital period. They completely freeze at apoastron and when approaching periastron an ocean appears around the substellar point. We conclude that the higher the eccentricity and the higher the luminosity of the star, the less reliable the mean flux approximation.

  9. Alignment of the stellar spin with the orbits of a three-planet system

    CERN Document Server

    Sanchis-Ojeda, Roberto; Winn, Josh N; Barclay, Thomas; Clarke, Bruce D; Ford, Eric B; Fortney, Jonathan J; Geary, John C; Holman, Matthew J; Howard, Andrew W; Jenkins, Jon M; Koch, David G; Lissauer, Jack J; Marcy, Geoffrey W; Mullally, Fergal; Ragozzine, Darin; Seader, Shawn E; Still, Martin; Thompson, Susan E; 10.1038/nature11301

    2012-01-01

    The Sun's equator and the planets' orbital planes are nearly aligned, which is presumably a consequence of their formation from a single spinning gaseous disk. For exoplanetary systems this well-aligned configuration is not guaranteed: dynamical interactions may tilt planetary orbits, or stars may be misaligned with the protoplanetary disk through chaotic accretion, magnetic interactions or torques from neighbouring stars. Indeed, isolated 'hot Jupiters' are often misaligned and even orbiting retrograde. Here we report an analysis of transits of planets over starspots on the Sun-like star Kepler-30, and show that the orbits of its three planets are aligned with the stellar equator. Furthermore, the orbits are aligned with one another to within a few degrees. This configuration is similar to that of our Solar System, and contrasts with the isolated hot Jupiters. The orderly alignment seen in the Kepler-30 system suggests that high obliquities are confined to systems that experienced disruptive dynamical intera...

  10. DIRECT IMAGING CONFIRMATION AND CHARACTERIZATION OF A DUST-ENSHROUDED CANDIDATE EXOPLANET ORBITING FOMALHAUT

    Energy Technology Data Exchange (ETDEWEB)

    Currie, Thayne [Department of Astronomy and Astrophysics, University of Toronto, Toronto, ON (Canada); Debes, John [Space Telescope Science Institute, Baltimore, MD (United States); Rodigas, Timothy J. [Steward Observatory, University of Arizona, Tucson, AZ (United States); Burrows, Adam [Department of Astrophysical Sciences, Princeton University, Princeton, NJ (United States); Itoh, Yoichi [Nishi-Harima Observatory, University of Hyogo, Kobe (Japan); Fukagawa, Misato [Department of Earth and Space Sciences, Osaka University, Osaka (Japan); Kenyon, Scott J. [Smithsonian Astrophysical Observatory, Cambridge, MA (United States); Kuchner, Marc [Stellar and Exoplanets Laboratory, NASA-Goddard Space Flight Center, Greenbelt, MD (United States); Matsumura, Soko, E-mail: currie@astro.utoronto.ca [Department of Astronomy, University of Maryland-College Park, College Park, MD (United States)

    2012-12-01

    We present Subaru/IRCS J-band data for Fomalhaut and a (re)reduction of archival 2004-2006 HST/ACS data first presented by Kalas et al. We confirm the existence of a candidate exoplanet, Fomalhaut b, in both the 2004 and 2006 F606W data sets at a high signal-to-noise ratio. Additionally, we confirm the detection at F814W and present a new detection in F435W. Fomalhaut b's space motion may be consistent with it being in an apsidally aligned, non-debris ring-crossing orbit, although new astrometry is required for firmer conclusions. We cannot confirm that Fomalhaut b exhibits 0.7-0.8 mag variability cited as evidence for planet accretion or a semi-transient dust cloud. The new, combined optical spectral energy distribution and IR upper limits confirm that emission identifying Fomalhaut b originates from starlight scattered by small dust, but this dust is most likely associated with a massive body. The Subaru and IRAC/4.5 {mu}m upper limits imply M < 2 M{sub J} , still consistent with the range of Fomalhaut b masses needed to sculpt the disk. Fomalhaut b is very plausibly 'a planet identified from direct imaging' even if current images of it do not, strictly speaking, show thermal emission from a directly imaged planet.

  11. The unstable fate of the planet orbiting the A-star in the HD 131399 triple stellar system

    CERN Document Server

    Veras, Dimitri; Gaensicke, Boris T

    2016-01-01

    Validated planet candidates need not lie on long-term stable orbits, and instability triggered by post-main-sequence stellar evolution can generate architectures which transport rocky material to white dwarfs, polluting them. The giant planet HD 131399Ab orbits its parent A star at a projected separation of about 50-100 au. The host star, HD 131399A, is part of a hierarchical triple with HD 131399BC being a close binary separated by a few hundred au from the A star. Here, we determine the fate of this system, and find that (i) stability along the main sequence is achieved only for a favourable choice of parameters within the errors, and (ii) even for this choice, in almost every instance the planet is ejected during the transition between the giant branch and white dwarf phases of HD 131399A. This result provides an example of both how the free-floating planet population may be enhanced by similar systems, and how instability can manifest in the polluted white dwarf progenitor population.

  12. The unstable fate of the planet orbiting the A star in the HD 131399 triple stellar system

    Science.gov (United States)

    Veras, Dimitri; Mustill, Alexander J.; Gänsicke, Boris T.

    2017-02-01

    Validated planet candidates need not lie on long-term stable orbits, and instability triggered by post-main-sequence stellar evolution can generate architectures which transport rocky material to white dwarfs, hence polluting them. The giant planet HD 131399Ab orbits its parent A star at a projected separation of about 50-100 au. The host star, HD 131399A, is part of a hierarchical triple with HD 131399BC being a close binary separated by a few hundred au from the A star. Here, we determine the fate of this system, and find the following: (i) Stability along the main sequence is achieved only for a favourable choice of parameters within the errors. (ii) Even for this choice, in almost every instance, the planet is ejected during the transition between the giant branch and white dwarf phases of HD 131399A. This result provides an example of both how the free-floating planet population may be enhanced by similar systems and how instability can manifest in the polluted white dwarf progenitor population.

  13. Finding Planets Orbiting Bright Stars with SuperWASP-South

    Science.gov (United States)

    Turner, O.; Anderson, D. R.; Maxted, P. L. F.; Hellier, C.

    2015-10-01

    Over the past decade the Wide Angle Search for Planets(WASP) project has been at the forefront of the ground-based hunt for transiting planets. In that time, WASP has found many systems that push the boundaries of our understanding of planet formation and evolution. In recent years both the North and South installations have changed their observing strategies with the aim of discovering rarer objects to further fill gaps in our knowledge and test current theory. Here we look at the performance and potential of the new WASP-South instrument, which we modified to target brighter stars. We also present some new discoveries from this brighter, southern campaign.

  14. Five New Exoplanets Orbiting Three Metal-Rich, Massive Stars: Two-Planet Systems Including Long-Period Planets, and an Eccentric Planet

    CERN Document Server

    Harakawa, Hiroki; Omiya, Masashi; Fischer, Debra A; Hori, Yasunori; Ida, Shigeru; Kambe, Eiji; Yoshida, Michitoshi; Izumiura, Hideyuki; Koyano, Hisashi; Nagayama, Shogo; Shimizu, Yasuhiro; Okada, Norio; Okita, Kiichi; Sakamoto, Akihiro; Yamamuro, Tomoyasu

    2015-01-01

    We report detections of new exoplanets from a radial velocity (RV) survey of metal-rich FGK stars by using three telescopes. By optimizing our RV analysis method to long time-baseline observations, we have succeeded in detecting five new Jovian-planets around three metal-rich stars HD 1605, HD 1666, and HD 67087 with the masses of $1.3 M_{\\odot}$, $1.5 M_{\\odot}$, and $1.4 M_{\\odot}$, respectively. A K1 subgiant star HD 1605 hosts two planetary companions with the minimum masses of $ M_p \\sin i = 0.96 M_{\\mathrm{JUP}}$ and $3.5 M_{\\mathrm{JUP}}$ in circular orbits with the planets' periods $P = 577.9$ days and $2111$ days, respectively. HD 1605 shows a significant linear trend in RVs. Such a system consisting of Jovian planets in circular orbits has rarely been found and thus HD 1605 should be an important example of a multi-planetary system that is likely unperturbed by planet-planet interactions. HD 1666 is a F7 main sequence star which hosts an eccentric and massive planet of $ M_p \\sin i = 6.4 M_{\\mathrm{...

  15. Asymmetric Orbital Distribution near Mean Motion Resonance: Application to Planets Observed by Kepler and Radial Velocities

    CERN Document Server

    Xie, Ji-Wei

    2016-01-01

    Many multiple-planet systems have been found by the Kepler transit survey and various radial velocity (RV) surveys. Kepler planets show an asymmetric feature, namely, there are small but significant deficits/excesses of planet pairs with orbital period spacing slightly narrow/wide of the exact resonance, particularly near the first order mean motion resonance (MMR), such as 2:1 and 3:2 MMR. Similarly, if not exactly the same, an asymmetric feature (pileup wide of 2:1 MMR) is also seen in RV planets, but only for massive ones. We analytically and numerically study planets' orbital evolutions near and in the MMR. We find that their orbital period ratios could be asymmetrically distributed around the MMR center regardless of dissipation. In the case of no dissipation, Kepler planets' asymmetric orbital distribution could be partly reproduced for 3:2 MMR but not for 2:1 MMR, implying that dissipation might be more important to the latter. The pileup of massive RV planets just wide of 2:1 MMR is found to be consis...

  16. Stellar and Planetary Properties of K2 Campaign 1 Candidates and Validation of 18 Systems, Including a Planet Receiving Earth-like Insolation

    CERN Document Server

    Montet, Benjamin T; Foreman-Mackey, Daniel; Johnson, John Asher; Hogg, David W; Bowler, Brendan P; Latham, David W; Bieryla, Allyson; Mann, Andrew W

    2015-01-01

    The extended Kepler mission, K2, is now providing photometry of new fields every three months in a search for transiting planets. In a recent study, Foreman-Mackey and collaborators presented a list of 36 planet candidates orbiting 31 stars in K2 Campaign 1. In this contribution, we present stellar and planetary properties for all systems. We combine ground-based seeing-limited survey data and adaptive optics imaging with an automated transit analysis scheme to validate 18 candidates as planets and identify 6 candidates as likely false positives. Of particular interest is EPIC 201912552, a bright (K=8.9) M2 dwarf hosting a 2.24 \\pm 0.25 Earth radius planet with an equilibrium temperature of 271 \\pm 16 K and an orbital period of 33 days. We also present two new open-source software packages that enabled this analysis: isochrones, a flexible tool for fitting theoretical stellar models to observational data to determine stellar properties, and vespa, a new general-purpose procedure to calculate false positive pr...

  17. Planetary Candidates Observed by \\ik V: Planet Sample from Q1-Q12 (36 Months)

    CERN Document Server

    Rowe, Jason F; Antoci, Victoria; Barclay, Thomas; Batalha, Natalie M; Borucki, William J; Burke, Christopher J; Bryson, Steven T; Caldwell, Douglas A; Campbell, Jennifer R; Catanzarite, Joseph H; Christiansen, Jessie L; Cochran, William; Gilliland, Ronald L; Girouard, Forrest R; Haas, Michael R; Helminiak, Krzysztof G; Henze, Christopher E; Hoffman, Kelsey L; Howell, Steve B; Huber, Daniel; Hunter, Roger C; Jang-Condell, Hannah; Jenkins, Jon M; Klaus, Todd C; Latham, David W; Li, Jie; Lissauer, Jack J; McCauliff, Sean D; Morris, Robert L; Mullally, F; Ofir, Aviv; Quarles, Billy; Quintana, Elisa; Sabale, Anima; Seader, Shawn; Shporer, Avi; Smith, Jeffrey C; Steffen, Jason H; Still, Martin; Tenenbaum, Peter; Thompson, Susan E; Twicken, Joseph D; Van Laerhoven, Christa; Wolfgang, Angie; Zamudio, Khadeejah A

    2015-01-01

    The Kepler mission discovered 2842 exoplanet candidates with 2 years of data. We provide updates to the Kepler planet candidate sample based upon 3 years (Q1-Q12) of data. Through a series of tests to exclude false-positives, primarily caused by eclipsing binary stars and instrumental systematics, 855 additional planetary candidates have been discovered, bringing the total number known to 3697. We provide revised transit parameters and accompanying posterior distributions based on a Markov Chain Monte Carlo algorithm for the cumulative catalogue of Kepler Objects of Interest. There are now 130 candidates in the cumulative catalogue that receive less than twice the flux the Earth receives and more than 1100 have a radius less than 1.5 Rearth. There are now a dozen candidates meeting both criteria, roughly doubling the number of candidate Earth analogs. A majority of planetary candidates have a high probability of being bonafide planets, however, there are populations of likely false-positives. We discuss and s...

  18. Habitability of planets on eccentric orbits: limits of the mean flux approximation

    Science.gov (United States)

    Bolmont, Emeline; Libert, Anne-Sophie; Leconte, Jérémy; Selsis, Franck; Turbet, Martin; Forget, François

    2016-04-01

    A few of the planets found in the insolation habitable zone (region in which a planet with an atmosphere can sustain surface liquid water, Kasting et al. 1993) are on eccentric orbits, such as GJ 667Cc (eccentricity of < 0.3, Anglada-Escude et al. 2012) or HD 16175 b (eccentricity of 0.6, Peek et al. 2009). This raises the question of the potential habitability of planets that only spend a fraction of their orbit in the habitable zone. Usually for a planet of semi-major axis a and eccentricity e, the averaged flux over one orbit received by the planet is considered. This averaged flux corresponds to the flux received by a planet on a circular orbit of radius r = a(1 -e2)1/4. If this orbital distance is within the habitable zone, the planet is said "habitable". However, for a hot star, for which the habitable zone is far from the star, the climate can be degraded when the planet is temporarily outside the habitable zone. We investigate here the limits of validity of the mean flux approximation used to assess the potential habitability of eccentric planets. For this study, we consider ocean planets in synchronized rotation and planets with a rotation period of 24 hr. We investigate the influence of the type of host star and the eccentricity of the orbit on the climate of a planet. We do so by scaling the duration of its orbital period and its apastron and periastron distance to ensure that it receives in average the same incoming flux as Earth's. We performed sets of 3D simulations using the Global Climate Model LMDz (Wordsworth et al. 2011, Forget et al. 2013, Leconte et al. 2013). The atmosphere is composed of N2, CO2 and H2O (gas, liquid, solid) in Earth-like proportions. First, we do not take into account the spectral difference between a low luminosity star and a Sun-like star. Second, the dependence of the albedo of ice and snow on the spectra of the host star is taken into account. This influences the positive ice-albedo feedback and can lead to a different

  19. The effect of lunarlike satellites on the orbital infrared light curves of Earth-analog planets.

    Science.gov (United States)

    Moskovitz, Nicholas A; Gaidos, Eric; Williams, Darren M

    2009-04-01

    We have investigated the influence of lunarlike satellites on the infrared orbital light curves of Earth-analog extrasolar planets. Such light curves will be obtained by NASA's Terrestrial Planet Finder (TPF) and ESA's Darwin missions as a consequence of repeat observations to confirm the companion status of a putative planet and determine its orbit. We used an energy balance model to calculate disk-averaged infrared (bolometric) fluxes from planet-satellite systems over a full orbital period (one year). The satellites are assumed to lack an atmosphere, have a low thermal inertia like that of the Moon, and span a range of plausible radii. The planets are assumed to have thermal and orbital properties that mimic those of Earth, while their obliquities and orbital longitudes of inferior conjunction remain free parameters. Even if the gross thermal properties of the planet can be independently constrained (e.g., via spectroscopy or visible-wavelength detection of specular glint from a surface ocean), only the largest (approximately Mars-sized) lunarlike satellites can be detected by light curve data from a TPF-like instrument (i.e., one that achieves a photometric signal-to-noise ratio of 10 to 20 at infrared wavelengths). Nondetection of a lunarlike satellite can obfuscate the interpretation of a given system's infrared light curve so that it may resemble a single planet with high obliquity, different orbital longitude of vernal equinox relative to inferior conjunction, and in some cases drastically different thermal characteristics. If the thermal properties of the planet are not independently established, then the presence of a lunarlike satellite cannot be inferred from infrared data, which would thus demonstrate that photometric light curves alone can only be used for preliminary study, and the addition of spectroscopic data will be necessary.

  20. Search for a circum-planetary material and orbital period variations of short-period Kepler exoplanet candidates

    CERN Document Server

    Garai, Z; Budaj, J; Stellingwerf, R F

    2014-01-01

    A unique short-period Mercury-size Kepler exoplanet candidate KIC012557548b has been discovered recently by Rappaport et al. (2012). This object is a transiting disintegrating exoplanet with a circum-planetary material - comet-like tail. Close-in exoplanets, like KIC012557548b, are subjected to the greatest planet-star interactions. This interaction may have various forms. In certain cases it may cause formation of the comet-like tail. Strong interaction with the host star, and/or presence of an additional planet may lead to variations in the orbital period of the planet. Our main aim is to search for comet-like tails similar to KIC012557548b and for long-term orbital period variations. We are curious about frequency of comet-like tail formation among short-period Kepler exoplanet candidates. We concentrate on a sample of 20 close-in candidates with a period similar to KIC012557548b from the Kepler mission.

  1. The Gravitational Interaction between Planets on Inclined Orbits and Protoplanetary Disks As the Origin of Primordial Spin–Orbit Misalignments

    Science.gov (United States)

    Matsakos, Titos; Königl, Arieh

    2017-02-01

    Many of the observed spin–orbit alignment properties of exoplanets can be explained in the context of the primordial disk misalignment model, in which an initially aligned protoplanetary disk is torqued by a distant stellar companion on a misaligned orbit, resulting in a precessional motion that can lead to large-amplitude oscillations of the spin–orbit angle. We consider a variant of this model in which the companion is a giant planet with an orbital radius of a few astronomical units. Guided by the results of published numerical simulations, we model the dynamical evolution of this system by dividing the disk into inner and outer parts—separated at the location of the planet—that behave as distinct, rigid disks. We show that the planet misaligns the inner disk even as the orientation of the outer disk remains unchanged. In addition to the oscillations induced by the precessional motion, whose amplitude is larger the smaller the initial inner-disk-to-planet mass ratio, the spin–orbit angle also exhibits a secular growth in this case—driven by ongoing mass depletion from the disk—that becomes significant when the inner disk’s angular momentum drops below that of the planet. Altogether, these two effects can produce significant misalignment angles for the inner disk, including retrograde configurations. We discuss these results within the framework of the Stranded Hot Jupiter scenario and consider their implications, including the interpretation of the alignment properties of debris disks.

  2. Orbit Determination and Differential-drag Control of Planet Labs Cubesat Constellations

    CERN Document Server

    Foster, Cyrus; Mason, James

    2015-01-01

    We present methodology and mission results from orbit determination of Planet Labs nanosatellites and differential-drag control of their relative motion. Orbit determination (OD) is required on Planet Labs satellites to accurately predict the positioning of satellites during downlink passes and we present a scalable OD solution for large fleets of small satellites utilizing two-way ranging. In the second part of this paper, we present mission results from relative motion differential-drag control of a constellation of satellites deployed in the same orbit.

  3. SOPHIE velocimetry of Kepler transit candidates. XV. KOI-614b, KOI-206b, and KOI-680b: a massive warm Jupiter orbiting a G0 metallic dwarf and two highly inflated planets with a distant companion around evolved F-type stars

    CERN Document Server

    Almenara, J M; Bouchy, F; Havel, M; Bruno, G; Hébrard, G; Diaz, R F; Deleuil, M; Barros, S C C; Boisse, I; Bonomo, A; Montagnier, G; Santerne, A

    2015-01-01

    We report the validation and characterization of three new transiting exoplanets using SOPHIE radial velocities: KOI-614b, KOI-206b, and KOI-680b. KOI-614b has a mass of $2.86\\pm0.35~{\\rm M_{Jup}}$ and a radius of $1.13^{+0.26}_{-0.18}~{\\rm R_{Jup}}$, and it orbits a G0, metallic ([Fe/H]=$0.35\\pm0.15$) dwarf in 12.9 days. Its mass and radius are familiar and compatible with standard planetary evolution models, so it is one of the few known transiting planets in this mass range to have an orbital period over ten days. With an equilibrium temperature of $T_{eq}=1000 \\pm 45$ K, this places KOI-614b at the transition between what is usually referred to as "hot" and "warm" Jupiters. KOI-206b has a mass of $2.82\\pm 0.52~{\\rm M_{Jup}}$ and a radius of $1.45\\pm0.16~{\\rm R_{Jup}}$, and it orbits a slightly evolved F7-type star in a 5.3-day orbit. It is a massive inflated hot Jupiter that is particularly challenging for planetary models because it requires unusually large amounts of additional dissipated energy in the ...

  4. Gravitational Microlensing Evidence for a Planet Orbiting a Binary Star System

    CERN Document Server

    Bennett, D P; Becker, A C; Butler, N; Dann, J H; Kaspi, S; Leibowitz, E M; Lipkin, Yu M; Maoz, D; Mendelson, H; Peterson, B A; Quinn, J; Shemmer, O; Thomson, S; Turner, S E

    1999-01-01

    The study of extra-solar planetary systems has emerged as a new discipline of observational astronomy in the past few years with the discovery of a number of extra-solar planets. The properties of most of these extra-solar planets were not anticipated by theoretical work on the formation of planetary systems. Here we report observations and light curve modeling of gravitational microlensing event MACHO-97-BLG-41, which indicates that the lens system consists of a planet orbiting a binary star system. According to this model, the mass ratio of the binary star system is 3.8:1 and the stars are most likely to be a late K dwarf and an M dwarf with a separation of about 1.8 AU. A planet of about 3 Jupiter masses orbits this system at a distance of about 7 AU. If our interpretation of this light curve is correct, it represents the first discovery of a planet orbiting a binary star system and the first detection of a Jovian planet via the gravitational microlensing technique. It suggests that giant planets may be co...

  5. Multiplicity and properties of Kepler planet candidates: High spatial imaging and RV studies*

    Directory of Open Access Journals (Sweden)

    Aceituno J.

    2013-04-01

    Full Text Available The Kepler space telescope is discovering thousands of new planet candidates. However, a follow up program is needed in order to reject false candidates and to fully characterize the bona-fide exoplanets. Our main aims are: 1./ Detect and analyze close companions inside the typical Kepler PSF to study if they are the responsible of the dim in the Kepler light curves, 2./ Study the change in the stellar and planetary parameters due to the presence of an unresolved object, 3./ Help to validate those Kepler Objects of Interest that do not present any object inside the Kepler PSF and 4./ Study the multiplicity rate in planet host candidates. Such a large sample of observed planet host candidates allows us to do statistics about the presence of close (visual or bounded companions to the harboring star. We present here Lucky Imaging observations for a total amount of 98 Kepler Objects of Interest. This technique is based on the acquisition of thousands of very short exposure time images. Then, a selection and combination of a small amount of the best quality frames provides a high resolution image with objects having a 0.1 arcsec PSF. We applied this technique to carry out observations in the Sloan i and Sloan z filters of our Kepler candidates. We find blended objects inside the Kepler PSF for a significant percentage of KOIs. On one hand, only 58.2% of the hosts do not present any object within 6 arcsec. On the other hand, we have found 19 companions closer than 3 arcsec in 17 KOIs. According to their magnitudes and i − z color, 8 of them could be physically bounded to the host star. We are also collecting high-spectral resolution spectroscopuy in order to derive the planet properties.

  6. Orbital Architectures of Planet-Hosting Binaries: I. Forming Five Small Planets in the Truncated Disk of Kepler-444A

    CERN Document Server

    Dupuy, Trent J; Kraus, Adam L; Isaacson, Howard; Mann, Andrew W; Ireland, Michael J; Howard, Andrew W; Huber, Daniel

    2015-01-01

    We present the first results from our Keck program investigating the orbital architectures of planet-hosting multiple star systems. Kepler-444 is a metal-poor triple star system that hosts five sub-Earth-sized planets orbiting the primary star (Kepler-444A), as well as a spatially unresolved pair of M dwarfs (Kepler-444BC) at a projected distance of 1.8" (66 AU). We combine our Keck/NIRC2 adaptive optics astrometry with multi-epoch Keck/HIRES RVs of all three stars to determine a precise orbit for the BC pair around A, given their empirically constrained masses. We measure minimal astrometric motion ($1.0\\pm0.6$ mas yr$^{-1}$, or $0.17\\pm0.10$ km s$^{-1}$), but our RVs reveal significant orbital velocity ($1.7\\pm0.2$ km s$^{-1}$) and acceleration ($7.8\\pm0.5$ m s$^{-1}$ yr$^{-1}$). We determine a highly eccentric stellar orbit ($e=0.864\\pm0.023$) that brings the tight M dwarf pair within $5.0^{+0.9}_{-1.0}$ AU of the planetary system. We validate that the system is dynamically stable in its present configurat...

  7. The signature of orbital motion from the dayside of the planet tau Bootis b

    CERN Document Server

    Brogi, M; de Kok, R J; Albrecht, S; Birkby, J; de Mooij, E J W

    2012-01-01

    The giant planet orbiting tau Bootis was among the first extrasolar planets to be discovered through the reflex motion of its host star. It is one of the brightest known and most nearby planets with an orbital period of just a few days. Over the course of more than a decade, measurements of its orbital inclination have been announced and refuted, and have subsequently remained elusive until now. Here we report on the detection of carbon monoxide absorption in the thermal day-side spectrum of tau Bootis b. At a spectral resolution of R~100,000, we trace the change in the radial velocity of the planet over a large range in phase, determining an orbital inclination of i=44.5+-1.5 degrees and a true planet mass of 5.95+-0.28 MJup. This result extends atmospheric characterisation to non-transiting planets. The strong absorption signal points to an atmosphere with a temperature that is decreasing towards higher altitudes. This is a stark contrast to the temperature inversion invoked for other highly irradiated plan...

  8. Prevalence of Earth-size planets orbiting Sun-like stars.

    Science.gov (United States)

    Petigura, Erik A; Howard, Andrew W; Marcy, Geoffrey W

    2013-11-26

    Determining whether Earth-like planets are common or rare looms as a touchstone in the question of life in the universe. We searched for Earth-size planets that cross in front of their host stars by examining the brightness measurements of 42,000 stars from National Aeronautics and Space Administration's Kepler mission. We found 603 planets, including 10 that are Earth size ( ) and receive comparable levels of stellar energy to that of Earth (1 - 2 R[Symbol: see text] ). We account for Kepler's imperfect detectability of such planets by injecting synthetic planet-caused dimmings into the Kepler brightness measurements and recording the fraction detected. We find that 11 ± 4% of Sun-like stars harbor an Earth-size planet receiving between one and four times the stellar intensity as Earth. We also find that the occurrence of Earth-size planets is constant with increasing orbital period (P), within equal intervals of logP up to ~200 d. Extrapolating, one finds 5.7(-2.2)(+1.7)% of Sun-like stars harbor an Earth-size planet with orbital periods of 200-400 d.

  9. On the origin of planets at very wide orbits from re-capture of free floating planets

    CERN Document Server

    Perets, Hagai B

    2012-01-01

    In recent years several planets have been discovered at wide orbits (>100 AU) around their host stars. Theoretical studies encounter difficulties in explaining their formation and origin. Here we propose a novel scenario for the production of planetary systems at such orbits, through the dynamical recapture of free floating planets (FFPs) in dispersing stellar clusters. This process is a natural extension of the recently suggested scenario for the formation of wide stellar binaries. We use N-body simulations of dispersing clusters with 10-1000 and f_FFP=0.5-2 to study this process. We find that planets are captured into wide orbits, ~100-10^6 AU, and a thermal eccentricity distribution. Typically, 3-6x(f_FFP/1) % of all stars capture a planetary companion (f_FFP is the number of FFP per star). The planetary capture efficiency is comparable to that of capture-formed stellar-binaries, and shows a similar dependence on the cluster size and structure. The capture efficiency is almost independent of the specific p...

  10. Two Jupiter-Mass Planets Orbiting HD 154672 and HD 205739

    CERN Document Server

    Lopez-Morales, Mercedes; Fischer, Debra A; Minniti, Dante; Shectman, Stephen A; Takeda, Genya; Adams, Fred C; Wright, Jason T; Arriagada, Pamela

    2008-01-01

    We report the detection of the first two planets from the N2K Doppler planet search program at the Magellan telescopes. The first planet has a mass of M sin i = 4.96 M_Jup and is orbiting the G3 IV star HD154672 with an orbital period of 163.9 days. The second planet is orbiting the F7 V star HD205739 with an orbital period of 279.8 days and has a mass of M sin i = 1.37 M_Jup. Both planets are in eccentric orbits, with eccentricities e = 0.61 and e = 0.27, respectively. Both stars are metal rich and appear to be chromospherically inactive, based on inspection of their Ca II H and K lines. Finally, the best Keplerian model fit to HD205739b shows a trend of 0.0649 m/s/day, suggesting the presence of an additional outer body in that system.

  11. HAT-P-7: A Retrograde or Polar Orbit, and a Second Planet

    CERN Document Server

    Winn, Joshua N; Albrecht, Simon; Howard, Andrew W; Marcy, Geoffrey W; Crossfield, Ian J; Holman, Matthew J

    2009-01-01

    We show that the exoplanet HAT-P-7b has an extremely tilted orbit, with a true angle of at least 86 degrees with respect to its parent star's equatorial plane, and a strong possibility of retrograde motion. We also report evidence for a second planet in a more distant orbit. The evidence for the unparalleled orbit and the additional planet is based on precise observations of the star's apparent radial velocity. The anomalous radial velocity due to rotation (the Rossiter-McLaughlin effect) was found to be a blueshift during the first half of the transit and a redshift during the second half, an inversion of the usual effect, implying that the angle between the sky-projected orbital and stellar angular momentum vectors is 182.5 +/- 9.4 deg. The second planet is implicated by excess radial-velocity variation of the host star over 2 yr. Possibly, the second planet tilted the orbit of the inner planet through a close encounter or the Kozai effect.

  12. 3D climate modeling of Earth-like extrasolar planets orbiting different types of host stars

    CERN Document Server

    Godolt, M; Hamann-Reinus, A; Kitzmann, D; Kunze, M; Langematz, U; von Paris, P; Patzer, A B C; Rauer, H; Stracke, B

    2015-01-01

    The potential habitability of a terrestrial planet is usually defined by the possible existence of liquid water on its surface. The potential presence of liquid water depends on many factors such as, most importantly, surface temperatures. The properties of the planetary atmosphere and its interaction with the radiative energy provided by the planet's host star are thereby of decisive importance. In this study we investigate the influence of different main-sequence stars upon the climate of Earth-like extrasolar planets and their potential habitability by applying a 3D Earth climate model accounting for local and dynamical processes. The calculations have been performed for planets with Earth-like atmospheres at orbital distances where the total amount of energy received from the various host stars equals the solar constant. In contrast to previous 3D modeling studies, we include the effect of ozone radiative heating upon the vertical temperature structure of the atmospheres. The global orbital mean results o...

  13. Exoplanet detection. A terrestrial planet in a ~1-AU orbit around one member of a ~15-AU binary.

    Science.gov (United States)

    Gould, A; Udalski, A; Shin, I-G; Porritt, I; Skowron, J; Han, C; Yee, J C; Kozłowski, S; Choi, J-Y; Poleski, R; Wyrzykowski, Ł; Ulaczyk, K; Pietrukowicz, P; Mróz, P; Szymański, M K; Kubiak, M; Soszyński, I; Pietrzyński, G; Gaudi, B S; Christie, G W; Drummond, J; McCormick, J; Natusch, T; Ngan, H; Tan, T-G; Albrow, M; DePoy, D L; Hwang, K-H; Jung, Y K; Lee, C-U; Park, H; Pogge, R W; Abe, F; Bennett, D P; Bond, I A; Botzler, C S; Freeman, M; Fukui, A; Fukunaga, D; Itow, Y; Koshimoto, N; Larsen, P; Ling, C H; Masuda, K; Matsubara, Y; Muraki, Y; Namba, S; Ohnishi, K; Philpott, L; Rattenbury, N J; Saito, To; Sullivan, D J; Sumi, T; Suzuki, D; Tristram, P J; Tsurumi, N; Wada, K; Yamai, N; Yock, P C M; Yonehara, A; Shvartzvald, Y; Maoz, D; Kaspi, S; Friedmann, M

    2014-07-04

    Using gravitational microlensing, we detected a cold terrestrial planet orbiting one member of a binary star system. The planet has low mass (twice Earth's) and lies projected at ~0.8 astronomical units (AU) from its host star, about the distance between Earth and the Sun. However, the planet's temperature is much lower, planets in binary systems. With more detections, such binary-star planetary systems could constrain models of planet formation and evolution.

  14. The Orbital Stability of Planets Trapped in the First-Order Mean-Motion Resonances

    CERN Document Server

    Matsumoto, Yuji; Ida, Shigeru

    2012-01-01

    Many extrasolar planetary systems containing multiple super-Earths have been discovered. N-body simulations taking into account standard type-I planetary migration suggest that protoplanets are captured into mean-motion resonant orbits near the inner disk edge at which the migration is halted. Previous N-body simulations suggested that orbital stability of the resonant systems depends on number of the captured planets. In the unstable case, through close scattering and merging between planets, non-resonant multiple systems are finally formed. In this paper, we investigate the critical number of the resonantly trapped planets beyond which orbital instability occurs after disk gas depletion. We find that when the total number of planets ($N$) is larger than the critical number ($N_{\\rm crit}$), crossing time that is a timescale of initiation of the orbital instability is similar to non-resonant cases, while the orbital instability never occurs within the orbital calculation time ($10^8$ Kepler time) for $N\\leq ...

  15. The Solar Twin Planet Search. V. Close-in, low-mass planet candidates and evidence of planet accretion in the solar twin HIP 68468

    Science.gov (United States)

    Meléndez, Jorge; Bedell, Megan; Bean, Jacob L.; Ramírez, Iván; Asplund, Martin; Dreizler, Stefan; Yan, Hong-Liang; Shi, Jian-Rong; Lind, Karin; Ferraz-Mello, Sylvio; Galarza, Jhon Yana; dos Santos, Leonardo; Spina, Lorenzo; Maia, Marcelo Tucci; Alves-Brito, Alan; Monroe, TalaWanda; Casagrande, Luca

    2017-01-01

    Context. More than two thousand exoplanets have been discovered to date. Of these, only a small fraction have been detected around solar twins, which are key stars because we can obtain accurate elemental abundances especially for them, which is crucial for studying the planet-star chemical connection with the highest precision. Aims: We aim to use solar twins to characterise the relationship between planet architecture and stellar chemical composition. Methods: We obtained high-precision (1 m s-1) radial velocities with the HARPS spectrograph on the ESO 3.6 m telescope at La Silla Observatory and determined precise stellar elemental abundances ( 0.01 dex) using spectra obtained with the MIKE spectrograph on the Magellan 6.5 m telescope. Results: Our data indicate the presence of a planet with a minimum mass of 26 ± 4 Earth masses around the solar twin HIP 68468. The planet is more massive than Neptune (17 Earth masses), but unlike the distant Neptune in our solar system (30 AU), HIP 68468c is close-in, with a semi-major axis of 0.66 AU, similar to that of Venus. The data also suggest the presence of a super-Earth with a minimum mass of 2.9 ± 0.8 Earth masses at 0.03 AU; if the planet is confirmed, it will be the fifth least massive radial velocity planet candidate discovery to date and the first super-Earth around a solar twin. Both isochrones (5.9 ± 0.4 Gyr) and the abundance ratio [Y/Mg] (6.4 ± 0.8 Gyr) indicate an age of about 6 billion years. The star is enhanced in refractory elements when compared to the Sun, and the refractory enrichment is even stronger after corrections for Galactic chemical evolution. We determined a nonlocal thermodynamic equilibrium Li abundance of 1.52 ± 0.03 dex, which is four times higher than what would be expected for the age of HIP 68468. The older age is also supported by the low log () (-5.05) and low jitter (existence of the planets that are indicated by our data and to better constrain the nature of the planetary system

  16. NEWLY DISCOVERED PLANETS ORBITING HD 5319, HD 11506, HD 75784 AND HD 10442 FROM THE N2K CONSORTIUM

    Energy Technology Data Exchange (ETDEWEB)

    Giguere, Matthew J.; Fischer, Debra A.; Brewer, John M. [Department of Astronomy, Yale University, 260 Whitney Avenue, New Haven, CT 06511 (United States); Payne, Matthew J.; Johnson, John Asher [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Howard, Andrew W. [Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822 (United States); Isaacson, Howard T. [Department of Astronomy, University of California, Berkeley, Berkeley, California 94720 (United States)

    2015-01-20

    Initially designed to discover short-period planets, the N2K campaign has since evolved to discover new worlds at large separations from their host stars. Detecting such worlds will help determine the giant planet occurrence at semi-major axes beyond the ice line, where gas giants are thought to mostly form. Here we report four newly discovered gas giant planets (with minimum masses ranging from 0.4 to 2.1 M {sub Jup}) orbiting stars monitored as part of the Next 2000 target stars (N2K) Doppler Survey program. Two of these planets orbit stars already known to host planets: HD 5319 and HD 11506. The remaining discoveries reside in previously unknown planetary systems: HD 10442 and HD 75784. The refined orbital period of the inner planet orbiting HD 5319 is 641 days. The newly discovered outer planet orbits in 886 days. The large masses combined with the proximity to a 4:3 mean motion resonance make this system a challenge to explain with current formation and migration theories. HD 11506 has one confirmed planet, and here we confirm a second. The outer planet has an orbital period of 1627.5 days, and the newly discovered inner planet orbits in 223.6 days. A planet has also been discovered orbiting HD 75784 with an orbital period of 341.7 days. There is evidence for a longer period signal; however, several more years of observations are needed to put tight constraints on the Keplerian parameters for the outer planet. Lastly, an additional planet has been detected orbiting HD 10442 with a period of 1043 days.

  17. Newly Discovered Planets Orbiting HD 5319, HD 11506, HD 75784 and HD 10442 from the N2K Consortium

    Science.gov (United States)

    Giguere, Matthew J.; Fischer, Debra A.; Payne, Matthew J.; Brewer, John M.; Johnson, John Asher; Howard, Andrew W.; Isaacson, Howard T.

    2015-01-01

    Initially designed to discover short-period planets, the N2K campaign has since evolved to discover new worlds at large separations from their host stars. Detecting such worlds will help determine the giant planet occurrence at semi-major axes beyond the ice line, where gas giants are thought to mostly form. Here we report four newly discovered gas giant planets (with minimum masses ranging from 0.4 to 2.1 M Jup) orbiting stars monitored as part of the Next 2000 target stars (N2K) Doppler Survey program. Two of these planets orbit stars already known to host planets: HD 5319 and HD 11506. The remaining discoveries reside in previously unknown planetary systems: HD 10442 and HD 75784. The refined orbital period of the inner planet orbiting HD 5319 is 641 days. The newly discovered outer planet orbits in 886 days. The large masses combined with the proximity to a 4:3 mean motion resonance make this system a challenge to explain with current formation and migration theories. HD 11506 has one confirmed planet, and here we confirm a second. The outer planet has an orbital period of 1627.5 days, and the newly discovered inner planet orbits in 223.6 days. A planet has also been discovered orbiting HD 75784 with an orbital period of 341.7 days. There is evidence for a longer period signal; however, several more years of observations are needed to put tight constraints on the Keplerian parameters for the outer planet. Lastly, an additional planet has been detected orbiting HD 10442 with a period of 1043 days. Based on observations obtained at the W. M. Keck Observatory, which is operated by the University of California and the California Institute of Technology. Keck time has been granted by NOAO and NASA.

  18. Water loss from terrestrial planets orbiting ultracool dwarfs: implications for the planets of TRAPPIST-1

    Science.gov (United States)

    Bolmont, E.; Selsis, F.; Owen, J. E.; Ribas, I.; Raymond, S. N.; Leconte, J.; Gillon, M.

    2017-01-01

    Ultracool dwarfs (UCD; Teff TRAPPIST-1. Despite assumptions maximizing the FUV photolysis of water and the XUV-driven escape of hydrogen, we find that planets can retain significant amount of water in the HZ of UCDs, with a sweet spot in the 0.04-0.06 M⊙ range. We also studied the TRAPPIST-1 system using observed constraints on the XUV flux. We find that TRAPPIST-1b and c may have lost as much as 15 Earth oceans and planet d - which might be inside the HZ - may have lost less than 1 Earth ocean. Depending on their initial water contents, they could have enough water to remain habitable. TRAPPIST-1 planets are key targets for atmospheric characterization and could provide strong constraints on the water erosion around UCDs.

  19. Zero Age Planetary Orbit of Gas Giant Planets Revisited: Reinforcement of the Link with Stellar Metallicity

    CERN Document Server

    Pinotti, Rafael; de Mello, Gustavo Frederico Porto

    2016-01-01

    In 2005 we suggested a relation between the optimal locus of gas giant planet formation, prior to migration, and the metallicity of the host star, based on the core accretion model and radial profiles of dust surface density and gas temperature. At that time, less than two hundred extrasolar planets were known, limiting the scope of our analysis. Here we take into account the expanded statistics allowed by new discoveries, in order to check the validity of some premises. We compare predictions with the present available data and results for different stellar mass ranges. We find that the Zero Age Planetary Orbit (ZAPO) hypothesis continues to hold after a one order of magnitude increase in discovered planets. In particular, the prediction that metal poor stars harbor planets with an average radius distinctively lower than metal rich ones is still evident in the statistics, and cannot be explained away by chaotic planetary formation mechanisms involving migration and gravitational interaction between planets. ...

  20. A Terrestrial Planet in a ~1 AU Orbit Around One Member of a ~15 AU Binary

    CERN Document Server

    Gould, A; Shin, I -G; Porritt, I; Skowron, J; Han, C; Yee, J C; Kozłowski, S; Choi, J -Y; Poleski, R; Wyrzykowski, Ł; Ulaczyk, K; Pietrukowicz, P; Mróz, P; Szymański, M K; Kubiak, M; Soszyński, I; Pietrzyński, G; Gaudi, B S; Christie, G W; Drummond, J; McCormick, J; Natusch, T; Ngan, H; Tan, T -G; Albrow, M; DePoy, D L; Hwang, K -H; Jung, Y K; Lee, C -U; Park, H; Pogge, R W; Abe, F; Bennett, D P; Bond, I A; Botzler, C S; Freeman, M; Fukui, A; Fukunaga, D; Itow, Y; Koshimoto, N; Larsen, P; Ling, C H; Masuda, K; Matsubara, Y; Muraki, Y; Namba, S; Ohnishi, K; Philpott, L; Rattenbury, N J; Saito, To; Sullivan, D J; Sumi, T; Suzuki, D; Tristram, P J; Tsurumi, N; Wada, K; Yamai, N; Yock, P C M; Yonehara, A; Shvartzvald, Y; Maoz, D; Kaspi, S; Friedmann, M

    2014-01-01

    We detect a cold, terrestrial planet in a binary-star system using gravitational microlensing. The planet has low mass (2 Earth masses) and lies projected at $a_{\\perp,ph}$ ~ 0.8 astronomical units (AU) from its host star, similar to the Earth-Sun distance. However, the planet temperature is much lower, T<60 Kelvin, because the host star is only 0.10--0.15 solar masses and therefore more than 400 times less luminous than the Sun. The host is itself orbiting a slightly more massive companion with projected separation $a_{\\perp,ch}=$10--15 AU. Straightforward modification of current microlensing search strategies could increase their sensitivity to planets in binary systems. With more detections, such binary-star/planetary systems could place constraints on models of planet formation and evolution. This detection is consistent with such systems being very common.

  1. Possible Implications of the Planet Orbiting the Red Horizontal Branch Star HIP 13044

    CERN Document Server

    Bear, Ealeal; Harpaz, Amos

    2011-01-01

    We propose a scenario to account for the surprising orbital properties of the planet orbiting the metal poor red horizontal branch star HIP 13044. The orbital period of 16.2 days implies that the planet went through a common envelope phase inside the red giant branch (RGB) stellar progenitor of HIP 13044. The present properties of the star imply that the star maintained a substantial envelope mass of 0.3Mo, raising the question of how the planet survived the common envelope before the envelope itself was lost? If such a planet enters the envelope of an RGB star, it is expected to spiral-in to the very inner region within <100yr, and be evaporated or destructed by the core. We speculate that the planet was engulfed by the star as a result of the core helium flash that caused this metal poor star to swell by a factor of ~3-4. The evolution following the core helium flash is very rapid, and some of the envelope is lost due to the interaction with the planet, and the rest of the envelope shrinks within about a...

  2. The Orbits of Terrestrial Planets in the Habitable Zones of Known Exoplanetary Systems

    CERN Document Server

    Jones, B W; Jones, Barrie W

    2002-01-01

    We show that terrestrial planets could survive in variously restricted regions of the habitable zones of 47 Ursae Majoris, Epsilon Eridani, and Rho Coronae Borealis, but nowhere in the habitable zones of Gliese 876 and Upsilon Andromedae. The first three systems between them are representative of a large proportion of the 90 or so extrasolar planetary systems discovered by mid-2002, and thus there are many known systems worth searching for terrestrial planets in habitable zones. We reach our conclusions by launching putative Earth-mass planets in various orbits and following their fate with a mixed-variable symplectic integrator.

  3. Habitability of planets on eccentric orbits: the limits of the mean flux approximation

    CERN Document Server

    Bolmont, Emeline; Leconte, Jérémy; Selsis, Franck

    2016-01-01

    Contrary to Earth, which has a small orbital eccentricity, some exoplanets discovered in the insolation habitable zone (HZ) have high orbital eccentricities (e.g., up to an eccentricity of $\\sim0.97$ for HD~20782~b). This raises the question of the capacity of these planets to host surface liquid water. In order to assess the habitability of an eccentric planet, the mean flux approximation is often used. It states that a planet on an eccentric orbit is called habitable if it receives on average a flux compatible with the presence of surface liquid water. However, as the planets do experience important insolation variations over one orbit and even spend some time outside the HZ for high eccentricities, the question of their habitability might not be as straightforward. We performed a set of simulations using the Global Climate Model LMDz, exploring the limits of the mean flux approximation when varying the luminosity of the host star and the eccentricity of the planet. We computed the climate of tidally locked...

  4. The Gemini NICI Planet-Finding Campaign: The Orbit of the Young Exoplanet β Pictoris b

    Science.gov (United States)

    Nielsen, Eric L.; Liu, Michael C.; Wahhaj, Zahed; Biller, Beth A.; Hayward, Thomas L.; Males, Jared R.; Close, Laird M.; Morzinski, Katie M.; Skemer, Andrew J.; Kuchner, Marc J.; Rodigas, Timothy J.; Hinz, Philip M.; Chun, Mark; Ftaclas, Christ; Toomey, Douglas W.

    2014-10-01

    We present new astrometry for the young (12-21 Myr) exoplanet β Pictoris b taken with the Gemini/NICI and Magellan/MagAO instruments between 2009 and 2012. The high dynamic range of our observations allows us to measure the relative position of β Pic b with respect to its primary star with greater accuracy than previous observations. Based on a Markov Chain Monte Carlo analysis, we find the planet has an orbital semi-major axis of 9.1+5.3-0.5 AU and orbital eccentricity parameters than previously possible, and that the planet's projected separation is currently decreasing. With unsaturated data of the entire β Pic system (primary star, planet, and disk) obtained thanks to NICI's semi-transparent focal plane mask, we are able to tightly constrain the relative orientation of the circumstellar components. We find the orbital plane of the planet lies between the inner and outer disks: the position angle (P.A.) of nodes for the planet's orbit (211.8 ± 0.°3) is 7.4σ greater than the P.A. of the spine of the outer disk and 3.2σ less than the warped inner disk P.A., indicating the disk is not collisionally relaxed. Finally, for the first time we are able to dynamically constrain the mass of the primary star β Pic to 1.76+0.18-0.17 M ⊙.

  5. Tidal Interactions and Disruptions of Giant Planets on Highly Eccentric Orbits

    CERN Document Server

    Faber, J A; Willems, B; Faber, Joshua A.; Rasio, Frederic A.; Willems, Bart

    2004-01-01

    We calculate the evolution of planets undergoing a strong tidal encounter using smoothed particle hydrodynamics (SPH), for a range of periastron separations. We find that outside the Roche limit, the evolution of the planet is well-described by the standard model of linear, non-radial, adiabatic oscillations. If the planet passes within the Roche limit at periastron, however, mass can be stripped from it, but in no case do we find enough energy transferred to the planet to lead to complete disruption. In light of the three new extrasolar planets discovered with periods shorter than two days, we argue that the shortest-period cases observed in the period-mass relation may be explained by a model whereby planets undergo strong tidal encounters with stars, after either being scattered by dynamical interactions into highly eccentric orbits, or tidally captured from nearly parabolic orbits. Although this scenario does provide a natural explanation for the edge found for planets at twice the Roche limit, it does no...

  6. Detectability of Red-Edge-shifted Vegetation on Terrestrial Planets Orbiting M Stars

    Science.gov (United States)

    Tinetti, Giovanna; Rashby, Sky; Yung, Yuk L.

    2006-06-01

    We have explored the detectability of exovegetation on the surface of a terrestrial planet orbiting an M star. The exovegetation is responsible for producing a pigment-derived surface signature that is redshifted with respect to the Earth vegetation's red edge. The redshift was estimated using a model of leaf optical property spectra (Jacquemoud & Baret) combined with a 3 photon photosynthetic scheme calculated by Wolstencroft & Raven for a possible exovegetation growing on an M star planet. To study the detectability of this surface biosignature on an M star terrestrial planet, we have used the three-dimensional model developed by Tinetti et al. for the case of the Earth. This model can generate disk-averaged spectra and broadband integrated fluxes, which will be useful for future terrestrial planet exploration missions, such as the NASA Terrestrial Planet Finder Coronagraph. Input to this model were the atmospheric profiles and cloud distributions predicted by Joshi and coworkers for a synchronous planet orbiting an M dwarf and the distinctive surface reflectance of the exovegetation. While on Earth this pigment-derived surface feature would be almost completely masked by water absorption, even in a cloud-free atmosphere, we found that the strength of the edge feature on our simulated M star terrestrial planet can exceed that on Earth, given the right conditions. Obviously, the detectability of such biosignatures would be highly dependent on the extent of vegetation surface area, cloud cover, and viewing angle.

  7. The CRIRES Search for Planets Around the Lowest-Mass Stars. II. No Giant Planet Orbiting VB10

    CERN Document Server

    Bean, Jacob L; Hartman, Henrik; Nilsson, Hampus; Reiners, Ansgar; Dreizler, Stefan; Henry, Todd J; Wiedemann, Guenter

    2009-01-01

    We present radial velocities of the very low-mass star VB10 obtained over a time span of 0.61 yr as part of an ongoing search for planets around stars at the end of the main sequence. The radial velocities were measured from high-resolution near-infrared spectra obtained using the CRIRES instrument on the VLT with an ammonia gas cell. The typical internal precision of the measurements is 10 m/s. These data do not exhibit significant variability and are essentially constant at a level consistent with the measurement uncertainties. Therefore, we do not detect the radial velocity variations of VB10 expected due to the presence of an orbiting giant planet similar to that recently proposed by Pravdo and Shaklan based on apparent astrometric perturbations. In addition, we do not confirm the ~1 km/s radial velocity variability of the star tentatively detected by Zapatero Osorio and colleagues with lower precision measurements. Our measurements rule out planets with M > 3 M_Jup and the orbital period and inclination ...

  8. Alignment of the stellar spin with the orbits of a three-planet system.

    Science.gov (United States)

    Sanchis-Ojeda, Roberto; Fabrycky, Daniel C; Winn, Joshua N; Barclay, Thomas; Clarke, Bruce D; Ford, Eric B; Fortney, Jonathan J; Geary, John C; Holman, Matthew J; Howard, Andrew W; Jenkins, Jon M; Koch, David; Lissauer, Jack J; Marcy, Geoffrey W; Mullally, Fergal; Ragozzine, Darin; Seader, Shawn E; Still, Martin; Thompson, Susan E

    2012-07-25

    The Sun's equator and the planets' orbital planes are nearly aligned, which is presumably a consequence of their formation from a single spinning gaseous disk. For exoplanetary systems this well-aligned configuration is not guaranteed: dynamical interactions may tilt planetary orbits, or stars may be misaligned with the protoplanetary disk through chaotic accretion , magnetic interactions or torques from neighbouring stars. Indeed, isolated 'hot Jupiters' are often misaligned and even orbiting retrograde. Here we report an analysis of transits of planets over starspots on the Sun-like star Kepler-30 (ref. 8), and show that the orbits of its three planets are aligned with the stellar equator. Furthermore, the orbits are aligned with one another to within a few degrees. This configuration is similar to that of our Solar System, and contrasts with the isolated hot Jupiters. The orderly alignment seen in the Kepler-30 system suggests that high obliquities are confined to systems that experienced disruptive dynamical interactions. Should this be corroborated by observations of other coplanar multi-planet systems, then star-disk misalignments would be ruled out as the explanation for the high obliquities of hot Jupiters, and dynamical interactions would be implicated as the origin of hot Jupiters.

  9. First limits on the occurrence rate of short-period planets orbiting brown dwarfs

    Science.gov (United States)

    He, Matthias Y.; Triaud, Amaury H. M. J.; Gillon, Michaël

    2017-01-01

    Planet formation theories predict a large but still undetected population of short-period terrestrial planets orbiting brown dwarfs. Should specimens of this population be discovered transiting relatively bright and nearby brown dwarfs, the Jupiter-size and the low luminosity of their hosts would make them exquisite targets for detailed atmospheric characterization with JWST and future ground-based facilities. The eventual discovery and detailed study of a significant sample of transiting terrestrial planets orbiting nearby brown dwarfs could prove to be useful not only for comparative exoplanetology but also for astrobiology, by bringing us key information on the physical requirements and time-scale for the emergence of life. In this context, we present a search for transit-signals in archival time series photometry acquired by the Spitzer Space Telescope for a sample of 44 nearby brown dwarfs. While these 44 targets were not particularly selected for their brightness, the high precision of their Spitzer light curves allows us to reach sensitivities below Earth-sized planets for 75 per cent of the sample and down to Europa-sized planets on the brighter targets. We could not identify any unambiguous planetary signal. Instead, we could compute the first limits on the presence of planets on close-in orbits. We find that within a 1.28 d orbit, the occurrence rate of planets with a radius between 0.75 and 3.25 R⊕ is η TRAPPIST-1b systems would suggest, we estimate that 175 brown dwarfs need to be monitored in order to guarantee (95 per cent) at least one detection.

  10. The Gemini NICI planet-finding campaign: the orbit of the young exoplanet β Pictoris b

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Eric L.; Liu, Michael C.; Chun, Mark; Ftaclas, Christ [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Wahhaj, Zahed [European Southern Observatory, Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago (Chile); Biller, Beth A. [Institute for Astronomy, The University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Hayward, Thomas L. [Gemini Observatory, Southern Operations Center, c/o AURA, Casilla 603, La Serena (Chile); Males, Jared R.; Close, Laird M.; Morzinski, Katie M.; Skemer, Andrew J.; Hinz, Philip M. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Kuchner, Marc J. [Goddard Space Flight Center, Code 667, Greenbelt, MD 20771 (United States); Rodigas, Timothy J. [Department of Terrestrial Magnetism, Carnegie Institute of Washington, 5241 Broad Branch Road, NW, Washington, DC 20015 (United States); Toomey, Douglas W. [Mauna Kea Infrared, LLC, 21 Pookela Street, Hilo, HI 96720 (United States)

    2014-10-20

    We present new astrometry for the young (12-21 Myr) exoplanet β Pictoris b taken with the Gemini/NICI and Magellan/MagAO instruments between 2009 and 2012. The high dynamic range of our observations allows us to measure the relative position of β Pic b with respect to its primary star with greater accuracy than previous observations. Based on a Markov Chain Monte Carlo analysis, we find the planet has an orbital semi-major axis of 9.1{sub −0.5}{sup +5.3} AU and orbital eccentricity <0.15 at 68% confidence (with 95% confidence intervals of 8.2-48 AU and 0.00-0.82 for semi-major axis and eccentricity, respectively, due to a long narrow degenerate tail between the two). We find that the planet has reached its maximum projected elongation, enabling higher precision determination of the orbital parameters than previously possible, and that the planet's projected separation is currently decreasing. With unsaturated data of the entire β Pic system (primary star, planet, and disk) obtained thanks to NICI's semi-transparent focal plane mask, we are able to tightly constrain the relative orientation of the circumstellar components. We find the orbital plane of the planet lies between the inner and outer disks: the position angle (P.A.) of nodes for the planet's orbit (211.8 ± 0.°3) is 7.4σ greater than the P.A. of the spine of the outer disk and 3.2σ less than the warped inner disk P.A., indicating the disk is not collisionally relaxed. Finally, for the first time we are able to dynamically constrain the mass of the primary star β Pic to 1.76{sub −0.17}{sup +0.18} M {sub ☉}.

  11. The impact of red noise in radial velocity planet searches: Only three planets orbiting GJ581?

    CERN Document Server

    Baluev, Roman V

    2012-01-01

    We perform a detailed analysis of the latest HARPS and Keck radial velocity data for the planet-hosting red dwarf GJ581, which attracted a lot of attention in recent time. We show that these data contain important correlated noise component ("red noise") with the correlation timescale of the order of 10 days. This red noise imposes a lot of misleading effects while we work in the traditional white-noise model. To eliminate these misleading effects, we propose a maximum-likelihood algorithm equipped by an extended model of the noise structure. We treat the red noise as a Gaussian random process with exponentially decaying correlation function. Using this method we prove that: (i) planets b and c do exist in this system, since they can be independently detected in the HARPS and Keck data, and regardless of the assumed noise models; (ii) planet e can also be confirmed independently by the both datasets, although to reveal it in the Keck data it is mandatory to take the red noise into account; (iii) the recently ...

  12. The Eccentricity Distribution of Short-Period Planet Candidates Detected by Kepler in Occultation

    CERN Document Server

    Shabram, Megan; Cisewski, Jessi; Ford, Eric B; Rogers, Leslie

    2015-01-01

    We characterize the eccentricity distribution of a sample of ~50 short-period planet candidates using transit and occultation measurements from NASA's Kepler Mission. First, we evaluate the sensitivity of our hierarchical Bayesian modeling and test its robustness to model misspecification using simulated data. When analyzing actual data assuming a Rayleigh distribution for eccentricity, we find that the posterior mode for the dispersion parameter is $\\sigma=0.081 \\pm^{0.014}_{0.003}$. We find that a two-component Gaussian mixture model for $e \\cos \\omega$ and $e \\sin \\omega$ provides a better model than either a Rayleigh or Beta distribution. Based on our favored model, we find that $\\sim90\\%$ of planet candidates in our sample come from a population with an eccentricity distribution characterized by a small dispersion ($\\sim0.01$), and $\\sim10\\%$ come from a population with a larger dispersion ($\\sim0.22$). Finally, we investigate how the eccentricity distribution correlates with selected planet and host sta...

  13. The Dynamics of the Multi-planet System Orbiting Kepler-56

    CERN Document Server

    Li, Gongjie; Valsecchi, Francesca; Johnson, John Asher; Rasio, Frederic A

    2014-01-01

    Kepler-56 is a multi-planet system containing two coplanar inner planets that are in orbits misaligned with respect to the spin axis of the host star, and an outer planet. Various mechanisms have been proposed to explain the broad distribution of spin-orbit angles among exoplanets, and these theories fall under two broad categories. The first is based on dynamical interactions in a multi-body system, while the other assumes that disk migration is the driving mechanism in planetary configuration and that the star (or disk) is titled with respect to the planetary plane. Here we show that the large observed obliquity of Kepler-56 system is consistent with a dynamical origin. In addition, we use observations by Huber et al. (2013) to derive the obliquity's probability distribution function, thus improving the constrained lower limit. The outer planet may be the cause of the inner planets' large obliquities, and we give the probability distribution function of its inclination, which depends on the initial orbital ...

  14. XUV-driven mass loss from extrasolar giant planets orbiting active stars

    Science.gov (United States)

    Chadney, J. M.; Galand, M.; Unruh, Y. C.; Koskinen, T. T.; Sanz-Forcada, J.

    2015-04-01

    Upper atmospheres of Hot Jupiters are subject to extreme radiation conditions that can result in rapid atmospheric escape. The composition and structure of the upper atmospheres of these planets are affected by the high-energy spectrum of the host star. This emission depends on stellar type and age, which are thus important factors in understanding the behaviour of exoplanetary atmospheres. In this study, we focus on Extrasolar Giant Planets (EPGs) orbiting K and M dwarf stars. XUV spectra for three different stars - ɛ Eridani, AD Leonis and AU Microscopii - are constructed using a coronal model. Neutral density and temperature profiles in the upper atmosphere of hypothetical EGPs orbiting these stars are then obtained from a fluid model, incorporating atmospheric chemistry and taking atmospheric escape into account. We find that a simple scaling based solely on the host star's X-ray emission gives large errors in mass loss rates from planetary atmospheres and so we have derived a new method to scale the EUV regions of the solar spectrum based upon stellar X-ray emission. This new method produces an outcome in terms of the planet's neutral upper atmosphere very similar to that obtained using a detailed coronal model of the host star. Our results indicate that in planets subjected to radiation from active stars, the transition from Jeans escape to a regime of hydrodynamic escape at the top of the atmosphere occurs at larger orbital distances than for planets around low activity stars (such as the Sun).

  15. Hot Jupiters with relatives: discovery of additional planets in orbit around WASP-41 and WASP-47

    CERN Document Server

    Neveu-VanMalle, M; Anderson, D R; Brown, D J A; Cameron, A Collier; Delrez, L; Díaz, R F; Gillon, M; Hellier, C; Jehin, E; Lister, T; Pepe, F; Rojo, P; Ségransan, D; Triaud, A H M J; Turner, O D; Udry, S

    2015-01-01

    We report the discovery of two additional planetary companions to WASP-41 and WASP-47. WASP-41 c is a planet of minimum mass 3.18 $\\pm$ 0.20 M$_{\\rm Jup}$, eccentricity 0.29 $\\pm$ 0.02 and orbiting in 421 $\\pm$ 2 days. WASP-47 c is a planet of minimum mass 1.24 $\\pm$ 0.22 M$_{\\rm Jup}$, eccentricity 0.13 $\\pm$ 0.10 and orbiting in 572 $\\pm$ 7 days. Unlike most of the planetary systems including a hot Jupiter, these two systems with a hot Jupiter have a long period planet located at only $\\sim$1 AU from their host star. WASP-41 is a rather young star known to be chromospherically active. To differentiate its magnetic cycle from the radial velocity effect due the second planet, we use the emission in the H$\\alpha$ line and find this indicator well suited to detect the stellar activity pattern and the magnetic cycle. The analysis of the Rossiter-McLaughlin effect induced by WASP-41 b suggests that the planet could be misaligned, though an aligned orbit cannot be excluded. WASP-47 has recently been found to host ...

  16. EPIC 211351816.01: A (Re-?)Inflated Planet Orbiting a Red Giant Star

    CERN Document Server

    Grunblatt, Samuel K; Gaidos, Eric J; Lopez, Eric D; Fulton, Benjamin J; Fortney, Jonathan J; Howard, Andrew W; Sinukoff, Evan J; Mann, Andrew W; Isaacson, Howard

    2016-01-01

    Giant planets with high incident fluxes have been observed with radii larger than thermal evolution models would allow. Although these inflated planets have been known for almost two decades, it is unclear whether their inflation is caused by deposition of energy from the host star, or inhibited cooling of the planet. These processes can be distinguished if the planet becomes highly irradiated only when the host star evolves onto the red giant branch. We report the discovery of EPIC 211351816.01, a 1.27 +/- 0.09 RJ, 1.10 +/- 0.11 MJ planet orbiting a 4.20 +/- 0.14 Rsun, 1.16 +/- 0.12 Msun red giant star with an orbital period of 8.4 days. We precisely constrained stellar and planetary parameters by combining asteroseismology, spectroscopy, and granulation noise modeling along with transit and radial velocity measurements. Our calculations suggest the incident flux on this planet was ~200 +/- 100 times the flux on Earth while the star was on the main sequence, comparable to the suggested threshold flux for pla...

  17. Present status of Japanese Venus Climate Orbiter Planet-C in 2009

    Science.gov (United States)

    Nakamura, M.

    2009-04-01

    Japanese Venus climate orbiter PLANET-C is JAXA's third planetary explorer succeeding Suisei (PLANET-A) and Nozomi (PLANET-B). PLANET-C will be launched in 2010 and travel around the sun to reach Venus within the same year, then it will enter the Venusian orbit. PLANET-C will research the Venusian atmosphere, which is covered by thick clouds. It carries five cameras including ultraviolet and optical devices and even infrared cameras. Each of them will capture images of the clouds at different altitudes. The infrared cameras will look through the top layer of the clouds to see the lower atmosphere. Using these cameras, PLANET-C will take one photo every two hours at various wavelengths. We have finished the Proto-Model integration test of major components of VCO in December 2007. In March 2008, we finished the CDR for the phase-up (to Phase D). The flight model development will be finalized by 2009 and the final integration test will be done during whole 2009. There is no delay in schedule so far.

  18. The Orbit and Mass of the Third Planet in the Kepler-56 System

    CERN Document Server

    Otor, Oderah Justin; Johnson, John Asher; Charbonneau, David; Collier-Cameron, Andrew; Howard, Andrew W; Isaacson, Howard; Latham, David W; Lopez-Morales, Mercedes; Lovis, Christophe; Mayor, Michel; Micela, Giusi; Molinari, Emilio; Pepe, Francesco; Piotto, Giampaolo; Phillips, David F; Queloz, Didier; Rice, Ken; Sasselov, Dimitar; Ségransan, Damien; Sozzetti, Alessandro; Udry, Stéphane; Watson, Chris

    2016-01-01

    While the vast majority of multiple-planet systems have their orbital angular momentum axes aligned with the spin axis of their host star, Kepler-56 is an exception: its two transiting planets are coplanar yet misaligned by at least 40 degrees with respect to their host star. Additional follow-up observations of Kepler-56 suggest the presence of a massive, non-transiting companion that may help explain this misalignment. We model the transit data along with Keck/HIRES and HARPS-N radial velocity data to update the masses of the two transiting planets and infer the physical properties of the third, non-transiting planet. We employ a Markov Chain Monte Carlo sampler to calculate the best-fitting orbital parameters and their uncertainties for each planet. We find the outer planet has a period of 1002 $\\pm$ 5 days and minimum mass of 5.61 $\\pm$ 0.38 Jupiter masses. We also place a 95% upper limit of 0.80 m/s/yr on long-term trends caused by additional, more distant companions.

  19. The K2-ESPRINT Project V: a short-period giant planet orbiting a subgiant star

    CERN Document Server

    Van Eylen, Vincent; Gandolfi, Davide; Dai, Fei; Winn, Joshua N; Hirano, Teriyuki; Narita, Norio; Bruntt, Hans; Prieto-Arranz, Jorge; Bejar, Victor J S; Nowak, Grzegorz; Lund, Mikkel N; Palle, Enric; Ribas, Ignasi; Sanchis-Ojeda, Roberto; Yu, Liang; Arriagada, Pamela; Butler, R Paul; Crane, Jeffrey D; Handberg, Rasmus; Deeg, Hans; Jessen-Hansen, Jens; Johnson, John A; Nespral, David; Rogers, Leslie; Ryu, Tsuguru; Shectman, Stephen; Shrotriya, Tushar; Slumstrup, Ditte; Takeda, Yoichi; Teske, Johanna; Thompson, Ian; Vanderburg, Andrew; Wittenmyer, Robert

    2016-01-01

    We report on the discovery and characterization of the transiting planet K2-39b (EPIC 206247743b). With an orbital period of 4.6 days, it is the shortest-period planet orbiting a subgiant star known to date. Such planets are rare, with only a handful of known cases. The reason for this is poorly understood, but may reflect differences in planet occurrence around the relatively high-mass stars that have been surveyed, or may be the result of tidal destruction of such planets. K2-39 is an evolved star with a spectroscopically derived stellar radius and mass of $3.88^{+0.48}_{-0.42}~\\mathrm{R_\\odot}$ and $1.53^{+0.13}_{-0.12}~\\mathrm{M_\\odot}$, respectively, and a very close-in transiting planet, with $a/R_\\star = 3.4$. Radial velocity (RV) follow-up using the HARPS, FIES and PFS instruments leads to a planetary mass of $50.3^{+9.7}_{-9.4}~\\mathrm{M_\\oplus}$. In combination with a radius measurement of $8.3 \\pm 1.1~\\mathrm{R_\\oplus}$, this results in a mean planetary density of $0.50^{+0.29}_{-0.17}$ g~cm$^{-3}$...

  20. The K2-ESPRINT Project V: a short-period giant planet orbiting a subgiant star

    DEFF Research Database (Denmark)

    Van Eylen, Vincent; Albrecht, Simon; Gandolfi, Davide;

    2016-01-01

    {R_\\odot}$ and $1.53^{+0.13}_{-0.12}~\\mathrm{M_\\odot}$, respectively, and a very close-in transiting planet, with $a/R_\\star = 3.4$. Radial velocity (RV) follow-up using the HARPS, FIES and PFS instruments leads to a planetary mass of $50.3^{+9.7}_{-9.4}~\\mathrm{M_\\oplus}$. In combination with a radius measurement......We report on the discovery and characterization of the transiting planet K2-39b (EPIC 206247743b). With an orbital period of 4.6 days, it is the shortest-period planet orbiting a subgiant star known to date. Such planets are rare, with only a handful of known cases. The reason for this is poorly...... understood, but may reflect differences in planet occurrence around the relatively high-mass stars that have been surveyed, or may be the result of tidal destruction of such planets. K2-39 is an evolved star with a spectroscopically derived stellar radius and mass of $3.88^{+0.48}_{-0.42}~\\mathrm...

  1. First limits on the occurrence rate of short-period planets orbiting brown dwarfs

    CERN Document Server

    He, Matthias Y; Gillon, Michaël

    2016-01-01

    Planet formation theories predict a large but still undetected population of short-period terrestrial planets orbiting brown dwarfs. Should specimens of this population be discovered transiting relatively bright and nearby brown dwarfs, the Jupiter-size and the low luminosity of their hosts would make them exquisite targets for detailed atmospheric characterisation with JWST and future ground-based facilities. The eventual discovery and detailed study of a significant sample of transiting terrestrial planets orbiting nearby brown dwarfs could prove to be useful not only for comparative exoplanetology but also for astrobiology, by bringing us key information on the physical requirements and timescale for the emergence of life. In this context, we present a search for transit-signals in archival time-series photometry acquired by the Spitzer Space Telescope for a sample of 44 nearby brown dwarfs. While these 44 targets were not particularly selected for their brightness, the high precision of their Spitzer ligh...

  2. UV SURFACE ENVIRONMENT OF EARTH-LIKE PLANETS ORBITING FGKM STARS THROUGH GEOLOGICAL EVOLUTION

    Energy Technology Data Exchange (ETDEWEB)

    Rugheimer, S.; Sasselov, D. [Harvard Smithsonian Center for Astrophysics, 60 Garden st., 02138 MA Cambridge (United States); Segura, A. [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, México (Mexico); Kaltenegger, L., E-mail: srugheimer@cfa.harvard.edu [Carl Sagan Institute, Cornell University, Ithaca, NY 14853 (United States)

    2015-06-10

    The UV environment of a host star affects the photochemistry in the atmosphere, and ultimately the surface UV environment for terrestrial planets and therefore the conditions for the origin and evolution of life. We model the surface UV radiation environment for Earth-sized planets orbiting FGKM stars in the circumstellar Habitable Zone for Earth through its geological evolution. We explore four different types of atmospheres corresponding to an early-Earth atmosphere at 3.9 Gyr ago and three atmospheres covering the rise of oxygen to present-day levels at 2.0 Gyr ago, 0.8 Gyr ago, and modern Earth. In addition to calculating the UV flux on the surface of the planet, we model the biologically effective irradiance, using DNA damage as a proxy for biological damage. We find that a pre-biotic Earth (3.9 Gyr ago) orbiting an F0V star receives 6 times the biologically effective radiation as around the early Sun and 3520 times the modern Earth–Sun levels. A pre-biotic Earth orbiting GJ 581 (M3.5 V) receives 300 times less biologically effective radiation, about 2 times modern Earth–Sun levels. The UV fluxes calculated here provide a grid of model UV environments during the evolution of an Earth-like planet orbiting a range of stars. These models can be used as inputs into photo-biological experiments and for pre-biotic chemistry and early life evolution experiments.

  3. Prevalence of Earth-size planets orbiting Sun-like stars

    CERN Document Server

    Petigura, Erik A; Marcy, Geoffrey W

    2013-01-01

    Determining whether Earth-like planets are common or rare looms as a touchstone in the question of life in the universe. We searched for Earth-size planets that cross in front of their host stars by examining the brightness measurements of 42,000 stars from National Aeronautics and Space Administration's Kepler mission. We found 603 planets, including 10 that are Earth size (1-2 Earth-radii) and receive comparable levels of stellar energy to that of Earth (within a factor of four). We account for Kepler's imperfect detectability of such planets by injecting synthetic planet-caused dimmings into the Kepler brightness measurements and recording the fraction detected. We find that $11\\pm4%$ of Sun-like stars harbor an Earth-size planet receiving between one and four times the stellar intensity as Earth. We also find that the occurrence of Earth-size planets is constant with increasing orbital period (P), within equal intervals of logP up to $\\sim200$ d. Extrapolating, one finds $5.7^{+1.7}_{-2.2}%$ of Sun-like s...

  4. On the orbital evolution of a pair of giant planets in mean motion resonance

    Science.gov (United States)

    André, Q.; Papaloizou, J. C. B.

    2016-10-01

    Pairs of extrasolar giant planets in a mean motion commensurability are common with 2:1 resonance occurring most frequently. Disc-planet interaction provides a mechanism for their origin. However, the time-scale on which this could operate in particular cases is unclear. We perform 2D and 3D numerical simulations of pairs of giant planets in a protoplanetary disc as they form and maintain a mean motion commensurability. We consider systems with current parameters similar to those of HD 155358, 24 Sextantis and HD 60532, and disc models of varying mass, decreasing mass corresponding to increasing age. For the lowest mass discs, systems with planets in the Jovian mass range migrate inwards maintaining a 2:1 commensurability. Systems with the inner planet currently at around 1 au from the central star could have originated at a few au and migrated inwards on a time-scale comparable to protoplanetary disc lifetimes. Systems of larger mass planets such as HD 60532 attain 3:1 resonance as observed. For a given mass accretion rate, results are insensitive to the disc model for the range of viscosity prescriptions adopted, there being good agreement between 2D and 3D simulations. However, in a higher mass disc a pair of Jovian mass planets passes through 2:1 resonance before attaining a temporary phase lasting a few thousand orbits in an unstable 5:3 resonance prior to undergoing a scattering. Thus, finding systems in this commensurability is unlikely.

  5. Zero age planetary orbit of gas giant planets revisited: reinforcement of the link with stellar metallicity

    Science.gov (United States)

    Pinotti, R.; Boechat-Roberty, H. M.; Porto de Mello, G. F.

    2017-01-01

    In 2005, we suggested a relation between the optimal locus of gas giant planet formation, prior to migration, and the metallicity of the host star, based on the core accretion model, and radial profiles of dust surface density and gas temperature. At that time, less than 200 extrasolar planets were known, limiting the scope of our analysis. Here, we take into account the expanded statistics allowed by new discoveries, in order to check the validity of some premises. We compare predictions with the present available data and results for different stellar mass ranges. We find that the zero age planetary orbit (ZAPO) hypothesis continues to hold after an order of magnitude increase in discovered planets. In particular, the prediction that metal-poor stars harbour planets with average radii distinctively lower than metal-rich ones is still evident in the statistics, and cannot be explained by chaotic planetary formation mechanisms involving migration and gravitational interaction between planets. The ZAPO hypothesis predicts that in metal-poor stars the planets are formed near their host stars; as a consequence, they are more frequently engulfed by the stars during the migration process or stripped of their gaseous envelops. The depleted number of gas giant planets around metal-poor stars would then be the result of the synergy between low formation probability, as predicted by the core accretion model, and high destruction probability, for the ones that are formed.

  6. A Search for Rocky Planets in Close Orbits around White Dwarfs

    Science.gov (United States)

    Debes, John; Sandhaus, Phoebe; Ely, Justin

    2015-12-01

    The search for transiting habitable exoplanets has broadened to include several types of stars that are smaller than the Sun in order to increase the observed transit depth and hence the atmospheric signal of the planet. Of all current spectral types, white dwarfs are the most favorable for this type of investigation. The fraction of white dwarfs that possess close-in rocky planets is unknown, but several large angle surveys of stars have the photometric precision and cadence to discover at least one if they are common. Ultraviolet observations of white dwarfs may allow for detection of molecular oxygen or ozone in the atmosphere of a terrestrial planet. We use archival Hubble Space Telescope data from the Cosmic Origins Spectrograph to search for transiting rocky planets around UV-bright white dwarfs. In the process, we discovered unusual variability in the pulsating white dwarf GD~133, which shows slow sinusoidal variations in the UV. While we detect no planets around our small sample of targets, we do place stringent limits on the possibility of transiting planets, down to sub-lunar radii. We also point out that non-transiting small planets in thermal equilibrium are detectable around hotter white dwarfs through infrared excesses, and identify two candidates.

  7. Specific effects of large asteroids on the orbits of terrestrial planets and the ASETEP database

    Science.gov (United States)

    Aljbaae, S.; Souchay, J.

    2012-04-01

    The necessity to take into account the perturbations caused by a large number of asteroids on the terrestrial planets is fundamental in the construction of modern numerical ephemeris on the solar system. Therefore about 300 of the largest asteroids were taken into account in recent ephemeris. Yet, the uncertainty on the mass values of the great majority of these asteroids constitutes a crucial and the main limit of accuracy of this ephemeris. Consequently, it is important to conduct a specific and detailed study of their individual effects especially on the terrestrial planets, which are far more affected than the giant planets. This was already done explicitly, but only for Mars and for only two orbital elements (a and λ). We aim both to confirm these previous results and to extend the study to all orbital elements and to the other three terrestrial planets (Mercury, Venus and the Earth), which are priori less affected by asteroid perturbations. Our methodology consists in several steps: we carried out precise computations of the orbital motions of the planets at short (100 y) and longer (1000 y) time scales with numerical integration. For that purpose we included the eight planets and also considered 43 of the most powerful asteroids. These were added to the numerical integrations once separately and once combined to determine their specific effects on the orbital elements of the Earth and the three other terrestrial planets. This procedure also allowed us to assess the spatial geocentric coordinates of the three terrestrial planets. We determined the signal that represents the effects by simple subtraction. Then we systematically analyzed this signal by FFT (fast Fourier transform), and finally we adjusted the signal with a set of sinusoidal components. We analyzed in detail the variations of the six orbital elements a, e, i, Ω, ˜ ω and λ of Mercury, Venus, the Earth-Moon barycenter (EMB) and Mars that are caused by the individual influences of the set of

  8. Thermal-orbital coupled tidal heating and habitability of Martian-sized extrasolar planets around M stars

    Energy Technology Data Exchange (ETDEWEB)

    Shoji, D.; Kurita, K. [Earthquake Research Institute, University of Tokyo, Tokyo (Japan)

    2014-07-01

    M-type stars are good targets in the search for habitable extrasolar planets. Due to their low effective temperatures, the habitable zone of M stars is very close to the stars themselves. For planets that are close to their stars, tidal heating plays an important role in thermal and orbital evolutions, especially when the planet's orbit has a relatively large eccentricity. Although tidal heating interacts with the thermal state and the orbit of the planet, such coupled calculations for extrasolar planets around M stars have not been conducted. We perform coupled calculations using simple structural and orbital models and analyze the thermal state and habitability of a terrestrial planet. Considering this planet to be Martian-sized, the tide heats up and partially melts the mantle, maintaining an equilibrium state if the mass of the star is less than 0.2 times the mass of the Sun and the initial eccentricity of the orbit is more than 0.2. The reduction of heat dissipation due to the melted mantle allows the planet to stay in the habitable zone for more than 10 Gyr even though the orbital distance is small. The surface heat flux at the equilibrium state is between that of Mars and Io. The thermal state of the planet mainly depends on the initial value of the eccentricity and the mass of the star.

  9. KOI-372: a young extrasolar system with two giant planets on wide and eccentric orbits

    CERN Document Server

    Mancini, L; Southworth, J; Borsato, L; Gandolfi, D; Ciceri, S; Barrado, D; Brahm, R; Henning, Th

    2015-01-01

    We confirm the planetary nature of KOI-372b (aka Kepler object of interest K00372.01), a giant transiting exoplanet orbiting a solar-analog G2V star. The mass of KOI-372b and the eccentricity of its orbit were accurately derived thanks to a series of precise radial velocity measurements obtained with the CAFE spectrograph mounted on the CAHA 2.2-m telescope. A simultaneous fit of the radial-velocity data and Kepler photometry revealed that KOI-372b is a dense Jupiter-like planet with a mass of Mp=3.25 Mjup and a radius of Rp=0.882 Rjup. KOI-372b is moving on a quite eccentric orbit, e=0.172, making a complete revolution around its parent star in 125.6 days. The semi-major axis of the orbit is 0.4937 au, implying that the planet is close to its habitable zone (roughly 0.5 au from it). By analysing the mid-transit times of the 12 transit events of KOI-372b recorded by the Kepler spacecraft, we found a clear transit time variation, which is attributable to the presence of a planet c in a wider orbit. We estimate...

  10. Photosynthetic potential of planets in 3 : 2 spin-orbit resonances

    Science.gov (United States)

    Brown, S. P.; Mead, A. J.; Forgan, D. H.; Raven, J. A.; Cockell, C. S.

    2014-10-01

    Photosynthetic life requires sufficient photosynthetically active radiation to metabolize. On Earth, plant behaviour, physiology and metabolism are sculpted around the night-day cycle by an endogenous biological circadian clock. The evolution of life was influenced by the Earth-Sun orbital dynamic, which generates the photo-environment incident on the planetary surface. In this work, the unusual photo-environment of an Earth-like planet (ELP) in 3 : 2 spin-orbit resonance is explored. Photo-environments on the ELP are longitudinally differentiated, in addition to differentiations related to latitude and depth (for aquatic organisms) which are familiar on Earth. The light environment on such a planet could be compatible with Earth's photosynthetic life although the threat of atmospheric freeze-out and prolonged periods of darkness would present significant challenges. We emphasize the relationship between the evolution of life on a planetary body with its orbital dynamics.

  11. Photosynthetic Potential of Planets in 3:2 Spin Orbit Resonances

    CERN Document Server

    Brown, S P; Forgan, D H; Raven, J A; Cockell, C S

    2014-01-01

    Photosynthetic life requires sufficient photosynthetically active radiation (PAR) to metabolise. On Earth, plant behaviour, physiology and metabolism are sculpted around the night-day cycle by an endogenous biological circadian clock. The evolution of life was influenced by the Earth-Sun orbital dynamic, which generates the photo-environment incident on the planetary surface. In this work the unusual photo-environment of an Earth-like planet (ELP) in 3:2 spin orbit resonance is explored. Photo-environments on the ELP are longitudinally differentiated, in addition to differentiations relating to latitude and depth (for aquatic organisms) which are familiar on Earth. The light environment on such a planet could be compatible with Earth's photosynthetic life although the threat of atmospheric freeze-out and prolonged periods of darkness would present significant challenges. We emphasise the relationship between the evolution of life on a planetary body with its orbital dynamics.

  12. Detection of transit timing variations in excess of one hour in the Kepler multi-planet candidate system KOI 806 with the GTC

    CERN Document Server

    Tingley, Brandon; Parviainen, Hannu; Deeg, Hans-Jörg; Osorio, Maria Rosa Zapatero; Cabrera-Lavers, Antonio; Belmonte, Juan Antonio; Rodriguez, Pilar Montañés; Murgas, Felipe; Ribas, Ignasi

    2011-01-01

    We report the detection of transit timing variations (TTVs) well in excess of one hour in the Kepler multi-planet candidate system KOI 806. This system exhibits transits consistent with three separate planets -- a Super-Earth, a Jupiter, and a Saturn -- lying very nearly in a 1:2:5 resonance, respectively. We used the Kepler public data archive and observations with the Gran Telescopio de Canarias to compile the necessary photometry. For the largest candidate planet (KOI 806.02) in this system, we detected a large transit timing variation of -103.5$\\pm$6.9 minutes against previously published ephemeris. We did not obtain a strong detection of a transit color signature consistent with a planet-sized object; however, we did not detect a color difference in transit depth, either. The large TTV is consistent with theoretical predictions that exoplanets in resonance can produce large transit timing variations, particularly if the orbits are eccentric. The presence of large TTVs among the bodies in this systems ind...

  13. The potential of planets orbiting red dwarf stars to support oxygenic photosynthesis and complex life

    Science.gov (United States)

    Gale, Joseph; Wandel, Amri

    2017-01-01

    We review the latest findings on extra-solar planets and their potential of having environmental conditions that could support Earth-like life. Focusing on planets orbiting red dwarf (RD) stars, the most abundant stellar type in the Milky Way, we show that including RDs as potential life supporting host stars could increase the probability of finding biotic planets by a factor of up to a thousand, and reduce the estimate of the distance to our nearest biotic neighbour by up to 10. We argue that binary and multiple star systems need to be taken into account when discussing habitability and the abundance of biotic exoplanets, in particular RDs in such systems. Early considerations indicated that conditions on RD planets would be inimical to life, as their habitable zones would be so close to the host star as to make planets tidally locked. This was thought to cause an erratic climate and expose life forms to flares of ionizing radiation. Recent calculations show that these negative factors are less severe than originally thought. It has also been argued that the lesser photon energy of the radiation of the relatively cool RDs would not suffice for oxygenic photosynthesis (OP) and other related energy expending reactions. Numerous authors suggest that OP on RD planets may evolve to utilize photons in the infrared. We however argue, by analogy to the evolution of OP and the environmental physiology and distribution of land-based vegetation on Earth, that the evolutionary pressure to utilize infrared radiation would be small. This is because vegetation on RD planets could enjoy continuous illumination of moderate intensity, containing a significant component of photosynthetic 400-700 nm radiation. We conclude that conditions for OP could exist on RD planets and consequently the evolution of complex life might be possible. Furthermore, the huge number and the long lifetime of RDs make it more likely to find planets with photosynthesis and life around RDs than around

  14. Advances in the Kepler Transit Search Engine and Automated Approaches to Identifying Likely Planet Candidates in Transit Surveys

    Science.gov (United States)

    Jenkins, Jon Michael

    2015-08-01

    Twenty years ago, no planets were known outside our own solar system. Since then, the discoveries of ~1500 exoplanets have radically altered our views of planets and planetary systems. This revolution is due in no small part to the Kepler Mission, which has discovered >1000 of these planets and >4000 planet candidates. While Kepler has shown that small rocky planets and planetary systems are quite common, the quest to find Earth’s closest cousins and characterize their atmospheres presses forward with missions such as NASA Explorer Program’s Transiting Exoplanet Survey Satellite (TESS) slated for launch in 2017 and ESA’s PLATO mission scheduled for launch in 2024.These future missions pose daunting data processing challenges in terms of the number of stars, the amount of data, and the difficulties in detecting weak signatures of transiting small planets against a roaring background. These complications include instrument noise and systematic effects as well as the intrinsic stellar variability of the subjects under scrutiny. In this paper we review recent developments in the Kepler transit search pipeline improving both the yield and reliability of detected transit signatures.Many of the phenomena in light curves that represent noise can also trigger transit detection algorithms. The Kepler Mission has expended great effort in suppressing false positives from its planetary candidate catalogs. While over 18,000 transit-like signatures can be identified for a search across 4 years of data, most of these signatures are artifacts, not planets. Vetting all such signatures historically takes several months’ effort by many individuals. We describe the application of machine learning approaches for the automated vetting and production of planet candidate catalogs. These algorithms can improve the efficiency of the human vetting effort as well as quantifying the likelihood that each candidate is truly a planet. This information is crucial for obtaining valid planet

  15. How terrestrial planets traverse spin-orbit resonances: A camel goes through a needle's eye

    CERN Document Server

    Makarov, Valeri V

    2011-01-01

    The dynamical evolution of terrestrial planets resembling Mercury in the vicinity of spin-orbit resonances is investigated using comprehensive harmonic expansions of the tidal torque with accurate expressions for the frequency-dependent quality factors and Love numbers. The torque equations are integrated numerically with a small step in time, taking into account the oscillating triaxial torque components but neglecting the layered structure of the planet and assuming a zero obliquity. We find that a Mercury-like planet with its current value of orbital eccentricity (0.2056) is always captured in the 3:2 resonance, and invariably traverses all higher resonances. The circumstances of a resonance passage are remarkable, in that it happens very quickly, in a sudden lunge. Considering the phase space parameters at the times of periastron, a Mercury-like planet can traverse the resonance only if its angle with respect to the star is close to $\\pm\\pi/2$, i.e., if the planet is positioned sidewise, with the longest ...

  16. OGLE-2011-BLG-0265Lb: a Jovian Microlensing Planet Orbiting an M Dwarf

    CERN Document Server

    Skowron, J; Udalski, A; Han, C; Sumi, T; Shvartzvald, Y; Gould, A; Dominis-Prester, D; Street, R A; Jørgensen, U G; Bennett, D P; Bozza, V; Szymański, M K; Kubiak, M; Pietrzyński, G; Soszyński, I; Poleski, R; Kozłowski, S; Pietrukowicz, P; Ulaczyk, K; Wyrzykowski, Ł; Abe, F; Bhattacharya, A; Bond, I A; Botzler, C S; Freeman, M; Fukui, A; Fukunaga, D; Itow, Y; Ling, C H; Koshimoto, N; Masuda, K; Matsubara, Y; Muraki, Y; Namba, S; Ohnishi, K; Philpott, L C; Rattenbury, N; Saito, T; Sullivan, D J; Suzuki, D; Tristram, P J; Yock, P C M; Maoz, D; Kaspi, S; Friedman, M; Almeida, L A; Batista, V; Christie, G; Choi, J -Y; DePoy, D L; Gaudi, B S; Henderson, C; Hwang, K -H; Jablonski, F; Jung, Y K; Lee, C -U; McCormick, J; Natusch, T; Ngan, H; Park, H; Pogge, R W; Yee, J; Albrow, M D; Bachelet, E; Beaulieu, J -P; Brillant, S; Caldwell, J A R; Cassan, A; Cole, A; Corrales, E; Coutures, Ch; Dieters, S; Donatowicz, J; Fouqué, P; Greenhill, J; Kains, N; Kane, S R; Kubas, D; Marquette, J -B; Martin, R; Menzies, J; Pollard, K R; Ranc, C; Sahu, K C; Wambsganss, J; Williams, A; Wouters, D; Tsapras, Y; Bramich, D M; Horne, K; Hundertmark, M; Snodgrass, C; Steele, I A; Alsubai, K A; Browne, P; Burgdorf, M J; Novati, S Calchi; Dodds, P; Dominik, M; Dreizler, S; Fang, X -S; Gu, C -H; Hardis,; Harpsøe, K; Hessman, F V; Hinse, T C; Hornstrup, A; Jessen-Hansen, J; Kerins, E; Liebig, C; Lund, M; Lundkvist, M; Mancini, L; Mathiasen, M; Penny, M T; Rahvar, S; Ricci, D; Scarpetta, G; Skottfelt, J; Southworth, J; Surdej, J; Tregloan-Reed, J; Wertz, O

    2014-01-01

    We report the discovery of a Jupiter-mass planet orbiting an M-dwarf star that gave rise to the microlensing event OGLE-2011-BLG-0265. Such a system is very rare among known planetary systems and thus the discovery is important for theoretical studies of planetary formation and evolution. High-cadence temporal coverage of the planetary signal combined with extended observations throughout the event allows us to accurately model the observed light curve. The final microlensing solution remains, however, degenerate yielding two possible configurations of the planet and the host star. In the case of the preferred solution, the mass of the planet is $M_{\\rm p}$ = 1.0 $\\pm$ 0.3 $M_{\\rm J}$, and the planet is orbiting a star with a mass $M$ = 0.23 $\\pm$ 0.07 $M_\\odot$. The second possible configuration (2\\sigma away) consists of a planet with $M_{\\rm p}$ = 0.6 $\\pm$ 0.2 $M_{\\rm J}$ and host star with $M$ = 0.15 $\\pm$ 0.06 $M_{\\odot}$. The system is located in the Galactic disk 3-4 kpc towards the Galactic bulge. In...

  17. Orbital Stability of Multi-Planet Systems: Behavior at High Masses

    CERN Document Server

    Morrison, Sarah J

    2016-01-01

    In the coming years, high contrast imaging surveys are expected to reveal the characteristics of the population of wide-orbit, massive, exoplanets. To date, a handful of wide planetary mass companions are known, but only one such multi-planet system has been discovered: HR8799. For low mass planetary systems, multi-planet interactions play an important role in setting system architecture. In this paper, we explore the stability of these high mass, multi-planet systems. While empirical relationships exist that predict how system stability scales with planet spacing at low masses, we show that extrapolating to super-Jupiter masses can lead to up to an order of magnitude overestimate of stability for massive, tightly packed systems. We show that at both low and high planet masses, overlapping mean motion resonances trigger chaotic orbital evolution, which leads to system instability. We attribute some of the difference in behavior as a function of mass to the increasing importance of second order resonances at h...

  18. Production of Star-Grazing and Star-Impacting Planetestimals via Orbital Migration of Extrasolar Planets

    Science.gov (United States)

    Quillen, A. C.; Holman, M.

    2000-01-01

    During the orbital migration of a giant extrasolar planet via ejection of planetesimals (as studied by Murray et al. in 1998), inner mean-motion resonances can be strong enough to cause planetesimals to graze or impact the star. We integrate numerically the motions of particles which pass through the 3:1 or 4:1 mean-motion resonances of a migrating Jupiter-mass planet. We find that many particles can be trapped in the 3:1 or 4:1 resonances and pumped to high enough eccentricities that they impact the star. This implies that for a planet migrating a substantial fraction of its semimajor axis, a fraction of its mass in planetesimals could impact the star. This process may be capable of enriching the metallicity of the star at a time when the star is no longer fully convective. Upon close approaches to the star, the surfaces of these planetesimals will be sublimated. Orbital migration should cause continuing production of evaporating bodies, suggesting that this process should be detectable with searches for transient absorption lines in young stars. The remainder of the particles will not impact the star but can be ejected subsequently by the planet as it migrates further inward. This allows the planet to migrate a substantial fraction of its initial semimajor axis by ejecting planetesimals.

  19. The Gemini NICI Planet-Finding Campaign: The Orbit of the Young Exoplanet beta Pictoris b

    CERN Document Server

    Nielsen, Eric L; Wahhaj, Zahed; Biller, Beth A; Hayward, Thomas L; Males, Jared R; Close, Laird M; Morzinski, Katie M; Skemer, Andrew J; Kuchner, Marc J; Chun, Mark; Ftaclas, Christ; Toomey, Douglas W

    2014-01-01

    We present new astrometry for the young (12-21 Myr) exoplanet beta Pictoris b taken with the Gemini/NICI, Magellan/MagAO+Clio2, and Magellan/MagAO+VisAO instruments between 2009 and 2012. The high dynamic range of our observations allows us to measure the relative position of beta Pic b with respect to its primary star with greater accuracy than previous observations. Based on a Markov Chain Monte Carlo analysis, we find the planet has an orbital semi-major axis of 9.2 [+8.3, -0.5] AU and orbital eccentricity <0.15 at 68% confidence (with 95% confidence intervals of 8.2-72.3 AU and 0.00-0.88 for semi-major axis and eccentricity, respectively). We find that the planet has reached its maximum projected elongation, enabling higher precision determination of the orbital parameters than previously possible, and that the planet's projected separation is currently decreasing. With unsaturated data of the entire beta Pic system (primary star, planet, and disk) obtained thanks to NICI's semi-transparent focal plane...

  20. Astrometric Monitoring of the HR 8799 Planets: Orbit Constraints from Self-consistent Measurements

    Science.gov (United States)

    Konopacky, Q. M.; Marois, C.; Macintosh, B. A.; Galicher, R.; Barman, T. S.; Metchev, S. A.; Zuckerman, B.

    2016-08-01

    We present new astrometric measurements from our ongoing monitoring campaign of the HR 8799 directly imaged planetary system. These new data points were obtained with NIRC2 on the W.M. Keck II 10 m telescope between 2009 and 2014. In addition, we present updated astrometry from previously published observations in 2007 and 2008. All data were reduced using the SOSIE algorithm, which accounts for systematic biases present in previously published observations. This allows us to construct a self-consistent data set derived entirely from NIRC2 data alone. From this data set, we detect acceleration for two of the planets (HR 8799b and e) at >3σ. We also assess possible orbital parameters for each of the four planets independently. We find no statistically significant difference in the allowed inclinations of the planets. Fitting the astrometry while forcing coplanarity also returns χ 2 consistent to within 1σ of the best fit values, suggesting that if inclination offsets of ≲20° are present, they are not detectable with current data. Our orbital fits also favor low eccentricities, consistent with predictions from dynamical modeling. We also find period distributions consistent to within 1σ with a 1:2:4:8 resonance between all planets. This analysis demonstrates the importance of minimizing astrometric systematics when fitting for solutions to highly undersampled orbits.

  1. The SOPHIE search for northern extrasolar planets. XI. Three new companions and an orbit update: Giant planets in the habitable zone

    Science.gov (United States)

    Díaz, R. F.; Rey, J.; Demangeon, O.; Hébrard, G.; Boisse, I.; Arnold, L.; Astudillo-Defru, N.; Beuzit, J.-L.; Bonfils, X.; Borgniet, S.; Bouchy, F.; Bourrier, V.; Courcol, B.; Deleuil, M.; Delfosse, X.; Ehrenreich, D.; Forveille, T.; Lagrange, A.-M.; Mayor, M.; Moutou, C.; Pepe, F.; Queloz, D.; Santerne, A.; Santos, N. C.; Sahlmann, J.; Ségransan, D.; Udry, S.; Wilson, P. A.

    2016-07-01

    We report the discovery of three new substellar companions to solar-type stars, HD 191806, HD 214823, and HD 221585, based on radial velocity measurements obtained at the Haute-Provence Observatory. Data from the SOPHIE spectrograph are combined with observations acquired with its predecessor, ELODIE, to detect and characterise the orbital parameters of three new gaseous giant and brown dwarf candidates. Additionally, we combine SOPHIE data with velocities obtained at the Lick Observatory to improve the parameters of an already known giant planet companion, HD 16175 b. Thanks to the use of different instruments, the data sets of all four targets span more than ten years. Zero-point offsets between instruments are dealt with using Bayesian priors to incorporate the information we possess on the SOPHIE/ELODIE offset based on previous studies. The reported companions have orbital periods between three and five years and minimum masses between 1.6 MJup and 19 MJup. Additionally, we find that the star HD 191806 is experiencing a secular acceleration of over 11 m s-1 per year, potentially due to an additional stellar or substellar companion. A search for the astrometric signature of these companions was carried out using Hipparcos data. No orbit was detected, but a significant upper limit to the companion mass can be set for HD 221585, whose companion must be substellar. With the exception of HD 191806 b, the companions are located within the habitable zone of their host star. Therefore, satellites orbiting these objects could be a propitious place for life to develop. Based on observations collected with the SOPHIE spectrograph on the 1.93-m telescope at Observatoire de Haute-Provence (CNRS), France by the SOPHIE Consortium (programme 07A.PNP.CONS to 15A.PNP.CONS).

  2. The Solar Neighborhood. 34. A Search for Planets Orbiting Nearby M Dwarfs Using Astrometry

    Science.gov (United States)

    2014-11-01

    REPORT DATE NOV 2014 2. REPORT TYPE 3. DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE The Solar Neighborhood, XXXIV. A Search...data. The lower panel indicates that for the best case targets (stars at close distances and of low mass). We are most sensitive to Jovian- type planets...THE SOLAR NEIGHBORHOOD. XXXIV. A SEARCH FOR PLANETS ORBITING NEARBY M DWARFS USING ASTROMETRY John C. Lurie1,7, Todd J. Henry2,7, Wei-Chun Jao3,7

  3. The SOPHIE search for northern extrasolar planets. XI. Three new companions and an orbit update: Giant planets in the habitable zone

    CERN Document Server

    Díaz, R F; Demangeon, O; Hébrard, G; Boisse, I; Arnold, L; Astudillo-Defru, N; Beuzit, J -L; Bonfils, X; Borgniet, S; Bouchy, F; Bourrier, V; Courcol, B; Deleuil, M; Delfosse, X; Ehrenreich, D; Forveille, T; Lagrange, A -M; Mayor, M; Moutou, C; Pepe, F; Queloz, D; Santerne, A; Santos, N C; Sahlmann, J; Ségransan, D; Udry, S; Wilson, P A

    2016-01-01

    We report the discovery of three new substellar companions to solar-type stars, HD191806, HD214823, and HD221585, based on radial velocity measurements obtained at the Haute-Provence Observatory. Data from the SOPHIE spectrograph are combined with observations acquired with its predecessor, ELODIE, to detect and characterise the orbital parameters of three new gaseous giant and brown dwarf candidates. Additionally, we combine SOPHIE data with velocities obtained at the Lick Observatory to improve the parameters of an already known giant planet companion, HD16175 b. Thanks to the use of different instruments, the data sets of all four targets span more than ten years. Zero-point offsets between instruments are dealt with using Bayesian priors to incorporate the information we possess on the SOPHIE/ELODIE offset based on previous studies. The reported companions have orbital periods between three and five years and minimum masses between 1.6 Mjup and 19 Mjup. Additionally, we find that the star HD191806 is expe...

  4. The Five Planets in the Kepler-296 Binary System All Orbit the Primary: A Statistical and Analytical Analysis

    CERN Document Server

    Barclay, Thomas; Adams, Fred C; Ciardi, David R; Huber, Daniel; Foreman-Mackey, Daniel; Montet, Benjamin T; Caldwell, Douglas

    2015-01-01

    Kepler-296 is a binary star system with two M-dwarf components separated by 0.2 arcsec. Five transiting planets have been confirmed to be associated with the Kepler-296 system; given the evidence to date, however, the planets could in principle orbit either star. This ambiguity has made it difficult to constrain both the orbital and physical properties of the planets. Using both statistical and analytical arguments, this paper shows that all five planets are highly likely to orbit the primary star in this system. We performed a Markov-Chain Monte Carlo simulation using a five transiting planet model, leaving the stellar density and dilution with uniform priors. Using importance sampling, we compared the model probabilities under the priors of the planets orbiting either the brighter or the fainter component of the binary. A model where the planets orbit the brighter component, Kepler-296A, is strongly preferred by the data. Combined with our assertion that all five planets orbit the same star, the two outer p...

  5. Tidal decay and orbital circularization in close-in two-planet systems

    CERN Document Server

    Rodríguez, Adrián; Michtchenko, Tatiana A; Beaugé, Cristian; Miloni, Octavio

    2011-01-01

    The motion of two planets around a Sun-like star under the combined effects of mutual interaction and tidal dissipation is investigated. The secular behaviour of the system is analyzed using two different approaches. First, we solve the exact equations of motion through the numerical simulation of the system evolution. In addition to the orbital decay and circularization, we show that the final configuration of the system is affected by the shrink of the inner orbit. Our second approach consist in the analysis of the stationary solutions of mean equations of motion based on a Hamiltonian formalism. We consider the case of a hot super-Earth planet with a more massive outer companion. As a real example, the CoRoT-7 system is analyzed solving the exact and mean equations of motion. The star-planet tidal interaction produces orbital decay and circularization of the orbit of CoRoT-7b. In addition, the long-term tidal evolution is such that the eccentricity of CoRoT-7c is also circularized and a pair of final circu...

  6. OGLE-2008-BLG-513Lb: The Orbital Solution for a Microlensing Planet

    CERN Document Server

    Yee, J C; Dong, Subo; Greenhill, J; Tsapras, Y; Bond, I A; Gould, A; Kozlowski, S; Fouque, P; Albrow, M D; Han, C; Monard, L A G; McCormick, J; Williams, A; Kains, N; An, J; Dominik, M

    2011-01-01

    The dominant features of the microlensing event OGLE-2008-BLG-513 arise from a 2-body lens with a mass ratio q=0.027+/-0.001. The light curve cannot be adequately described by a static, 2-body lens model, which forces us to consider the orbital motion of the lens system. Including orbital motion improves the fit by Delta chi^2>1000. We model the orbital motion as a Keplerian orbit, and with the additional information from microlens parallax, we are able to place constraints on all eight parameters of the orbit. If our model is correct, this gives us the most complete orbital information of any microlensing planet. We find that the host star is 0.18planet is 5.0

  7. No large population of unbound or wide-orbit Jupiter-mass planets

    Science.gov (United States)

    Mróz, Przemek; Udalski, Andrzej; Skowron, Jan; Poleski, Radosław; Kozłowski, Szymon; Szymański, Michał K.; Soszyński, Igor; Wyrzykowski, Łukasz; Pietrukowicz, Paweł; Ulaczyk, Krzysztof; Skowron, Dorota; Pawlak, Michał

    2017-08-01

    Planet formation theories predict that some planets may be ejected from their parent systems as result of dynamical interactions and other processes. Unbound planets can also be formed through gravitational collapse, in a way similar to that in which stars form. A handful of free-floating planetary-mass objects have been discovered by infrared surveys of young stellar clusters and star-forming regions as well as wide-field surveys, but these studies are incomplete for objects below five Jupiter masses. Gravitational microlensing is the only method capable of exploring the entire population of free-floating planets down to Mars-mass objects, because the microlensing signal does not depend on the brightness of the lensing object. A characteristic timescale of microlensing events depends on the mass of the lens: the less massive the lens, the shorter the microlensing event. A previous analysis of 474 microlensing events found an excess of ten very short events (1-2 days)—more than known stellar populations would suggest—indicating the existence of a large population of unbound or wide-orbit Jupiter-mass planets (reported to be almost twice as common as main-sequence stars). These results, however, do not match predictions of planet-formation theories and surveys of young clusters. Here we analyse a sample of microlensing events six times larger than that of ref. 11 discovered during the years 2010-15. Although our survey has very high sensitivity (detection efficiency) to short-timescale (1-2 days) microlensing events, we found no excess of events with timescales in this range, with a 95 per cent upper limit on the frequency of Jupiter-mass free-floating or wide-orbit planets of 0.25 planets per main-sequence star. We detected a few possible ultrashort-timescale events (with timescales of less than half a day), which may indicate the existence of Earth-mass and super-Earth-mass free-floating planets, as predicted by planet-formation theories.

  8. ELODIE metallicity-biased search for transiting Hot Jupiters. IV. Intermediate period planets orbiting the stars HD 43691 and HD 132406

    Science.gov (United States)

    da Silva, R.; Udry, S.; Bouchy, F.; Moutou, C.; Mayor, M.; Beuzit, J.-L.; Bonfils, X.; Delfosse, X.; Desort, M.; Forveille, T.; Galland, F.; Hébrard, G.; Lagrange, A.-M.; Loeillet, B.; Lovis, C.; Pepe, F.; Perrier, C.; Pont, F.; Queloz, D.; Santos, N. C.; Ségransan, D.; Sivan, J.-P.; Vidal-Madjar, A.; Zucker, S.

    2007-10-01

    We report here the discovery of two planet candidates as a result of our planet-search programme biased in favour of high-metallicity stars, using the ELODIE spectrograph at the Observatoire de Haute Provence. One candidate has a minimum mass m_2 sin i = 2.5 M_Jup and is orbiting the metal-rich star HD 43691 with period P = 40 days and eccentricity e=0.14. The other planet has a minimum mass m_2 sin{i} = 5.6 M_Jup and orbits the slightly metal-rich star HD 132406 with period P=974 days and eccentricity e = 0.34. Additional observations for both stars were performed using the new SOPHIE spectrograph that replaces the ELODIE instrument, allowing an improved orbital solution for the systems. Based on radial velocities collected with the ELODIE spectrograph mounted on the 193-cm telescope at the Observatoire de Haute Provence, France. Additional observations were made using the new SOPHIE spectrograph (run 06B.PNP.CONS) that replaces ELODIE.

  9. Richest Planetary System Discovered - Up to seven planets orbiting a Sun-like star

    Science.gov (United States)

    2010-08-01

    Astronomers using ESO's world-leading HARPS instrument have discovered a planetary system containing at least five planets, orbiting the Sun-like star HD 10180. The researchers also have tantalising evidence that two other planets may be present, one of which would have the lowest mass ever found. This would make the system similar to our Solar System in terms of the number of planets (seven as compared to the Solar System's eight planets). Furthermore, the team also found evidence that the distances of the planets from their star follow a regular pattern, as also seen in our Solar System. "We have found what is most likely the system with the most planets yet discovered," says Christophe Lovis, lead author of the paper reporting the result. "This remarkable discovery also highlights the fact that we are now entering a new era in exoplanet research: the study of complex planetary systems and not just of individual planets. Studies of planetary motions in the new system reveal complex gravitational interactions between the planets and give us insights into the long-term evolution of the system." The team of astronomers used the HARPS spectrograph, attached to ESO's 3.6-metre telescope at La Silla, Chile, for a six-year-long study of the Sun-like star HD 10180, located 127 light-years away in the southern constellation of Hydrus (the Male Water Snake). HARPS is an instrument with unrivalled measurement stability and great precision and is the world's most successful exoplanet hunter. Thanks to the 190 individual HARPS measurements, the astronomers detected the tiny back and forth motions of the star caused by the complex gravitational attractions from five or more planets. The five strongest signals correspond to planets with Neptune-like masses - between 13 and 25 Earth masses [1] - which orbit the star with periods ranging from about 6 to 600 days. These planets are located between 0.06 and 1.4 times the Earth-Sun distance from their central star. "We also have

  10. Transiting exoplanets from the CoRoT space mission XXV. CoRoT-27b: a massive and dense planet on a short-period orbit

    CERN Document Server

    Parviainen, H; Deleuil, M; Moutou, C; Deeg, H J; Ferraz-Mello, S; Samuel, B; Csizmadia, Sz; Pasternacki, T; Wuchterl, G; Havel, M; Fridlund, M; Agnus, R; Tingley, B; Aigrain, S; Almenara, J M; Alonso, R; Baglin, A; Barros, S; Bordé, A S P; Bouchy, F; Cabrera, J; Díaz, R; Dvorak, R; Erikson, A; Guillot, T; Hatzes, A; Hébrard, G; Mazeh, T; Montagnier, G; Ofir, A; Ollivier, M; Pätzold, M; Rauer, H; Rouan, D; Santerne, A; Schneider, J

    2014-01-01

    We report the discovery of a massive and dense transiting planet CoRoT-27b on a 3.58 day orbit around a 4.2 Gyr-old G2~star. The planet candidate was identified from the CoRoT photometry, and was confirmed as a planet with ground-based spectroscopy. The confirmation of the planet candidate is based on radial velocity observations combined with imaging to rule out blends. The characterisation of the planet and its host star is carried out using a Bayesian approach where all the data (CoRoT photometry, radial velocities, and spectroscopic characterisation of the star) are used jointly. The Bayesian analysis includes a study whether the assumption of white normally distributed noise holds for the CoRoT photometry, and whether the use of a non-normal noise distribution offers advantages in parameter estimation and model selection. CoRoT-27b has a mass of $10.39 \\pm 0.55$ $\\mathrm{M}_{\\rm Jup}$, a radius of $1.01 \\pm 0.04$ $\\mathrm{R}_{\\rm Jup}$, a mean density of $12.6_{-1.67}^{+1.92}$ $\\mathrm{g\\,cm^{-3}}$, and ...

  11. A possible correlation between planetary radius and orbital period for small planets

    CERN Document Server

    Helled, Ravit; Zucker, Shay

    2015-01-01

    We suggest the existence of a correlation between the planetary radius and orbital period for planets with radii smaller than 4 R_Earth. Using the Kepler data, we find a correlation coefficient of 0.5120, and suggest that the correlation is not caused solely by survey incompleteness. While the correlation coefficient could change depending on the statistical analysis, the statistical significance of the correlation is robust. Further analysis shows that the correlation originates from two contributing factors. One seems to be a power-law dependence between the two quantities for intermediate periods (3-100 days), and the other is a dearth of planets with radii larger than 2 R_Earth in short periods. This correlation may provide important constraints for small-planet formation theories and for understanding the dynamical evolution of planetary systems.

  12. The K2-ESPRINT Project V: A Short-period Giant Planet Orbiting a Subgiant Star*

    Science.gov (United States)

    Van Eylen, Vincent; Albrecht, Simon; Gandolfi, Davide; Dai, Fei; Winn, Joshua N.; Hirano, Teriyuki; Narita, Norio; Bruntt, Hans; Prieto-Arranz, Jorge; Béjar, Víctor J. S.; Nowak, Grzegorz; Lund, Mikkel N.; Palle, Enric; Ribas, Ignasi; Sanchis-Ojeda, Roberto; Yu, Liang; Arriagada, Pamela; Butler, R. Paul; Crane, Jeffrey D.; Handberg, Rasmus; Deeg, Hans; Jessen-Hansen, Jens; Johnson, John A.; Nespral, David; Rogers, Leslie; Ryu, Tsuguru; Shectman, Stephen; Shrotriya, Tushar; Slumstrup, Ditte; Takeda, Yoichi; Teske, Johanna; Thompson, Ian; Vanderburg, Andrew; Wittenmyer, Robert

    2016-11-01

    We report on the discovery and characterization of the transiting planet K2-39b (EPIC 206247743b). With an orbital period of 4.6 days, it is the shortest-period planet orbiting a subgiant star known to date. Such planets are rare, with only a handful of known cases. The reason for this is poorly understood but may reflect differences in planet occurrence around the relatively high-mass stars that have been surveyed, or may be the result of tidal destruction of such planets. K2-39 (EPIC 206247743) is an evolved star with a spectroscopically derived stellar radius and mass of {3.88}-0.42+0.48 {R}ȯ and {1.53}-0.12+0.13 {M}ȯ , respectively, and a very close-in transiting planet, with a/{R}\\star =3.4. Radial velocity (RV) follow-up using the HARPS, FIES, and PFS instruments leads to a planetary mass of {50.3}-9.4+9.7 {M}\\oplus . In combination with a radius measurement of 8.3+/- 1.1 {R}\\oplus , this results in a mean planetary density of {0.50}-0.17+0.29 g cm‑3. We furthermore discover a long-term RV trend, which may be caused by a long-period planet or stellar companion. Because K2-39b has a short orbital period, its existence makes it seem unlikely that tidal destruction is wholly responsible for the differences in planet populations around subgiant and main-sequence stars. Future monitoring of the transits of this system may enable the detection of period decay and constrain the tidal dissipation rates of subgiant stars. Based on observations made with the NOT telescope under program ID. 50-022/51-503, 50-213(CAT), 52-201 (CAT), 52-108 (OPTICON), 51-211 (CAT), and ESOs 3.6 m telescope at the La Silla Paranal Observatory under program ID 095.C-0718(A).

  13. 3D climate modeling of Earth-like extrasolar planets orbiting different types of host stars

    Science.gov (United States)

    Godolt, M.; Grenfell, J. L.; Hamann-Reinus, A.; Kitzmann, D.; Kunze, M.; Langematz, U.; von Paris, P.; Patzer, A. B. C.; Rauer, H.; Stracke, B.

    2015-06-01

    The potential habitability of a terrestrial planet is usually defined by the possible existence of liquid water on its surface, since life as we know it needs liquid water at least during a part of its life cycle. The potential presence of liquid water on a planetary surface depends on many factors such as, most importantly, surface temperatures. The properties of the planetary atmosphere and its interaction with the radiative energy provided by the planet's host star are thereby of decisive importance. In this study we investigate the influence of different main-sequence stars (F, G, and K-type stars) upon the climate of Earth-like extrasolar planets and their potential habitability by applying a state-of-the-art three-dimensional (3D) Earth climate model accounting for local and dynamical processes. The calculations have been performed for planets with Earth-like atmospheres at orbital distances (and corresponding orbital periods) where the total amount of energy received from the various host stars equals the solar constant. In contrast to previous 3D modeling studies, we include the effect of ozone radiative heating upon the vertical temperature structure of the atmospheres. The global orbital mean results obtained have been compared to those of a one-dimensional (1D) radiative convective climate model to investigate the approximation of global mean 3D results by those of 1D models. The different stellar spectral energy distributions lead to different surface temperatures and due to ozone heating to very different vertical temperature structures. As previous 1D studies we find higher surface temperatures for the Earth-like planet around the K-type star, and lower temperatures for the planet around the F-type star compared to an Earth-like planet around the Sun. However, this effect is more pronounced in the 3D model results than in the 1D model because the 3D model accounts for feedback processes such as the ice-albedo and the water vapor feedback. Whether the

  14. The solar neighborhood. XXXIV. A search for planets orbiting nearby M dwarfs using astrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lurie, John C. [Department of Astronomy, University of Washington, Seattle, WA 98195 (United States); Henry, Todd J.; Ianna, Philip A. [RECONS Institute, Chambersburg, PA 17201 (United States); Jao, Wei-Chun; Quinn, Samuel N.; Winters, Jennifer G. [Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30302 (United States); Koerner, David W. [Department of Physics and Astronomy, Northern Arizona University, Flagstaff, AZ 86011 (United States); Riedel, Adric R. [Department of Astrophysics, American Museum of Natural History, New York, NY 10034 (United States); Subasavage, John P., E-mail: lurie@uw.edu [United States Naval Observatory, Flagstaff, AZ 86001 (United States)

    2014-11-01

    Astrometric measurements are presented for seven nearby stars with previously detected planets: six M dwarfs (GJ 317, GJ 667C, GJ 581, GJ 849, GJ 876, and GJ 1214) and one K dwarf (BD-10 -3166). Measurements are also presented for six additional nearby M dwarfs without known planets, but which are more favorable to astrometric detections of low mass companions, as well as three binary systems for which we provide astrometric orbit solutions. Observations have baselines of 3 to 13 years, and were made as part of the RECONS long-term astrometry and photometry program at the CTIO/SMARTS 0.9 m telescope. We provide trigonometric parallaxes and proper motions for all 16 systems, and perform an extensive analysis of the astrometric residuals to determine the minimum detectable companion mass for the 12 M dwarfs not having close stellar secondaries. For the six M dwarfs with known planets, we are not sensitive to planets, but can rule out the presence of all but the least massive brown dwarfs at periods of 2–12 years. For the six more astrometrically favorable M dwarfs, we conclude that none have brown dwarf companions, and are sensitive to companions with masses as low as 1 M{sub Jup} for periods longer than two years. In particular, we conclude that Proxima Centauri has no Jovian companions at orbital periods of 2–12 years. These results complement previously published M dwarf planet occurrence rates by providing astrometrically determined upper mass limits on potential super-Jupiter companions at orbits of two years and longer. As part of a continuing survey, these results are consistent with the paucity of super-Jupiter and brown dwarf companions we find among the over 250 red dwarfs within 25 pc observed longer than five years in our astrometric program.

  15. Hot Jupiters with relatives: discovery of additional planets in orbit around WASP-41 and WASP-47

    Science.gov (United States)

    Neveu-VanMalle, M.; Queloz, D.; Anderson, D. R.; Brown, D. J. A.; Collier Cameron, A.; Delrez, L.; Díaz, R. F.; Gillon, M.; Hellier, C.; Jehin, E.; Lister, T.; Pepe, F.; Rojo, P.; Ségransan, D.; Triaud, A. H. M. J.; Turner, O. D.; Udry, S.

    2016-02-01

    We report the discovery of two additional planetary companions to WASP-41 and WASP-47. WASP-41 c is a planet of minimum mass 3.18 ± 0.20 MJup and eccentricity 0.29 ± 0.02, and it orbits in 421 ± 2 days. WASP-47 c is a planet of minimum mass 1.24 ± 0.22 MJup and eccentricity 0.13 ± 0.10, and it orbits in 572 ± 7 days. Unlike most of the planetary systems that include a hot Jupiter, these two systems with a hot Jupiter have a long-period planet located at only ~1 au from their host star. WASP-41 is a rather young star known to be chromospherically active. To differentiate its magnetic cycle from the radial velocity effect induced by the second planet, we used the emission in the Hα line and find this indicator well suited to detecting the stellar activity pattern and the magnetic cycle. The analysis of the Rossiter-McLaughlin effect induced by WASP-41 b suggests that the planet could be misaligned, though an aligned orbit cannot be excluded. WASP-47 has recently been found to host two additional transiting super Earths. With such an unprecedented architecture, the WASP-47 system will be very important for understanding planetary migration. Using data collected at ESO's La Silla Observatory, Chile: HARPS on the ESO 3.6 m (Prog ID 087.C-0649 & 089.C-0151), the Swiss Euler Telescope, TRAPPIST, the 1.54-m Danish telescope (Prog CN2013A-159), and at the LCOGT's Faulkes Telescope South.Photometric lightcurve and RV tables are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/586/A93

  16. Gearbox Reliability Collaborative: Test and Model Investigation of Sun Orbit and Planet Load Share in a Wind Turbine Gearbox; Preprint

    Energy Technology Data Exchange (ETDEWEB)

    LaCava, W.; Keller, J.; McNiff, B.

    2012-04-01

    This paper analyzes experimental measurement of the sun gear orbit in dynamometer testing and describes its relation to the other measured responses of the planetary stage. The relation of the sun orbit to component runout, component flexibility, gear coupling alignment, planet load share, and planet position error will be investigated. Equations describing the orbit of the sun gear in the test cases are derived. Rigid and flexible multibody models of the full gearbox are investigated and compared to sun and planet measurements. This paper shows that the sun gear's path may be influenced by gear coupling responses and gearbox structural flexibilities.

  17. Capture of Planets Into Mean Motion Resonances and the Origins of Extrasolar Orbital Architectures

    CERN Document Server

    Batygin, Konstantin

    2015-01-01

    The early stages of dynamical evolution of planetary systems are often shaped by dissipative processes that drive orbital migration. In multi-planet systems, convergent amassing of orbits inevitably leads to encounters with rational period ratios, which may result in establishment of mean motion resonances. The success or failure of resonant capture yields exceedingly different subsequent evolutions, and thus plays a central role in determining the ensuing orbital architecture of planetary systems. In this work, we employ an integrable Hamiltonian formalism for first order planetary resonances that allows both secondary bodies to have finite masses and eccentricities, and construct a comprehensive theory for resonant capture. Particularly, we derive conditions under which orbital evolution lies within the adiabatic regime, and provide a generalized criterion for guaranteed resonant locking as well as a procedure for calculating capture probabilities when capture is not certain. Subsequently, we utilize the de...

  18. Resonant capture of multiple planet systems under dissipation and stable orbital configurations

    CERN Document Server

    Voyatzis, George

    2016-01-01

    Migration of planetary systems caused by the action of dissipative forces may lead the planets to be trapped in a resonance. In this work we study the conditions and the dynamics of such resonant trapping. Particularly, we are interested in finding out whether resonant capture ends up in a long-term stable planetary configuration. For two planet systems we associate the evolution of migration with the existence of families of periodic orbits in the phase space of the three-body problem. The family of circular periodic orbits exhibits a gap at the 2:1 resonance and an instability and bifurcation at the 3:1 resonance. These properties explain the high probability of 2:1 and 3:1 resonant capture at low eccentricities. Furthermore, we study the resonant capture of three-planet systems. We show that such a resonant capture is possible and can occur under particular conditions. Then, from the migration path of the system, stable three-planet configurations, either symmetric or asymmetric, can be determined.

  19. Newly-Discovered Planets Orbiting HD~5319, HD~11506, HD~75784 and HD~10442 from the N2K Consortium

    CERN Document Server

    Giguere, Matthew J; Payne, Matthew J; Brewer, John M; Johnson, John Asher; Howard, Andrew W; Isaacson, Howard T

    2014-01-01

    Initially designed to discover short-period planets, the N2K campaign has since evolved to discover new worlds at large separations from their host stars. Detecting such worlds will help determine the giant planet occurrence at semi-major axes beyond the ice line, where gas giants are thought to mostly form. Here we report four newly-discovered gas giant planets (with minimum masses ranging from 0.4 to 2.1 MJup) orbiting stars monitored as part of the N2K program. Two of these planets orbit stars already known to host planets: HD 5319 and HD 11506. The remaining discoveries reside in previously-unknown planetary systems: HD 10442 and HD 75784. The refined orbital period of the inner planet orbiting HD 5319 is 641 days. The newly-discovered outer planet orbits in 886 days. The large masses combined with the proximity to a 4:3 mean motion resonance make this system a challenge to explain with current formation and migration theories. HD 11506 has one confirmed planet, and here we confirm a second. The outer pla...

  20. The NASA-UC Eta-Earth Program: III. A Super-Earth orbiting HD 97658 and a Neptune-mass planet orbiting Gl 785

    CERN Document Server

    Howard, Andrew W; Marcy, Geoffrey W; Fischer, Debra A; Wright, Jason T; Henry, Gregory W; Isaacson, Howard; Valenti, Jeff A; Anderson, Jay; Piskunov, Nikolai E

    2010-01-01

    We report the discovery of planets orbiting two bright, nearby early K dwarf stars, HD 97658 and Gl 785. These planets were detected by Keplerian modelling of radial velocities measured with Keck-HIRES for the NASA-UC Eta-Earth Survey. HD 97658 b is a close-in super-Earth with minimum mass Msini = 8.2 +/- 1.2 M_Earth, orbital period P = 9.494 +/- 0.005 d, and an orbit that is consistent with circular. Gl 785 b is a Neptune-mass planet with Msini = 21.6 +/- 2.0 M_Earth, P = 74.39 +/- 0.12 d, and orbital eccentricity 0.30 +/- 0.09. Photometric observations with the T12 0.8 m automatic photometric telescope at Fairborn Observatory show that HD 97658 is photometrically constant at the radial velocity period to 0.09 mmag, supporting the existence of the planet.

  1. UV Surface Environment of Earth-like Planets Orbiting FGKM Stars Through Geological Evolution

    CERN Document Server

    Rugheimer, S; Kaltenegger, L; Sasselov, D

    2015-01-01

    The UV environment of a host star affects the photochemistry in the atmosphere, and ultimately the surface UV environment for terrestrial planets and therefore the conditions for the origin and evolution of life. We model the surface UV radiation environment for Earth-sized planets orbiting FGKM stars at the 1AU equivalent distance for Earth through its geological evolution. We explore four different types of atmospheres corresponding to an early Earth atmosphere at 3.9 Gyr ago and three atmospheres covering the rise of oxygen to present day levels at 2.0 Gyr ago, 0.8 Gyr ago and modern Earth (Following Kaltenegger et al. 2007). In addition to calculating the UV flux on the surface of the planet, we model the biologically effective irradiance, using DNA damage as a proxy for biological damage. We find that a pre-biotic Earth (3.9 Gyr ago) orbiting an F0V star receives 6 times the biologically effective radiation as around the early Sun and 3520 times the modern Earth-Sun levels. A pre-biotic Earth orbiting GJ...

  2. Magnetospheric Emissions from the Planet Orbiting tau Boo: A Multi-Epoch Search

    CERN Document Server

    Lazio, T Joseph W

    2007-01-01

    All of the solar system gas giants produce electron cyclotron masers, driven by the solar wind impinging on their magnetospheres. Extrapolating to the planet orbiting tau Boo, various authors have predicted that it may be within the detection limits of the 4-meter wavelength (74 MHz) system on the Very Large Array. This paper reports three epochs of observations of tau Boo. In no epoch do we detect the planet; various means of determining the upper limit to the emission yield single-epoch limits ranging from 135 to 300 mJy. We develop a likelihood method for multi-epoch observations and use it to constrain various radiation properties of the planet. Assuming that the planet does radiate at our observation wavelength, its typical luminosity must be less than about 10^{16} W, unless its radiation is highly beamed into a solid angle Omega << 1 sr. While within the range of luminosities predicted by various authors for this planet, this value is lower than recent estimates which attempt to take into account...

  3. The Potential of Planets Orbiting Red Dwarf Stars to Support Oxygenic Photosynthesis and Complex Life

    CERN Document Server

    Gale, Joseph

    2015-01-01

    We review the latest findings on extra-solar planets and their potential to support Earth-like life. Focusing on planets orbiting Red Dwarf (RD) stars, the most abundant stellar type, we show that including RDs as potential host stars could increase the probability of finding biotic planets by a factor of up to a thousand, and reduce the estimate of the distance to our nearest biotic neighbor by up to 10. We argue that binary and multiple star systems need to be taken into account when discussing exoplanet habitability. Early considerations indicated that conditions on RD planets would be inimical to life, as their Habitable Zones (where liquid water could exist) would be so close as to make planets tidally locked to their star. This was thought to cause an erratic climate and expose life forms to flares of ionizing radiation. Recent calculations show that these negative factors are less severe than originally thought. It has been argued that the lesser photon energy of the radiation of the relatively cool RD...

  4. On the Search For Transits of the Planets Orbiting Gl 876

    CERN Document Server

    Shankland, P D; Laughlin, G; Blank, D L; Price, A; Gary, B; Bissinger, R; Ringwald, F; White, G; Henry, G W; McGee, P; Wolf, A S; Carter, B; Lee, S; Biggs, J; Monard, B; Ashley, M C B

    2006-01-01

    We report the results of a globally coordinated photometric campaign to search for transits by the P ~ 30 d and P ~ 60 d outer planets of the 3-planet system orbiting the nearby M-dwarf Gl 876. These two planets experience strong mutual perturbations, which necessitate use of a dynamical (four-body) model to compute transit ephemerides for the system. Our photometric data have been collected from published archival sources, as well as from our photometric campaigns that were targeted to specific transit predictions. Our analysis indicates that transits by planet "c" (P ~ 30 d) do not currently occur, in concordance with the best-fit i = 50 degree co-planar configuration obtained by dynamical fits to the most recent radial velocity data for the system. Transits by planet "b" (P ~ 60 d) are not entirely ruled out by our observations, but our data indicate that it is very unlikely that they occur. Our experience with the Gl 876 system suggests that a distributed ground-based network of small telescopes can be us...

  5. Planet Occurrence within 0.25 AU of Solar-type Stars from Kepler

    DEFF Research Database (Denmark)

    Howard, Andrew W.; Marcy, Geoffrey W.; Bryson, Stephen T.

    2012-01-01

    We report the distribution of planets as a function of planet radius, orbital period, and stellar effective temperature for orbital periods less than 50 days around solar-type (GK) stars. These results are based on the 1235 planets (formally "planet candidates") from the Kepler mission that inclu...

  6. Reduced Activity And Large Particles From the Disintegrating Planet Candidate KIC 12557548b

    CERN Document Server

    Schlawin, Everett; Zhao, Ming; Teske, Johanna K; Chen, Howard

    2016-01-01

    The intriguing exoplanet candidate KIC 12557548b is believed to have a comet-like tail of dusty debris trailing a small rocky planet. The tail of debris scatters up to 1.3% of the stellar light in the Kepler observatory's bandpass (0.42 um to 0.9 um). Observing the tail's transit depth at multiple wavelengths can reveal the composition and particle size of the debris, constraining the makeup and lifetime of the sub-Mercury planet. Early dust particle size predictions from the scattering of the comet-like tail pointed towards a dust size of ~0.1 um for silicate compositions. These small particles would produce a much deeper optical transit depth than near-infrared transit depth. We measure a transmission spectrum for KIC 12557548b using the SpeX spectrograph (covering 0.8 um to 2.4 um) simultaneously with the MORIS imager taking r' (0.63 um) photometry on the Infrared Telescope Facility for eight nights and one night in H band (1.63 um) using the Wide-Field IR Camera at the Palomar 200-inch telescope. The infr...

  7. Orbital stability of coplanar two-planet exosystems with high eccentricities

    Science.gov (United States)

    Antoniadou, Kyriaki I.; Voyatzis, George

    2016-10-01

    The long-term stability of the evolution of two-planet systems is considered by using the general three body problem (GTBP). Our study is focused on the stability of systems with adjacent orbits when at least one of them is highly eccentric. In these cases, in order for close encounters, which destabilize the planetary systems, to be avoided, phase protection mechanisms should be considered. Additionally, since the GTBP is a non-integrable system, chaos may also cause the destabilization of the system after a long time interval. By computing dynamical maps, based on Fast Lyapunov Indicator, we reveal regions in phase space with stable orbits even for very high eccentricities (e > 0.5). Such regions are present in mean motion resonances (MMRs). We can determine the position of the exact MMR through the computation of families of periodic orbits in a rotating frame. Elliptic periodic orbits are associated with the presence of apsidal corotation resonances (ACRs). When such solutions are stable, they are associated with neighbouring domains of initial conditions that provide long-term stability. We apply our methodology so that the evolution of planetary systems of highly eccentric orbits is assigned to the existence of such stable domains. Particularly, we study the orbital evolution of the extrasolar systems HD 82943, HD 3651, HD 7449, HD 89744 and HD 102272 and discuss the consistency between the orbital elements provided by the observations and the dynamical stability.

  8. Coupled thermo-orbital evolution of tidally-evolved Earth-like planets

    Science.gov (United States)

    Behounkova, Marie; Walterova, Michaela; Cadek, Ondrej; Tobie, Gabriel; Choblet, Gael

    2016-10-01

    Progress in detection techniques of exoplanets inspired increasing number of studies focused on their internal dynamics and evolution. The detection methods tend to favor the discovery of short-period exoplanets, that are predicted to get rapidly tidally locked. During the locking process planets despin and a significant amount of tidal heating may contribute to the thermal budget of the planet. Moreover, tidally locked exoplanets exhibit large surface temperature contrasts between sub-stellar and anti-stellar sides due to uneven insolation which influence the convection pattern and cooling of the planet. Here, we will present the evolution of tidally locked Earth-like exoplanets using numerical tool Antigone (Behounkova et al., 2010, 2011) coupling long-term internal evolution, tidal dissipation (taking into account Maxwell or Andrade rheology) and uneven insolation pattern. For constant orbital parameters, we will focus on numerical simulation of the heat transfer in exoEarths for various rheological properties of planet and various values of spin-orbit resonance, semi-major axis, eccentricity and luminosity of star. In the case of effective heat transfer, our results suggest that the melting is mainly observed within the upper part of the mantle for tidal heating lower than 100TW . For tidal heating higher than 100TW, the melt is produced also within the deep part of the mantle and degree-2 convection is enhanced due to tidal heating pattern. For large tidal heating (larger than 1000TW), global melting is observed and temperature field is homogenized due to global melting, the heat transfer is mainly due to melt extraction and advection is suppressed. We will further present first results of coupled orbital-internal evolution of planets without companion using numerical model of orbital evolution with realistic (Maxwell or Andrade) rheology (Walterova et al., in prep). We will concentrate on the capture into the spin-orbit resonance. Special attention will be

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

    Science.gov (United States)

    David, Trevor J.

    2016-10-01

    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. A prominent question is: how early can one find fully formed planets like those frequently detected on short orbital periods around mature stars? Some theories suggest the in situ formation of planets close to their host stars is unlikely and the existence of such planets is evidence for large scale migration. Other theories posit that planet assembly at small orbital separations may be common. Here we report on a newly-born, transiting planet orbiting its star every 5.4 days. The planet is 50 per cent larger than Neptune, and its mass is less than 3.6 times Jupiter (at 99.7 per cent confidence), with a true mass likely to be within a factor of several of Neptune's. The 5-10 million year old star has a tenuous dust disk extending outwards from about 2 times the Earth-Sun separation, in addition to the large planet located at less than one-twentieth the Earth-Sun separation.

  10. Magnetospheric Structure and Atmospheric Joule Heating of Habitable Planets Orbiting M-dwarf Stars

    CERN Document Server

    Cohen, O; Glocer, A; Garraffo, C; Poppenhaeger, K; Bell, J M; Ridley, A J; Gombosi, T I

    2014-01-01

    We study the magnetospheric structure and the ionospheric Joule Heating of planets orbiting M-dwarf stars in the habitable zone using a set of magnetohydrodynamic (MHD) models. The stellar wind solution is used to drive a model for the planetary magnetosphere, which is coupled with a model for the planetary ionosphere. Our simulations reveal that the space environment around close-in habitable planets is extreme, and the stellar wind plasma conditions change from sub- to super-Alfvenic along the planetary orbit. As a result, the magnetospheric structure changes dramatically with a bow shock forming in the super-Alfvenic sectors, while no bow shock forms in the sub-Alfvenic sectors. The planets reside most of the time in the sub-Alfvenic sectors with poor atmospheric protection. A significant amount of Joule Heating is provided at the top of the atmosphere as a result of the planetary interaction with the stellar wind. For the steady-state solution, the heating is about 0.1-3\\% of the total incoming stellar ir...

  11. WASP-41b: A Transiting Hot Jupiter Planet Orbiting a Magnetically Active G8V Star

    Science.gov (United States)

    Maxted, P. F. L.; Anderson, D. R.; Collier Cameron, A.; Hellier, C.; Queloz, D.; Smalley, B.; Street, R. A.; Triaud, A. H. M. J.; West, R. G.; Gillon, M.; Lister, T. A.; Pepe, F.; Pollacco, D.; Ségransan, D.; Smith, A. M. S.; Udry, S.

    2011-05-01

    We report the discovery of a transiting planet with an orbital period of 3.05 days orbiting the star TYC 7247-587-1. The star, WASP-41, is a moderately bright G8 V star (V = 11.6) with a metallicity close to solar ([Fe/H] = -0.08 ± 0.09). The star shows evidence of moderate chromospheric activity, both from emission in the cores of the Ca ii H and K ines and photometric variability with a period of 18.4 days and an amplitude of about 1%. We use a new method to show quantitatively that this periodic signal has a low false-alarm probability. The rotation period of the star implies a gyrochronological age for WASP-41 of 1.8 Gyr with an error of about 15%. We have used a combined analysis of the available photometric and spectroscopic data to derive the mass and radius of the planet (0.92 ± 0.06 MJup, 1.20 ± 0.06 RJup). Further observations of WASP-41 can be used to explore the connections between the properties of hot Jupiter planets and the level of chromospheric activity in their host stars.

  12. EUV-driven ionospheres and electron transport on extrasolar giant planets orbiting active stars

    CERN Document Server

    Chadney, J M; Koskinen, T T; Miller, S; Sanz-Forcada, J; Unruh, Y C; Yelle, R V

    2016-01-01

    The composition and structure of the upper atmospheres of Extrasolar Giant Planets (EGPs) are affected by the high-energy spectrum of their host stars from soft X-rays to EUV. This emission depends on the activity level of the star, which is primarily determined by its age. We focus upon EGPs orbiting K- and M-dwarf stars of different ages. XUV spectra for these stars are constructed using a coronal model. These spectra are used to drive both a thermospheric model and an ionospheric model, providing densities of neutral and ion species. Ionisation is included through photo-ionisation and electron-impact processes. We find that EGP ionospheres at all orbital distances considered and around all stars selected are dominated by the long-lived H$^+$ ion. In addition, planets with upper atmospheres where H$_2$ is not substantially dissociated have a layer in which H$_3^+$ is the major ion at the base of the ionosphere. For fast-rotating planets, densities of short-lived H$_3^+$ undergo significant diurnal variation...

  13. Orbits and Masses of the Satellites of the Dwarf Planet Haumea = 2003 EL61

    CERN Document Server

    Ragozzine, Darin

    2009-01-01

    Using precise relative astrometry from the Hubble Space Telescope and the W. M. Keck Telescope, we have determined the orbits and masses of the two dynamically interacting satellites of the dwarf planet (136108) Haumea, formerly 2003 EL61. The orbital parameters of Hi'iaka, the outer, brighter satellite, match well the previously derived orbit. On timescales longer than a few weeks, no Keplerian orbit is sufficient to describe the motion of the inner, fainter satellite Namaka. Using a fully-interacting three point-mass model, we have recovered the orbital parameters of both orbits and the mass of Haumea and Hi'iaka; Namaka's mass is marginally detected. The data are not sufficient to uniquely determine the gravitational quadrupole of the non-spherical primary (described by $J_2$). The nearly co-planar nature of the satellites, as well as an inferred density similar to water ice, strengthen the hypothesis that Haumea experienced a giant collision billions of years ago. The excited eccentricities and mutual inc...

  14. The Solar Neighborhood. XXXIV. A Search for Planets Orbiting Nearby M Dwarfs using Astrometry

    CERN Document Server

    Lurie, John C; Jao, Wei-Chun; Quinn, Samuel N; Winters, Jennifer G; Ianna, Philip A; Koerner, David W; Riedel, Adric R; Subasavage, John P

    2014-01-01

    Astrometric measurements are presented for seven nearby stars with previously detected planets: six M dwarfs (GJ 317, GJ 667C, GJ 581, GJ 849, GJ 876, and GJ 1214) and one K dwarf (BD $-$10 3166). Measurements are also presented for six additional nearby M dwarfs without known planets, but which are more favorable to astrometric detections of low mass companions, as well as three binary systems for which we provide astrometric orbit solutions. Observations have baselines of three to thirteen years, and were made as part of the RECONS long-term astrometry and photometry program at the CTIO/SMARTS 0.9m telescope. We provide trigonometric parallaxes and proper motions for all 16 systems, and perform an extensive analysis of the astrometric residuals to determine the minimum detectable companion mass for the 12 M dwarfs not having close stellar secondaries. For the six M dwarfs with known planets, we are not sensitive to planets, but can rule out the presence of all but the least massive brown dwarfs at periods o...

  15. Correlations between compositions and orbits established by the giant impact era of planet formation

    CERN Document Server

    Dawson, Rebekah I; Chiang, Eugene

    2015-01-01

    The giant impact phase of terrestrial planet formation establishes connections between super-Earths' orbital properties (semimajor axis spacings, eccentricities, mutual inclinations) and interior compositions (the presence or absence of gaseous envelopes). Using N-body simulations and analytic arguments, we show that spacings derive not only from eccentricities, but also from inclinations. Flatter systems attain tighter spacings, a consequence of an eccentricity equilibrium between gravitational scatterings, which increase eccentricities, and mergers, which damp them. Dynamical friction by residual disk gas plays a critical role in regulating mergers and in damping inclinations and eccentricities. Systems with moderate gas damping and high solid surface density spawn gas-enveloped super-Earths with tight spacings, small eccentricities, and small inclinations. Systems in which super-Earths coagulate without as much ambient gas, in disks with low solid surface density, produce rocky planets with wider spacings,...

  16. A planet in an 840-d orbit around a Kepler main-sequence A star found from phase modulation of its pulsations

    CERN Document Server

    Murphy, Simon J; Shibahashi, Hiromoto

    2016-01-01

    We have detected a 12 M$_{\\rm Jup}$ planet orbiting in or near the habitable zone of a main-sequence A star via the pulsational phase shifts induced by orbital motion. The planet has an orbital period of $840\\pm20$ d and an eccentricity of 0.15. All known planets orbiting main-sequence A stars have been found via the transit method or by direct imaging. The absence of astrometric or radial-velocity detections of planets around these hosts makes ours the first discovery using the orbital motion. It is also the first A star known to host a planet within 1$\\sigma$ of the habitable zone. We find evidence for planets in a large fraction of the parameter space where we are able to detect them. This supports the idea that A stars harbor high-mass planets in wide orbits.

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

    CERN Document Server

    David, Trevor J; 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

    2016-01-01

    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. A prominent question is: how early can one find fully formed planets like those frequently detected on short orbital periods around mature stars? Some theories suggest the in situ formation of planets close to their host stars is unlikely and the existence of such planets is evidence for large scale migration. Other theories posit that planet assembly at small orbital separations may be common. Here we report on a newly-born, transiting planet orbiting its star every 5.4 days. The planet is 50 per cent larger than Neptune, and its mass is less than 3.6 times Jupiter (at 99.7 per cent confidence), with a true mass likely to be with...

  18. 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.

  19. Reduced Activity and Large Particles from the Disintegrating Planet Candidate KIC 12557548b

    Science.gov (United States)

    Schlawin, E.; Herter, T.; Zhao, M.; Teske, J. K.; Chen, H.

    2016-08-01

    The intriguing exoplanet candidate KIC 12557548b is believed to have a comet-like tail of dusty debris trailing a small rocky planet. The tail of debris scatters up to 1.3% of the stellar light in the Kepler observatory’s bandpass (0.42-0.9 μm). Observing the tail’s transit depth at multiple wavelengths can reveal the composition and particle size of the debris, constraining the makeup and lifetime of the sub-Mercury planet. Early dust particle size predictions from the scattering of the comet-like tail pointed toward a dust size of ˜0.1 μm for silicate compositions. These small particles would produce a much deeper optical transit depth than near-infrared transit depth. We measure a transmission spectrum for KIC 12557548b using the SpeX spectrograph (covering 0.8-2.4 μm) simultaneously with the MORIS imager taking r‧ (0.63 μm) photometry on the Infrared Telescope Facility for eight nights and one night in H band (1.63 μm) using the Wide-field IR Camera at the Palomar 200 inch telescope. The infrared spectra are plagued by systematic errors, but we argue that sufficient precision is obtained when using differential spectroscopic calibration when combining multiple nights. The average differential transmission spectrum is flat, supporting findings that KIC 12557548b’s debris is likely composed of larger particles ≳0.5 μm for pyroxene and olivine and ≳0.2 μm for iron and corundum. The r‧ photometric transit depths are all below the average Kepler value, suggesting that the observations occurred during a weak period or that the mechanisms producing optical broadband transit depths are suppressed.

  20. Extended study of the Surface Heterogeneity of candidate dwarf-planets (II)

    Science.gov (United States)

    Pinilla-Alonso, Noemi; Emery, Joshua; Cruikshank, Dale P.

    2016-08-01

    We propose to continue with our investigation of the volatile activity and migration of volatiles on dwarf-planets (DP) and some candidates to dwarf-planets (CDP). We also extend this study to cover the list of targets for the Kuiper Extended Mission (KEM, second phase of New horizons mission submitted by the New Horizons Team to NASA for extension, and yet to be approved) and extend our continuous monitoring of Pluto's surface. Surface heterogeneity on these bodies can be indicative of the presence of an atmosphere, and active collisional history, or even cometary activity. In cycle 12 we were awarded with ~ 38hr to study three DPs and three CDPs. Five of these objects have been announced in 2016 as targets of the KEM. On cycle 13 we ask for 145.5 hours to study 11 CDP plus five targets of the KEM (one object belongs to both lists but will be observed only once) plus Pluto. By using the proven capability of Spitzer to detect and map the presence of volatile ices, complex organics and silicates on the surface of these distant bodies, we will 1) test the hypothesis that KBOs on the scale of >450 km in diameter could retain a higher content of volatiles than the smaller and more abundant KBOs; 2) characterize the distribution of silicates/organics/ices on the surface of these bodies. These points are key to understanding chemical and dynamical history of the outer Solar System, which acts as a model for the new systems discovered around other stars. Our study will be be of special interest in the eve of James Webb Telescope operation, in 2019 and will pave the road for a detailed characterization of the targets of the Kuiper Extended Mission (if approved).

  1. Dynamics of stellar spin driven by planets undergoing Lidov-Kozai migration: paths to spin-orbit misalignment

    Science.gov (United States)

    Storch, Natalia I.; Lai, Dong; Anderson, Kassandra R.

    2017-03-01

    Many exoplanetary systems containing hot Jupiters (HJs) exhibit significant misalignment between the spin axes of the host stars and the orbital angular momentum axes of the planets ('spin-orbit misalignment'). High-eccentricity migration involving Lidov-Kozai oscillations of the planet's orbit induced by a distant perturber is a possible channel for producing such misaligned HJ systems. Previous works have shown that the dynamical evolution of the stellar spin axis during the high-e migration plays a dominant role in generating the observed spin-orbit misalignment. Numerical studies have also revealed various patterns of the evolution of the stellar spin axis leading to the final misalignment. Here, we develop an analytic theory to elucidate the evolution of spin-orbit misalignment during the Lidov-Kozai migration of planets in stellar binaries. Secular spin-orbit resonances play a key role in the misalignment evolution. We include the effects of short-range forces and tidal dissipation, and categorize the different possible paths to spin-orbit misalignment as a function of various physical parameters (e.g. planet mass and stellar rotation period). We identify five distinct spin-orbit evolution paths and outcomes, only two of which are capable of producing retrograde orbits. We show that these paths to misalignment and the outcomes depend only on two dimensionless parameters, which compare the stellar spin precession frequency with the rate of change of the planet's orbital axis, and the Lidov-Kozai oscillation frequency. Our analysis reveals a number of novel phenomena for the stellar spin evolution, ranging from bifurcation, adiabatic advection, to fully chaotic evolution of spin-orbit angles.

  2. The Hunt for Exomoons with Kepler (HEK): II. Analysis of Seven Viable Satellite-Hosting Planet Candidates

    CERN Document Server

    Kipping, David M; Buchhave, Lars A; Schmitt, Allan R; Bakos, Gáspár Á; Nesvorny, David

    2013-01-01

    From the list of 2321 transiting planet candidates announced by the Kepler Mission, we identify seven targets as having favorable properties for the capacity to dynamically maintain an exomoon and present a detectable signal. These seven candidates were identified through our automatic target selection (TSA) algorithm and target selection prioritization (TSP) filtering, whereby we excluded systems exhibiting significant time-correlated noise and focussed on those with a single transiting planet candidate of radius less than 6 Earth radii. We find no compelling evidence for an exomoon around any of the seven KOIs but constrain the satellite-to-planet mass ratios for each. For four of the seven KOIs, we estimate a 95% upper quantile of M_S/M_P<0.04, which given the radii of the candidates, likely probes down to sub-Earth masses. We also derive precise transit times and durations for each candidate and find no evidence for dynamical variations in any of the KOIs. With just a few systems analyzed thus far in t...

  3. Strong Constraints to the Putative Planet Candidate around VB 10 using Doppler spectroscopy

    CERN Document Server

    Anglada-Escude, Guillem; Weinberger, Alycia J; Thompson, Ian B; Osip, David J

    2010-01-01

    We present new radial velocity measurements of the ultra-cool dwarf VB 10, which was recently announced to host a giant planet detected with astrometry. The new observations were obtained using optical spectrographs(MIKE/Magellan and ESPaDOnS/CHFT) and cover a 63% of the reported period of 270 days. We apply Least-squares periodograms to identify the most significant signals and evaluate their corresponding False Alarm Probabilities. We show that this method is the proper generalization to astrometric data because (1) it mitigates the coupling of the orbital parameters with the parallax and proper motion, and (2) it permits a direct generalization to include non-linear Keplerian parameters in a combined fit to astrometry and radial velocity data. In fact, our analysis of the astrometry alone uncovers the reported 270 d period and an even stronger signal at 50 days. We estimate the uncertainties in the parameters using a Markov Chain Monte Carlo approach. The nominal precision of the new Doppler measurements i...

  4. Kepler-63b: A Giant Planet in a Polar Orbit around a Young Sun-like Star

    CERN Document Server

    Sanchis-Ojeda, Roberto; Marcy, Geoffrey W; Howard, Andrew W; Isaacson, Howard; Johnson, John Asher; Torres, Guillermo; Albrecht, Simon; Campante, Tiago L; Chaplin, William J; Davies, Guy R; Lund, Mikkel L; Carter, Joshua A; Dawson, Rebekah I; Buchhave, Lars A; Everett, Mark E; Fischer, Debra A; Geary, John C; Gilliland, Ronald L; Horch, Elliott P; Howell, Steve B; Latham, David W

    2013-01-01

    We present the discovery and characterization of a giant planet orbiting the young Sun-like star Kepler-63 (KOI-63, $m_{\\rm Kp} = 11.6$, $T_{\\rm eff} = 5576$ K, $M_\\star = 0.98\\, M_\\odot$). The planet transits every 9.43 days, with apparent depth variations and brightening anomalies caused by large starspots. The planet's radius is $6.1 \\pm 0.2 R_{\\earth}$, based on the transit light curve and the estimated stellar parameters. The planet's mass could not be measured with the existing radial-velocity data, due to the high level of stellar activity, but if we assume a circular orbit we can place a rough upper bound of $120 M_{\\earth}$ (3$\\sigma$). The host star has a high obliquity ($\\psi$ = $104^{\\circ}$), based on the Rossiter-McLaughlin effect and an analysis of starspot-crossing events. This result is valuable because almost all previous obliquity measurements are for stars with more massive planets and shorter-period orbits. In addition, the polar orbit of the planet combined with an analysis of spot-cross...

  5. MEASUREMENT OF SPIN-ORBIT MISALIGNMENT AND NODAL PRECESSION FOR THE PLANET AROUND PRE-MAIN-SEQUENCE STAR PTFO 8-8695 FROM GRAVITY DARKENING

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, Jason W. [Department of Physics, University of Idaho, Moscow, ID 83844-0903 (United States); Van Eyken, Julian C. [Department of Physics, University of California Santa Barbara, Santa Barbara, CA 93106-9530 (United States); Jackson, Brian K. [Carnegie Institution of Washington, DTM, 5241 Broad Branch Road, NW Washington, DC 20015-1305 (United States); Ciardi, David R. [NASA Exoplanet Science Institute, Caltech M/S 100-22, Pasadena, CA 91125 (United States); Fortney, Jonathan J., E-mail: jwbarnes@uidaho.edu [Department of Astronomy, University of California Santa Cruz, Santa Cruz, CA 95064 (United States)

    2013-09-01

    PTFO 8-8695b represents the first transiting exoplanet candidate orbiting a pre-main-sequence star (van Eyken et al. 2012, ApJ, 755, 42). We find that the unusual lightcurve shapes of PTFO 8-8695 can be explained by transits of a planet across an oblate, gravity-darkened stellar disk. We develop a theoretical framework for understanding precession of a planetary orbit's ascending node for the case when the stellar rotational angular momentum and the planetary orbital angular momentum are comparable in magnitude. We then implement those ideas to simultaneously and self-consistently fit two separate lightcurves observed in 2009 December and 2010 December. Our two self-consistent fits yield M{sub p} = 3.0 M{sub Jup} and M{sub p} = 3.6 M{sub Jup} for assumed stellar masses of M{sub *} = 0.34 M{sub Sun} and M{sub *} = 0.44 M{sub Sun} respectively. The two fits have precession periods of 293 days and 581 days. These mass determinations (consistent with previous upper limits) along with the strength of the gravity-darkened precessing model together validate PTFO 8-8695b as just the second hot Jupiter known to orbit an M-dwarf. Our fits show a high degree of spin-orbit misalignment in the PTFO 8-8695 system: 69 Degree-Sign {+-} 2 Degree-Sign or 73. Degree-Sign 1 {+-} 0. Degree-Sign 5, in the two cases. The large misalignment is consistent with the hypothesis that planets become hot Jupiters with random orbital plane alignments early in a system's lifetime. We predict that as a result of the highly misaligned, precessing system, the transits should disappear for months at a time over the course of the system's precession period. The precessing, gravity-darkened model also predicts other observable effects: changing orbit inclination that could be detected by radial velocity observations, changing stellar inclination that would manifest as varying vsin i, changing projected spin-orbit alignment that could be seen by the Rossiter-McLaughlin effect, changing

  6. Shocks and a Giant Planet in the Disk Orbiting BP Piscium?

    CERN Document Server

    Melis, C; Chen, C H; Rhee, Joseph H; Song, Inseok; Zuckerman, B

    2010-01-01

    Spitzer IRS spectroscopy supports the interpretation that BP Piscium, a gas and dust enshrouded star residing at high Galactic latitude, is a first-ascent giant rather than a classical T Tauri star. Our analysis suggests that BP Piscium's spectral energy distribution can be modeled as a disk with a gap that is opened by a giant planet. Modeling the rich mid-infrared emission line spectrum indicates that the solid-state emitting grains orbiting BP Piscium are primarily composed of ~75 K crystalline, magnesium-rich olivine; ~75 K crystalline, magnesium-rich pyroxene; ~200 K amorphous, magnesium-rich pyroxene; and ~200 K annealed silica ('cristobalite'). These dust grains are all sub-micron sized. The giant planet and gap model also naturally explains the location and mineralogy of the small dust grains in the disk. Disk shocks that result from disk-planet interaction generate the highly crystalline dust which is subsequently blown out of the disk mid-plane and into the disk atmosphere.

  7. Astrometric Monitoring of the HR 8799 Planets: Orbit Constraints from Self-Consistent Measurements

    CERN Document Server

    Konopacky, Q M; Macintosh, B A; Galicher, R; Barman, T S; Metchev, S A; Zuckerman, B

    2016-01-01

    We present new astrometric measurements from our ongoing monitoring campaign of the HR 8799 directly imaged planetary system. These new data points were obtained with NIRC2 on the W.M. Keck II 10 meter telescope between 2009 and 2014. In addition, we present updated astrometry from previously published observations in 2007 and 2008. All data were reduced using the SOSIE algorithm, which accounts for systematic biases present in previously published observations. This allows us to construct a self-consistent data set derived entirely from NIRC2 data alone. From this dataset, we detect acceleration for two of the planets (HR 8799b and e) at $>$3$\\sigma$. We also assess possible orbital parameters for each of the four planets independently. We find no statistically significant difference in the allowed inclinations of the planets. Fitting the astrometry while forcing coplanarity also returns $\\chi^2$ consistent to within 1$\\sigma$ of the best fit values, suggesting that if inclination offsets of $\\lesssim$20$^{o...

  8. "Dry" Mercury and "wet" Mars: comparison of two terrestrial planets with strongly differing orbital frequencies

    Science.gov (United States)

    Kochemasov, G.

    The modern wave planetology states that "orbits make structures". It means that all celestial bodies moving in non-round keplerian elliptical (and parabolic) orbits and rotating (all bodies rotate) are subjected to warping action of inertia-gravity waves . The waves appear in bodies due to periodically changing accelerations during cyclic orbital movements; they have a stationary character, 4 intersecting ortho- and diagonal directions and various lengths. Wave intersections and superpositions produce uplifting (+), subsiding (-) and neutral (0) regularly disposed tectonic blocks. Their sizes depend on wavelengths. The longest in a globe fundamental wave1 long 2πR is responsible for ubiquitous appearance in all celestial bodies of tectonic dichotomy or segmentation (2πR-structure). The first overtone wave2 produces tectonic sectoring (πR-structure). On this already complex wave structurization are superposed individual waves whose lengths are proportional to orbital periods or inversely proportional to orbital frequencies: higher frequency - smaller waves, lower frequency - larger waves. These waves are responsible for production of tectonic granules. In a row of terrestrial planets according to their orb. fr. sizes of the granules are as follows (this row can be started with the solar photosphere that orbits around the center of the solar system with about one month period): Photosphere πR/60, Mercury πR/16, Venus πR/6, Earth πR/4, Mars πR/2, asteroids πR/1. By this way a bridging is made between planets and stars in that concerns their wave structurization. The calculated granule sizes are rather known in nature. The solar supergranulation about 30-40 thousand km across, prevailing sizes of mercurian craters ˜500 km in diameter (a radar image from Earth), venusian "blobs" ˜3000 km across, superstructures of the Earth's cratons ˜ 5000 km across (seen now on NASA image PIA04159), martian elongated shape due to 2 waves inscribed in equator, asteroids

  9. XUV-driven mass loss from extrasolar giant planets orbiting active stars

    CERN Document Server

    Chadney, J M; Unruh, Y C; Koskinen, T T; Sanz-Forcada, J

    2014-01-01

    Upper atmospheres of Hot Jupiters are subject to extreme radiation conditions that can result in rapid atmospheric escape. The composition and structure of the upper atmospheres of these planets are affected by the high-energy spectrum of the host star. This emission depends on stellar type and age, which are thus important factors in understanding the behaviour of exoplanetary atmospheres. In this study, we focus on Extrasolar Giant Planets (EPGs) orbiting K and M dwarf stars. XUV spectra for three different stars - epsilon Eridani, AD Leonis and AU Microscopii - are constructed using a coronal model. Neutral density and temperature profiles in the upper atmosphere of hypothetical EGPs orbiting these stars are then obtained from a fluid model, incorporating atmospheric chemistry and taking atmospheric escape into account. We find that a simple scaling based solely on the host star's X-ray emission gives large errors in mass loss rates from planetary atmospheres and so we have derived a new method to scale th...

  10. Orbital stability of coplanar two-planet exosystems with high eccentricities

    CERN Document Server

    Antoniadou, Kyriaki I

    2016-01-01

    The long-term stability of the evolution of two-planet systems is considered by using the general three body problem (GTBP). Our study is focused on the stability of systems with adjacent orbits when at least one of them is highly eccentric. In these cases, in order for close encounters, which destabilize the planetary systems, to be avoided, phase protection mechanisms should be considered. Additionally, since the GTBP is a non-integrable system, chaos may also cause the destabilization of the system after a long time interval. By computing dynamical maps, based on Fast Lyapunov Indicator, we reveal regions in phase space with stable orbits even for very high eccentricities (e>0.5). Such regions are present in mean motion resonances (MMR). We can determine the position of the exact MMR through the computation of families of periodic orbits in a rotating frame. Elliptic periodic orbits are associated with the presence of apsidal corotation resonances (ACR). When such solutions are stable, they are associated ...

  11. CIRCUMBINARY PLANETS ORBITING THE RAPIDLY PULSATING SUBDWARF B-TYPE BINARY NY Vir

    Energy Technology Data Exchange (ETDEWEB)

    Qian, S.-B.; Zhu, L.-Y.; Dai, Z.-B.; He, J.-J. [National Astronomical Observatories/Yunnan Observatory, Chinese Academy of Sciences (CAS), P.O. Box 110, 650011 Kunming (China); Fernandez-Lajus, E. [Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, 1900 La Plata, Buenos Aires (Argentina); Xiang, F.-Y., E-mail: qsb@ynao.ac.cn [Physics Department, Xiangtan University, 411105 Xiangtan, Funan Province (China)

    2012-02-15

    We report here the tentative discovery of a Jovian planet in orbit around the rapidly pulsating subdwarf B-type (sdB-type) eclipsing binary NY Vir. By using newly determined eclipse times together with those collected from the literature, we detect that the observed-calculated (O - C) curve of NY Vir shows a small-amplitude cyclic variation with a period of 7.9 yr and a semiamplitude of 6.1 s, while it undergoes a downward parabolic change (revealing a period decrease at a rate of P-dot = -9.2 x 10{sup -12}). The periodic variation was analyzed for the light-travel-time effect via the presence of a third body. The mass of the tertiary companion was determined to be M{sub 3}sin i' = 2.3({+-} 0.3)M{sub Jupiter} when a total mass of 0.60 M{sub Sun} for NY Vir is adopted. This suggests that it is most probably a giant circumbinary planet orbiting NY Vir at a distance of about 3.3 astronomical units (AU). Since the rate of period decrease cannot be explained by true angular momentum loss caused by gravitational radiation or/and magnetic braking, the observed downward parabolic change in the O - C diagram may be only a part of a long-period (longer than 15 years) cyclic variation, which may reveal the presence of another Jovian planet ({approx}2.5 M{sub Jupiter}) in the system.

  12. The Stability of the Orbits of Earth-mass Planets in and near the Habitable Zones of Known Exoplanetary Systems

    CERN Document Server

    Jones, B W; Sleep, P N; Underwood, David R

    2003-01-01

    We have shown that Earth-mass planets could survive in variously restricted regions of the habitable zones (HZs) of most of a sample of nine of the 93 main-sequence exoplanetary systems confirmed by May 2003. In a preliminary extrapolation of our results to the other systems, we estimate that roughly a third of the 93 systems might be able to have Earth-mass planets in stable, confined orbits somewhere in their HZs. Clearly, these systems should be high on the target list for exploration for terrestrial planets. We have reached this conclusion by launching putative Earth-mass planets in various orbits and following their fate with a mixed-variable symplectic integrator.

  13. Planet Hunters X: Searching for Nearby Neighbors of 75 Planet and Eclipsing Binary Candidates from the K2 Kepler extended mission

    CERN Document Server

    Schmitt, Joseph R; Wang, Ji; Fischer, Debra A; Kristiansen, Martti H; LaCourse, Daryll M; Gagliano, Robert; Tan, Arvin Joseff V; Schwengeler, Hans Martin; Omohundro, Mark R; Venner, Alexander; Terentev, Ivan; Schmitt, Allan R; Jacobs, Thomas L; Winarski, Troy; Sejpka, Johann; Jek, Kian J; Boyajian, Tabetha S; Brewer, John M; Ishikawa, Sascha T; Lintott, Chris; Lynn, Stuart; Schawinski, Kevin; Weiksnar, Alex

    2016-01-01

    We present high resolution observations of a sample of 75 K2 targets from Campaigns 1-3 using speckle interferometry on the Southern Astrophysical Research (SOAR) telescope and adaptive optics (AO) imaging at the Keck II telescope. The median SOAR $I$-band and Keck $K_s$-band detection limits at 1'' were $\\Delta m_{I}=4.4$ mag and $\\Delta m_{K_s}=6.1$ mag, respectively. This sample includes 37 stars likely to host planets, 32 targets likely to be EBs, and 6 other targets previously labeled as likely planetary false positives. We find nine likely physically bound companion stars within 3'' of three candidate transiting exoplanet host stars and six likely eclipsing binaries (EB). Six of the nine detected companions are new discoveries, one of them associated with a planet candidate (EPIC 206061524). Among the EB candidates, companions were only found near the shortest period ones ($P<3$ days), which is in line with previous results showing high multiplicity near short-period binary stars. This high resolutio...

  14. Orbital circularization of a planet accreting disk gas: the formation of distant jupiters in circular orbits based on a core accretion model

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Akihiro; Higuchi, Arika [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551 (Japan); Ida, Shigeru, E-mail: kikuchi.a@geo.titech.ac.jp, E-mail: higuchia@geo.titech.ac.jp, E-mail: ida@elsi.jp [Earth-Life Science Institute, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8550 (Japan)

    2014-12-10

    Recently, gas giant planets in nearly circular orbits with large semimajor axes (a ∼ 30-1000 AU) have been detected by direct imaging. We have investigated orbital evolution in a formation scenario for such planets, based on a core accretion model. (1) Icy cores accrete from planetesimals at ≲ 30 AU, (2) they are scattered outward by an emerging nearby gas giant to acquire highly eccentric orbits, and (3) their orbits are circularized through the accretion of disk gas in outer regions, where they spend most of their time. We analytically derived equations to describe the orbital circularization through gas accretion. Numerical integrations of these equations show that the eccentricity decreases by a factor of more than 5 while the planetary mass increases by a factor of 10. Because runaway gas accretion increases planetary mass by ∼10-300, the orbits are sufficiently circularized. On the other hand, a is reduced at most only by a factor of two, leaving the planets in the outer regions. If the relative velocity damping by shock is considered, the circularization slows down, but is still efficient enough. Therefore, this scenario potentially accounts for the formation of observed distant jupiters in nearly circular orbits. If the apocenter distances of the scattered cores are larger than the disk sizes, their a shrink to a quarter of the disk sizes; the a-distribution of distant giants could reflect the outer edges of the disks in a similar way that those of hot jupiters may reflect inner edges.

  15. HIGH-MASS, FOUR-PLANET CONFIGURATIONS FOR HR 8799: CONSTRAINING THE ORBITAL INCLINATION AND AGE OF THE SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Sudol, Jeffrey J. [Department of Physics, West Chester University, 720 S. Church Street, West Chester, PA 19383 (United States); Haghighipour, Nader, E-mail: jsudol@wcupa.edu, E-mail: nader@ifa.hawaii.edu [Institute for Astronomy and NASA Astrobiology Institute, University of Hawaii-Manoa, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)

    2012-08-10

    Debates regarding the age and inclination of the planetary system orbiting HR 8799, and the release of additional astrometric data following the discovery of the fourth planet, prompted us to examine the possibility of constraining these two quantities by studying the long-term stability of this system at different orbital inclinations and in its high-mass configuration (7-10-10-10 M{sub Jup}). We carried out {approx}1.5 million N-body integrations for different combinations of orbital elements of the four planets. The most dynamically stable combinations survived less than {approx}5 Myr at inclinations of 0 Degree-Sign and 13 Degree-Sign , and 41, 46, and 31 Myr at 18 Degree-Sign , 23 Degree-Sign , and 30 Degree-Sign , respectively. Given such short lifetimes and the location of the system on the age-luminosity diagram for low-mass objects, the most reasonable conclusion of our study is that the planetary masses are less than 7-10-10-10 M{sub Jup} and the system is quite young. Two trends to note from our work are as follows. (1) In the most stable systems, the higher the inclination, the more the coordinates for planets b and c diverge from the oldest archival astrometric data (released after we completed our N-body integrations), suggesting that either these planets are in eccentric orbits or have lower orbital inclinations than that of planet d. (2) The most stable systems place planet e closer to the central star than is observed, supporting the conclusion that the planets are more massive and the system is young. We present the details of our simulations and discuss the implications of the results.

  16. HAT-P-2b: A Super-Massive Planet in an Eccentric Orbit Transiting a Bright Star

    CERN Document Server

    Bakos, G A; Torres, G; Fischer, D A; Latham, D W; Noyes, R W; Sasselov, D D; Mazeh, T; Shporer, A; Butler, R P; Stefanik, R P; Fernández, J M; Sozzetti, A; Pal, A; Johnson, J; Marcy, G W; Sipocz, B; Lázár, J; Papp, I; Sari, P

    2007-01-01

    We report the discovery of HAT-P-2b, a massive (Mp=8.17+/-0.72 M_Jup) planet transiting the bright (V=8.7) F8 star HD 147506, with an orbital period of 5.63 days and an eccentricity of e=0.5. From the transit light curve we determine that the radius of the planet is Rp = 1.18+/-0.16 R_Jup. HAT-P-2b has a mass about 9 times the average mass of previously-known transiting exoplanets, and a density of rho = 6.6gcm^-3, similar to that of rocky planets like the Earth. Nevertheless, its mass and radius are in accord with theories of structure of massive giant planets composed of pure H and He. The high eccentricity causes a 9-fold variation of insolation of the planet between peri- and apastron.

  17. Influence of Stellar Multiplicity On Planet Formation. IV. Adaptive Optics Imaging of Kepler Stars With Multiple Transiting Planet Candidates

    CERN Document Server

    Wang, Ji; Xie, Ji-Wei; Ciardi, David R

    2015-01-01

    The Kepler mission provides a wealth of multiple transiting planet systems (MTPS). The formation and evolution of multi-planet systems are likely to be influenced by companion stars given the abundance of multi stellar systems. We study the influence of stellar companions by measuring the stellar multiplicity rate of MTPS. We select 138 bright (KP < 13.5) Kepler MTPS and search for stellar companions with AO imaging data and archival radial velocity (RV) data. We obtain new AO images for 73 MTPS. Other MTPS in the sample have archival AO imaging data from the Kepler Community Follow-up Observation Program (CFOP). From these imaging data, we detect 42 stellar companions around 35 host stars. For stellar separation 1 AU < a < 100 AU, the stellar multiplicity rate is 5.2 $\\pm$ 5.0% for MTPS, which is 2.8{\\sigma} lower than 21.1 $\\pm$ 2.8% for the control sample, i.e., the field stars in the solar neighborhood. We identify two origins for the deficit of stellar companions within 100 AU to MTPS: (1) a sup...

  18. CoRoT LRa02_E2_0121: Neptune-size planet candidate turns into a hierarchical triple system with a giant primary

    CERN Document Server

    Tal-Or, L; Mazeh, T; Bouchy, F; Moutou, C; Alonso, R; Gandolfi, D; Aigrain, S; Auvergne, M; Barge, P; Bonomo, A S; Borde, P; Deeg, H; Ferraz-Mello, S; Deleuil, M; Dvorak, R; Erikson, A; Fridlund, M; Gillon, M; Guenther, E W; Guillot, T; Hatzes, A; Jorda, L; Lammer, H; Leger, A; Llebaria, A; Ollivier, M; Patzold, M; Queloz, D; Rauer, H; Rouan, D; Tsodikovich, Y; Wuchterl, G

    2011-01-01

    This paper presents the case of CoRoT LRa02_E2_0121, which was initially classified as a Neptune-size transiting-planet candidate on a relatively wide orbit of 36.3 days. Follow-up observations were performed with UVES, Sandiford, SOPHIE and HARPS. These observations revealed a faint companion in the spectra. To find the true nature of the system we derived the radial velocities of the faint companion using TODMOR - a two-dimensional correlation technique, applied to the SOPHIE spectra. Modeling the lightcurve with EBAS we discovered a secondary eclipse with a depth of ~0.07%, indicating a diluted eclipsing binary. Combined MCMC modeling of the lightcurve and the radial velocities suggested that CoRoT LRa02_E2_0121 is a hierarchical triple system with an evolved G-type primary and an A-type:F-type grazing eclipsing binary. Such triple systems are difficult to discover.

  19. The signature of orbital motion from the dayside of the planet τ Boötis b.

    Science.gov (United States)

    Brogi, Matteo; Snellen, Ignas A G; de Kok, Remco J; Albrecht, Simon; Birkby, Jayne; de Mooij, Ernst J W

    2012-06-27

    The giant planet orbiting τ Boötis (named τ Boötis b) was amongst the first extrasolar planets to be discovered. It is one of the brightest exoplanets and one of the nearest to us, with an orbital period of just a few days. Over the course of more than a decade, measurements of its orbital inclination have been announced and refuted, and have hitherto remained elusive. Here we report the detection of carbon monoxide absorption in the thermal dayside spectrum of τ Boötis b. At a spectral resolution of ∼100,000, we trace the change in the radial velocity of the planet over a large range in phase, determining an orbital inclination of 44.5° ± 1.5° and a mass 5.95 ± 0.28 times that of Jupiter, demonstrating that atmospheric characterization is possible for non-transiting planets. The strong absorption signal points to an atmosphere with a temperature that is decreasing towards higher altitudes, in contrast to the temperature inversion inferred for other highly irradiated planets. This supports the hypothesis that the absorbing compounds believed to cause such atmospheric inversions are destroyed in τ Boötis b by the ultraviolet emission from the active host star.

  20. ORBITAL PHASE VARIATIONS OF THE ECCENTRIC GIANT PLANET HAT-P-2b

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Nikole K.; Showman, Adam P. [Department of Planetary Sciences and Lunar and Planetary Laboratory, The University of Arizona, Tucson, AZ 85721 (United States); Knutson, Heather A.; Desert, Jean-Michel; Kao, Melodie [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Cowan, Nicolas B. [Center for Interdisciplinary Exploration and Research in Astrophysics and Department of Physics and Astronomy, Northwestern University, 2131 Tech Drive, Evanston, IL 60208 (United States); Laughlin, Gregory; Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Burrows, Adam; Bakos, Gaspar A.; Hartman, Joel D. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Deming, Drake [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Crepp, Justin R. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Mighell, Kenneth J. [National Optical Astronomy Observatories, Tucson, AZ 85726 (United States); Agol, Eric [Department of Astronomy, University of Washington, Seattle, WA 98195 (United States); Charbonneau, David [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Fischer, Debra A. [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Hinkley, Sasha; Johnson, John Asher [Department of Astrophysics, California Institute of Technology, MC 249-17, Pasadena, CA 91125 (United States); Howard, Andrew W., E-mail: nklewis@mit.edu [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); and others

    2013-04-01

    We present the first secondary eclipse and phase curve observations for the highly eccentric hot Jupiter HAT-P-2b in the 3.6, 4.5, 5.8, and 8.0 {mu}m bands of the Spitzer Space Telescope. The 3.6 and 4.5 {mu}m data sets span an entire orbital period of HAT-P-2b (P = 5.6334729 d), making them the longest continuous phase curve observations obtained to date and the first full-orbit observations of a planet with an eccentricity exceeding 0.2. We present an improved non-parametric method for removing the intrapixel sensitivity variations in Spitzer data at 3.6 and 4.5 {mu}m that robustly maps position-dependent flux variations. We find that the peak in planetary flux occurs at 4.39 {+-} 0.28, 5.84 {+-} 0.39, and 4.68 {+-} 0.37 hr after periapse passage with corresponding maxima in the planet/star flux ratio of 0.1138% {+-} 0.0089%, 0.1162% {+-} 0.0080%, and 0.1888% {+-} 0.0072% in the 3.6, 4.5, and 8.0 {mu}m bands, respectively. Our measured secondary eclipse depths of 0.0996% {+-} 0.0072%, 0.1031% {+-} 0.0061%, 0.071%{sub -0.013%}{sup +0.029,} and 0.1392% {+-} 0.0095% in the 3.6, 4.5, 5.8, and 8.0 {mu}m bands, respectively, indicate that the planet cools significantly from its peak temperature before we measure the dayside flux during secondary eclipse. We compare our measured secondary eclipse depths to the predictions from a one-dimensional radiative transfer model, which suggests the possible presence of a transient day side inversion in HAT-P-2b's atmosphere near periapse. We also derive improved estimates for the system parameters, including its mass, radius, and orbital ephemeris. Our simultaneous fit to the transit, secondary eclipse, and radial velocity data allows us to determine the eccentricity (e = 0.50910 {+-} 0.00048) and argument of periapse ({omega} = 188. Degree-Sign 09 {+-} 0. Degree-Sign 39) of HAT-P-2b's orbit with a greater precision than has been achieved for any other eccentric extrasolar planet. We also find evidence for a long

  1. Magnitudes of selected stellar occultation candidates for Pluto and other planets, with new predictions for Mars and Jupiter

    Science.gov (United States)

    Sybert, C. B.; Bosh, A. S.; Sauter, L. M.; Elliot, J. L.; Wasserman, L. H.

    1992-01-01

    Occultation predictions for the planets Mars and Jupiter are presented along with BVRI magnitudes of 45 occultation candidates for Mars, Jupiter, Saturn, Uranus, and Pluto. Observers can use these magnitudes to plan observations of occultation events. The optical depth of the Jovian ring can be probed by a nearly central occultation on 1992 July 8. Mars occults an unusually red star in early 1993, and the occultations for Pluto involving the brightest candidates would possibly occur in the spring of 1992 and the fall of 1993.

  2. Spin-Orbit Alignment for the Circumbinary Planet Host Kepler-16A

    CERN Document Server

    Winn, Joshua N; Johnson, John Asher; Torres, Guillermo; Cochran, William D; Marcy, Geoffrey W; Howard, Andrew; Isaacson, Howard; Fischer, Debra; Doyle, Laurance; Welsh, William; Carter, Joshua A; Fabrycky, Daniel C; Ragozzine, Darin; Quinn, Samuel N; Shporer, Avi; Howell, Steve B; Latham, David W; Orosz, Jerome; Prsa, Andrej; Slawson, Robert W; Borucki, William J; Koch, David; Barclay, Thomas; Boss, Alan P; Christensen-Dalsgaard, Jorgen; Girouard, Forrest R; Jenkins, Jon; Klaus, Todd C; Meibom, Soren; Morris, Robert L; Sasselov, Dimitar; Still, Martin; Van Cleve, Jeffrey

    2011-01-01

    Kepler-16 is an eccentric low-mass eclipsing binary with a circumbinary transiting planet. Here we investigate the angular momentum of the primary star, based on Kepler photometry and Keck spectroscopy. The primary star's rotation period is 35.1 +/- 1.0 days, and its projected obliquity with respect to the stellar binary orbit is 1.6 +/- 2.4 degrees. Therefore the three largest sources of angular momentum---the stellar orbit, the planetary orbit, and the primary's rotation---are all closely aligned. This finding supports a formation scenario involving accretion from a single disk. Alternatively, tides may have realigned the stars despite their relatively wide separation (0.2 AU), a hypothesis that is supported by the agreement between the measured rotation period and the "pseudosynchronous" period of tidal evolution theory. The rotation period, chromospheric activity level, and fractional light variations suggest a main-sequence age of 2-4 Gyr. Evolutionary models of low-mass stars can reproduce the observed ...

  3. The Solar Twin Planet Search. V. Close-in, low-mass planet candidates and evidence of planet accretion in the solar twin HIP 68468

    CERN Document Server

    Melendez, Jorge; Bean, Jacob L; Ramirez, Ivan; Asplund, Martin; Dreizler, Stefan; Yan, Hong-Liang; Shi, Jian-Rong; Lind, Karin; Ferraz-Mello, Sylvio; Galarza, Jhon Yana; Santos, Leonardo dos; Spina, Lorenzo; Maia, Marcelo Tucci; Alves-Brito, Alan; Monroe, TalaWanda; Casagrande, Luca

    2016-01-01

    [Methods]. We obtained high-precision radial velocities with HARPS on the ESO 3.6 m telescope and determined precise stellar elemental abundances (~0.01 dex) using MIKE spectra on the Magellan 6.5m telescope. [Results]. Our data indicate the presence of a planet with a minimum mass of 26 Earth masses around the solar twin HIP 68468. The planet is a super-Neptune, but unlike the distant Neptune in our solar system (30 AU), HIP 68468c is close-in, with a semi-major axis of 0.66 AU, similar to that of Venus. The data also suggest the presence of a super-Earth with a minimum mass of 2.9 Earth masses at 0.03 AU; if the planet is confirmed, it will be the fifth least massive radial velocity planet discovery to date and the first super-Earth around a solar twin. Both isochrones (5.9 Gyr) and the abundance ratio [Y/Mg] (6.4 Gyr) indicate an age of about 6 billion years. The star is enhanced in refractory elements when compared to the Sun, and the refractory enrichment is even stronger after corrections for Galactic c...

  4. Lightning Detection by LAC Onboard the Japanese Venus Climate Orbiter, Planet-C

    Science.gov (United States)

    Takahashi, Y.; Yoshida, J.; Yair, Y.; Imamura, T.; Nakamura, M.

    2008-06-01

    Lightning activity in Venus has been a mystery for a long period, although many studies based on observations both by spacecraft and by ground-based telescope have been carried out. This situation may be attributed to the ambiguity of these evidential measurements. In order to conclude this controversial subject, we are developing a new type of lightning detector, LAC (Lightning and Airglow Camera), which will be onboard Planet-C (Venus Climate Orbiter: VCO). Planet-C will be launched in 2010 by JAXA. To distinguish an optical lightning flash from other pulsing noises, high-speed sampling at 50 kHz for each pixel, that enables us to investigate the time variation of each lightning flash phenomenon, is adopted. On the other hand, spatial resolution is not the first priority. For this purpose we developed a new type of APD (avalanche photo diode) array with a format of 8×8. A narrow band interference filter at wavelength of 777.4 nm (OI), which is the expected lightning color based on laboratory discharge experiment, is chosen for lightning measurement. LAC detects lightning flash with an optical intensity of average of Earth’s lightning or less at a distance of 3 Rv. In this paper, firstly we describe the background of the Venus lightning study to locate our spacecraft project, and then introduce the mission details.

  5. Effect of UV Radiation on the Spectral Fingerprints of Earth-like Planets Orbiting M dwarfs

    CERN Document Server

    Rugheimer, S; Segura, A; Linsky, J; Mohanty, S

    2015-01-01

    We model the atmospheres and spectra of Earth-like planets orbiting the entire grid of M dwarfs for active and inactive stellar models with $T_{eff}$ = 2300K to $T_{eff}$ = 3800K and for six observed MUSCLES M dwarfs with UV radiation data. We set the Earth-like planets at the 1AU equivalent distance and show spectra from the VIS to IR (0.4$\\mu$m - 20$\\mu$m) to compare detectability of features in different wavelength ranges with JWST and other future ground- and spaced-based missions to characterize exo-Earths. We focus on the effect of UV activity levels on detectable atmospheric features that indicate habitability on Earth, namely: H$_2$O, O$_3$, CH$_4$, N$_2$O and CH$_3$Cl. To observe signatures of life - O$_2$/O$_3$ in combination with reducing species like CH$_4$, we find that early and active M dwarfs are the best targets of the M star grid for future telescopes. The O$_2$ spectral feature at 0.76$\\mu$m is increasingly difficult to detect in reflected light of later M dwarfs due to low stellar flux in ...

  6. Characterizing the Cool KOIs VIII. Parameters of the Planets Orbiting Kepler's Coolest Dwarfs

    CERN Document Server

    Swift, Jonathan J; Vanderburg, Andrew; Morton, Timothy; Muirhead, Philip S; Johnson, John Asher

    2015-01-01

    The coolest dwarf stars targeted by the Kepler Mission constitute a relatively small but scientifically valuable subset of the Kepler target stars, and provide a high-fidelity and nearby sample of transiting planetary systems. Using archival Kepler data spanning the entire primary mission we perform a uniform analysis to extract, confirm and characterize the transit signals discovered by the Kepler pipeline toward M-type dwarf stars. We recover all but two of the signals reported in a recent listing from the Exoplanet Archive resulting in 165 planet candidates associated with a sample of 106 low-mass stars. We fitted the observed light curves to transit models using Markov Chain Monte Carlo and we have made the posterior samples publicly available to facilitate further studies. We fitted empirical transit times to individual transit signals with significantly non-linear ephemerides for accurate recovery of transit parameters and measuring precise transit timing variations. We also provide the physical paramet...

  7. A super-Earth-sized planet orbiting in or near the habitable zone around Sun-like star

    CERN Document Server

    Barclay, Thomas; Howell, Steve B; Rowe, Jason F; Huber, Daniel; Isaacson, Howard; Jenkins, Jon M; Kolbl, Rea; Marcy, Geoffrey W; Quintana, Elisa V; Still, Martin; Twicken, Joseph D; Bryson, Stephen T; Borucki, William J; Caldwell, Douglas A; Ciardi, David; Clarke, Bruce D; Christiansen, Jessie L; Coughlin, Jeffrey L; Fischer, Debra A; Li, Jie; Haas, Michael R; Hunter, Roger; Lissauer, Jack J; Mullally, Fergal; Sabale, Anima; Seader, Shawn E; Smith, Jeffrey C; Tenenbaum, Peter; Uddin, AKM Kamal; Thompson, Susan E

    2013-01-01

    We present the discovery of a super-earth-sized planet in or near the habitable zone of a sun-like star. The host is Kepler-69, a 13.7 mag G4V-type star. We detect two periodic sets of transit signals in the three-year flux time series of Kepler-69, obtained with the Kepler spacecraft. Using the very high precision Kepler photometry, and follow-up observations, our confidence that these signals represent planetary transits is >99.1%. The inner planet, Kepler-69b, has a radius of 2.24+/-0.4 Rearth and orbits the host star every 13.7 days. The outer planet, Kepler-69c, is a super-Earth-size object with a radius of 1.7+/-0.3 Rearth and an orbital period of 242.5 days. Assuming an Earth-like Bond albedo, Kepler-69c has an equilibrium temperature of 299 +/- 19 K, which places the planet close to the habitable zone around the host star. This is the smallest planet found by Kepler to be orbiting in or near habitable zone of a Sun-like star and represents an important step on the path to finding the first true Earth ...

  8. Dynamics of Stellar Spin Driven by Planets Undergoing Lidov-Kozai Migration: Paths to Spin-Orbit Misalignment

    CERN Document Server

    Storch, Natalia I; Anderson, Kassandra R

    2016-01-01

    Many exoplanetary systems containing hot Jupiters (HJs) exhibit significant misalignment between the spin axes of the host stars and the orbital angular momentum axes of the planets ("spin-orbit misalignment"). High-eccentricity migration involving Lidov-Kozai oscillations of the planet's orbit induced by a distant perturber is a possible channel for producing such misaligned HJ systems. Previous works have shown that the dynamical evolution of the stellar spin axis during the high-$e$ migration plays a dominant role in generating the observed spin-orbit misalignment. Numerical studies have also revealed various patterns of the evolution of the stellar spin axis leading to the final misalignment. Here we develop an analytic theory to elucidate the evolution of spin-orbit misalignment during the Lidov-Kozai migration of planets in stellar binaries. Secular spin-orbit resonances play a key role in the misalignment evolution. We include the effects of short-range forces and tidal dissipation, and categorize the ...

  9. An orbital period of 0.94 days for the hot-Jupiter planet WASP-18b.

    Science.gov (United States)

    Hellier, Coel; Anderson, D R; Cameron, A Collier; Gillon, M; Hebb, L; Maxted, P F L; Queloz, D; Smalley, B; Triaud, A H M J; West, R G; Wilson, D M; Bentley, S J; Enoch, B; Horne, K; Irwin, J; Lister, T A; Mayor, M; Parley, N; Pepe, F; Pollacco, D L; Segransan, D; Udry, S; Wheatley, P J

    2009-08-27

    The 'hot Jupiters' that abound in lists of known extrasolar planets are thought to have formed far from their host stars, but migrate inwards through interactions with the proto-planetary disk from which they were born, or by an alternative mechanism such as planet-planet scattering. The hot Jupiters closest to their parent stars, at orbital distances of only approximately 0.02 astronomical units, have strong tidal interactions, and systems such as OGLE-TR-56 have been suggested as tests of tidal dissipation theory. Here we report the discovery of planet WASP-18b with an orbital period of 0.94 days and a mass of ten Jupiter masses (10 M(Jup)), resulting in a tidal interaction an order of magnitude stronger than that of planet OGLE-TR-56b. Under the assumption that the tidal-dissipation parameter Q of the host star is of the order of 10(6), as measured for Solar System bodies and binary stars and as often applied to extrasolar planets, WASP-18b will be spiralling inwards on a timescale less than a thousandth that of the lifetime of its host star. Therefore either WASP-18 is in a rare, exceptionally short-lived state, or the tidal dissipation in this system (and possibly other hot-Jupiter systems) must be much weaker than in the Solar System.

  10. First results of the Kourovka Planet Search: discovery of transiting exoplanet candidates in the first three target fields

    CERN Document Server

    Burdanov, Artem Y; Krushinsky, Vadim V; Popov, Alexander A; Sokov, Evgenii N; Sokova, Iraida A; Rusov, Sergei A; Lyashenko, Artem Yu; Ivanov, Kirill I; Moiseev, Alexei V; Rastegaev, Denis A; Dyachenko, Vladimir V; Balega, Yuri Yu; Baştürk, Özgür; Özavcı, Ibrahim; Puchalski, Damian; Marchini, Alessandro; Naves, Ramon; Shadick, Stan; Bretton, Marc

    2016-01-01

    We present the first results of our search for transiting exoplanet candidates as part of the Kourovka Planet Search (KPS) project. The primary objective of the project is to search for new hot Jupiters which transit their host stars, mainly in the Galactic plane, in the $R_c$ magnitude range of 11 to 14 mag. Our observations were performed with the telescope of the MASTER robotic network, installed at the Kourovka astronomical observatory of the Ural Federal University (Russia), and the Rowe-Ackermann Schmidt Astrograph, installed at the private Acton Sky Portal Observatory (USA). As test observations, we observed three celestial fields of size $2\\times2$ deg$^2$ during the period from 2012 to 2015. As a result, we discovered four transiting exoplanet candidates among the 39000 stars of the input catalogue. In this paper, we provide the description of the project and analyse additional photometric, spectral, and speckle interferometric observations of the discovered transiting exoplanet candidates. Three of ...

  11. The Lick-Carnegie Exoplanet Survey: Gliese 687 b—A Neptune-mass Planet Orbiting a Nearby Red Dwarf

    Science.gov (United States)

    Burt, Jennifer; Vogt, Steven S.; Butler, R. Paul; Hanson, Russell; Meschiari, Stefano; Rivera, Eugenio J.; Henry, Gregory W.; Laughlin, Gregory

    2014-07-01

    Precision radial velocities from the Automated Planet Finder (APF) and Keck/HIRES reveal an Msin (i) = 18 ± 2 M ⊕ planet orbiting the nearby M3V star GJ 687. This planet has an orbital period P = 38.14 days and a low orbital eccentricity. Our Strömgren b and y photometry of the host star suggests a stellar rotation signature with a period of P = 60 days. The star is somewhat chromospherically active, with a spot filling factor estimated to be several percent. The rotationally induced 60 day signal, however, is well separated from the period of the radial velocity variations, instilling confidence in the interpretation of a Keplerian origin for the observed velocity variations. Although GJ 687 b produces relatively little specific interest in connection with its individual properties, a compelling case can be argued that it is worthy of remark as an eminently typical, yet at a distance of 4.52 pc, a very nearby representative of the galactic planetary census. The detection of GJ 687 b indicates that the APF telescope is well suited to the discovery of low-mass planets orbiting low-mass stars in the as yet relatively un-surveyed region of the sky near the north celestial pole.

  12. The Intrinsic Neptune Trojan Orbit Distribution: Implications for the Primordial Disk and Planet Migration

    CERN Document Server

    Parker, Alex H

    2014-01-01

    The present-day orbit distribution of the Neptune Trojans is a powerful probe of the dynamical environment of the outer solar system during the late stages of planet migration. In this work, I conservatively debias the inclination, eccentricity, and libration amplitude distributions of the Neptune Trojans by reducing a priori unknown discovery and follow-up survey properties to nuisance parameters and using a likelihood-free Bayesian rejection sampler for parameter estimation. Using this survey-agnostic approach, I confirm that the Neptune Trojans are a dynamically excited population: at $>$95% confidence, the Neptune Trojans' inclination width must be $\\sigma_i > 11^\\circ$. For comparison and motivation purposes, I also model the Jupiter Trojan orbit distributions in the same basis and produce new estimates of their parameters (Jupiter Trojan $\\sigma_i=14.4^\\circ \\pm 0.5^\\circ$, $\\sigma_{L11} = 11.8^\\circ \\pm 0.5^\\circ$, and $\\sigma_e = 0.061\\pm 0.002$). The debiased inclination, libration amplitude, and ecc...

  13. The orbital evolution of asteroids, pebbles and planets from giant branch stellar radiation and winds

    CERN Document Server

    Veras, Dimitri; Gaensicke, Boris T

    2015-01-01

    The discovery of over 50 planets around evolved stars and more than 35 debris discs orbiting white dwarfs highlight the increasing need to understand small body evolution around both early and asymptotic giant branch (GB) stars. Pebbles and asteroids are susceptible to strong accelerations from the intense luminosity and winds of GB stars. Here, we establish equations that can model time-varying GB stellar radiation, wind drag and mass loss. We derive the complete three-dimensional equations of motion in orbital elements due to (1) the Epstein and Stokes regimes of stellar wind drag, (2) Poynting-Robertson drag, and (3) the Yarkovsky drift with seasonal and diurnal components. We prove through averaging that the potential secular eccentricity and inclination excitation due to Yarkovsky drift can exceed that from Poynting-Robertson drag and radiation pressure by at least three orders of magnitude, possibly flinging asteroids which survive YORP spin-up into a widely dispersed cloud around the resulting white dw...

  14. Measuring Transit Signal Recovery in the Kepler Pipeline. III. Completeness of the Q1-Q17 DR24 Planet Candidate Catalogue with Important Caveats for Occurrence Rate Calculations

    Science.gov (United States)

    Christiansen, Jessie L.; Clarke, Bruce D.; Burke, Christopher J.; Jenkins, Jon M.; Bryson, Stephen T.; Coughlin, Jeffrey L.; Mullally, Fergal; Thompson, Susan E.; Twicken, Joseph D.; Batalha, Natalie M.; Haas, Michael R.; Catanzarite, Joseph; Campbell, Jennifer R.; Kamal Uddin, AKM; Zamudio, Khadeejah; Smith, Jeffrey C.; Henze, Christopher E.

    2016-09-01

    With each new version of the Kepler pipeline and resulting planet candidate catalog, an updated measurement of the underlying planet population can only be recovered with a corresponding measurement of the Kepler pipeline detection efficiency. Here we present measurements of the sensitivity of the pipeline (version 9.2) used to generate the Q1-Q17 DR24 planet candidate catalog. We measure this by injecting simulated transiting planets into the pixel-level data of 159,013 targets across the entire Kepler focal plane, and examining the recovery rate. Unlike previous versions of the Kepler pipeline, we find a strong period dependence in the measured detection efficiency, with longer (>40 day) periods having a significantly lower detectability than shorter periods, introduced in part by an incorrectly implemented veto. Consequently, the sensitivity of the 9.2 pipeline cannot be cast as a simple one-dimensional function of the signal strength of the candidate planet signal, as was possible for previous versions of the pipeline. We report on the implications for occurrence rate calculations based on the Q1-Q17 DR24 planet candidate catalog, and offer important caveats and recommendations for performing such calculations. As before, we make available the entire table of injected planet parameters and whether they were recovered by the pipeline, enabling readers to derive the pipeline detection sensitivity in the planet and/or stellar parameter space of their choice.

  15. DISCOVERY OF A COMPANION CANDIDATE IN THE HD 169142 TRANSITION DISK AND THE POSSIBILITY OF MULTIPLE PLANET FORMATION

    Energy Technology Data Exchange (ETDEWEB)

    Reggiani, Maddalena; Quanz, Sascha P.; Meyer, Michael R.; Amara, Adam; Avenhaus, Henning; Meru, Farzana [Institute for Astronomy, ETH Zurich, CH-8093 Zurich (Switzerland); Pueyo, Laurent; Wolff, Schuyler [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Absil, Olivier [Département d' Astrophysique, Géophysique et Océanographie, Université de Liège, 17 Allée du Six Août, B-4000 Liège (Belgium); Anglada, Guillem; Osorio, Mayra [Instituto de Astrofísica de Andalucía, CSIC, Glorieta de la Astronomía s/n, E-18008 Granada (Spain); Girard, Julien H.; Mawet, Dimitri; Milli, Julien [European Southern Observatory, Alonso de Cordova 3107, Casilla 19001 Vitacura, Santiago 19 (Chile); Gonzalez, Carlos Carrasco [Centro de Radioastronomía y Astrofísica (UNAM), Apartado Postal 3-72 (Xangari), 58089 Morelia (Mexico); Graham, James [University of California, 644 Campbell Hall, Berkeley, CA (United States); Torrelles, Jose-Maria, E-mail: reggiani@phys.ethz.ch [Instituto de Ciencias del Espacio (CSIC)-UB/IEEC, Universitat de Barcelona, Martí i Franquès 1, E-08028 Barcelona (Spain)

    2014-09-01

    We present L'- and J-band high-contrast observations of HD 169142, obtained with the Very Large Telescope/NACO AGPM vector vortex coronagraph and the Gemini Planet Imager, respectively. A source located at 0.''156 ± 0.''032 north of the host star (P.A. = 7.°4 ± 11.°3) appears in the final reduced L' image. At the distance of the star (∼145 pc), this angular separation corresponds to a physical separation of 22.7 ± 4.7 AU, locating the source within the recently resolved inner cavity of the transition disk. The source has a brightness of L' = 12.2 ± 0.5 mag, whereas it is not detected in the J band (J >13.8 mag). If its L' brightness arose solely from the photosphere of a companion and given the J – L' color constraints, it would correspond to a 28-32 M {sub Jupiter} object at the age of the star, according to the COND models. Ongoing accretion activity of the star suggests, however, that gas is left in the inner disk cavity from which the companion could also be accreting. In this case, the object could be lower in mass and its luminosity enhanced by the accretion process and by a circumplanetary disk. A lower-mass object is more consistent with the observed cavity width. Finally, the observations enable us to place an upper limit on the L'-band flux of a second companion candidate orbiting in the disk annular gap at ∼50 AU, as suggested by millimeter observations. If the second companion is also confirmed, HD 169142 might be forming a planetary system, with at least two companions opening gaps and possibly interacting with each other.

  16. SPOTS: The Search for Planets Orbiting Two Stars. II. First constraints on the frequency of sub-stellar companions on wide circumbinary orbits

    Science.gov (United States)

    Bonavita, M.; Desidera, S.; Thalmann, C.; Janson, M.; Vigan, A.; Chauvin, G.; Lannier, J.

    2016-09-01

    A large number of direct imaging surveys for exoplanets have been performed in recent years, yielding the first directly imaged planets and providing constraints on the prevalence and distribution of wide planetary systems. However, like most of the radial velocity ones, these generally focus on single stars, hence binaries and higher-order multiples have not been studied to the same level of scrutiny. This motivated the Search for Planets Orbiting Two Stars (SPOTS) survey, which is an ongoing direct imaging study of a large sample of close binaries, started with VLT/NACO and now continuing with VLT/SPHERE. To complement this survey, we have identified the close binary targets in 24 published direct imaging surveys. Here we present our statistical analysis of this combined body of data. We analysed a sample of 117 tight binary systems, using a combined Monte Carlo and Bayesian approach to derive the expected values of the frequency of companions, for different values of the companion's semi-major axis. Our analysis suggest that the frequency of sub-stellar companions in wide orbit is moderately low (≲ 13% with a best value of 6% at 95% confidence level) and not significantly different between single stars and tight binaries. One implication of this result is that the very high frequency of circumbinary planets in wide orbits around post-common envelope binaries, implied by eclipse timing, cannot be uniquely due to planets formed before the common-envelope phase (first generation planets), supporting instead the second generation planet formation or a non-Keplerian origin of the timing variations.

  17. The SOPHIE search for northern extrasolar planets. V. Follow-up of ELODIE candidates: Jupiter-analogs around Sun-like stars

    Science.gov (United States)

    Boisse, I.; Pepe, F.; Perrier, C.; Queloz, D.; Bonfils, X.; Bouchy, F.; Santos, N. C.; Arnold, L.; Beuzit, J.-L.; Díaz, R. F.; Delfosse, X.; Eggenberger, A.; Ehrenreich, D.; Forveille, T.; Hébrard, G.; Lagrange, A.-M.; Lovis, C.; Mayor, M.; Moutou, C.; Naef, D.; Santerne, A.; Ségransan, D.; Sivan, J.-P.; Udry, S.

    2012-09-01

    We present radial-velocity measurements obtained in one of a number of programs underway to search for extrasolar planets with the spectrograph SOPHIE at the 1.93-m telescope of the Haute-Provence Observatory. Targets were selected from catalogs observed with ELODIE, which had been mounted previously at the telescope, in order to detect long-period planets with an extended database close to 15 years. Two new Jupiter-analog candidates are reported to orbit the bright stars HD 150706 and HD 222155 in 16.1 yr and 10.9 yr at 6.7-1.4+4.0 AU and 5.1-0.7+0.6 AU, and to have minimum masses of 2.71-0.66+1.14 MJup and 1.90-0.53+0.67 MJup, respectively. Using the measurements from ELODIE and SOPHIE, we refine the parameters of the long-period planets HD 154345b and HD 89307b, and publish the first reliable orbit for HD 24040b. This last companion has a minimum mass of 4.01 ± 0.49 MJup orbiting its star in 10.0 yr at 4.92 ± 0.38 AU. Moreover, the data provide evidence of a third bound object in the HD 24040 system. With a surrounding dust debris disk, HD 150706 is an active G0 dwarf for which we partially corrected the effect of the stellar spot on the SOPHIE radial-velocities. In contrast, HD 222155 is an inactive G2V star. In the SOPHIE measurements, an instrumental effect could be characterized and partly corrected. On the basis of the previous findings of Lovis and collaborators and since no significant correlation between the radial-velocity variations and the activity index are found in the SOPHIE data, these variations are not expected to be only due to stellar magnetic cycles. Finally, we discuss the main properties of this new population of long-period Jupiter-mass planets, which for the moment consists of fewer than 20 candidates. These stars are preferential targets either for direct-imaging or astrometry follow-up surveys to constrain the system parameters and for higher-precision radial-velocity searches for lower mass planets, aiming to find a solar system twin

  18. KIC 2831097 - A 2-year orbital-period RR Lyrae binary candidate

    CERN Document Server

    Sódor, Á; Liška, J; Bognár, Zs

    2016-01-01

    We report the discovery of a new Kepler first-overtone RR Lyrae pulsator, KIC 2831097. The pulsation shows large, 0.1 d amplitude, systematic phase variations that can be interpreted as light travel-time effect caused by orbital motion in a binary system, superimposed on a linear pulsation-period decrease. The assumed eccentric (e=0.47) orbit with the period of approximately 2 yr is the shortest among the non-eclipsing RR Lyrae binary candidates. The binary model gives a lowest estimate for the mass of the companion of 8.4 M_Sun, that places it among black hole candidates. Beside the first-overtone pulsation, numerous additional non-radial pulsation frequencies were also identified. We detected an ~47-d Blazhko-like irregular light-curve modulation.

  19. Precise radial velocities of giant stars. IX. HD 59686 Ab: a massive circumstellar planet orbiting a giant star in a 13.6 au eccentric binary system

    Science.gov (United States)

    Ortiz, Mauricio; Reffert, Sabine; Trifonov, Trifon; Quirrenbach, Andreas; Mitchell, David S.; Nowak, Grzegorz; Buenzli, Esther; Zimmerman, Neil; Bonnefoy, Mickaël; Skemer, Andy; Defrère, Denis; Lee, Man Hoi; Fischer, Debra A.; Hinz, Philip M.

    2016-10-01

    Context. For over 12 yr, we have carried out a precise radial velocity (RV) survey of a sample of 373 G- and K-giant stars using the Hamilton Échelle Spectrograph at the Lick Observatory. There are, among others, a number of multiple planetary systems in our sample as well as several planetary candidates in stellar binaries. Aims: We aim at detecting and characterizing substellar and stellar companions to the giant star HD 59686 A (HR 2877, HIP 36616). Methods: We obtained high-precision RV measurements of the star HD 59686 A. By fitting a Keplerian model to the periodic changes in the RVs, we can assess the nature of companions in the system. To distinguish between RV variations that are due to non-radial pulsation or stellar spots, we used infrared RVs taken with the CRIRES spectrograph at the Very Large Telescope. Additionally, to characterize the system in more detail, we obtained high-resolution images with LMIRCam at the Large Binocular Telescope. Results: We report the probable discovery of a giant planet with a mass of mp sin i = 6.92-0.24+0.18 MJup orbiting at ap = 1.0860-0.0007+0.0006 au from the giant star HD 59686 A. In addition to the planetary signal, we discovered an eccentric (eB = 0.729-0.003+0.004) binary companion with a mass of mB sin i = 0.5296-0.0008+0.0011 M⊙ orbiting at a close separation from the giant primary with a semi-major axis of aB = 13.56-0.14+0.18 au. Conclusions: The existence of the planet HD 59686 Ab in a tight eccentric binary system severely challenges standard giant planet formation theories and requires substantial improvements to such theories in tight binaries. Otherwise, alternative planet formation scenarios such as second-generation planets or dynamical interactions in an early phase of the system's lifetime need to be seriously considered to better understand the origin of this enigmatic planet. Based on observations collected at the Lick Observatory, University of California.Based on observations collected at the

  20. Exploring the Planet Mercury: 1.5 Years of MESSENGER Orbital Observations

    Science.gov (United States)

    Solomon, Sean C.; Nittler, L. R.; McNutt, R. L., Jr.

    2012-10-01

    Launched in 2004, MESSENGER flew by Mercury three times in 2008-2009 en route to becoming the first spacecraft to orbit the solar system’s innermost planet in March 2011. MESSENGER’s chemical remote sensing measurements of Mercury’s surface indicate that the planet’s bulk silicate fraction, low in Fe and high in Mg, differs from those of the other inner planets. Moreover, surface materials are richer in the moderately volatile constituents S and K than predicted by most current models for inner planet formation. Global image mosaics and targeted high-resolution images reveal that Mercury experienced globally extensive volcanism, with large expanses of plains emplaced as flood lavas and widespread examples of pyroclastic deposits likely emplaced during explosive eruptions of volatile-bearing magmas. Bright deposits within impact craters host fresh-appearing, rimless depressions or hollows, often with high-reflectance interiors and halos and likely formed through processes involving the geologically recent loss of volatiles. The large-scale deformational history of Mercury, although dominated by near-global contractional deformation as first seen by Mariner 10, is more complex than first appreciated, with numerous examples of extensional deformation that accompanied impact crater and basin modification. Mercury’s magnetic field is dominantly dipolar, but the field is axially symmetric and equatorially asymmetric, a geometry that poses challenges to dynamo models for field generation. The interaction between the solar wind and Mercury’s magnetosphere, among the most dynamic in the solar system, serves both to replenish the exosphere and space weather the planet’s surface. Plasma ions of planetary origin are seen throughout the sampled volume of Mercury’s magnetosphere, with maxima in heavy-ion fluxes in the planet’s magnetic-cusp regions. Bursts of energetic electrons, seen at most local times, point to an efficient acceleration mechanism operating

  1. CoRoT-10b: a giant planet in a 13.24 day eccentric orbit

    CERN Document Server

    Bonomo, A S; Alonso, R; Gazzano, J -C; Havel, M; Aigrain, S; Auvergne, M; Baglin, A; Barbieri, M; Barge, P; Benz, W; Bordé, P; Bouchy, F; Bruntt, H; Cabrera, J; Cameron, A C; Carone, L; Carpano, S; Csizmadia, Sz; Deleuil, M; Deeg, H J; Dvorak, R; Erikson, A; Ferraz-Mello, S; Fridlund, M; Gandolfi, D; Gillon, M; Guenther, E; Guillot, T; Hatzes, A; Hébrard, G; Jorda, L; Lammer, H; Lanza, A F; Léger, A; Llebaria, A; Mayor, M; Mazeh, T; Moutou, C; Ollivier, M; Pätzold, M; Pepe, F; Queloz, D; Rauer, H; Rouan, D; Samuel, B; Schneider, J; Tingley, B; Udry, S; Wuchterl, G

    2010-01-01

    The space telescope CoRoT searches for transiting extrasolar planets by continuously monitoring the optical flux of thousands of stars in several fields of view. We report the discovery of CoRoT-10b, a giant planet on a highly eccentric orbit (e=0.53 +/- 0.04) revolving in 13.24 days around a faint (V=15.22) metal-rich K1V star. We use CoRoT photometry, radial velocity observations taken with the HARPS spectrograph, and UVES spectra of the parent star to derive the orbital, stellar and planetary parameters. We derive a radius of the planet of 0.97 +/- 0.07 R_Jup and a mass of 2.75 +/- 0.16 M_Jup. The bulk density, rho_pl=3.70 +/- 0.83 g/cm^3, is ~2.8 that of Jupiter. The core of CoRoT-10b could contain up to 240 M_Earth of heavy elements. Moving along its eccentric orbit, the planet experiences a 10.6-fold variation in insolation. Owing to the long circularisation time, tau_circ > 7 Gyr, a resonant perturber is not required to excite and maintain the high eccentricity of CoRoT-10b.

  2. First results of the Kourovka Planet Search: discovery of transiting exoplanet candidates in the first three target fields

    Science.gov (United States)

    Burdanov, Artem Y.; Benni, Paul; Krushinsky, Vadim V.; Popov, Alexander A.; Sokov, Evgenii N.; Sokova, Iraida A.; Rusov, Sergei A.; Lyashenko, Artem Yu.; Ivanov, Kirill I.; Moiseev, Alexei V.; Rastegaev, Denis A.; Dyachenko, Vladimir V.; Balega, Yuri Yu.; Baştürk, Özgür; Özavcı, Ibrahim; Puchalski, Damian; Marchini, Alessandro; Naves, Ramon; Shadick, Stan; Bretton, Marc

    2016-10-01

    We present the first results of our search for transiting exoplanet candidates as part of the Kourovka Planet Search (KPS) project. The primary objective of the project is to search for new hot Jupiters which transit their host stars, mainly in the Galactic plane, in the Rc magnitude range of 11-14 mag. Our observations were performed with the telescope of the MASTER robotic network, installed at the Kourovka astronomical observatory of the Ural Federal University (Russia), and the Rowe-Ackermann Schmidt Astrograph, installed at the private Acton Sky Portal Observatory (USA). As test observations, we observed three celestial fields of size 2 × 2 deg2 during the period from 2012 to 2015. As a result, we discovered four transiting exoplanet candidates among the 39 000 stars of the input catalogue. In this paper, we provide the description of the project and analyse additional photometric, spectral, and speckle interferometric observations of the discovered transiting exoplanet candidates. Three of the four transiting exoplanet candidates are most likely astrophysical false positives, while the nature of the fourth (most promising) candidate remains to be ascertained. Also, we propose an alternative observing strategy that could increase the project's exoplanet haul.

  3. Limits on surface gravities of Kepler planet-candidate host stars from non-detection of solar-like oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Campante, T. L.; Chaplin, W. J.; Handberg, R.; Miglio, A.; Davies, G. R.; Elsworth, Y. P. [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Lund, M. N.; Arentoft, T.; Christensen-Dalsgaard, J.; Karoff, C.; Kjeldsen, H.; Lundkvist, M. [Stellar Astrophysics Centre (SAC), Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Huber, D. [NASA Ames Research Center, MS 244-30, Moffett Field, CA 94035 (United States); Hekker, S. [Astronomical Institute, " Anton Pannekoek," University of Amsterdam, Amsterdam (Netherlands); García, R. A. [Laboratoire AIM, CEA/DSM-CNRS-Université Paris Diderot (France); IRFU/SAp, Centre de Saclay, F-91191 Gif-sur-Yvette Cedex (France); Corsaro, E. [Instituut voor Sterrenkunde, KU Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Basu, S. [Department of Astronomy, Yale University, New Haven, CT 06520 (United States); Bedding, T. R. [Sydney Institute for Astronomy, School of Physics, University of Sydney, Sydney (Australia); Gilliland, R. L. [Center for Exoplanets and Habitable Worlds, The Pennsylvania State University, University Park, PA 16802 (United States); Kawaler, S. D., E-mail: campante@bison.ph.bham.ac.uk [Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States); and others

    2014-03-10

    We present a novel method for estimating lower-limit surface gravities (log g) of Kepler targets whose data do not allow the detection of solar-like oscillations. The method is tested using an ensemble of solar-type stars observed in the context of the Kepler Asteroseismic Science Consortium. We then proceed to estimate lower-limit log g for a cohort of Kepler solar-type planet-candidate host stars with no detected oscillations. Limits on fundamental stellar properties, as provided by this work, are likely to be useful in the characterization of the corresponding candidate planetary systems. Furthermore, an important byproduct of the current work is the confirmation that amplitudes of solar-like oscillations are suppressed in stars with increased levels of surface magnetic activity.

  4. Limits on surface gravities of Kepler planet-candidate host stars from non-detection of solar-like oscillations

    CERN Document Server

    Campante, T L; Lund, M N; Huber, D; Hekker, S; García, R A; Corsaro, E; Handberg, R; Miglio, A; Arentoft, T; Basu, S; Bedding, T R; Christensen-Dalsgaard, J; Davies, G R; Elsworth, Y P; Gilliland, R L; Karoff, C; Kawaler, S D; Kjeldsen, H; Lundkvist, M; Metcalfe, T S; Aguirre, V Silva; Stello, D

    2014-01-01

    We present a novel method for estimating lower-limit surface gravities log g of Kepler targets whose data do not allow the detection of solar-like oscillations. The method is tested using an ensemble of solar-type stars observed in the context of the Kepler Asteroseismic Science Consortium. We then proceed to estimate lower-limit log g for a cohort of Kepler solar-type planet-candidate host stars with no detected oscillations. Limits on fundamental stellar properties, as provided by this work, are likely to be useful in the characterization of the corresponding candidate planetary systems. Furthermore, an important byproduct of the current work is the confirmation that amplitudes of solar-like oscillations are suppressed in stars with increased levels of surface magnetic activity.

  5. VizieR Online Data Catalog: Planet candidates discovered using K2's 1st yr (Crossfield+, 2016)

    Science.gov (United States)

    Crossfield, I. J. M.; Ciardi, D. R.; Petigura, E. A.; Sinukoff, E.; Schlieder, J. E.; Howard, A. W.; Beichman, C. A.; Isaacson, H.; Dressing, C. D.; Christiansen, J. L.; Fulton, B. J.; Lepine, S.; Weiss, L.; Hirsch, L.; Livingston, J.; Baranec, C.; Law, N. M.; Riddle, R.; Ziegler, C.; Howell, S. B.; Horch, E.; Everett, M.; Teske, J.; Martinez, A. O.; Obermeier, C.; Benneke, B.; Scott, N.; Deacon, N.; Aller, K. M.; Hansen, B. M. S.; Mancini, L.; Ciceri, S.; Brahm, R.; Jordan, A.; Knutson, H. A.; Henning, T.; Bonnefoy, M.; Liu, M. C.; Crepp, J. R.; Lothringer, J.; Hinz, P.; Bailey, V.; Skemer, A.; Defrere, D.

    2016-10-01

    We select our FGK stellar sample from the all-sky Transiting Exoplanet Survey Satellite (TESS) Dwarf Catalog (TDC; Stassun et al. 2014, arXiv:1410.6379). We extract time-series photometry from the target pixel files provided by the K2 project using circular, stationary, soft-edged apertures. See section 2 for further explanations. We obtained high-resolution optical spectra of 83 planet candidate hosts using the HIRES echelle spectrometer on the 10m Keck I telescope (R=55000). We obtained spectra of 27 candidate host stars using the Levy high-resolution optical spectrograph mounted at the Automated Planet Finder (APF; R~80000 or 100000). We obtained spectra of a small number of candidate stellar hosts using the FEROS fiber-fed echelle spectrograph at the 2.2m MPG telescope (R~48000). See section 3.1 for further details. We obtained high-resolution imaging (HRI) for 164 of our candidate systems. Our primary instrument for this work was NIRC2 at the 10m Keck II telescope, with which we observed 110 systems. As part of multi-semester program GN-2015B-LP-5 (PI Crossfield) at Gemini Observatory, we observed 40 systems with the NIRI camera in the K-band. We also observed 33 stars with PHARO/PALM-3000 at the 5m Hale Telescope and 14 systems with LMIRCam at LBT, all at the K-band. We observed 39 stars at visible wavelengths using the automated Robo-AO laser adaptive optics system at the Palomar 1.5m telescope. Through our Long-Term Gemini program we also acquired high-resolution speckle imaging of 32 systems in narrowband filters centered at 692 and 880nm using the DSSI camera at the Gemini North telescope. See section 3.3 for further explanations. (7 data files).

  6. HATS-2b: A transiting extrasolar planet orbiting a K-type star showing starspot activity

    CERN Document Server

    Mohler-Fischer, M; Hartman, J D; Bakos, G B; Penev, K; Bayliss, D; Jordan, A; Csubry, Z; Zhou, G; Rabus, M; Nikolov, N; Brahm, R; Espinoza, N; Buchhave, L A; Beky, B; Suc, V; Csak, B; Henning, T; Wright, D J; Tinney, C G; Addison, B C; Schmidt, B; Noyes, R W; Papp, I; Lazar, J; Sari, P; Conroy, P

    2013-01-01

    We report the discovery of HATS-2b, the second transiting extrasolar planet detected by the HATSouth survey. HATS-2b is moving on a circular orbit around a V=13.6 mag, K-type dwarf star (GSC 6665-00236), at a separation of 0.0230 \\pm 0.0003 AU and with a period of 1.3541 days. The planetary parameters have been robustly determined using a simultaneous fit of the HATSouth, MPG/ESO~2.2\\,m/GROND, Faulkes Telescope South/Spectral transit photometry and MPG/ESO~2.2\\,m/FEROS, Euler~1.2\\,m/CORALIE, AAT~3.9\\,m/CYCLOPS radial-velocity measurements. HATS-2b has a mass of 1.37 \\pm 0.16 M_J, a radius of 1.14 \\pm 0.03 R_J and an equilibrium temperature of 1567 \\pm 30 K. The host star has a mass of 0.88 \\pm 0.04 M_Sun, radius of 0.89 \\pm 0.02 R_Sun and shows starspot activity. We characterized the stellar activity by analysing two photometric follow-up transit light curves taken with the GROND instrument, both obtained simultaneously in four optical bands (covering the wavelength range of 3860-9520 \\AA). The two light curv...

  7. KOI-1299 b: a massive planet in a highly eccentric orbit transiting a red giant

    CERN Document Server

    Ciceri, Simona; Southworth, John; Mancini, Luigi; Henning, Thomas; Barrado, David

    2014-01-01

    We confirm the planetary nature of the Kepler object of interest KOI-1299 b. We accurately constrained its mass and eccentricity by high-precision radial velocity measurements obtained with the CAFE spectrograph at the CAHA 2.2-m telescope. By a simultaneous fit of these new data and Kepler photometry, we found that KOI-1299 b is a dense transiting exoplanet, having a mass of Mp = 4.87 +/- 0.48 MJup and radius of Rp = 1.120 +/- 0.036 RJup. The planet revolves around a K giant star, ascending the red giant branch, every 52.5 d, moving on a highly eccentric orbit with e = 0.535 +/- 0.030. By analysing two NIR high-resolution images, we found that a star occurs at 1.1 from KOI-1299, but it is too faint to cause significant effects on the transit depth. Together with Kepler-56 and Kepler-91, KOI-1299 occupies an almost-desert region of parameter space, which is important to constrain the evolutionary processes of planetary systems.

  8. Investigation of a transiting planet candidate in Trumpler 37: an astrophysical false positive eclipsing spectroscopic binary star

    CERN Document Server

    Errmann, R; Schmidt, T O B; Seeliger, M; Howard, A W; Maciejewski, G; Neuhäuser, R; Meibom, S; Kellerer, A; Dimitrov, D P; Dincel, B; Marka, C; Mugrauer, M; Ginski, Ch; Adam, Ch; Raetz, St; Schmidt, J G; Hohle, M M; Berndt, A; Kitze, M; Trepl, L; Moualla, M; Eisenbeiß, T; Fiedler, S; Dathe, A; Graefe, Ch; Pawellek, N; Schreyer, K; Kjurkchieva, D P; Radeva, V S; Yotov, V; Chen, W P; Hu, S C -L; Wu, Z -Y; Zhou, X; Pribulla, T; Budaj, J; Vaňko, M; Kundra, E; Hambálek, Ľ; Krushevska, V; Bukowiecki, Ł; Nowak, G; Marschall, L; Terada, H; Tomono, D; Fernandez, M; Sota, A; Takahashi, H; Oasa, Y; Briceño, C; Chini, R; Broeg, C H

    2014-01-01

    We report our investigation of the first transiting planet candidate from the YETI project in the young (~4 Myr old) open cluster Trumpler 37. The transit-like signal detected in the lightcurve of the F8V star 2M21385603+5711345 repeats every 1.364894+/-0.000015 days, and has a depth of 54.5+/-0.8 mmag in R. Membership to the cluster is supported by its mean radial velocity and location in the color-magnitude diagram, while the Li diagnostic and proper motion are inconclusive in this regard. Follow-up photometric monitoring and adaptive optics imaging allow us to rule out many possible blend scenarios, but our radial-velocity measurements show it to be an eclipsing single-lined spectroscopic binary with a late-type (mid-M) stellar companion, rather than one of planetary nature. The estimated mass of the companion is 0.15-0.44 solar masses. The search for planets around very young stars such as those targeted by the YETI survey remains of critical importance to understand the early stages of planet formation a...

  9. Coupled orbital and spin evolution of the CoRoT-7 two-planet system using a Maxwell viscoelastic rheology

    CERN Document Server

    Colucci, Adrián Rodríguez; Correia, Alexandre

    2016-01-01

    We investigate the orbital and rotational evolution of the CoRoT-7 two-planet system, assuming that the innermost planet behaves like a Maxwell body. We numerically resolve the coupled differential equations governing the instantaneous deformation of the inner planet together with the orbital motion of the system. We show that, depending on the relaxation time for the deformation of the planet, the orbital evolution has two distinct behaviours: for relaxation times shorter than the orbital period, we reproduce the results from classic tidal theories, for which the eccentricity is always damped. However, for longer relaxation times, the eccentricity of the inner orbit is secularly excited and can grow to high values. This mechanism provides an explanation for the present high eccentricity observed for CoRoT-7 b, as well as for other close-in super-Earths in multiple planetary systems.

  10. Coupled orbital and spin evolution of the CoRoT-7 two-planet system using a Maxwell viscoelastic rheology

    Science.gov (United States)

    Rodríguez, A.; Callegari, N.; Correia, A. C. M.

    2016-12-01

    We investigate the orbital and rotational evolution of the CoRoT-7 two-planet system, assuming that the innermost planet behaves like a Maxwell body. We numerically resolve the coupled differential equations governing the instantaneous deformation of the inner planet together with the orbital motion of the system. We show that, depending on the relaxation time for the deformation of the planet, the orbital evolution has two distinct behaviours: for relaxation times shorter than the orbital period, we reproduce the results from classic tidal theories, for which the eccentricity is always damped. However, for longer relaxation times, the eccentricity of the inner orbit is secularly excited and can grow to high values. This mechanism provides an explanation for the present high eccentricity observed for CoRoT-7 b, as well as for other close-in super-Earths in multiple planetary systems.

  11. Constraints on Planet Nine’s Orbit and Sky Position within a Framework of Mean-motion Resonances

    Science.gov (United States)

    Millholland, Sarah; Laughlin, Gregory

    2017-03-01

    A number of authors have proposed that the statistically significant orbital alignment of the most distant Kuiper Belt Objects (KBOs) is evidence of an as-yet undetected planet in the outer solar system, now referred to colloquially as “Planet Nine.” Dynamical simulations by Batygin & Brown have provided constraints on the range of the planet’s possible orbits and sky locations. We extend these investigations by exploring the suggestion of Malhotra et al. that Planet Nine is in small integer ratio mean-motion resonances (MMRs) with several of the most distant KBOs. We show that the observed KBO semimajor axes present a set of commensurabilities with an unseen planet at ˜654 au (P ˜ 16,725 years) that has a greater than 98% chance of stemming from a sequence of MMRs rather than from a random distribution. We describe and implement a Monte-Carlo optimization scheme that drives billion-year dynamical integrations of the outer solar system to pinpoint the orbital properties of perturbers that are capable of maintaining the KBOs’ apsidal alignment. This optimization exercise suggests that the unseen planet is most consistently represented with mass, m ˜ 6-12 M ⊕, semimajor axis, a ˜ 654 au, eccentricity, e ˜ 0.45, inclination, i ˜ 30°, argument of periastron, ω ˜ 150°, longitude of ascending node, Ω ˜ 50°, and mean anomaly, M ˜ 180°. A range of sky locations relative to this fiducial ephemeris are possible. We find that the region 30° ≲ R.A. ≲ 50°, -20° ≲ decl. ≲ 20° is promising.

  12. Stability of habitable exomoons of circumbinary planets

    Science.gov (United States)

    Satyal, Suman; Haghighipour, Nader; Quarles, Billy

    2015-12-01

    Among the currently known Kepler circumbinary planets, three, namely Kepler-453b, Kepler-16b, and Kepler-47c are in the binary habitable zone (HZ). Given the large sizes of these planets, it is unlikely that they would be habitable. However, similar to the giant planets in our solar system, these planets may have large moons, which orbit their host planets while in the HZ. These exomoons, if exist, present viable candidates for habitability. As a condition for habitability, the planet-moon system has to maintain its orbital stability for long time. Usually, the empirical formula by Holeman & Wiegert (1999) is used as a measure of orbital stability in circumbinary systems. However, this formula was obtained by assuming planets to be test particles and therefore does not include possible perturbation of the planet on the binary. In this work, we present results of more realistic calculations of stability of circumbinary planets where the interactions between planets and their central binaries are taken into account. We map the region of stability, which in this case will be specific to each system, and determine the range of the orbital parameters of the moons for which their orbits will be long-term stable.

  13. MESSENGER, MErcury: Surface, Space ENvironment, GEochemistry, and Ranging; A Mission to Orbit and Explore the Planet Mercury

    Science.gov (United States)

    1999-01-01

    MESSENGER is a scientific mission to Mercury. Understanding this extraordinary planet and the forces that have shaped it is fundamental to understanding the processes that have governed the formation, evolution, and dynamics of the terrestrial planets. MESSENGER is a MErcury Surface, Space ENvironment, GEochemistry and Ranging mission to orbit Mercury for one Earth year after completing two flybys of that planet following two flybys of Venus. The necessary flybys return significant new data early in the mission, while the orbital phase, guided by the flyby data, enables a focused scientific investigation of this least-studied terrestrial planet. Answers to key questions about Mercury's high density, crustal composition and structure, volcanic history, core structure, magnetic field generation, polar deposits, exosphere, overall volatile inventory, and magnetosphere are provided by an optimized set of miniaturized space instruments. Our goal is to gain new insight into the formation and evolution of the solar system, including Earth. By traveling to the inner edge of the solar system and exploring a poorly known world, MESSENGER fulfills this quest.

  14. The Spin-Orbit Evolution of GJ 667C System: The Effect of Composition and Other Planet's Perturbations

    CERN Document Server

    Cuartas-Restrepo, P; Zuluaga, J; Portilla, B; Sucerquia, M; Miloni, O

    2016-01-01

    Potentially habitable planets within the habitable zone of M-dwarfs are affected by tidal interaction. We studied the tidal evolution in GJ 667C using a numerical code we call TIDEV. We reviewed the problem of the dynamical evolution focusing on the effects that a rheological treatment, different compositions and the inclusion of orbital perturbations, have on the spin-down time and the probability to be trapped in a low spin-orbit resonance. Composition have a strong effect on the spin-down time, changing, in some cases, by almost a factor of 2 with respect to the value estimated for a reference Earth-like model. We calculated the time to reach a low resonance value (3:2) for the configuration of 6 planets. Capture probabilities are affected when assuming different compositions and eccentricities variations. We chose planets b and c to evaluate the probabilities of capture in resonances below 5:2 for two compositions: Earth-like and Waterworld planets. We found that perturbations, although having a secular e...

  15. Spin-orbit evolution of the GJ 667C system: the effect of composition and other planets' perturbations

    Science.gov (United States)

    Cuartas-Restrepo, P. A.; Melita, M.; Zuluaga, J. I.; Portilla-Revelo, B.; Sucerquia, M.; Miloni, O.

    2016-12-01

    Potentially habitable planets within the habitable zone of M dwarfs are affected by tidal interaction. We studied tidal evolution in GJ 667C using a numerical code we call TIDEV. We reviewed the problem of dynamical evolution, focusing on the effects of a rheological treatment, different compositions and the inclusion of orbital perturbations on the spin-down time and the probability of becoming trapped in a low spin-orbit resonance. The composition has a noticeable effect on the spin-down time, which changes, in some cases, by almost a factor of 2 with respect to the value estimated for a reference Earth-like model. We calculated the time required to reach a low resonance value (3:2) for a configuration of six planets. Capture probabilities are affected when assuming different compositions and eccentricity variations. We chose planets b and c to evaluate the probabilities of capture in resonances below 5:2 for two compositions: Earth-like and Waterworld planets. We found that perturbations, although having a secular effect on eccentricities, have a low impact on capture probabilities and no effect on spin-down times. The implications of the eccentricity variations and actual habitability of the GJ 667C system are discussed.

  16. The HARPS search for southern extra-solar planets. XXVII. Up to seven planets orbiting HD 10180: probing the architecture of low-mass planetary systems

    CERN Document Server

    Lovis, C; Mayor, M; Udry, S; Benz, W; Bertaux, J -L; Bouchy, F; Correia, A C M; Laskar, J; Curto, G Lo; Mordasini, C; Pepe, F; Queloz, D; Santos, N C

    2010-01-01

    Context. Low-mass extrasolar planets are presently being discovered at an increased pace by radial velocity and transit surveys, opening a new window on planetary systems. Aims. We are conducting a high-precision radial velocity survey with the HARPS spectrograph which aims at characterizing the population of ice giants and super-Earths around nearby solar-type stars. This will lead to a better understanding of their formation and evolution, and yield a global picture of planetary systems from gas giants down to telluric planets. Methods. Progress has been possible in this field thanks in particular to the sub-m/s radial velocity precision achieved by HARPS. We present here new high-quality measurements from this instrument. Results. We report the discovery of a planetary system comprising at least five Neptune-like planets with minimum masses ranging from 12 to 25 M_Earth, orbiting the solar-type star HD 10180 at separations between 0.06 and 1.4 AU. A sixth radial velocity signal is present at a longer perio...

  17. SOPHIE velocimetry of Kepler transit candidates. XIV. KOI-189 B and KOI-686 B: two very low-mass stars in long-period orbits

    CERN Document Server

    Díaz, R F; Bonomo, A S; Deleuil, M; Almenara, J M; Barros, S C C; Bouchy, F; Bruno, G; Damiani, C; Hébrard, G; Moutou, C; Santerne, A

    2014-01-01

    We present the radial-velocity follow-up of two Kepler planetary transiting candidates (KOI-189 and KOI-686) carried out with the SOPHIE spectrograph at the Observatoire de Haute Provence. These data promptly discard these objects as viable planet candidates and show that the transiting objects are in the regime of very low-mass stars, where a strong discrepancy between observations and models persists for the mass and radius parameters. By combining the SOPHIE spectra with the Kepler light curve and photometric measurements found in the literature, we obtain a full characterization of the transiting companions, their orbits, and their host stars. The two companions are in significantly eccentric orbits with relatively long periods (30 days and 52.5 days), which makes them suitable objects for a comparison with theoretical models, since the effects invoked to understand the discrepancy with observations are weaker for these orbital distances. KOI-189 B has a mass M = 0.0745 +/- 0.0033 Msun and a radius R = 0....

  18. Spin-orbit angle measurements for six southern transiting planets; New insights into the dynamical origins of hot Jupiters

    CERN Document Server

    Triaud, Amaury H M J; Queloz, Didier; Anderson, David R; Gillon, Michaël; Hebb, Leslie; Hellier, Coel; Loeillet, Benoît; Maxted, Pierre F; Mayor, Michel; Pepe, Francesco; Pollacco, Don; Ségransan, Damien; Smalley, Barry; Udry, Stéphane; West, Richard G; Wheatley, Peter J

    2010-01-01

    For transiting planets, the Rossiter-McLaughlin effect allows the measurement of the sky-projected angle beta between the stellar rotation axis and a planet's orbital axis. Using the HARPS spectrograph, we observed the Rossiter-McLaughlin effect for six transiting hot Jupiters found by the WASP consortium. We combine these with long term radial velocity measurements obtained with CORALIE. We found that three of our targets have a projected spin-orbit angle above 90 degrees: WASP-2b: beta = 153 (+11 -15), WASP-15b: beta = 139.6 (+5.2 -4.3) and WASP-17b: beta = 148.5 (+5.1 -4.2); the other three (WASP-4b, WASP-5b and WASP-18b) have angles compatible with 0 degrees. There is no dependence between the misaligned angle and planet mass nor with any other planetary parameter. All orbits are close to circular, with only one firm detection of eccentricity on WASP-18b with e = 0.00848 (+0.00085 -0.00095). No long term radial acceleration was detected for any of the targets. Combining all previous 20 measurements of bet...

  19. The Lick-Carnegie Exoplanet Survey: Gliese 687b: A Neptune-Mass Planet Orbiting a Nearby Red Dwarf

    CERN Document Server

    Burt, Jennifer; Butler, R Paul; Hanson, Russell; Meschiari, Stefano; Rivera, Eugenio J; Henry, Gregory W; Laughlin, Gregory

    2014-01-01

    Precision radial velocities from the Automated Planet Finder and Keck/HIRES reveal an M*sin(i) =18 +/- 2 Earth mass planet orbiting the nearby M3V star GJ 687. This planet has an orbital period, P = 38.14 days, and a low orbital eccentricity. Our Stromgren b and y photometry of the host star suggests a stellar rotation signature with a period of P = 60 days. The star is somewhat chromospherically active, with a spot filling factor estimated to be several percent. The rotationally{induced 60-day signal, however, is well-separated from the period of the radial velocity variations, instilling confidence in the interpretation of a Keplerian origin for the observed velocity variations. Although GJ 687b produces relatively little specific interest in connection with its individual properties, a compelling case can be argued that it is worthy of remark as an eminently typical, yet at a distance of 4.52 pc, a very nearby representative of the galactic planetary census. The detection of GJ 687b indicates that the APF...

  20. Consequences of tidal interaction between disks and orbiting protoplanets for the evolution of multi-planet systems with architecture resembling that of Kepler 444

    CERN Document Server

    Papaloizou, J C B

    2016-01-01

    We study orbital evolution of multi-planet systems with masses in the terrestrial planet regime induced through tidal interaction with a protoplanetary disk assuming that this is the dominant mechanism for producing orbital migration and circularization. We develop a simple analytic model for a system that maintains consecutive pairs in resonance while undergoing orbital circularization and migration. Migration times for each planet may be estimated once planet masses, circularization times and the migration time for the innermost planet are given. We applied it to a model system with the current architecture of Kepler 444 interacting with a protoplanetary disk, the evolution time for the system as a whole being comparable to current protoplanetary disk lifetimes. In addition we performed numerical simulations with input data obtained from this model. These indicate that although the analytic model is inexact, relatively small corrections to estimated migration rates yield systems for which period ratios vary...

  1. The stability of tightly-packed, evenly-spaced systems of Earth-mass planets orbiting a Sun-like star

    Science.gov (United States)

    Obertas, Alysa; Van Laerhoven, Christa; Tamayo, Daniel

    2017-09-01

    Many of the multi-planet systems discovered to date have been notable for their compactness, with neighbouring planets closer together than any in the Solar System. Interestingly, planet-hosting stars have a wide range of ages, suggesting that such compact systems can survive for extended periods of time. We have used numerical simulations to investigate how quickly systems go unstable in relation to the spacing between planets, focusing on hypothetical systems of Earth-mass planets on evenly-spaced orbits (in mutual Hill radii). In general, the further apart the planets are initially, the longer it takes for a pair of planets to undergo a close encounter. We recover the results of previous studies, showing a linear trend in the initial planet spacing between 3 and 8 mutual Hill radii and the logarithm of the stability time. Investigating thousands of simulations with spacings up to 13 mutual Hill radii reveals distinct modulations superimposed on this relationship in the vicinity of first and second-order mean motion resonances of adjacent and next-adjacent planets. We discuss the impact of this structure and the implications on the stability of compact multi-planet systems. Applying the outcomes of our simulations, we show that isolated systems of up to five Earth-mass planets can fit in the habitable zone of a Sun-like star without close encounters for at least 109 orbits.

  2. STARSPOTS-TRANSIT DEPTH RELATION OF THE EVAPORATING PLANET CANDIDATE KIC 12557548b

    Energy Technology Data Exchange (ETDEWEB)

    Kawahara, Hajime; Kurosaki, Kenji; Ito, Yuichi; Ikoma, Masahiro [Department of Earth and Planetary Science, The University of Tokyo, Tokyo 113-0033 (Japan); Hirano, Teruyuki, E-mail: kawahara@eps.s.u-tokyo.ac.jp [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Tokyo 152-8550 (Japan)

    2013-10-10

    Violent variation of transit depths and an ingress-egress asymmetry of the transit light curve discovered in KIC 12557548 have been interpreted as evidence of a catastrophic evaporation of atmosphere with dust ( M-dot {sub p}∼>1 M{sub ⊕} Gyr{sup –1}) from a close-in small planet. To explore what drives the anomalous atmospheric escape, we perform time-series analysis of the transit depth variation of Kepler archival data for ∼3.5 yr. We find a ∼30% periodic variation of the transit depth with P {sub 1} = 22.83 ± 0.21 days, which is within the error of the rotation period of the host star estimated using the light curve modulation, P {sub rot} = 22.91 ± 0.24 days. We interpret the results as evidence that the atmospheric escape of KIC 12557548b correlates with stellar activity. We consider possible scenarios that account for both the mass loss rate and the correlation with stellar activity. X-ray and ultraviolet (XUV)-driven evaporation is possible if one accepts a relatively high XUV flux and a high efficiency for converting the input energy to the kinetic energy of the atmosphere. Star-planet magnetic interaction is another possible scenario, though huge uncertainty remains for the mass loss rate.

  3. The Thermal Expansion of Ring Particles and the Secular Orbital Evolution of Rings Around Planets and Asteroids

    Science.gov (United States)

    Rubincam, David P.

    2013-01-01

    The thermal expansion and contraction of ring particles orbiting a planet or asteroid can cause secular orbit evolution. This effect, called here the thermal expansion effect, depends on ring particles entering and exiting the shadow of the body they orbit. A particle cools off in the shadow and heats up again in the sunshine, suffering thermal contraction and expansion. The changing cross-section it presents to solar radiation pressure plus time lags due to thermal inertia lead to a net along-track force. The effect causes outward drift for rocky particles. For the equatorial orbits considered here, the thermal expansion effect is larger than Poynting-Robertson drag in the inner solar system for particles in the size range approx. 0.001 - 0.02 m. This leads to a net increase in the semimajor axis from the two opposing effects at rates ranging from approx. 0.1 R per million years for Mars to approx. 1 R per million years for Mercury, for distances approx. 2R from the body, where R is the body's radius. Asteroid 243 Ida has approx. 10 R per million years, while a hypothetical Near-Earth Asteroid (NEA) can have faster rates of approx. 0.5 R per thousand years, due chiefly to its small radius compared to the planets. The thermal expansion effect weakens greatly at Jupiter and is overwhelmed by Poynting-Robertson for icy particles orbiting Saturn. Meteoroids in eccentric orbits about the Sun also suffer the thermal expansion effect, but with only approx. 0.0003e2 AU change in semimajor axis over a million years for a 2 m meteoroid orbiting between Mercury and Earth.

  4. Extrasolar planets.

    Science.gov (United States)

    Lissauer, J J; Marcy, G W; Ida, S

    2000-11-07

    The first known extrasolar planet in orbit around a Sun-like star was discovered in 1995. This object, as well as over two dozen subsequently detected extrasolar planets, were all identified by observing periodic variations of the Doppler shift of light emitted by the stars to which they are bound. All of these extrasolar planets are more massive than Saturn is, and most are more massive than Jupiter. All orbit closer to their stars than do the giant planets in our Solar System, and most of those that do not orbit closer to their star than Mercury is to the Sun travel on highly elliptical paths. Prevailing theories of star and planet formation, which are based on observations of the Solar System and of young stars and their environments, predict that planets should form in orbit about most single stars. However, these models require some modifications to explain the properties of the observed extrasolar planetary systems.

  5. Tracing a planet's orbit with a straight hedge and a compass with the help of the hodograph and the Hamilton vector

    CERN Document Server

    Guillaumín-España, E; Salas-Brito, A L

    2003-01-01

    We describe a geometrical method for tracing a planet's orbit using its velocity hodograph, that is, the path of the planet's velocity. The method requires only a straight edge, a compass, and the help of the hodograph. We also obtain analitically the hodograph and some of the features of the motion that can be obtained from it.

  6. MOA-2009-BLG-387Lb: a massive planet orbiting an M dwarf

    DEFF Research Database (Denmark)

    Batista, V.; Gould, A.; Dieters, S.

    2011-01-01

    We report the discovery of a planet with a high planet-to-star mass ratio in the microlensing event MOA-2009-BLG-387, which exhibited pronounced deviations over a 12-day interval, one of the longest for any planetary event. The host is an M dwarf, with a mass in the range 0.07 M_sun < M_host < 0....

  7. MOA-2009-BLG-387Lb: a massive planet orbiting an M dwarf

    DEFF Research Database (Denmark)

    Batista, V.; Gould, A.; Dieters, S.

    2011-01-01

    We report the discovery of a planet with a high planet-to-star mass ratio in the microlensing event MOA-2009-BLG-387, which exhibited pronounced deviations over a 12-day interval, one of the longest for any planetary event. The host is an M dwarf, with a mass in the range 0.07 M_sun < M_host < 0....

  8. Indication of a massive circumbinary planet orbiting the low-mass X-ray binary MXB 1658-298

    Science.gov (United States)

    Jain, Chetana; Paul, Biswajit; Sharma, Rahul; Jaleel, Abdul; Dutta, Anjan

    2017-06-01

    We present an X-ray timing analysis of the transient X-ray binary MXB 1658-298, using data obtained from the RXTE and XMM-Newton observatories. We have made 27 new mid-eclipse time measurements from observations made during the two outbursts of the source. These new measurements have been combined with the previously known values to study long-term changes in orbital period of the binary system. We have found that the mid-eclipse timing record of MXB 1658-298 is quite unusual. The long-term evolution of mid-eclipse times indicates an overall orbital period decay with a time-scale of -6.5(7) × 107 yr. Over and above this orbital period decay, the O-C residual curve also shows a periodic residual on shorter time-scales. This sinusoidal variation has an amplitude of ˜9 lt-s and a period of ˜760 d. This is indicative of the presence of a third body around the compact X-ray binary. The mass and orbital radius of the third body are estimated to lie in the ranges 20.5-26.9 Jupiter mass and 750-860 lt-s, respectively. If true, then it will be the most massive circumbinary planet and also the smallest period binary known to host a planet.

  9. Fast Rise of "Neptune-Size" Planets (4-8 R_Earth) from P~10 to ~250 days -- Statistics of Kepler Planet Candidates Up to ~0.75 AU

    CERN Document Server

    Dong, Subo

    2013-01-01

    We infer period (P) and size (R_p) distribution of Kepler transiting planet candidates with R_p> 1 R_Earth and P10 days, the planet frequency dN_p/d logP for "Neptune-size" planets (R_p = 4-8 R_Earth) increases with period as \\propto P^{0.7\\pm0.1}. In contrast, dN_p/dlogP for Super-Earth-Size (2-4 R_Earth) as well as Earth-size (1-2 R_Earth) planets are consistent with a nearly flat distribution as a function of period (\\propto P^{0.11\\pm0.05}) and \\propto P^{-0.10\\pm0.12}, respectively), and the normalizations are remarkably similar (within a factor of ~ 1.5). The shape of the distribution function is found to be not sensitive to changes in selection criteria of the sample. The implied nearly flat or rising planet frequency at long period appears to be in tension with the sharp decline at ~100 days in planet frequency for low mass planets (planet mass m_p < 30 M_Earth) recently suggested by the HARPS survey.

  10. A Test of Stellar Cohabitation in Multiple Transiting Planet Systems

    Science.gov (United States)

    Morehead, Robert C.; Ford, E. B.

    2013-01-01

    The Kepler mission has discovered over 2,300 exoplanet candidates, including more than 885 associated with target stars with multiple transiting planet candidates. While these putative multiple planet systems are predicted to have an extremely low false positive rate, it is important to test what fraction are indeed transiting a single star and what fraction are some sort of blend (e.g., one transiting planet and an eclipsing binary, or two planet-hosting stars blended within the photometric aperture). We perform such a test for stellar cohabitation using the observed distribution of ξ, the period-normalized transit duration ratio of pairs of transiting planet candidates. We developed a Bayesian framework to estimate the probability that two candidates orbit the target star based on the observed orbital periods and light curve properties with an emphasis on ξ. For priors distributions, we use empirical planet, binary star, and hierarchical triple star occurrence rates and galactic population synthesis models. Using Monte Carlo simulations, we calculate the implied distributions of ξ for all plausible blend scenarios; i.e., a planet around the target star and a background or physically associated eclipsing binary star, a planet around the the target star and a planet around a background or physically associated secondary star, as well as a single star with two planets and no blend. Finally, we compute the posterior probability that a given pair of transiting planet candidates are indeed a pair of planets in orbit around the target star given the observed values. We present the results of our test for a selection Kepler multiple planet candidates and for systems confirmed through other methods, such as transit timing variations. We demonstrate the utility of this technique for the confirmation and characterization of multiple transiting planet systems.

  11. Architecture of Kepler's Multi-transiting Systems: II. New investigations with twice as many candidates

    CERN Document Server

    Fabrycky, Daniel C; Ragozzine, Darin; Rowe, Jason F; Agol, Eric; Barclay, Thomas; Batalha, Natalie; Borucki, William; Ciardi, David R; Ford, Eric B; Geary, John C; Holman, Matthew J; Jenkins, Jon M; Li, Jie; Morehead, Robert C; Shporer, Avi; Smith, Jeffrey C; Steffen, Jason H; Still, Martin

    2012-01-01

    Having discovered 885 planet candidates in 361 multiple-planet systems, Kepler has made transits a powerful method for studying the statistics of planetary systems. The orbits of only two pairs of planets in these candidate systems are apparently unstable. This indicates that a high percentage of the candidate systems are truly planets orbiting the same star, motivating physical investigations of the population. Pairs of planets in this sample are typically not in orbital resonances. However, pairs with orbital period ratios within a few percent of a first-order resonance (e.g. 2:1, 3:2) prefer orbital spacings just wide of the resonance and avoid spacings just narrow of the resonance. Finally, we investigate mutual inclinations based on transit duration ratios. We infer that the inner planets of pairs tend to have a smaller impact parameter than their outer companions, suggesting these planetary systems are typically coplanar to within a few degrees.

  12. Kepler-539: A young extrasolar system with two giant planets on wide orbits and in gravitational interaction

    Science.gov (United States)

    Mancini, L.; Lillo-Box, J.; Southworth, J.; Borsato, L.; Gandolfi, D.; Ciceri, S.; Barrado, D.; Brahm, R.; Henning, Th.

    2016-05-01

    We confirm the planetary nature of Kepler-539 b (aka Kepler object of interest K00372.01), a giant transiting exoplanet orbiting a solar-analogue G2 V star. The mass of Kepler-539 b was accurately derived thanks to a series of precise radial velocity measurements obtained with the CAFE spectrograph mounted on the CAHA 2.2-m telescope. A simultaneous fit of the radial-velocity data and Kepler photometry revealed that Kepler-539 b is a dense Jupiter-like planet with a mass of Mp = 0.97 ± 0.29 MJup and a radius of Rp = 0.747 ± 0.018 RJup, making a complete circular revolution around its parent star in 125.6 days. The semi-major axis of the orbit is roughly 0.5 au, implying that the planet is at ≈0.45 au from the habitable zone. By analysing the mid-transit times of the 12 transit events of Kepler-539 b recorded by the Kepler spacecraft, we found a clear modulated transit time variation (TTV), which is attributable to the presence of a planet c in a wider orbit. The few timings available do not allow us to precisely estimate the properties of Kepler-539 c and our analysis suggests that it has a mass between 1.2 and 3.6 MJup, revolving on a very eccentric orbit (0.4 CAFE spectra revealed a relatively high photospheric lithium content, A(Li) = 2.48 ± 0.12 dex, which, together with both a gyrochronological and isochronal analysis, suggests that the parent star is relatively young. RV/BVS measurements are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/590/A112

  13. WASP-41b: A transiting hot Jupiter planet orbiting a magnetically-active G8V star

    CERN Document Server

    Maxted, P F L; Cameron, A Collier; Hellier, C; Queloz, D; Smalley, B; Street, R A; Triaud, A H M J; West, R G; Gillon, M; Lister, T A; Pepe, F; Pollacco, D; Segransan, D; Smith, A M S; Udry, S

    2010-01-01

    We report the discovery of a transiting planet with an orbital period of 3.05d orbiting the star TYC 7247-587-1. The star, WASP-41, is a moderately bright G8V star (V=11.6) with a metallicity close to solar ([Fe/H]=-0.08+-0.09). The star shows evidence of moderate chromospheric activity, both from emission in the cores of the CaII H and K lines and photometric variability with a period of 18.3d and an amplitude of about 1%. The rotation period of the star implies a gyrochronological age for WASP-41 of 1.8Gyr with an error of about 15%. We have used a combined analysis of the available photometric and spectroscopic data to derive the mass and radius of the planet (0.93+-0.06M_Jup, 1.21+-0.06R_Jup). Further observations of WASP-41 can be used to explore the connections between the properties of hot Jupiter planets and the level of chromospheric activity in their host stars.

  14. The Response of Atmospheric Chemistry on Earthlike Planets around F, G and K Stars to Small Variations in Orbital Distance

    CERN Document Server

    Grenfell, J L; Von Paris, P; Patzer, B; Titz, R; Segura, A; Rauer, H; Grenfell, John Lee; Stracke, Barbara; Paris, Philip von; Patzer, Beate; Titz, Ruth; Segura, Antigona; Rauer, Heike

    2006-01-01

    One of the prime goals of future investigations of extrasolar planets is to search for life as we know it. The Earth's biosphere is adapted to current conditions. How would the atmospheric chemistry of the Earth respond if we moved it to different orbital distances or changed its host star? This question is central to astrobiology and aids our understanding of how the atmospheres of terrestrial planets develop. To help address this question, we have performed a sensitivity study using a coupled radiative-convective photochemical column model to calculate changes in atmospheric chemistry on a planet having Earth's atmospheric composition, which we subjected to small changes in orbital position, of the order of 5-10 per cent for a solar-type G2V, F2V, and K2V star. We then applied a chemical source-sink analysis to the biomarkers in order to understand how chemical processes affect biomarker concentrations. We start with the composition of the present Earth, since this is the only example we know for which a sp...

  15. MINERVA-Red: A telescope dedicated to the discovery of planets orbiting the nearest low-mass stars

    Science.gov (United States)

    Sliski, David; Blake, Cullen; Johnson, John A.; Plavchan, Peter; Wittenmyer, Robert A.; Eastman, Jason D.; Barnes, Stuart; Baker, Ashley

    2017-01-01

    Results from Kepler and ground-based exoplanet surveys suggest that M-dwarfs host numerous small sized planets. Additionally, the discovery of the Earth-sized exoplanets orbiting Proxima Centauri and Trappist 1 demonstrate that these stars can host terrestrial planets in their habitable zones. Since low-mass stars are intrinsically faint at optical wavelengths, obtaining 1 m/s Doppler resolution to detect their planetary companions remains a challenge for instruments designed for sun-like stars. We describe a novel, high-cadence approach aimed at detecting and characterizing planets orbiting the closest low-mass stars to the Sun. MINERVA-Red is an echelle spectrograph optimized for the 'deep red', between 800 nm and 900 nm, where M-dwarfs are brightest. The spectrograph will be temperature controlled at 20C +/- 10mk and in a vacuum chamber which maintains a pressure below 0.01 mbar while using a Fabry-Perot etalon and U/Ne lamp for wavelength calibration. The spectrometer will operate with a robotic, 0.7-meter telescope at Mt. Hopkins, Arizona. We expect first light in 2017.

  16. THE PHOTOECCENTRIC EFFECT AND PROTO-HOT JUPITERS. II. KOI-1474.01, A CANDIDATE ECCENTRIC PLANET PERTURBED BY AN UNSEEN COMPANION

    Energy Technology Data Exchange (ETDEWEB)

    Dawson, Rebekah I.; Murray-Clay, Ruth A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St, MS-10, Cambridge, MA 02138 (United States); Johnson, John Asher; Morton, Timothy D. [Department of Astronomy, California Institute of Technology, 1200 East California Boulevard, MC 249-17, Pasadena, CA 91125 (United States); Crepp, Justin R. [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556 (United States); Fabrycky, Daniel C. [Department of Astronomy and Astrophysics, University of California Santa Cruz, Santa Cruz, California 95064 (United States); Howard, Andrew W., E-mail: rdawson@cfa.harvard.edu [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822-1839 (United States)

    2012-12-20

    The exoplanets known as hot Jupiters-Jupiter-sized planets with periods of less than 10 days-likely are relics of dynamical processes that shape all planetary system architectures. Socrates et al. argued that high eccentricity migration (HEM) mechanisms proposed for situating these close-in planets should produce an observable population of highly eccentric proto-hot Jupiters that have not yet tidally circularized. HEM should also create failed-hot Jupiters, with periapses just beyond the influence of fast circularization. Using the technique we previously presented for measuring eccentricities from photometry (the ''photoeccentric effect''), we are distilling a collection of eccentric proto- and failed-hot Jupiters from the Kepler Objects of Interest (KOI). Here, we present the first, KOI-1474.01, which has a long orbital period (69.7340 days) and a large eccentricity e 0.81{sup +0.10}{sub -0.07}, skirting the proto-hot Jupiter boundary. Combining Kepler photometry, ground-based spectroscopy, and stellar evolution models, we characterize host KOI-1474 as a rapidly rotating F star. Statistical arguments reveal that the transiting candidate has a low false-positive probability of 3.1%. KOI-1474.01 also exhibits transit-timing variations of the order of an hour. We explore characteristics of the third-body perturber, which is possibly the ''smoking-gun'' cause of KOI-1474.01's large eccentricity. We use the host star's period, radius, and projected rotational velocity to measure the inclination of the stellar spin. Comparing KOI 1474.01's inclination, we find that its orbit is marginally consistent with being aligned with the stellar spin axis, although a reanalysis is warranted with future additional data. Finally, we discuss how the number and existence of proto-hot Jupiters will not only demonstrate that hot Jupiters migrate via HEM, but also shed light on the typical timescale for the mechanism.

  17. Origin of the wide-orbit circumbinary giant planet HD 106906. A dynamical scenario and its impact on the disk

    Science.gov (United States)

    Rodet, L.; Beust, H.; Bonnefoy, M.; Lagrange, A.-M.; Galli, P. A. B.; Ducourant, C.; Teixeira, R.

    2017-06-01

    Context. A giant planet has been recently resolved at a projected distance of 730 au from the tight pair of young ( 13 Myr) intermediate-mass stars HD 106906AB in the Lower Centaurus Crux (LCC) group. The stars are surrounded by a debris disk which displays a ring-like morphology and strong asymmetries at multiple scales. Aims: We aim to study the likelihood of a scenario where the planet formed closer to the stars in the disk, underwent inward disk-induced migration, and got scattered away by the binary star before being stabilized by a close encounter (fly-by). Methods: We performed semi-analytical calculations and numerical simulations (Swift_HJS package) to model the interactions between the planet and the two stars. We accounted for the migration as a simple force. We studied the LCC kinematics to set constraints on the local density of stars, and therefore on the fly-by likelihood. We performed N-body simulations to determine the effects of the planet trajectories (ejection and secular effects) onto the disk morphology. Results: The combination of the migration and mean-motion resonances with the binary star (often 1:6) can eject the planet. Nonetheless, we estimate that the fly-by hypothesis decreases the scenario probability to less than 10-7 for a derived local density of stars of 0.11 stars/pc3. We show that the concomitant effect of the planet and stars trajectories induce spiral-features in the disk which may correspond to the observed asymmetries. Moreover, the present disk shape suggests that the planet is on an eccentric orbit. Conclusions: The scenario we explored is a natural hypothesis if the planet formed within a disk. Conversely, its low probability of occurrence and the fact that HD 106906 b shares some characteristics with other systems in Sco-Cen (e.g., HIP 78530, in terms of mass ratio and separation) may indicate an alternative formation pathway for those objects.

  18. Direct Detection of Planets Orbiting Large Angular Diameter Stars: Sensitivity of an Internally-Occulting Space-Based Coronagraph

    CERN Document Server

    Crepp, Justin R; Ge, Jian

    2009-01-01

    High-contrast imaging observations of large angular diameter stars enable complementary science questions to be addressed compared to the baseline goals of proposed missions like the Terrestrial Planet Finder-Coronagraph, New World's Observer, and others. Such targets however present a practical problem in that finite stellar size results in unwanted starlight reaching the detector, which degrades contrast. In this paper, we quantify the sensitivity, in terms of contrast, of an internally-occulting, space-based coronagraph as a function of stellar angular diameter, from unresolved dwarfs to the largest evolved stars. Our calculations show that an assortment of band-limited image masks can accommodate a diverse set of observations to help maximize mission scientific return. We discuss two applications based on the results: the spectro-photometric study of planets already discovered with the radial velocity technique to orbit evolved stars, which we elucidate with the example of Pollux b, and the direct detecti...

  19. VizieR Online Data Catalog: SPOTS II. Planets Orbiting Two Stars (Bonavita+, 2016)

    Science.gov (United States)

    Bonavita, M.; Desidera, S.; Thalmann, C.; Janson, M.; Vigan, A.; Chauvin, G.; Lannier, J.

    2016-11-01

    We present a statistical analysis of the combined body of existing high-contrast imaging constraints on circumbinary planets, to complement our ongoing SPOTS direct imaging survey dedicated to such planets. The sample of stars considered includes 117 objects and comes from a search for tight binaries within the target lists of 23 published direct imaging surveys, including some of the deepest ones performed to data. (2 data files).

  20. MARVELS-1b: A Short-Period, Brown Dwarf Desert Candidate from the SDSS-III MARVELS Planet Search

    CERN Document Server

    Lee, Brian L; Fleming, Scott W; Stassun, Keivan G; Gaudi, B Scott; Barnes, Rory; Mahadevan, Suvrath; Eastman, Jason D; Wright, Jason; Siverd, Robert J; Gary, Bruce; Ghezzi, Luan; Laws, Chris; Wisniewski, John P; de Mello, G F Porto; Ogando, Ricardo L C; Maia, Marcio A G; da Costa, Luiz Nicolaci; Sivarani, Thirupathi; Pepper, Joshua; Nguyen, Duy Cuong; Hebb, Leslie; De Lee, Nathan; Wang, Ji; Wan, Xiaoke; Zhao, Bo; Chang, Liang; Groot, John; Varosi, Frank; Hearty, Fred; Hanna, Kevin; van Eyken, J C; Kane, Stephen R; Agol, Eric; Bizyaev, Dmitry; Bochanski, John J; Brewington, Howard; Chen, Zhiping; Costello, Erin; Dou, Liming; Eisenstein, Daniel J; Fletcher, Adam; Ford, Eric B; Guo, Pengcheng; Holtzman, Jon A; Jiang, Peng; Leger, R French; Liu, Jian; Long, Daniel C; Malanushenko, Elena; Malanushenko, Viktor; Malik, Mohit; Oravetz, Daniel; Pan, Kaike; Rohan, Pais; Schneider, Donald P; Shelden, Alaina; Snedden, Stephanie A; Simmons, Audrey; Weaver, B A; Weinberg, David H; Xie, Ji-Wei

    2010-01-01

    We present a new short-period brown dwarf candidate around the star TYC 1240-00945-1. This candidate was discovered in the first year of the Multi-object APO Radial Velocity Exoplanets Large-area Survey (MARVELS), which is part of the third phase of the Sloan Digital Sky Survey (SDSS-III), and we designate the brown dwarf as MARVELS-1b. MARVELS uses the technique of dispersed fixed-delay interferometery to simultaneously obtain radial velocity measurements for 60 objects per field using a single, custom-built instrument that is fiber fed from the SDSS 2.5-m telescope. From our 20 radial velocity measurements spread over a ~370 d time baseline, we derive a Keplerian orbital fit with semi-amplitude K=2.533+/-0.025 km/s, period P=5.8953+/-0.0004 d, and eccentricity consistent with circular. Independent follow-up radial velocity data confirm the orbit. Adopting a mass of 1.37+/-0.11 M_Sun for the slightly evolved F9 host star, we infer that the companion has a minimum mass of 28.0+/-1.5 M_Jup, a semimajor axis 0....

  1. A Search for Rocky Planets in Close Orbits around White Dwarfs with COS

    Science.gov (United States)

    Sandhaus, Phoebe; Debes, John H.; Ely, Justin; Hines, Dean C.

    2016-01-01

    The search for transiting habitable exoplanets has broadened to include several types of stars that are smaller than the Sun in order to increase the observed transit depth and hence the atmospheric signal of the planet. Of all current spectral types, white dwarfs are the most favorable for this type of investigation. The fraction of white dwarfs that possess close-in rocky planets is unknown, but several large angle surveys of stars have the photometric precision and cadence to discover at least one if they are common. Ultraviolet observations of white dwarfs may allow for detection of molecular oxygen or ozone in the atmosphere of a terrestrial planet. We use archival Hubble Space Telescope data from the Cosmic Origins Spectrograph to search for transiting rocky planets around UV-bright white dwarfs. In the process, we discovered unusual variability in the pulsating white dwarf GD~133, which shows slow sinusoidal variations in the UV. While we detect no planets around our small sample of targets, we do place stringent limits on the possibility of transiting planets, down to sub-lunar radii.

  2. On the orbital evolution of a pair of giant planets in mean motion resonance

    CERN Document Server

    André, Q

    2016-01-01

    Pairs of extrasolar giant planets in a mean motion commensurability are common with 2:1 resonance occurring most frequently. Disc-planet interaction provides a mechanism for their origin. However, the time scale on which this could operate in particular cases is unclear. We perform 2D and 3D numerical simulations of pairs of giant planets in a protoplanetary disc as they form and maintain a mean motion commensurability. We consider systems with current parameters similar to those of HD 155358, 24 Sextantis and HD 60532, and disc models of varying mass, decreasing mass corresponding to increasing age. For the lowest mass discs, systems with planets in the Jovian mass range migrate inwards maintaining a 2:1 commensurability. Systems with the inner planet currently at around 1 au from the central star could have originated at a few au and migrated inwards on a time scale comparable to protoplanetary disc lifetimes. Systems of larger mass planets such as HD 60532 attain 3:1 resonance as observed. For a given mass...

  3. A Trend Between Cold Debris Disk Temperature and Stellar Type: Implications for the Formation and Evolution of Wide-Orbit Planets

    CERN Document Server

    Ballering, Nicholas P; Su, Kate Y L; Montiel, Edward

    2013-01-01

    Cold debris disks trace the limits of planet formation or migration in the outer regions of planetary systems, and thus have the potential to answer many of the outstanding questions in wide-orbit planet formation and evolution. We characterized the infrared excess spectral energy distributions of 174 cold debris disks around 546 main-sequence stars observed by both Spitzer IRS and MIPS. We found a trend between the temperature of the inner edges of cold debris disks and the stellar type of the stars they orbit. This argues against the importance of strictly temperature-dependent processes (e.g. non-water ice lines) in setting the dimensions of cold debris disks. Also, we found no evidence that delayed stirring causes the trend. The trend may result from outward planet migration that traces the extent of the primordial protoplanetary disk, or it may result from planet formation that halts at an orbital radius limited by the efficiency of core accretion.

  4. VizieR Online Data Catalog: Kepler planet host candidates imaging (Lillo-Box+, 2014)

    Science.gov (United States)

    Lillo-Box, J.; Barrado, D.; Bouy, H.

    2014-09-01

    We applied the lucky imaging technique to the selected targets to achieve diffraction-limited resolution. We used the AstraLux North instrument located at the 2.2m telescope at the Calar Alto Observatory (Almeria, Spain). The targets were observed along three visibility windows of the Kepler field during 2011, 2012, and 2013. The results regarding the non-isolated KOIs of observations on 2011 were published in Lillo-Box et al. (2012A&A...546A..10L, Cat. J/A+A/546/A10). In the present work, we report the results concerning the isolated candidates observed in 2011 and the new results for the 2012-2013 observing runs. (6 data files).

  5. Measuring Transit Signal Recovery in the Kepler Pipeline. III. Completeness of the Q1-Q17 DR24 Planet Candidate Catalogue, with Important Caveats for Occurrence Rate Calculations

    CERN Document Server

    Christiansen, Jessie L; Burke, Christopher J; Jenkins, Jon M; Bryson, Stephen T; Coughlin, Jeffrey L; Mullally, Fergal; Thompson, Susan E; Twicken, Joseph D; Batalha, Natalie M; Haas, Michael R; Catanzarite, Joseph; Campbell, Jennifer R; Uddin, AKM Kamal; Zamudio, Khadeejah; Smith, Jeffrey C; Henze, Christopher E

    2016-01-01

    With each new version of the Kepler pipeline and resulting planet candidate catalogue, an updated measurement of the underlying planet population can only be recovered with an corresponding measurement of the Kepler pipeline detection efficiency. Here, we present measurements of the sensitivity of the pipeline (version 9.2) used to generate the Q1-Q17 DR24 planet candidate catalog (Coughlin et al. 2016). We measure this by injecting simulated transiting planets into the pixel-level data of 159,013 targets across the entire Kepler focal plane, and examining the recovery rate. Unlike previous versions of the Kepler pipeline, we find a strong period dependence in the measured detection efficiency, with longer (>40 day) periods having a significantly lower detectability than shorter periods, introduced in part by an incorrectly implemented veto. Consequently, the sensitivity of the 9.2 pipeline cannot be cast as a simple one-dimensional function of the signal strength of the candidate planet signal as was possibl...

  6. MARVELS-1b: A Short-period, Brown Dwarf Desert Candidate from the SDSS-III Marvels Planet Search

    Science.gov (United States)

    Lee, Brian L.; Ge, Jian; Fleming, Scott W.; Stassun, Keivan G.; Gaudi, B. Scott; Barnes, Rory; Mahadevan, Suvrath; Eastman, Jason D.; Wright, Jason; Siverd, Robert J.; Gary, Bruce; Ghezzi, Luan; Laws, Chris; Wisniewski, John P.; Porto de Mello, G. F.; Ogando, Ricardo L. C.; Maia, Marcio A. G.; Nicolaci da Costa, Luiz; Sivarani, Thirupathi; Pepper, Joshua; Nguyen, Duy Cuong; Hebb, Leslie; De Lee, Nathan; Wang, Ji; Wan, Xiaoke; Zhao, Bo; Chang, Liang; Groot, John; Varosi, Frank; Hearty, Fred; Hanna, Kevin; van Eyken, J. C.; Kane, Stephen R.; Agol, Eric; Bizyaev, Dmitry; Bochanski, John J.; Brewington, Howard; Chen, Zhiping; Costello, Erin; Dou, Liming; Eisenstein, Daniel J.; Fletcher, Adam; Ford, Eric B.; Guo, Pengcheng; Holtzman, Jon A.; Jiang, Peng; French Leger, R.; Liu, Jian; Long, Daniel C.; Malanushenko, Elena; Malanushenko, Viktor; Malik, Mohit; Oravetz, Daniel; Pan, Kaike; Rohan, Pais; Schneider, Donald P.; Shelden, Alaina; Snedden, Stephanie A.; Simmons, Audrey; Weaver, B. A.; Weinberg, David H.; Xie, Ji-Wei

    2011-02-01

    We present a new short-period brown dwarf (BD) candidate around the star TYC 1240-00945-1. This candidate was discovered in the first year of the Multi-object APO Radial Velocity Exoplanets Large-area Survey (MARVELS), which is part of the Sloan Digital Sky Survey (SDSS) III, and we designate the BD as MARVELS-1b. MARVELS uses the technique of dispersed fixed-delay interferometery to simultaneously obtain radial velocity (RV) measurements for 60 objects per field using a single, custom-built instrument that is fiber fed from the SDSS 2.5 m telescope. From our 20 RV measurements spread over a ~370 day time baseline, we derive a Keplerian orbital fit with semi-amplitude K = 2.533 ± 0.025 km s-1, period P = 5.8953 ± 0.0004 days, and eccentricity consistent with circular. Independent follow-up RV data confirm the orbit. Adopting a mass of 1.37 ± 0.11 M sun for the slightly evolved F9 host star, we infer that the companion has a minimum mass of 28.0 ± 1.5 M Jup, a semimajor axis 0.071 ± 0.002 AU assuming an edge-on orbit, and is probably tidally synchronized. We find no evidence for coherent intrinsic variability of the host star at the period of the companion at levels greater than a few millimagnitudes. The companion has an a priori transit probability of ~14%. Although we find no evidence for transits, we cannot definitively rule them out for companion radii lsim1 R Jup.

  7. The first known Uranian Trojan and the frequency of temporary giant-planet co-orbitals

    Science.gov (United States)

    Greenstreet, Sarah; Alexandersen, M.; Gladman, B.; Kavelaars, J.; Petit, J.; Gwyn, S.

    2013-10-01

    We report the first discovery of a Uranian Trojan (2011 QF99) in 2011-2012 CFHT Megacam imaging taken for a 20 square degree outer Solar System survey designed to detect and track Trans-Neptunian Objects and Centaurs. The orbit of the newly discovered object was constrained with 29 astrometric measurements over 7 dark runs with a total arc of 419 days. Numerical integrations of both the nominal orbit and all other orbits within the (already small) orbital uncertainties show 2011 QF99 oscillates around the L4 Lagrange point 60 degrees ahead of Uranus for >70 kyr and remains co-orbital (in 1:1 resonance) for ~1 Myr before becoming a Centaur. We performed additional orbital integrations to investigate the possibility the object could have evolved to its current orbit from a nearby, stable niche of phase-space. However, test particles started on orbits in the small region of phase-space surrounding the nominal orbit remained co-orbital for model of Centaurs supplied from the transneptunian region over 1 Gyr, building a relative orbital distribution for the aAnalysis of the particle histories showed that at any given time, significant fractions (0.4% and 2.8%) of the aSciences and Engineering Research Council.

  8. A millisecond pulsar candidate in a 21-h orbit: 3FGL J0212.1+5320

    Science.gov (United States)

    Linares, Manuel; Miles-Páez, Paulo; Rodríguez-Gil, Pablo; Shahbaz, Tariq; Casares, Jorge; Fariña, Cecilia; Karjalainen, Raine

    2017-03-01

    We present the discovery of a variable optical counterpart to the unidentified gamma-ray source 3FGL J0212.1+5320 and argue that this is a new compact binary millisecond pulsar (MSP) candidate. We show 3FGL J0212.1+5320 hosts a semidetached binary with a 0.869 55 ± 0.000 15 d orbital period and an F6-type companion star at an estimated distance of D = 1.1 ± 0.2 kpc, with a radial velocity curve semi-amplitude K2 = 214.1 ± 5.0 km s-1 and a projected rotational velocity of V sin (i) = 73.2 ± 1.6 km s-1. We find a hard X-ray source at the same location with a 0.5-10 keV luminosity LX = 2.6 × 1032 (D/1.1 kpc)2 erg s-1, which strengthens the MSP identification. Our results imply a mass ratio q = M2/M1 = 0.26^{+0.02}_{-0.03} if the companion star fills its Roche lobe, and q ≳ 0.26 in any case. This classifies 3FGL J0212.1+5320 as a 'redback' binary MSP; if its MSP nature is confirmed, this will be the brightest compact binary MSP in the optical band (r″ ≃ 14.3 mag) and will have the longest orbital period among Galactic field systems (nearly 21 h). Based on the light curve peak-to-peak amplitude (Δr = 0.19 mag), we further suggest that the orbital inclination is high and the putative pulsar mass is close to canonical (M1 ≃ 1.3-1.6 M⊙). Finally, we discuss the lack of heating signatures and asymmetric optical light curves in the context of other redback MSPs.

  9. CHARACTERIZING THE COOL KOIs. VI. H- AND K-BAND SPECTRA OF KEPLER M DWARF PLANET-CANDIDATE HOSTS

    Energy Technology Data Exchange (ETDEWEB)

    Muirhead, Philip S. [Department of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Becker, Juliette; Price, Ellen M.; Thorp, Rachel; Riddle, Reed [California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Feiden, Gregory A. [Department of Physics and Astronomy, Uppsala University, Box 516, SE-75120 Uppsala (Sweden); Rojas-Ayala, Bárbara [Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Oporto (Portugal); Vanderburg, Andrew; Johnson, John Asher [Harvard College Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Law, Nicholas M. [Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3255 (United States); Baranec, Christoph [Institute for Astronomy, University of Hawai' i at Mānoa, Hilo, HI 96720-2700 (United States); Hamren, Katherine [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Schlawin, Everett; Lloyd, James P. [Department of Astronomy, Cornell University, Ithaca, NY 14583 (United States); Covey, Kevin R., E-mail: philipm@bu.edu [Lowell Observatory, 1400 W Mars Hill Road, Flagstaff, AZ 86001 (United States)

    2014-07-01

    We present H- and K-band spectra for late-type Kepler Objects of Interest (the {sup C}ool KOIs{sup )}: low-mass stars with transiting-planet candidates discovered by NASA's Kepler Mission that are listed on the NASA Exoplanet Archive. We acquired spectra of 103 Cool KOIs and used the indices and calibrations of Rojas-Ayala et al. to determine their spectral types, stellar effective temperatures, and metallicities, significantly augmenting previously published values. We interpolate our measured effective temperatures and metallicities onto evolutionary isochrones to determine stellar masses, radii, luminosities, and distances, assuming the stars have settled onto the main sequence. As a choice of isochrones, we use a new suite of Dartmouth predictions that reliably include mid-to-late M dwarf stars. We identify five M4V stars: KOI-961 (confirmed as Kepler 42), KOI-2704, KOI-2842, KOI-4290, and the secondary component to visual binary KOI-1725, which we call KOI-1725 B. We also identify a peculiar star, KOI-3497, which has Na and Ca lines consistent with a dwarf star but CO lines consistent with a giant. Visible-wavelength adaptive optics imaging reveals two objects within a 1 arcsec diameter; however, the objects' colors are peculiar. The spectra and properties presented in this paper serve as a resource for prioritizing follow-up observations and planet validation efforts for the Cool KOIs and are all available for download online using the ''data behind the figure'' feature.

  10. WASP-39b: a highly inflated Saturn-mass planet orbiting a late G-type star

    CERN Document Server

    Faedi, F; Anderson, D R; Brown, D J A; Cameron, A Collier; Pollacco, D; Boisse, I; Hebrard, G; Lendl, M; Lister, T A; Smalley, B; Street, R A; Triaud, A H M J; Bento, J; Butters, O W; Enoch, B; Bouchy, F; Haswell, C A; Hellier, C; Keenan, F P; Miller, G R M; Moulds, V; Moutou, C; Norton, A J; Queloz, D; Santerne, A; Simpson, E K; Skillen, I; Smith, A M S; Udry, S; Watson, C A; West, R G; Wheatley, P J

    2011-01-01

    We present the discovery of WASP-39b, a highly inflated transiting Saturn-mass planet orbiting a late G-type dwarf star with a period of 4.055259$\\pm0.000008$~d, Transit Epoch T$_{0}=2455342.9688\\pm0.0002$(HJD), of duration 0.1168$\\pm0.0008$~d. A combined analysis of the WASP photometry, high-precision follow up transit photometry and radial velocities yield a planetary mass of $\\mpl=0.28\\pm0.03$~\\mj\\ and a radius of $\\rpl=1.27\\pm0.04$~\\rj, resulting in a mean density of 0.14$\\pm0.02$~\\rhoj. The stellar parameters are mass $\\mstar = 0.93\\pm0.03\\msun$, radius $\\rstar = 0.895\\pm0.23\\rsun$, and age $9^{+3}_{-4}$~Gyr. Only WASP-17b and WASP-31b have lower densities than WASP-39b, although they are slightly more massive and highly irradiated planets. We measure, from our spectral analysis, the metallicity of WASP-39 to be [Fe/H]= $-0.12\\pm0.01$ dex, and we find the planet to have an equilibrium temperature of $1116^{+33}_{-32}$~K; both values strengthen the observed empirical correlation between these parameters a...

  11. Architecture of Kepler's Multi-transiting Systems: II. New investigations with twice as many candidates

    Energy Technology Data Exchange (ETDEWEB)

    Fabrycky, Daniel C.; Lissauer, Jack J.; Ragozzine, Darin; Rowe, Jason F.; Steffen, Jason H.; Agol, Eric; Barclay, Thomas; Batalha, Natalie; Borucki, William; Ciardi, David R.; Ford, Eric B.; Gautier, Thomas N.; Geary, John C.; Holman, Matthew J.; Jenkins, Jon M.; Li, Jie; Morehead, Robert C.; Morris, Robert L.; Shporer, Avi; Smith, Jeffrey C.; Still, Martin; Van Cleve, Jeffrey

    2014-07-16

    Having discovered 885 planet candidates in 361 multiple-planet systems, Kepler has made transits a powerful method for studying the statistics of planetary systems. The orbits of only two pairs of planets in these candidate systems are apparently unstable. This indicates that a high percentage of the candidate systems are truly planets orbiting the same star, motivating physical investigations of the population. Pairs of planets in this sample are typically not in orbital resonances. However, pairs with orbital period ratios within a few percent of a first-order resonance (e.g. 2:1, 3:2) prefer orbital spacings just wide of the resonance and avoid spacings just narrow of the resonance. Finally, we investigate mutual inclinations based on transit duration ratios. We infer that the inner planets of pairs tend to have a smaller impact parameter than their outer companions, suggesting these planetary systems are typically coplanar to within a few degrees.

  12. On the Orbital Evolution of a Giant Planet Pair Embedded in a Gaseous Disk. I. Jupiter-Saturn Configuration

    Science.gov (United States)

    Zhang, Hui; Zhou, Ji-Lin

    2010-05-01

    We carry out a series of high-resolution (1024 × 1024) hydrodynamical simulations to investigate the orbital evolution of Jupiter and Saturn embedded in a gaseous protostellar disk. Our work extends the results in the classical papers of Masset & Snellgrove and Morbidelli & Crida by exploring various surface density profiles (σ), where σ vprop r -α. The stability of the mean motion resonances (MMRs) caused by the convergent migration of the two planets is studied as well. Our results show that (1) the gap formation process of Saturn is greatly delayed by the tidal perturbation of Jupiter. These perturbations cause inward or outward runaway migration of Saturn, depending on the density profiles on the disk. (2) The convergent migration rate increases as α increases and the type of MMRs depends on α as well. When 0 4/3, Saturn passes through the 2:1 MMR with Jupiter and is captured into the 3:2 MMR. (3) The 3:2 MMR turns out to be unstable when the eccentricity of Saturn (es ) increases too high. The critical value above which instability will set in is es ~ 0.15. We also observe that the two planets are trapped into 2:1 MMR after the break of 3:2 MMR. This process may provide useful information for the formation of orbital configuration between Jupiter and Saturn in the solar system.

  13. Mars Express met l'Europe en orbite autour de la Planete rouge

    CERN Multimedia

    2003-01-01

    "Apres une nuit sans sommeil, le Centre europeen d'operations spatiales (ESOC) de Darmstadt, en Allemagne, a annonce la nouvelle, jeudi 25decembre au matin: la sonde Mars Express a bien ete "capturee" par la gravite de la Planete rouge, tandis que le petit atterrisseur Beagle-2 tentait de se poser dans la plaine d'Isidis Planitia" (1 page).

  14. VLT/SPHERE robust astrometry of the HR8799 planets at milliarcsecond-level accuracy. Orbital architecture analysis with PyAstrOFit

    Science.gov (United States)

    Wertz, O.; Absil, O.; Gómez González, C. A.; Milli, J.; Girard, J. H.; Mawet, D.; Pueyo, L.

    2017-02-01

    Context. HR8799 is orbited by at least four giant planets, making it a prime target for the recently commissioned Spectro-Polarimetric High-contrast Exoplanet REsearch (VLT/SPHERE). As such, it was observed on five consecutive nights during the SPHERE science verification in December 2014. Aims: We aim to take full advantage of the SPHERE capabilities to derive accurate astrometric measurements based on H-band images acquired with the Infra-Red Dual-band Imaging and Spectroscopy (IRDIS) subsystem, and to explore the ultimate astrometric performance of SPHERE in this observing mode. We also aim to present a detailed analysis of the orbital parameters for the four planets. Methods: We performed thorough post-processing of the IRDIS images with the Vortex Imaging Processing (VIP) package to derive a robust astrometric measurement for the four planets. This includes the identification and careful evaluation of the different contributions to the error budget, including systematic errors. Combining our astrometric measurements with the ones previously published in the literature, we constrain the orbital parameters of the four planets using PyAstrOFit, our new open-source python package dedicated to orbital fitting using Bayesian inference with Monte-Carlo Markov Chain sampling. Results: We report the astrometric positions for epoch 2014.93 with an accuracy down to 2.0 mas, mainly limited by the astrometric calibration of IRDIS. For each planet, we derive the posterior probability density functions for the six Keplerian elements and identify sets of highly probable orbits. For planet d, there is clear evidence for nonzero eccentricity (e 0.35), without completely excluding solutions with smaller eccentricities. The three other planets are consistent with circular orbits, although their probability distributions spread beyond e = 0.2, and show a peak at e ≃ 0.1 for planet e. The four planets have consistent inclinations of approximately 30° with respect to the sky

  15. Looking for Very Short-Period Planets with Re-Purposed Kepler

    CERN Document Server

    Jackson, Brian

    2013-01-01

    A re-purposed Kepler mission could continue the search for nearly Earth-sized planets in very short-period (< 1 day) orbits. Recent surveys of the Kepler data already available have revealed at least a dozen such planetary candidates, and a more complete and focused survey is likely to reveal more. Given the planets' short orbital periods, building the requisite signal-to-noise to detect the candidates by stacking multiple transits requires a much shorter observational baseline than for longer-period planets, and the transits are likely more robust against the much larger instrumental variations anticipated for the modified Kepler pointing capabilities. Searching for these unusual planets will also leverage the Kepler mission's already considerable expertise in planetary transit detection and analysis. These candidates may represent an entirely new class of planet. They may also provide unprecedented insights into planet formation and evolution and sensitive probes for planet-star interactions and the stel...

  16. Flow of Planets Raises Short Period Fall Off

    CERN Document Server

    Taylor, Stuart F

    2012-01-01

    After finding more planets than expected at the shortest period, there has been an effort to explain their numbers by weak tidal friction. However, we find that the strength of tidal dissipation that would produce the occurence distribution found from Kepler planet candidates is different for giant versus medium radii planets. This discrepancy can be resolved if there is a "flow" of the largest planets regularly arriving such that they go through a "hot Jupiter" stage. We also show a correlation of higher stellar Fe/H with higher eccentricity of giant planets that may be from smaller planets having been sent into the star by the migration of the larger planet. This disruption of the orbits of medium and smaller planets could account for the lower occurrence of "hot Neptune" medium radius planets.

  17. Microlensing Search for Planets with Two Simultaneously Rising Suns

    CERN Document Server

    Han, Cheongho

    2008-01-01

    Among more than 200 extrasolar planet candidates discovered to date, there is no known planet orbiting around normal binary stars. In this paper, we demonstrate that microlensing is a technique that can detect such planets. Microlensing discoveries of these planets are possible because the planet and host binary stars produce perturbations at a common region around center of mass of the binary stars and thus the signatures of both planet and binary can be detected in the light curves of high-magnification microlensing events. The ranges of the planetary and binary separations of systems for optimal detection vary depending on the planet mass. For a Jupiter-mass planet, we find that high detection efficiency is expected for planets located in the range of $\\sim$ 1 AU -- 5 AU from the binary stars which are separated by $\\sim$ 0.15 AU -- 0.5 AU

  18. Consequences of tidal interaction between disks and orbiting protoplanets for the evolution of multi-planet systems with architecture resembling that of Kepler 444

    Science.gov (United States)

    Papaloizou, J. C. B.

    2016-11-01

    We study orbital evolution of multi-planet systems with masses in the terrestrial planet regime induced through tidal interaction with a protoplanetary disk assuming that this is the dominant mechanism for producing orbital migration and circularization. We develop a simple analytic model for a system that maintains consecutive pairs in resonance while undergoing orbital circularization and migration. This model enables migration times for each planet to be estimated once planet masses, circularization times and the migration time for the innermost planet are specified. We applied it to a system with the current architecture of Kepler 444 adopting a simple protoplanetary disk model and planet masses that yield migration times inversely proportional to the planet mass, as expected if they result from torques due to tidal interaction with the protoplanetary disk. Furthermore the evolution time for the system as a whole is comparable to current protoplanetary disk lifetimes. In addition we have performed a number of numerical simulations with input data obtained from this model. These indicate that although the analytic model is inexact, relatively small corrections to the estimated migration rates yield systems for which period ratios vary by a minimal extent. Because of relatively large deviations from exact resonance in the observed system of up to 2 %, the migration times obtained in this way indicate only weak convergent migration such that a system for which the planets did not interact would contract by only {˜ }1 % although undergoing significant inward migration as a whole. We have also performed additional simulations to investigate conditions under which the system could undergo significant convergent migration before reaching its final state. These indicate that migration times have to be significantly shorter and resonances between planet pairs significantly closer during such an evolutionary phase. Relative migration rates would then have to decrease

  19. The Pan-Pacific Planet Search. IV. Two super-Jupiters in a 3:5 resonance orbiting the giant star HD33844

    CERN Document Server

    Wittenmyer, Robert A; Butler, R P; Horner, Jonathan; Wang, Liang; Robertson, Paul; Jones, M I; Jenkins, J S; Brahm, R; Tinney, C G; Mengel, M W; Clark, J

    2015-01-01

    We report the discovery of two giant planets orbiting the K giant HD 33844 based on radial velocity data from three independent campaigns. The planets move on nearly circular orbits with semimajor axes $a_b=1.60\\pm$0.02 AU and $a_c=2.24\\pm$0.05 AU, and have minimum masses (m sin $i$) of $M_b=1.96\\pm$0.12 Mjup and $M_c=1.76\\pm$0.18 Mjup. Detailed N-body dynamical simulations show that the two planets remain on stable orbits for more than $10^6$ years for low eccentricities, and are most likely trapped in a mutual 3:5 mean-motion resonance.

  20. SPOTS: The Search for Planets Orbiting Two Stars: II. First constraints on the frequency of sub-stellar companions on wide circumbinary orbits

    CERN Document Server

    Bonavita, Mariangela; Thalmann, Christian; Janson, Markus; Vigan, Arthur; Chauvin, Gael; Lannier, Justine

    2016-01-01

    A large number of direct imaging surveys for exoplanets have been performed in recent years, yielding the first directly imaged planets and providing constraints on the prevalence and distribution of wide planetary systems. However, like most of the radial velocity ones, these surveys generally focus on single stars, hence binaries and higher-order multiples have not been studied to the same level of scrutiny. This motivated the SPOTS (Search for Planets Orbiting Two Stars) survey, which is an ongoing direct imaging study of a large sample of close binaries, started with VLT/NACO and now continuing with VLT/SPHERE. To complement this survey, we have identified the close binary targets in 24 published direct imaging surveys. Here we present our statistical analysis of this combined body of data. We analysed a sample of 117 tight binary systems, using a combined Monte Carlo and Bayesian approach to derive the expected values of the frequency of companions, for different values of the companion's semi-major axis...

  1. The response of atmospheric chemistry on earthlike planets around F, G and K Stars to small variations in orbital distance

    Science.gov (United States)

    Grenfell, John Lee; Stracke, Barbara; von Paris, Philip; Patzer, Beate; Titz, Ruth; Segura, Antigona; Rauer, Heike

    2007-04-01

    One of the prime goals of future investigations of extrasolar planets is to search for life as we know it. The Earth's biosphere is adapted to current conditions. How would the atmospheric chemistry of the Earth respond if we moved it to different orbital distances or changed its host star? This question is central to astrobiology and aids our understanding of how the atmospheres of terrestrial planets develop. To help address this question, we have performed a sensitivity study using a coupled radiative-convective photochemical column model to calculate changes in atmospheric chemistry on a planet having Earth's atmospheric composition, which we subjected to small changes in orbital position, of the order of 5-10% for a solar-type G2V, F2V, and K2V star. We then applied a chemical source-sink analysis to the biomarkers in order to understand how chemical processes affect biomarker concentrations. We start with the composition of the present Earth, since this is the only example we know for which a spectrum of biomarker molecules has been measured. We then investigate the response of the biomarkers to changes in the input stellar flux. Computing the thermal profile for atmospheres rich in H 2O, CO 2 and CH 4 is a major challenge for current radiative schemes, due, among other things, to lacking spectroscopic data. Therefore, as a first step, we employ a more moderate approach, by investigating small shifts in planet-star distance and assuming an earthlike biosphere. To calculate this shift we assumed a criteria for complex life based on the Earth, i.e. the earthlike planetary surface temperature varied between 0 °Cfamily species (and their reservoirs), which can catalytically destroy ozone. Hydrochloric acid (HCl), for example, is a chlorine reservoir (storage) molecule, which increased by a factor 64 in the mid-stratosphere (32 km) on moving outwards for the solar case. For the F2V and K2V stars, similar sources and sinks dominated the chemical biomarker budget

  2. Suppression of the water ice and snow albedo feedback on planets orbiting red dwarf stars and the subsequent widening of the habitable zone

    CERN Document Server

    Joshi, M

    2012-01-01

    M-stars comprise 80% of main-sequence stars, and so their planetary systems provide the best chance for finding habitable planets, i.e.: those with surface liquid water. We have modelled the broadband albedo or reflectivity of water ice and snow for simulated planetary surfaces orbiting two observed red dwarf stars (or M-stars) using spectrally resolved data of the Earth's cryosphere. The gradual reduction of the albedos of snow and ice at wavelengths greater than 1 ?m, combined with M-stars emitting a significant fraction of their radiation at these same longer wavelengths, mean that the albedos of ice and snow on planets orbiting M-stars are much lower than their values on Earth. Our results imply that the ice/snow albedo climate feedback is significantly weaker for planets orbiting M-stars than for planets orbiting G-type stars such as the Sun. In addition, planets with significant ice and snow cover will have significantly higher surface temperatures for a given stellar flux if the spectral variation of c...

  3. Suppression of the water ice and snow albedo feedback on planets orbiting red dwarf stars and the subsequent widening of the habitable zone.

    Science.gov (United States)

    Joshi, Manoj M; Haberle, Robert M

    2012-01-01

    M stars comprise 80% of main sequence stars, so their planetary systems provide the best chance for finding habitable planets, that is, those with surface liquid water. We have modeled the broadband albedo or reflectivity of water ice and snow for simulated planetary surfaces orbiting two observed red dwarf stars (or M stars), using spectrally resolved data of Earth's cryosphere. The gradual reduction of the albedos of snow and ice at wavelengths greater than 1 μm, combined with M stars emitting a significant fraction of their radiation at these same longer wavelengths, means that the albedos of ice and snow on planets orbiting M stars are much lower than their values on Earth. Our results imply that the ice/snow albedo climate feedback is significantly weaker for planets orbiting M stars than for planets orbiting G-type stars such as the Sun. In addition, planets with significant ice and snow cover will have significantly higher surface temperatures for a given stellar flux if the spectral variation of cryospheric albedo is considered, which in turn implies that the outer edge of the habitable zone around M stars may be 10-30% farther away from the parent star than previously thought.

  4. A millisecond pulsar candidate in a 21-hr orbit: 3FGL J0212.1+5320

    CERN Document Server

    Linares, Manuel; Rodríguez-Gil, Pablo; Shahbaz, Tariq; Casares, Jorge; Fariña, Cecilia; Karjalainen, Raine

    2016-01-01

    We present the discovery of a variable optical counterpart to the unidentified gamma-ray source 3FGL J0212.1+5320, and argue this is a new compact binary millisecond pulsar (MSP) candidate. We show 3FGL J0212.1+5320 hosts a semi-detached binary with a 0.86955$\\pm$0.00015 d orbital period and a F6-type companion star at an estimated distance of D=1.1$\\pm$0.2 kpc, with a radial velocity curve semi-amplitude K$_2$=214.1$\\pm$5.0 km s$^{-1}$ and a projected rotational velocity of Vsin(i)=73.2$\\pm$1.6 km s$^{-1}$. We find a hard X-ray source at the same location with a 0.5$-$10 keV luminosity L$_\\mathrm{X}$=2.6$\\times$10$^{32}$ (D/1.1 kpc)$^2$ erg s$^{-1}$, which strengthens the MSP identification. Our results imply a mass ratio q=M$_2$/M$_1$=0.26$^{+0.02}_{-0.03}$ if the companion star fills its Roche lobe, and q$\\gtrsim$0.23 in any case. This classifies 3FGL J0212.1+5320 as a "redback" binary MSP; if its MSP nature is confirmed, this will be the brightest compact binary MSP in the optical band (r'$\\simeq$14.3 mag...

  5. Wobbling Ancient Binaries - Here Be Planets?

    CERN Document Server

    Horner, Jonathan; Hinse, Tobias; Marshall, Jonathan; Mustill, Alex

    2014-01-01

    In the last few years, a number of planets have been proposed to orbit several post main-sequence binary star systems on the basis of observed variations in the timing of eclipses between the binary components. A common feature of these planet candidates is that the best-fit orbits are often highly eccentric, such that the multiple planet systems proposed regularly feature mutually crossing orbits - a scenario that almost always leads to unstable planetary systems. In this work, we present the results of dynamical studies of all multiple-planet systems proposed to orbit these highly evolved binary stars, finding that most do not stand up to dynamical scrutiny. In one of the potentially stable cases (the NN Serpentis 2-planet system), we consider the evolution of the binary star system, and show that it is highly unlikely that planets could survive from the main sequence to obtain their current orbits - again casting doubt on the proposed planets. We conclude by considering alternative explanations for the obs...

  6. Long-term photometry of the eclipsing dwarf nova V893 Scorpii: Orbital period, oscillations, and a possible giant planet

    CERN Document Server

    Bruch, Albert

    2014-01-01

    The cataclysmic variable V893 Sco is an eclipsing dwarf nova which, apart from outbursts with comparatively low amplitudes, exhibits a particularly strong variability during quiescence on timescales of days to seconds.The present study aims to update the outdated orbital ephemerides published previously, to investigate deviations from linear ephemerides, and to characterize non-random brightness variations in a range of timescales. Light curves of V893 Sco were observed on 39 nights, spanning a total time base of about 14 years. They contain 114 eclipses which were used to significantly improve the precision of the orbital period and to study long-term variations of the time of revolution. Oscillations and similar brightness variations were studied with Fourier techniques in the individual light curves. The orbital period exhibits long-term variations with a cycle time of 10.2 years. They can be interpreted as a light travel time effect caused by the presence of a giant planet with approximately 9.5 Jupiter m...

  7. Astrometric Confirmation and Preliminary Orbital Parameters of the Young Exoplanet 51 Eridani b with the Gemini Planet Imager

    CERN Document Server

    De Rosa, Robert J; Blunt, Sarah C; Graham, James R; Konopacky, Quinn M; Marois, Christian; Pueyo, Laurent; Rameau, Julien; Wang, Jason J; Bailey, Vanessa; Chontos, Ashley; Fabrycky, Daniel C; Follette, Katherine B; Macintosh, Bruce; Marchis, Franck; Ammons, S Mark; Arriaga, Pauline; Chilcote, Jeffrey K; Doyon, René; Duchêne, Gaspard; Esposito, Thomas M; Fitzgerald, Michael P; Gerard, Benjamin; Goodsell, Stephen J; Greenbaum, Alexandra Z; Hibon, Pascale; Ingraham, Patrick; Johnson-Groh, Mara; Kalas, Paul G; Lafrenière, David; Maire, Jerome; Metchev, Stanimir; Millar-Blanchaer, Maxwell A; Morzinski, Katie M; Oppenheimer, Rebecca; Patel, Rahul I; Patience, Jennifer L; Perrin, Marshall D; Rajan, Abhijith; Rantakyrö, Fredrik T; Ruffio, Jean-Baptiste; Schneider, Adam C; Sivaramakrishnan, Anand; Song, Inseok; Tran, Debby; Ward-Duong, Kimberly; Wolff, Schuyler G

    2015-01-01

    We present new GPI observations of the young exoplanet 51 Eridani b which provide further evidence that the companion is physically associated with 51 Eridani. Combining this new astrometric measurement with those reported in the literature, we significantly reduce the posterior probability that 51 Eridani b is an unbound foreground or background T-dwarf in a chance alignment with 51 Eridani to $2\\times10^{-7}$, an order of magnitude lower than previously reported. If 51 Eridani b is indeed a bound object, then we have detected orbital motion of the planet between the discovery epoch and the latest epoch. By implementing a computationally efficient Monte Carlo technique, preliminary constraints are placed on the orbital parameters of the system. The current set of astrometric measurements suggest an orbital semi-major axis of $14^{+7}_{-3}$ AU, corresponding to a period of $41^{+35}_{-12}$ yr (assuming a mass of $1.75$ M$_{\\odot}$ for the central star), and an inclination of $138^{+15}_{-13}$ deg. The remaini...

  8. Formation of the planet orbiting the millisecond pulsar J1719-1438

    CERN Document Server

    van Haaften, L M; Voss, R; Jonker, P G

    2012-01-01

    In 2011, Bailes et al. reported on the discovery of a detached companion in a 131 minute orbit around PSR J1719-1438, a 173 Hz millisecond pulsar. The combination of the very low mass function and such a short orbital period is unique. The discoverers suggested that the progenitor system could be an ultracompact X-ray binary (UCXB), which is a binary with a sub-hour orbital period in which a (semi-)degenerate donor fills its Roche lobe and transfers mass to a neutron star. The standard gravitational-wave driven UCXB scenario, however, cannot produce a system like PSR J1719-1438 as it would take longer than the age of the Universe to reach an orbital period of 131 min. We investigate two modifications to the standard UCXB evolution that may resolve this discrepancy. The first involves significant heating and bloating of the donor by pulsar irradiation, and in the second modification the system loses orbital angular momentum via a fast stellar wind from the irradiated donor, additional to the losses via the usu...

  9. The first planet detected in the WTS: an inflated hot-Jupiter in a 3.35 day orbit around a late F-star

    CERN Document Server

    Cappetta, M; Birkby, J L; Koppenhoefer, J; Pinfield, D J; Hodgkin, S T; Cruz, P; Kovács, G; Sipöcz, B; Barrado, D; Nefs, B; Pavlenko, Y V; Fossati, L; del Burgo, C; Martín, E L; Snellen, I; Barnes, J; Bayo, A M; Campbell, D A; Catalan, S; Gálvez-Ortiz, M C; Goulding, N; Haswell, C; Ivanyuk, O; Jones, H; Kuznetsov, M; Lodieu, N; Marocco, F; Mislis, D; Murgas, F; Napiwotzki, R; Palle, E; Pollacco, D; Baro, L Sarro; Solano, E; Steele, P; Stoev, H; Tata, R; Zendejas, J

    2012-01-01

    We report the discovery of WTS-1b, the first extrasolar planet found by the WFCAM Transit Survey, which began observations at the 3.8-m United Kingdom Infrared Telescope. Light curves comprising almost 1200 epochs with a photometric precision of better than 1 per cent to J=16 were constructed for 60000 stars and searched for periodic transit signals. For one of the most promising transiting candidates, high-resolution spectra taken at the Hobby-Eberly Telescope allowed us to estimate the spectroscopic parameters of the host star, a late-F main sequence dwarf (V=16.13) with possibly slightly subsolar metallicity, and to measure its radial velocity variations. The combined analysis of the light curves and spectroscopic data resulted in an orbital period of the substellar companion of 3.35 days, a planetary mass of 4.01+-0.35 Mj and a planetary radius of 1.49+-0.17 Rj. WTS-1b has one of the largest radius anomalies among the known hot Jupiters in the mass range 3-5 Mj.

  10. The first planet detected in the WTS: an inflated hot-Jupiter in a 3.35 day orbit around a late F-star [ERRATUM

    CERN Document Server

    Cappetta, M; Birkby, J L; Koppenhoefer, J; Pinfield, D J; Hodgkin, S T; Cruz, P; Kovacs, G; Sipocz, B; Barrado, D; Nefs, B; Pavlenko, Y V; Fossati, L; del Burgo, C; Martin, E L; Snellen, I; Barnes, J; Campbell, D A; Catalan, S; Galvez-Ortiz, M C; Goulding, N; Haswell, C; Ivanyuk, O; Jones, H; Kuznetsov, M; Lodieu, N; Marocco, F; Mislis, D; Murgas, F; Napiwotzki, R; Palle, E; Pollacco, D; Baro, L Sarro; Solano, E; Steele, P; Stoev, H; Tata, R; Zendejas, J

    2014-01-01

    We report the discovery of WTS-1b, the first extrasolar planet found by the WFCAM Transit Survey, which began observations at the 3.8-m United Kingdom Infrared Telescope (UKIRT) in August 2007. Light curves comprising almost 1200 epochs with a photometric precision of better than 1 per cent to J ~ 16 were constructed for ~60000 stars and searched for periodic transit signals. For one of the most promising transiting candidates, high-resolution spectra taken at the Hobby-Eberly Telescope (HET) allowed us to estimate the spectroscopic parameters of the host star, a late-F main sequence dwarf (V=16.13) with possibly slightly subsolar metallicity, and to measure its radial velocity variations. The combined analysis of the light curves and spectroscopic data resulted in an orbital period of the substellar companion of 3.35 days, a planetary mass of 4.01 +- 0.35 Mj and a planetary radius of 1.49+0.16-0.18 Rj. WTS-1b has one of the largest radius anomalies among the known hot Jupiters in the mass range 3-5 Mj. The h...

  11. MOA-2010-BLG-477Lb: constraining the mass of a microlensing planet from microlensing parallax, orbital motion and detection of blended light

    CERN Document Server

    Bachelet, E; Han, C; Fouqué, P; Gould, A; Menzies, J W; Beaulieu, J -P; Bennett, D P; Bond, I A; Dong, Subo; Heyrovský, D; Marquette, J B; Marshall, J; Skowron, J; Street, R A; Sumi, T; Udalski, A; Abe, L; Agabi, K; Albrow, M D; Allen, W; Bertin, E; Bos, M; Bramich, D M; Chavez, J; Christie, G W; Cole, A A; Crouzet, N; Dieters, S; Dominik, M; Drummond, J; Greenhill, J; Guillot, T; Henderson, C B; Hessman, F V; Horne, K; Hundertmark, M; Johnson, J A; Jørgensen, U G; Kandori, R; Liebig, C; Mékarnia, D; McCormick, J; Moorhouse, D; Nagayama, T; Nataf, D; Natusch, T; Nishiyama, S; Rivet, J -P; Sahu, K C; Shvartzvald, Y; Thornley, G; Tomczak, A R; Tsapras, Y; Yee, J C; Batista, V; Bennett, C S; Brillant, S; Caldwell, J A R; Cassan, A; Corrales, E; Coutures, C; Prester, D Dominis; Donatowicz, J; Kubas, D; Martin, R; Williams, A; Zub, M; de Almeida, L Andrade; DePoy, D L; Gaudi, B S; Hung, L -W; Jablonski, F; Kaspi, S; Klein, N; Lee, C -U; Lee, Y; Koo, J -R; Maoz, D; Muñoz, J A; Pogge, R W; Polishook, D; Shporer, A; Abe, F; Botzler, C S; Chote, P; Freeman, M; Fukui, A; Furusawa, K; Harris, P; Itow, Y; Kobara, S; Ling, C H; Masuda, K; Matsubara, Y; Miyake, N; Ohmori, K; Ohnishi, K; Rattenbury, N J; Saito, To; Sullivan, D J; Suzuki, D; Sweatman, W L; Tristram, P J; Wada, K; Yock, P C M; Szymański, M K; Soszyński, I; Kubiak, M; Poleski, R; Ulaczyk, K; Pietrzyński, G; Wyrzykowski, Ł; Kains, N; Snodgrass, C; Steele, I A; Alsubai, K A; Bozza, V; Browne, P; Burgdorf, M J; Novati, S Calchi; Dodds, P; Dreizler, S; Finet, F; Gerner, T; Hardis, S; Harpsøe, K; Hinse, T C; Kerins, E; Mancini, L; Mathiasen, M; Penny, M T; Proft, S; Rahvar, S; Ricci, D; Scarpetta, G; Schäfer, S; Schönebeck, F; Southworth, J; Surdej, J; Wambsganss, J

    2012-01-01

    Microlensing detections of cool planets are important for the construction of an unbiased sample to estimate the frequency of planets beyond the snow line, which is where giant planets are thought to form according to the core accretion theory of planet formation. In this paper, we report the discovery of a giant planet detected from the analysis of the light curve of a high-magnification microlensing event MOA-2010-BLG-477. The measured planet-star mass ratio is $q=(2.181\\pm0.004)\\times 10^{-3}$ and the projected separation is $s=1.1228\\pm0.0006$ in units of the Einstein radius. The angular Einstein radius is unusually large $\\theta_{\\rm E}=1.38\\pm 0.11$ mas. Combining this measurement with constraints on the "microlens parallax" and the lens flux, we can only limit the host mass to the range $0.13planet orbital motion prevents us from measuring more accurate host and planet masses. However, we find that a...

  12. Coupled evolutions of the stellar obliquity, orbital distance, and planet's radius due to the Ohmic dissipation induced in a diamagnetic hot Jupiter around a magnetic T Tauri star

    CERN Document Server

    Chang, Yu-Ling; Gu, Pin-Gao

    2012-01-01

    We revisit the calculation of the Ohmic dissipation in a hot Jupiter presented in Laine et al. (2008) by considering more realistic interior structures, stellar obliquity, and the resulting orbital evolution. In this simplified approach, the young hot Jupiter of one Jupiter mass is modelled as a diamagnetic sphere with a finite resistivity, orbiting across tilted stellar magnetic dipole fields in vacuum. Since the induced Ohmic dissipation occurs mostly near the planet's surface, we find that the dissipation is unable to significantly expand the young hot Jupiter. Nevertheless, the planet inside a small co-rotation orbital radius can undergo orbital decay by the dissipation torque and finally overfill its Roche lobe during the T Tauri star phase. The stellar obliquity can evolve significantly if the magnetic dipole is parallel/anti-parallel to the stellar spin. Our results are validated by the general torque-dissipation relation in the presence of the stellar obliquity. We also run the fiducial model in Laine...

  13. WASP-32b: A transiting hot Jupiter planet orbiting a lithium-poor, solar-type star

    CERN Document Server

    Maxted, P F L; Cameron, A Collier; Gillon, M; Hellier, C; Queloz, D; Smalley, B; Triaud, A H M J; West, R G; Enoch, R; Lister, T A; Pepe, F; Pollacco, D L; Ségransan, D; Skillen, I; Udry, S

    2010-01-01

    We report the discovery of a transiting planet orbiting the star TYC 2-1155-1. The star, WASP-32, is a moderately bright (V=11.3) solar-type star (Teff=6100 +- 100K, [Fe/H] = -0.13 +- 0.10). The lightcurve of the star obtained with the WASP-South and WASP-North instruments shows periodic transit-like features with a depth of about 1% and a duration of 0.10d every 2.72d. The presence of a transit-like feature in the lightcurve is confirmed using z-band photometry obtained with Faulkes Telescope North. High resolution spectroscopy obtained with the CORALIE spectrograph confirms the presence of a planetary mass companion. From a combined analysis of the spectroscopic and photometric data, assuming that the star is a typical main-sequence star, we estimate that the planet has a mass M_p = 3.60 +- 0.07 M_Jup and a radius R_p = 1.19 +- 0.06R_Jup. WASP-32 is one of a small group of hot Jupiters with masses M_p > 3M_Jup. We find that some stars with hot Jupiter companions and with masses M_* =~ 1.2M_sun, including WA...

  14. WASP-32b: A Transiting Hot Jupiter Planet Orbiting a Lithium-Poor, Solar-Type Star

    Science.gov (United States)

    Maxted, P. F. L.; Anderson, D. R.; Collier Cameron, A.; Gillon, M.; Hellier, C.; Queloz, D.; Smalley, B.; Triaud, A. H. M. J.; West, R. G.; Enoch, R.; Lister, T. A.; Pepe, F.; Pollacco, D. L.; Ségransan, D.; Skillen, I.; Udry, S.

    2010-12-01

    We report the discovery of a transiting planet orbiting the star TYC 2-1155-1. The star, WASP-32, is a moderately bright (V = 11.3) solar-type star (Teff = 6100 ± 100 K, [Fe/H] = -0.13 ± 0.10). The light curve of the star obtained with the WASP-South and WASP-North instruments shows periodic transitlike features with a depth of about 1% and a duration of 0.10 day every 2.72 days. The presence of a transitlike feature in the light curve is confirmed using z -band photometry obtained with Faulkes Telescope North. High-resolution spectroscopy obtained with the Coralie spectrograph confirms the presence of a planetary mass companion. From a combined analysis of the spectroscopic and photometric data, assuming that the star is a typical main-sequence star, we estimate that the planet has a mass Mp of 3.60 ± 0.07 MJup and a radius Rp = 1.19 ± 0.06 RJup. WASP-32 is one of a small group of hot Jupiters with masses greater than 3 MJup. We find that some stars with hot Jupiter companions and with masses M⋆ ≈ 1.2 M⊙, including WASP-32, are depleted in lithium and that the majority of these stars have lithium abundances similar to field stars.

  15. The Orbit of Planet Earth in the Last 150 Million Years

    NARCIS (Netherlands)

    Noort, van den P.C.

    2011-01-01

    The structure of the world is a construction of philosophers and scientists. It changed all the time. Nowadays we have a chaotic Solar System. The orbit of Earth changes, therefore, on the very long run. With it changed the UV- radiation on the surface of Earth, influencing the number of mutations.

  16. The Orbit of Planet Earth in the Last 150 Million Years

    NARCIS (Netherlands)

    Noort, van den P.C.

    2011-01-01

    The structure of the world is a construction of philosophers and scientists. It changed all the time. Nowadays we have a chaotic Solar System. The orbit of Earth changes, therefore, on the very long run. With it changed the UV- radiation on the surface of Earth, influencing the number of mutations.

  17. Underlying Architecture of Planetary Systems Based on Kepler Data: Number of Planets and Coplanarity

    Science.gov (United States)

    Fang, Julia; Margot, J. L.

    2012-10-01

    We investigated the underlying architecture of planetary systems by deriving the distribution of planet multiplicity (number of planets) and the distribution of orbital inclinations based on the sample of planet candidates discovered by the Kepler mission. The scope of our study included solar-like stars and planets with orbital periods less than 200 days and with radii between 1.5 and 30 Earth radii, and was based on Kepler planet candidates detected during Quarters 1 through 6. Our analysis improves on previous work by including all available quarters, extending to 200-day periods, and fitting models to observables such as normalized transit duration ratios that contain information on mutual orbital inclinations; these improvements lend to a deeper investigation of the intrinsic distributions of planetary systems. We created models of planetary systems with different distributions of planet multiplicity and orbital inclinations, simulated observations of these systems by Kepler, and compared the number and properties of the transits of detectable objects to actual Kepler planet detections. Based on the underlying distributions of our best-fit models, 75-80% of planetary systems have 1 or 2 planets with orbital periods less than 200 days. In addition, over 85% of planets have orbital inclinations less than 3 degrees. This high degree of coplanarity is comparable to that seen in our Solar System, with the exception of Mercury. These results provide important constraints and insights into theories of planet formation and evolution.

  18. Fractal Growth on the Surface of a Planet and in Orbit around it

    CERN Document Server

    Haranas, Ioannis; Alexiou, Athanasios

    2015-01-01

    Fractals are defined as geometric shapes that exhibit symmetry of scale. This simply implies that fractal is a shape that it would still look the same even if somebody could zoom in on one of its parts an infinite number of times. This property is also called self-similarity with several applications including nano pharmacology and drug nano carriers. We are interested in the study of the properties of fractal aggregates in a microgravity environment above an orbiting spacecraft. To model the effect we use a complete expression for the gravitational acceleration. In particular on the surface of the Earth the acceleration is corrected for the effect of oblateness and rotation. In the gravitational acceleration the effect of oblateness can be modeled with the inclusion of a term that contains the J2 harmonic coefficient, as well as a term that depends on the square of angular velocity of the Earth. In orbit the acceleration of gravity at the point of the spacecraft is a function of the orbital elements and incl...

  19. On the Apparent Orbital Inclination Change of the Extrasolar Transiting Planet TrES-2b

    CERN Document Server

    Scuderi, Louis J; Males, Jared R; Green, Elizabeth M; Close, Laird M

    2009-01-01

    On June 15, 2009 UT the transit of TrES-2b was detected using the University of Arizona's 1.55 meter Kuiper Telescope with 2.0-2.5 millimag RMS accuracy in the I-band. We find a central transit time of T_c = 2454997.76286 +/- 0.00035 HJD, an orbital period of P = 2.4706127 +/- 0.0000009 days, and an inclination angle of i = 83.92 +/- 0.05 degrees, which is consistent with our re-fit of the original I-band light curve of O'Donovan et al. (2006) where we find i = 83.84 +/- 0.05 degrees. We calculate an inclination change of Delta i = -0.08 +/- 0.071 degrees over the last 3 years, and as such, our observations rule out, at the ~11 sigma level, the apparent change of orbital inclination to i_predicted = 83.35 +/- 0.1 degrees as predicted by Mislis & Schmitt (2009) for our epoch. Indeed, we detect no significant changes in any of the orbital parameters of TrES-2b when comparing the original I-band light curve to our recent I-band light curve.

  20. Stimulated Radiative Molecular Association in the Early Solar System. II. Orbital Radii of the Planets and Other Satellites of the Sun

    CERN Document Server

    Lombardi, James C

    2015-01-01

    In a previous investigation, the orbital radii of regular satellites of Uranus, Jupiter, Neptune, and Saturn are shown to be directly related to photon energies in the spectra of atomic and molecular hydrogen. To explain these observations a model was developed involving stimulated radiative molecular association (SRMA) reactions among photons and atoms in the protosatellite disks of the planets. In the present investigation, the previously developed model is applied to the planets and important satellites of the Sun. A key component of the model involves resonance associated with SRMA. Through this resonance, thermal energy is extracted from the protosun's protoplanetary disk at specific distances from the protosun wherever there is a match between the local thermal energy of the disk and the energy of photons impinging on the disk. Orbital radii of the planets and satellites are related to photon energies ($E_P$ values) in the spectrum of atomic hydrogen. An expression determined previously is used to relat...

  1. On turbulence driven by axial precession and tidal evolution of the spin-orbit angle of close-in giant planets

    CERN Document Server

    Barker, Adrian J

    2016-01-01

    The spin axis of a rotationally deformed planet is forced to precess about its orbital angular momentum vector, due to the tidal gravity of its host star, if these directions are misaligned. This induces internal fluid motions inside the planet that are subject to a hydrodynamic instability. We study the turbulent damping of precessional fluid motions, as a result of this instability, in the simplest local computational model of a giant planet (or star), with and without a weak internal magnetic field. Our aim is to determine the outcome of this instability, and its importance in driving tidal evolution of the spin-orbit angle in precessing planets (and stars). We find that this instability produces turbulent dissipation that is sufficiently strong that it could drive significant tidal evolution of the spin-orbit angle for hot Jupiters with orbital periods shorter than about 10-18 days. If this mechanism acts in isolation, this evolution would be towards alignment or anti-alignment, depending on the initial a...

  2. Three regimes of extrasolar planets inferred from host star metallicities

    CERN Document Server

    Buchhave, Lars A; Latham, David W; Sasselov, Dimitar; Cochran, William D; Endl, Michael; Isaacson, Howard; Juncher, Diana; Marcy, Geoffrey W

    2014-01-01

    Approximately half of the extrasolar planets (exoplanets) with radii less than four Earth radii are in orbits with short periods. Despite their sheer abundance, the compositions of such planets are largely unknown. The available evidence suggests that they range in composition from small, high-density rocky planets to low-density planets consisting of rocky cores surrounded by thick hydrogen and helium gas envelopes. Understanding the transition from the gaseous planets to Earth-like rocky worlds is important to estimate the number of potentially habitable planets in our Galaxy and provide constraints on planet formation theories. Here we report the abundances of heavy elements (that is, the metallicities) of more than 400 stars hosting 600 exoplanet candidates, and find that the exoplanets can be categorized into three populations defined by statistically distinct (~ 4.5{\\sigma}) metallicity regions. We interpret these regions as reflecting the formation regimes of terrestrial-like planets (radii less than 1...

  3. On the dynamical habitability of Trojan planets in exoplanetary systems

    Science.gov (United States)

    Schwarz, R.; Funk, B.; Bazsó, Á.; Eggl, S.

    2017-03-01

    Besides the hierarchical configurations exoplanets have been observed in so far, Earth-analogs can theoretically exist in co-orbital motion with giant planets. Those so-called Trojan planets share the same orbit as their Jovian hosts, trailing or leading by approximately 60 degrees in mean anomaly. If a giant planet was situated in the habitable zone (HZ) of an exoplanetary system coorbital terrestrial worlds could in principle also be habitable provided their orbits are "tame enough". In this paper, we study the dynamical properties of Earth-like Trojan planets in their host stars' respective HZs. We investigate the orbital stability of possible Trojan planets near the Lagrangian equilibrium points L_4 and L_5 for several candidate systems. Our numerical simulations have been carried out using the planar three-body problem, in case the extrasolar system contains only one known planet and the n-body problem with more than one planet in the system. We study the stability region around the equilibrium points and counted the number of stable orbits concentrating on the dependencies between the semimajor axis, the eccentricity and the argument of perihelion of the Trojan planet. We found that of the investigated 14 systems 6 support stable Trojan planets in the system's HZ, namely HD 5891, HD 28185, WASP-41, HD 11755, HD 221287 and HD 13908.

  4. Detection and Characterization of Extrasolar Planets through Mean-motion Resonances. II. The Effect of the Planet’s Orbital Eccentricity on Debris Disk Structures

    Science.gov (United States)

    Tabeshian, Maryam; Wiegert, Paul A.

    2017-09-01

    Structures observed in debris disks may be caused by gravitational interaction with planetary or stellar companions. These perturbed disks are often thought to indicate the presence of planets and offer insights into the properties of both the disk and the perturbing planets. Gaps in debris disks may indicate a planet physically present within the gap, but such gaps can also occur away from the planet’s orbit at mean-motion resonances (MMRs), and this is the focus of our interest here. We extend our study of planet–disk interaction through MMRs, presented in an earlier paper, to systems in which the perturbing planet has moderate orbital eccentricity, a common occurrence in exoplanetary systems. In particular, a new result is that the 3:1 MMR becomes distinct at higher eccentricity, while its effects are absent for circular planetary orbits. We also only consider gravitational interaction with a planetary body of at least 1 M J. Our earlier work shows that even a 1 Earth mass planet can theoretically open an MMR gap; however, given the narrow gap that can be opened by a low-mass planet, its observability would be questionable. We find that the widths, locations, and shapes of two prominent structures, the 2:1 and 3:1 MMRs, could be used to determine the mass, semimajor axis, and eccentricity of the planetary perturber and present an algorithm for doing so. These MMR structures can be used to narrow the position and even determine the planetary properties (such as mass) of any inferred but as-yet-unseen planets within a debris disk. We also briefly discuss the implications of eccentric disks on brightness asymmetries and their dependence on the wavelengths with which these disks are observed.

  5. Infrared radiation from an extrasolar planet.

    Science.gov (United States)

    Deming, Drake; Seager, Sara; Richardson, L Jeremy; Harrington, Joseph

    2005-04-07

    A class of extrasolar giant planets--the so-called 'hot Jupiters' (ref. 1)--orbit within 0.05 au of their primary stars (1 au is the Sun-Earth distance). These planets should be hot and so emit detectable infrared radiation. The planet HD 209458b (refs 3, 4) is an ideal candidate for the detection and characterization of this infrared light because it is eclipsed by the star. This planet has an anomalously large radius (1.35 times that of Jupiter), which may be the result of ongoing tidal dissipation, but this explanation requires a non-zero orbital eccentricity (approximately 0.03; refs 6, 7), maintained by interaction with a hypothetical second planet. Here we report detection of infrared (24 microm) radiation from HD 209458b, by observing the decrement in flux during secondary eclipse, when the planet passes behind the star. The planet's 24-microm flux is 55 +/- 10 microJy (1sigma), with a brightness temperature of 1,130 +/- 150 K, confirming the predicted heating by stellar irradiation. The secondary eclipse occurs at the midpoint between transits of the planet in front of the star (to within +/- 7 min, 1sigma), which means that a dynamically significant orbital eccentricity is unlikely.

  6. Architecture of Planetary Systems Based on Kepler Data: Number of Planets and Coplanarity

    CERN Document Server

    Fang, Julia

    2012-01-01

    We investigated the underlying architecture of planetary systems by deriving the distribution of planet multiplicity (number of planets) and the distribution of orbital inclinations based on the sample of planet candidates discovered by the Kepler mission. The scope of our study included solar-like stars and planets with orbital periods less than 200 days and with radii between 1.5 and 30 Earth radii, and was based on Kepler planet candidates detected during Quarters 1 through 6. We created models of planetary systems with different distributions of planet multiplicity and inclinations, simulated observations of these systems by Kepler, and compared the properties of the transits of detectable objects to actual Kepler planet detections. Specifically, we compared with both the Kepler sample's transit numbers and normalized transit duration ratios in order to determine each model's goodness-of-fit. We did not include any constraints from radial velocity surveys. Based on our best-fit models, 75-80% of planetary...

  7. Atmospheric Mining in the Outer Solar System: Outer Planet Orbital Transfer and Lander Analyses

    Science.gov (United States)

    Palaszewski, Bryan

    2016-01-01

    Atmospheric mining in the outer solar system has been investigated as a means of fuel production for high energy propulsion and power. Fusion fuels such as Helium 3 (3He) and deuterium can be wrested from the atmospheres of Uranus and Neptune and either returned to Earth or used in-situ for energy production. Helium 3 and deuterium were the primary gases of interest with hydrogen being the primary propellant for nuclear thermal solid core and gas core rocket-based atmospheric flight. A series of analyses were undertaken to investigate resource capturing aspects of atmospheric mining in the outer solar system. This included the gas capturing rate, storage options, and different methods of direct use of the captured gases. While capturing 3He, large amounts of hydrogen and 4He are produced. Analyses of orbital transfer vehicles (OTVs), landers, and the issues with in-situ resource utilization (ISRU) mining factories are included. Preliminary observations are presented on near-optimal selections of moon base orbital locations, OTV power levels, and OTV and lander rendezvous points. For analyses of round trip OTV flights from Uranus to Miranda or Titania, a 10- Megawatt electric (MWe) OTV power level and a 200 metricton (MT) lander payload were selected based on a relative short OTV trip time and minimization of the number of lander flights. A similar optimum power level is suggested for OTVs flying from low orbit around Neptune to Thalassa or Triton. Several moon base sites at Uranus and Neptune and the OTV requirements to support them are also addressed.

  8. Disruption of co-orbital (1:1) planetary resonances during gas-driven orbital migration

    CERN Document Server

    Pierens, Arnaud

    2014-01-01

    Planets close to their stars are thought to form farther out and migrate inward due to angular momentum exchange with gaseous protoplanetary disks. This process can produce systems of planets in co-orbital (Trojan or 1:1) resonance, in which two planets share the same orbit, usually separated by 60 degrees. Co-orbital systems are detectable among the planetary systems found by the Kepler mission either directly or by transit timing variations. However, no co-orbital systems have been found within the thousands of Kepler planets and candidates. Here we study the orbital evolution of co-orbital planets embedded in a protoplanetary disk using a grid-based hydrodynamics code. We show that pairs of similar-mass planets in co-orbital resonance are disrupted during large-scale orbital migration. Destabilization occurs when one or both planets is near the critical mass needed to open a gap in the gaseous disk. A confined gap is opened that spans the 60 degree azimuthal separation between planets. This alters the torq...

  9. Present Status of Venus Climate Orbiter (Planet-C) development in Japan

    Science.gov (United States)

    Nakamura, Masato

    Venus Climate Orbiter (VCO) is the first Japanese Venus orbiter to be launched in 2010. It aims at studying the atmospheric dynamics of Venus. We keep the time schedule of VCO development at ISAS/JAXA with the collaboration with university researchers and industrial engineers. In this talk we will report the present status of the VCO development in 2008. We have finished the Proto-Model integration test of major components of VCO in December 2007. Mechanical engineering model of the spacecraft has been built and its evaluation was done at Tsukuba Space Center and Sagamihara campus. The vibration levels are mostly consistent with the results from the mathematical modeling. It has been converted to the Thermal test model and is under evaluation in the thermal vacuum chamber at Sagamihara. In March 2008, we had the CDR for the phase-up (to Phase D). After the CDR, flight model of VCO has been built by NEC Corp. and ISAS/JAXA. It will be finalized by 2009 and the final integration test will be done during whole 2009.

  10. PLANETARY CANDIDATES OBSERVED BY KEPLER. III. ANALYSIS OF THE FIRST 16 MONTHS OF DATA

    Energy Technology Data Exchange (ETDEWEB)

    Batalha, Natalie M. [Department of Physics and Astronomy, San Jose State University, San Jose, CA 95192 (United States); Rowe, Jason F.; Burke, Christopher J.; Caldwell, Douglas A.; Mullally, Fergal; Thompson, Susan E. [SETI Institute/NASA Ames Research Center, Moffett Field, CA 94035 (United States); Bryson, Stephen T.; Christiansen, Jessie L. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Barclay, Thomas [Bay Area Environmental Research Institute/NASA Ames Research Center, Moffett Field, CA 94035 (United States); Brown, Timothy M. [Las Cumbres Observatory Global Telescope Network, Goleta, CA 93117 (United States); Dupree, Andrea K.; Latham, David W.; Quinn, Samuel N.; Ragozzine, Darin [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Fabrycky, Daniel C.; Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95060 (United States); Ford, Eric B. [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Gilliland, Ronald L. [Center for Exoplanets and Habitable Worlds, The Pennsylvania State University, University Park, PA 16802 (United States); Isaacson, Howard; Marcy, Geoffrey W., E-mail: Natalie.Batalha@nasa.gov [Department of Astronomy, University of California Berkeley, Berkeley, CA 94720 (United States); and others

    2013-02-15

    New transiting planet candidates are identified in 16 months (2009 May-2010 September) of data from the Kepler spacecraft. Nearly 5000 periodic transit-like signals are vetted against astrophysical and instrumental false positives yielding 1108 viable new planet candidates, bringing the total count up to over 2300. Improved vetting metrics are employed, contributing to higher catalog reliability. Most notable is the noise-weighted robust averaging of multi-quarter photo-center offsets derived from difference image analysis that identifies likely background eclipsing binaries. Twenty-two months of photometry are used for the purpose of characterizing each of the candidates. Ephemerides (transit epoch, T {sub 0}, and orbital period, P) are tabulated as well as the products of light curve modeling: reduced radius (R {sub P}/R {sub *}), reduced semimajor axis (d/R {sub *}), and impact parameter (b). The largest fractional increases are seen for the smallest planet candidates (201% for candidates smaller than 2 R {sub Circled-Plus} compared to 53% for candidates larger than 2 R {sub Circled-Plus }) and those at longer orbital periods (124% for candidates outside of 50 day orbits versus 86% for candidates inside of 50 day orbits). The gains are larger than expected from increasing the observing window from 13 months (Quarters 1-5) to 16 months (Quarters 1-6) even in regions of parameter space where one would have expected the previous catalogs to be complete. Analyses of planet frequencies based on previous catalogs will be affected by such incompleteness. The fraction of all planet candidate host stars with multiple candidates has grown from 17% to 20%, and the paucity of short-period giant planets in multiple systems is still evident. The progression toward smaller planets at longer orbital periods with each new catalog release suggests that Earth-size planets in the habitable zone are forthcoming if, indeed, such planets are abundant.

  11. HAT-P-16b: A 4 M J Planet Transiting a Bright Star on an Eccentric Orbit

    Science.gov (United States)

    Buchhave, L. A.; Bakos, G. Á.; Hartman, J. D.; Torres, G.; Kovács, G.; Latham, D. W.; Noyes, R. W.; Esquerdo, G. A.; Everett, M.; Howard, A. W.; Marcy, G. W.; Fischer, D. A.; Johnson, J. A.; Andersen, J.; Fűrész, G.; Perumpilly, G.; Sasselov, D. D.; Stefanik, R. P.; Béky, B.; Lázár, J.; Papp, I.; Sári, P.

    2010-09-01

    We report the discovery of HAT-P-16b, a transiting extrasolar planet orbiting the V = 10.8 mag F8 dwarf GSC 2792-01700, with a period P = 2.775960 ± 0.000003 days, transit epoch Tc = 2455027.59293 ± 0.00031 (BJD10), and transit duration 0.1276 ± 0.0013 days. The host star has a mass of 1.22 ± 0.04 M sun, radius of 1.24 ± 0.05 R sun, effective temperature 6158 ± 80 K, and metallicity [Fe/H] = +0.17 ± 0.08. The planetary companion has a mass of 4.193 ± 0.094 M J and radius of 1.289 ± 0.066 R J, yielding a mean density of 2.42 ± 0.35 g cm-3. Comparing these observed characteristics with recent theoretical models, we find that HAT-P-16b is consistent with a 1 Gyr H/He-dominated gas giant planet. HAT-P-16b resides in a sparsely populated region of the mass-radius diagram and has a non-zero eccentricity of e = 0.036 with a significance of 10σ. Based in part on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. Based in part on observations obtained at the W. M. Keck Observatory, which is operated by the University of California and the California Institute of Technology. Keck time has been granted by NASA (N018Hr).

  12. Warner Prize Lecture: A New View on Planetary Orbital Dynamics

    Science.gov (United States)

    Ford, Eric B.

    2013-01-01

    Prior to the discovery of exoplanets, astronomers fine tuned theories of planet formation to explain detailed properties of the solar system. Doppler planet searches revealed that many giant planets orbit close to their host star or in highly eccentric orbits. These and subsequent observations inspired new theories of planet formation that invoke strong mutual gravitation interactions in multiple planet systems to explain the excitation of orbital eccentricities and even short-period giant planets. NASA's Kepler mission has identified over 300 systems with multiple transiting planet candidates, including many potentially rocky planets. Most of these systems include multiple planets with sizes between Earth and Neptune and closely-spaced orbits. These systems represent another new and unexpected class of planetary systems and provide an opportunity to test the theories developed to explain the properties of giant exoplanets. I will describe how transit timing observations by Kepler are characterizing the gravitational effects of mutual planetary perturbations for hundreds of planets and providing precise (but complex) constraints on planetary masses, densities and orbits, even for planetary systems with faint host stars. I will discuss early efforts to translate these observations into new constraints on the formation and orbital evolution of planetary systems with low-mass planets.

  13. Habitable-zone super-Earth candidate in a six-planet system around the K2.5V star HD 40307

    Science.gov (United States)

    Tuomi, M.; Anglada-Escudé, G.; Gerlach, E.; Jones, H. R. A.; Reiners, A.; Rivera, E. J.; Vogt, S. S.; Butler, R. P.

    2013-01-01

    Context. The K2.5 dwarf HD 40307 has been reported to host three super-Earths. The system lacks massive planets and is therefore a potential candidate for having additional low-mass planetary companions. Aims: We re-derive Doppler measurements from public HARPS spectra of HD 40307 to confirm the significance of the reported signals using independent data analysis methods. We also investigate these measurements for additional low-amplitude signals. Methods: We used Bayesian analysis of our radial velocities to estimate the probability densities of different model parameters. We also estimated the relative probabilities of models with differing numbers of Keplerian signals and verified their significance using periodogram analyses. We investigated the relation of the detected signals with the chromospheric emission of the star. As previously reported for other objects, we found that radial velocity signals correlated with the S-index are strongly wavelength dependent. Results: We identify two additional clear signals with periods of 34 and 51 days, both corresponding to planet candidates with minimum masses a few times that of the Earth. An additional sixth candidate is initially found at a period of 320 days. However, this signal correlates strongly with the chromospheric emission from the star and is also strongly wavelength dependent. When analysing the red half of the spectra only, the five putative planetary signals are recovered together with a very significant periodicity at about 200 days. This signal has a similar amplitude as the other new signals reported in the current work and corresponds to a planet candidate with Msini ~ 7 M⊕ (HD 40307 g). Conclusions: We show that Doppler measurements can be filtered for activity-induced signals if enough photons and a sufficient wavelength interval are available. If the signal corresponding to HD 40307 g is a genuine Doppler signal of planetary origin, this candidate planet might be capable of supporting liquid

  14. VLT/SPHERE robust astrometry of the HR8799 planets at milliarcsecond-level accuracy Orbital architecture analysis with PyAstrOFit

    CERN Document Server

    Wertz, Olivier; González, Carlos A Gómez; Milli, Julien; Girard, Julen H; Mawet, Dimitri; Pueyo, Laurent

    2016-01-01

    HR8799 is orbited by at least four giant planets, making it a prime target for the recently commissioned Spectro-Polarimetric High-contrast Exoplanet REsearch (VLT/SPHERE). As such, it was observed on five consecutive nights during the SPHERE science verification in December 2014. We aim to take full advantage of the SPHERE capabilities to derive accurate astrometric measurements based on H-band images acquired with the Infra-Red Dual-band Imaging and Spectroscopy (IRDIS) subsystem, and to explore the ultimate astrometric performance of SPHERE in this observing mode. We also aim to present a detailed analysis of the orbital parameters for the four planets. We report the astrometric positions for epoch 2014.93 with an accuracy down to 2.0 mas, mainly limited by the astrometric calibration of IRDIS. For each planet, we derive the posterior probability density functions for the six Keplerian elements and identify sets of highly probable orbits. For planet d, there is clear evidence for nonzero eccentricity ($e \\...

  15. A TREND BETWEEN COLD DEBRIS DISK TEMPERATURE AND STELLAR TYPE: IMPLICATIONS FOR THE FORMATION AND EVOLUTION OF WIDE-ORBIT PLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Ballering, Nicholas P.; Rieke, George H.; Su, Kate Y. L. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Montiel, Edward, E-mail: ballerin@email.arizona.edu [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803, USA. (United States)

    2013-09-20

    Cold debris disks trace the limits of planet formation or migration in the outer regions of planetary systems, and thus have the potential to answer many of the outstanding questions in wide-orbit planet formation and evolution. We characterized the infrared excess spectral energy distributions of 174 cold debris disks around 546 main-sequence stars observed by both the Spitzer Infrared Spectrograph and the Multiband Imaging Photometer for Spitzer. We found a trend between the temperature of the inner edges of cold debris disks and the stellar type of the stars they orbit. This argues against the importance of strictly temperature-dependent processes (e.g., non-water ice lines) in setting the dimensions of cold debris disks. Also, we found no evidence that delayed stirring causes the trend. The trend may result from outward planet migration that traces the extent of the primordial protoplanetary disk, or it may result from planet formation that halts at an orbital radius limited by the efficiency of core accretion.

  16. The Surface UV Environment on Planets Orbiting M Dwarfs: Implications for Prebiotic Chemistry and the Need for Experimental Follow-up

    Science.gov (United States)

    Ranjan, Sukrit; Wordsworth, Robin; Sasselov, Dimitar D.

    2017-07-01

    Potentially habitable planets orbiting M dwarfs are of intense astrobiological interest because they are the only rocky worlds accessible to biosignature search over the next 10+ years because of a confluence of observational effects. Simultaneously, recent experimental and theoretical work suggests that UV light may have played a key role in the origin of life on Earth, especially the origin of RNA. Characterizing the UV environment on M-dwarf planets is important for understanding whether life as we know it could emerge on such worlds. In this work, we couple radiative transfer models to observed M-dwarf spectra to determine the UV environment on prebiotic Earth-analog planets orbiting M dwarfs. We calculate dose rates to quantify the impact of different host stars on prebiotically important photoprocesses. We find that M-dwarf planets have access to 100-1000 times less bioactive UV fluence than the young Earth. It is unclear whether UV-sensitive prebiotic chemistry that may have been important to abiogenesis, such as the only known prebiotically plausible pathways for pyrimidine ribonucleotide synthesis, could function on M-dwarf planets. This uncertainty affects objects like the recently discovered habitable-zone planets orbiting Proxima Centauri, TRAPPIST-1, and LHS 1140. Laboratory studies of the sensitivity of putative prebiotic pathways to irradiation level are required to resolve this uncertainty. If steady-state M-dwarf UV output is insufficient to power these pathways, transient elevated UV irradiation due to flares may suffice; laboratory studies can constrain this possibility as well.

  17. Planet Hunters: Assessing the Kepler Inventory of Short Period Planets

    CERN Document Server

    Schwamb, Megan E; Fischer, Debra A; Giguere, Matthew J; Lynn, Stuart; Smith, Arfon M; Brewer, John M; Parrish, Michael; Schawinski, Kevin; Simpson, Robert J

    2012-01-01

    We present the results from a search of data from the first 33.5 days of the Kepler science mission (Quarter 1) for exoplanet transits by the Planet Hunters citizen science project. Planet Hunters enlists members of the general public to visually identify transits in the publicly released Kepler light curves via the World Wide Web. Over 24,000 volunteers reviewed the Kepler Quarter 1 data set. We examine the abundance of \\geq 2 R\\oplus planets on short period (< 15 days) orbits based on Planet Hunters detections. We present these results along with an analysis of the detection efficiency of human classifiers to identify planetary transits including a comparison to the Kepler inventory of planet candidates. Although performance drops rapidly for smaller radii, \\geq 4 R\\oplus Planet Hunters \\geq 85% efficient at identifying transit signals for planets with periods less than 15 days for the Kepler sample of target stars. Our high efficiency rate for simulated transits along with recovery of the majority of Ke...

  18. Very Low-mass Stellar and Substellar Companions to Solar-like Stars from MARVELS. VI. A Giant Planet and a Brown Dwarf Candidate in a Close Binary System HD 87646

    Science.gov (United States)

    Ma, Bo; Ge, Jian; Wolszczan, Alex; Muterspaugh, Matthew W.; Lee, Brian; Henry, Gregory W.; Schneider, Donald P.; Martín, Eduardo L.; Niedzielski, Andrzej; Xie, Jiwei; Fleming, Scott W.; Thomas, Neil; Williamson, Michael; Zhu, Zhaohuan; Agol, Eric; Bizyaev, Dmitry; Nicolaci da Costa, Luiz; Jiang, Peng; Martinez Fiorenzano, A. F.; González Hernández, Jonay I.; Guo, Pengcheng; Grieves, Nolan; Li, Rui; Liu, Jane; Mahadevan, Suvrath; Mazeh, Tsevi; Nguyen, Duy Cuong; Paegert, Martin; Sithajan, Sirinrat; Stassun, Keivan; Thirupathi, Sivarani; van Eyken, Julian C.; Wan, Xiaoke; Wang, Ji; Wisniewski, John P.; Zhao, Bo; Zucker, Shay

    2016-11-01

    We report the detections of a giant planet (MARVELS-7b) and a brown dwarf (BD) candidate (MARVELS-7c) around the primary star in the close binary system, HD 87646. To the best of our knowledge, it is the first close binary system with more than one substellar circumprimary companion that has been discovered. The detection of this giant planet was accomplished using the first multi-object Doppler instrument (KeckET) at the Sloan Digital Sky Survey (SDSS) telescope. Subsequent radial velocity observations using the Exoplanet Tracker at the Kitt Peak National Observatory, the High Resolution Spectrograph at the Hobby Eberley telescope, the “Classic” spectrograph at the Automatic Spectroscopic Telescope at the Fairborn Observatory, and MARVELS from SDSS-III confirmed this giant planet discovery and revealed the existence of a long-period BD in this binary. HD 87646 is a close binary with a separation of ˜22 au between the two stars, estimated using the Hipparcos catalog and our newly acquired AO image from PALAO on the 200 inch Hale Telescope at Palomar. The primary star in the binary, HD 87646A, has {T}{eff} = 5770 ± 80 K, log g = 4.1 ± 0.1, and [Fe/H] = -0.17 ± 0.08. The derived minimum masses of the two substellar companions of HD 87646A are 12.4 ± 0.7 {M}{Jup} and 57.0 ± 3.7 {M}{Jup}. The periods are 13.481 ± 0.001 days and 674 ± 4 days and the measured eccentricities are 0.05 ± 0.02 and 0.50 ± 0.02 respectively. Our dynamical simulations show that the system is stable if the binary orbit has a large semimajor axis and a low eccentricity, which can be verified with future astrometry observations.

  19. The NASA-UC-UH Eta-Earth program. IV. A low-mass planet orbiting an M dwarf 3.6 PC from Earth

    Energy Technology Data Exchange (ETDEWEB)

    Howard, Andrew W. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Marcy, Geoffrey W.; Isaacson, Howard [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Fischer, Debra A.; Boyajian, Tabetha S. [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Muirhead, Philip S.; Becker, Juliette C. [Department of Astrophysics, California Institute of Technology, MC 249-17, Pasadena, CA 91125 (United States); Henry, Gregory W. [Center of Excellence in Information Systems, Tennessee State University, 3500 John A. Merritt Boulevard, Box 9501, Nashville, TN 37209 (United States); Von Braun, Kaspar [NASA Exoplanet Science Institute, California Institute of Technology, Pasadena, CA 91125 (United States); Wright, Jason T. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Johnson, John Asher [Center for Planetary Astronomy, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States)

    2014-10-10

    We report the discovery of a low-mass planet orbiting Gl 15 A based on radial velocities from the Eta-Earth Survey using HIRES at Keck Observatory. Gl 15 Ab is a planet with minimum mass Msin i = 5.35 ± 0.75 M {sub ⊕}, orbital period P = 11.4433 ± 0.0016 days, and an orbit that is consistent with circular. We characterize the host star using a variety of techniques. Photometric observations at Fairborn Observatory show no evidence for rotational modulation of spots at the orbital period to a limit of ∼0.1 mmag, thus supporting the existence of the planet. We detect a second RV signal with a period of 44 days that we attribute to rotational modulation of stellar surface features, as confirmed by optical photometry and the Ca II H and K activity indicator. Using infrared spectroscopy from Palomar-TripleSpec, we measure an M2 V spectral type and a sub-solar metallicity ([M/H] = –0.22, [Fe/H] = –0.32). We measure a stellar radius of 0.3863 ± 0.0021 R {sub ☉} based on interferometry from CHARA.

  20. The NASA-UC-UH Eta-Earth Program: IV. A Low-mass Planet Orbiting an M Dwarf 3.6 PC from Earth

    CERN Document Server

    Howard, Andrew W; Fischer, Debra A; Isaacson, Howard; Muirhead, Philip S; Henry, Gregory W; Boyajian, Tabetha S; von Braun, Kaspar; Becker, Juliette C; Wright, Jason T; Johnson, John Asher

    2014-01-01

    We report the discovery of a low-mass planet orbiting Gl 15 A based on radial velocities from the Eta-Earth Survey using HIRES at Keck Observatory. Gl 15 Ab is a planet with minimum mass Msini = 5.35 $\\pm$ 0.75 M$_\\oplus$, orbital period P = 11.4433 $\\pm$ 0.0016 days, and an orbit that is consistent with circular. We characterize the host star using a variety of techniques. Photometric observations at Fairborn Observatory show no evidence for rotational modulation of spots at the orbital period to a limit of ~0.1 mmag, thus supporting the existence of the planet. We detect a second RV signal with a period of 44 days that we attribute to rotational modulation of stellar surface features, as confirmed by optical photometry and the Ca II H & K activity indicator. Using infrared spectroscopy from Palomar-TripleSpec, we measure an M2 V spectral type and a sub-solar metallicity ([M/H] = -0.22, [Fe/H] = -0.32). We measure a stellar radius of 0.3863 $\\pm$ 0.0021 R$_\\odot$ based on interferometry from CHARA.

  1. The NASA-UC-UH ETA-Earth Program. IV. A Low-mass Planet Orbiting an M Dwarf 3.6 PC from Earth

    Science.gov (United States)

    Howard, Andrew W.; Marcy, Geoffrey W.; Fischer, Debra A.; Isaacson, Howard; Muirhead, Philip S.; Henry, Gregory W.; Boyajian, Tabetha S.; von Braun, Kaspar; Becker, Juliette C.; Wright, Jason T.; Johnson, John Asher

    2014-10-01

    We report the discovery of a low-mass planet orbiting Gl 15 A based on radial velocities from the Eta-Earth Survey using HIRES at Keck Observatory. Gl 15 Ab is a planet with minimum mass Msin i = 5.35 ± 0.75 M ⊕, orbital period P = 11.4433 ± 0.0016 days, and an orbit that is consistent with circular. We characterize the host star using a variety of techniques. Photometric observations at Fairborn Observatory show no evidence for rotational modulation of spots at the orbital period to a limit of ~0.1 mmag, thus supporting the existence of the planet. We detect a second RV signal with a period of 44 days that we attribute to rotational modulation of stellar surface features, as confirmed by optical photometry and the Ca II H & K activity indicator. Using infrared spectroscopy from Palomar-TripleSpec, we measure an M2 V spectral type and a sub-solar metallicity ([M/H] = -0.22, [Fe/H] = -0.32). We measure a stellar radius of 0.3863 ± 0.0021 R ⊙ based on interferometry from CHARA. 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 Hawaii, the University of California, and NASA.

  2. Coupled Evolutions of the Stellar Obliquity, Orbital Distance, and Planet's Radius due to the Ohmic Dissipation Induced in a Diamagnetic Hot Jupiter around a Magnetic T Tauri Star

    Science.gov (United States)

    Chang, Yu-Ling; Bodenheimer, Peter H.; Gu, Pin-Gao

    2012-10-01

    We revisit the calculation of the ohmic dissipation in a hot Jupiter presented by Laine et al. by considering more realistic interior structures, stellar obliquity, and the resulting orbital evolution. In this simplified approach, the young hot Jupiter of one Jupiter mass is modeled as a diamagnetic sphere with a finite resistivity, orbiting across tilted stellar magnetic dipole fields in vacuum. Since the induced ohmic dissipation occurs mostly near the planet's surface, we find that the dissipation is unable to significantly expand the young hot Jupiter. Nevertheless, the planet inside a small corotation orbital radius can undergo orbital decay by the dissipation torque and finally overfill its Roche lobe during the T Tauri star phase. The stellar obliquity can evolve significantly if the magnetic dipole is parallel/antiparallel to the stellar spin. Our results are validated by the general torque-dissipation relation in the presence of the stellar obliquity. We also run the fiducial model of Laine et al. and find that the planet's radius is sustained at a nearly constant value by the ohmic heating, rather than being thermally expanded to the Roche radius as suggested by the authors.

  3. THE GEMINI PLANET-FINDING CAMPAIGN: THE FREQUENCY OF GIANT PLANETS AROUND DEBRIS DISK STARS

    Energy Technology Data Exchange (ETDEWEB)

    Wahhaj, Zahed [European Southern Observatory, Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago (Chile); Liu, Michael C.; Nielsen, Eric L.; Ftaclas, Christ; Chun, Mark [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Biller, Beth A. [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany); Hayward, Thomas L. [Gemini Observatory, Southern Operations Center, c/o AURA, Casilla 603, La Serena (Chile); Close, Laird M.; Males, Jared R.; Skemer, Andrew [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Thatte, Niranjan; Tecza, Matthias [Department of Astronomy, University of Oxford, DWB, Keble Road, Oxford OX1 3RH (United Kingdom); Shkolnik, Evgenya L. [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States); Kuchner, Marc [NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics Laboratory, Greenbelt, MD 20771 (United States); Reid, I. Neill [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); De Gouveia Dal Pino, Elisabete M.; Gregorio-Hetem, Jane [Departamento de Astronomia, Universidade de Sao Paulo, IAG/USP, Rua do Matao 1226, 05508-900 Sao Paulo, SP (Brazil); Alencar, Silvia H. P. [Departamento de Fisica-ICEx-UFMG, Av. Antonio Carlos 6627, 30270-901 Belo Horizonte, MG (Brazil); Boss, Alan [Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road, NW, Washington, DC 20015 (United States); Lin, Douglas N. C. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA (United States); and others

    2013-08-20

    We have completed a high-contrast direct imaging survey for giant planets around 57 debris disk stars as part of the Gemini NICI Planet-Finding Campaign. We achieved median H-band contrasts of 12.4 mag at 0.''5 and 14.1 mag at 1'' separation. Follow-up observations of the 66 candidates with projected separation <500 AU show that all of them are background objects. To establish statistical constraints on the underlying giant planet population based on our imaging data, we have developed a new Bayesian formalism that incorporates (1) non-detections, (2) single-epoch candidates, (3) astrometric and (4) photometric information, and (5) the possibility of multiple planets per star to constrain the planet population. Our formalism allows us to include in our analysis the previously known {beta} Pictoris and the HR 8799 planets. Our results show at 95% confidence that <13% of debris disk stars have a {>=}5 M{sub Jup} planet beyond 80 AU, and <21% of debris disk stars have a {>=}3 M{sub Jup} planet outside of 40 AU, based on hot-start evolutionary models. We model the population of directly imaged planets as d {sup 2} N/dMda{proportional_to}m {sup {alpha}} a {sup {beta}}, where m is planet mass and a is orbital semi-major axis (with a maximum value of a{sub max}). We find that {beta} < -0.8 and/or {alpha} > 1.7. Likewise, we find that {beta} < -0.8 and/or a{sub max} < 200 AU. For the case where the planet frequency rises sharply with mass ({alpha} > 1.7), this occurs because all the planets detected to date have masses above 5 M{sub Jup}, but planets of lower mass could easily have been detected by our search. If we ignore the {beta} Pic and HR 8799 planets (should they belong to a rare and distinct group), we find that <20% of debris disk stars have a {>=}3 M{sub Jup} planet beyond 10 AU, and {beta} < -0.8 and/or {alpha} < -1.5. Likewise, {beta} < -0.8 and/or a{sub max} < 125 AU. Our Bayesian constraints are not strong enough to reveal any dependence

  4. Two planets around Kapteyn's star : a cold and a temperate super-Earth orbiting the nearest halo red-dwarf

    CERN Document Server

    Anglada-Escudé, Guillem; Tuomi, Mikko; Zechmeister, Mathias; Jenkins, James S; Ofir, Aviv; Dreizler, Stefan; Gerlach, Enrico; Marvin, Chris J; Reiners, Ansgar; Jeffers, Sandra V; Butler, R Paul; Vogt, Steven S; Amado, Pedro J; Rodríguez-López, Cristina; Berdiñas, Zaira M; Morin, Julian; Crane, Jeff D; Shectman, Stephen A; Thompson, Ian B; Díaz, Mateo; Rivera, Eugenio; Sarmiento, Luis F; Jones, Hugh R A

    2014-01-01

    Exoplanets of a few Earth masses can be now detected around nearby low-mass stars using Doppler spectroscopy. In this paper, we investigate the radial velocity variations of Kapteyn's star, which is both a sub-dwarf M-star and the nearest halo object to the Sun. The observations comprise archival and new HARPS, HIRES and PFS Doppler measurements. Two Doppler signals are detected at periods of 48 and 120 days using likelihood periodograms and a Bayesian analysis of the data. Using the same techniques, the activity indicies and archival ASAS-3 photometry show evidence for low-level activity periodicities of the order of several hundred days. However, there are no significant correlations with the radial velocity variations on the same time-scales. The inclusion of planetary Keplerian signals in the model results in levels of correlated and excess white noise that are remarkably low compared to younger G, K and M dwarfs. We conclude that Kapteyn's star is most probably orbited by two super-Earth mass planets, on...

  5. Light equation in eclipsing binary CV Boo: third body candidate in elliptical orbit

    CERN Document Server

    Bogomazov, A I; Satovskii, B L; Krushevska, V N; Kuznyetsova, Yu G; Ehgamberdiev, Sh A; Karimov, R G; Khalikova, A V; Ibrahimov, M A; Irsmambetova, T R; Tutukov, A V

    2016-01-01

    A short period eclipsing binary star CV Boo is tested for the possible existence of additional bodies in the system with a help of the light equation method. We use data on the moments of minima from the literature as well as from our observations during 2014 May--July. A variation of the CV Boo's orbital period is found with a period of $\\approx 75$ d. This variation can be explained by the influence of a third star with a mass of $\\approx 0.4M_{\\odot}$ in an eccentric orbit with $e\\approx 0.9$. A possibility that the orbital period changes on long time scales is discussed. The suggested tertiary companion is near the chaotic zone around the central binary, so CV Boo represents an interesting example to test its dynamical evolution. A list of 14 minima moments of the binary obtained from our observations is presented.

  6. EPIC 211391664b: A 32-M$_\\oplus$ Neptune-sized planet in a 10-day orbit transiting an F8 star

    CERN Document Server

    Barragán, Oscar; Gandolfi, Davide; Fridlund, Malcolm; Endl, Michael; Deeg, Hans J; Cagigal, Manuel P; Lanza, Antonino F; Moroni, Pier G Prada; Smith, Alexis; Korth, Judith; Bedell, Megan; Cabrera, Juan; Cochran, William D; Cusano, Felice; Csizmadia, Szilard; Eigmüller, Philipp; Erikson, Anders; Guenther, Eike W; Hatzes, Artie P; Nespral, David; Pätzold, Martin; Prieto-Arranz, Jorge; Rauer, Heike

    2016-01-01

    We report the discovery of EPIC 211391664b, a transiting Neptune-sized planet monitored by the K2 mission during its campaign 5. We combine the K2 time-series data with ground-based photometric and spectroscopic follow-up observations to confirm the planetary nature of the object and derive its mass, radius, and orbital parameters. EPIC 211391664 b is a warm Neptune-like planet in a 10-day orbit around a V=12.2~mag F-type star with $M_\\star$=$ 1.074\\pm0.042 M_{\\odot} $, $R_\\star$=$ 1.311 ^{+ 0.083}_{ - 0.048} R_{\\odot}$, and age of $5.2_{-1.0}^{+1.2}$~Gyr. We derive a planetary mass and radius of $M_\\mathrm{p}$=$ 32.2 \\pm 8.1 M_{\\oplus}$ and $R_\\mathrm{p}$=$4.3^{+0.3}_{-0.2} R_{\\oplus}$. EPIC 211391664b joins the relatively small group of Neptune-sized planets whose mass and radius have been derived with a precision better than 3-$\\sigma$. We estimate that the planet will be engulfed by EPIC 211391664 in $\\sim$3~Gyr, due to the evolution of the host star towards the red giant branch.

  7. Multiwavelength Transit Observations of the Candidate Disintegrating Planetesimals Orbiting WD 1145+017

    CERN Document Server

    Croll, Bryce; Vanderburg, Andrew; Eastman, Jason; Rappaport, Saul; DeVore, John; Bieryla, Allyson; Muirhead, Philip S; Han, Eunkyu; Latham, David W; Beatty, Thomas G; Wittenmyer, Robert A; Wright, Jason T; Johnson, John Asher; McCrady, Nate

    2015-01-01

    We present multiwavelength, multi-telescope, ground-based follow-up photometry of the white dwarf WD 1145+017, that has recently been suggested to be orbited by up to six or more, short-period, low-mass, disintegrating planetesimals. We detect 9 significant dips in flux of between 10% and 30% of the stellar flux from our ground-based photometry. We observe transits deeper than 10% on average every ~3.6 hr in our photometry. This suggests that WD 1145+017 is indeed being orbited by multiple, short-period objects. Through fits to the multiple asymmetric transits that we observe, we confirm that the transit egress timescale is usually longer than the ingress timescale, and that the transit duration is longer than expected for a solid body at these short periods, all suggesting that these objects have cometary tails streaming behind them. The precise orbital periods of the planetesimals in this system are unclear from the transit-times, but at least one object, and likely more, have orbital periods of ~4.5 hours....

  8. OGLE-2015-BLG-0051/KMT-2015-BLG-0048Lb: a Giant Planet Orbiting a Low-mass Bulge Star Discovered by High-cadence Microlensing Surveys

    CERN Document Server

    Han, C; Gould, A; Bozza, V; Jung, Y K; Albrow, M D; Kim, S -L; Lee, C -U; Cha, S -M; Kim, D -J; Lee, Y; Park, B -G; Shin, I -G; Szymański, M K; Soszyński, I; Skowron, J; Mróz, P; Poleski, R; Pietrukowicz, P; Kozłowski, S; Ulaczyk, K; Wyrzykowski, Ł; Pawlak, M

    2016-01-01

    We report the discovery of an extrasolar planet detected from the combined data of a microlensing event OGLE-2015-BLG-0051/KMT-2015-BLG-0048 acquired by two microlensing surveys. Despite that the short planetary signal occurred in the very early Bulge season during which the lensing event could be seen for just about an hour, the signal was continuously and densely covered. From the Bayesian analysis using models of the mass function, matter and velocity distributions combined with the information of the angular Einstein radius, it is found that the host of the planet is located in the Galactic bulge. The planet has a mass $0.72_{-0.07}^{+0.65}\\ M_{\\rm J}$ and it is orbiting a low-mass M-dwarf host with a projected separation $d_\\perp=0.73 \\pm 0.08$ AU. The discovery of the planet demonstrates the capability of the current high-cadence microlensing lensing surveys in detecting and characterizing planets.

  9. The NASA-UC Eta-Earth Program: II. A Planet Orbiting HD 156668 with a Minimum Mass of Four Earth Masses

    CERN Document Server

    Howard, Andrew W; Marcy, Geoffrey W; Fischer, Debra A; Wright, Jason T; Henry, Gregory W; Isaacson, Howard; Valenti, Jeff A; Anderson, Jay; Piskunov, Nikolai E

    2010-01-01

    We report the discovery of HD 156668b, an extrasolar planet with a minimum mass of M_P sin i = 4.15 M_Earth. This planet was discovered through Keplerian modeling of precise radial velocities from Keck-HIRES and is the second super-Earth to emerge from the NASA-UC Eta-Earth Survey. The best-fit orbit is consistent with circular and has a period of P = 4.6455 d. The Doppler semi-amplitude of this planet, K = 1.89 m/s, is among the lowest ever detected, on par with the detection of GJ 581e using HARPS. A longer period (P ~ 2.3 yr), low-amplitude signal of unknown origin was also detected in the radial velocities and was filtered out of the data while fitting the short-period planet. Additional data are required to determine if the long-period signal is due to a second planet, stellar activity, or another source. Photometric observations using the Automated Photometric Telescopes at Fairborn Observatory show that HD 156668 (an old, quiet K3 dwarf) is photometrically constant over the radial velocity period to 0....

  10. OGLE-2015-BLG-0051/KMT-2015-BLG-0048Lb: A Giant Planet Orbiting a Low-mass Bulge Star Discovered by High-cadence Microlensing Surveys

    Science.gov (United States)

    Han, C.; Udalski, A.; Gould, A.; Bozza, V.; Jung, Y. K.; Albrow, M. D.; Kim, S.-L.; Lee, C.-U.; Cha, S.-M.; Kim, D.-J.; Lee, Y.; Park, B.-G.; Shin, I.-G.; KMTNet Collaboration; Szymański, M. K.; Soszyński, I.; Skowron, J.; Mróz, P.; Poleski, R.; Pietrukowicz, P.; Kozłowski, S.; Ulaczyk, K.; Wyrzykowski, Ł.; Pawlak, M.; OGLE Collaboration

    2016-10-01

    We report the discovery of an extrasolar planet detected from the combined data of a microlensing event OGLE-2015-BLG-0051/KMT-2015-BLG-0048 acquired by two microlensing surveys. Despite the fact that the short planetary signal occurred in the very early Bulge season during which the lensing event could be seen for just about an hour, the signal was continuously and densely covered. From the Bayesian analysis using models of the mass function, and matter and velocity distributions, combined with information on the angular Einstein radius, it is found that the host of the planet is located in the Galactic bulge. The planet has a mass {0.72}-0.07+0.65 {M}{{J}} and it is orbiting a low-mass M-dwarf host with a projected separation {d}\\perp =0.73+/- 0.08 {{au}}. The discovery of the planet demonstrates the capability of the current high-cadence microlensing lensing surveys in detecting and characterizing planets.

  11. The Occurrence of Potentially Habitable Planets Orbiting M Dwarfs Estimated from the Full Kepler Dataset and an Empirical Measurement of the Detection Sensitivity

    CERN Document Server

    Dressing, Courtney D

    2015-01-01

    We present an improved estimate of the occurrence rate of small planets around small stars by searching the full four-year Kepler data set for transiting planets using our own planet detection pipeline and conducting transit injection and recovery simulations to empirically measure the search completeness of our pipeline. We identified 157 planet candidates, including 2 objects that were not previously identified as Kepler Objects of Interest (KOIs). We inspected all publicly available follow-up images, observing notes, and centroid analyses, and corrected for the likelihood of false positives. We evaluate the sensitivity of our detection pipeline on a star-by-star basis by injecting 2000 transit signals in the light curve of each target star. For periods shorter than 50 days, we found an occurrence rate of 0.57 (+0.06/-0.05) Earth-size planets (1-1.5 Earth radii) and 0.51 (+0.07/-0.06) super-Earths (1.5-2 Earth radii) per M dwarf. Within a conservatively defined habitable zone based on the moist greenhouse i...

  12. Planet Hunters: A Status Report

    Science.gov (United States)

    Schwamb, Megan E.; Orosz, J. A.; Carter, J. A.; Fischer, D. A.; Howard, A. W.; Crepp, J. R.; Welsh, W. F.; Kaib, N. A.; Lintott, C. J.; Terrell, D.; Jek, K. J.; Gagliano, R.; Parrish, M.; Smith, A. M.; Lynn, S.; Brewer, J. M.; Giguere, M. J.; Schawinski, K.; Simpson, R. J.

    2012-10-01

    The Planet Hunters (http://www.planethunters.org) citizen science project uses the power of human pattern recognition via the World Wide Web to identify transits in the Kepler public data. Planet Hunters uses the Zooniverse (http://www.zooniverse.org) platform to present visitors to the Planet Hunters website with a randomly selected 30-day light curve segment from one of Kepler's 160,000 target stars. Volunteers are asked to draw boxes to mark the locations of visible transits with multiple independent classifiers reviewing each 30-day light curve segment. Since December 2010, more than 170,000 members of the general public have participated in Planet Hunters contributing over 12.5 million classifications searching the 1 1/2 years of publicly released Kepler observations. Planet Hunters is a novel and complementary technique to the automated transit detection algorithms, providing an independent assessment of the completeness of the Kepler exoplanet inventory. We report the latest results from Planet Hunters, highlighting in particular our latest efforts to search for circumbinary planets (planets orbiting a binary star) and single transit events in the first 1.5 years of public Kepler data. We will present a status report of our search of the first 6 Quarters of Kepler data, introducing our new planet candidates and sharing the results of our observational follow-up campaign to characterize these planetary systems. Acknowledgements: MES is supported by a NSF Astronomy and Astrophysics Postdoctoral Fellowship under award AST-1003258. This is research is supported in part by an American Philosophical Society Franklin Grant.

  13. Swift/XRT orbital monitoring of the candidate supergiant fast X-ray transient IGR J17354-3255

    CERN Document Server

    Ducci, L; Esposito, P; Bozzo, E; Krimm, H A; Vercellone, S; Mangano, V; Kennea, J A

    2013-01-01

    We report on the Swift/X-ray Telescope (XRT) monitoring of the field of view around the candidate supergiant fast X-ray transient (SFXT) IGR J17354-3255, which is positionally associated with the AGILE/GRID gamma-ray transient AGL J1734-3310. Our observations, which cover 11 days for a total on-source exposure of about 24 ks, span 1.2 orbital periods (P_orb=8.4474 d) and are the first sensitive monitoring of this source in the soft X-rays. These new data allow us to exploit the timing variability properties of the sources in the field to unambiguously identify the soft X-ray counterpart of IGR J17354-3255. The soft X-ray light curve shows a moderate orbital modulation and a dip. We investigated the nature of the dip by comparing the X-ray light curve with the prediction of the Bondi-Hoyle-Lyttleton accretion theory, assuming both spherical and nonspherical symmetry of the outflow from the donor star. We found that the dip cannot be explained with the X-ray orbital modulation. We propose that an eclipse or the...

  14. Possible Outcomes of Coplanar High-eccentricity Migration: Hot Jupiters, Close-in Super-Earths, and Counter-orbiting Planets

    Science.gov (United States)

    Xue, Yuxin; Masuda, Kento; Suto, Yasushi

    2017-02-01

    We investigate the formation of close-in planets in near-coplanar eccentric hierarchical triple systems via the secular interaction between an inner planet and an outer perturber (Coplanar High-eccentricity Migration; CHEM). We generalize the previous work on the analytical condition for successful CHEM for point masses interacting only through gravity by taking into account the finite mass effect of the inner planet. We find that efficient CHEM requires that the systems should have m1 ≪ m0 and m1 ≪ m2. In addition to the gravity for point masses, we examine the importance of the short-range forces, and provide an analytical estimate of the migration timescale. We perform a series of numerical simulations in CHEM for systems consisting of a Sun-like central star, giant gas inner planet, and planetary outer perturber, including the short-range forces and stellar and planetary dissipative tides. We find that most of such systems end up with a tidal disruption; a small fraction of the systems produce prograde hot Jupiters (HJs), but no retrograde HJ. In addition, we extend CHEM to super-Earth mass range, and show that the formation of close-in super-Earths in prograde orbits is also possible. Finally, we carry out CHEM simulation for the observed hierarchical triple and counter-orbiting HJ systems. We find that CHEM can explain a part of the former systems, but it is generally very difficult to reproduce counter-orbiting HJ systems.

  15. EXTRASOLAR BINARY PLANETS. II. DETECTABILITY BY TRANSIT OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, K. M.; Ida, S. [Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Ochiai, H. [Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); Nagasawa, M., E-mail: nagasawa.m.ad@m.titech.ac.jp [Interactive Research Center of Science, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8551 (Japan)

    2015-05-20

    We discuss the detectability of gravitationally bound pairs of gas-giant planets (which we call “binary planets”) in extrasolar planetary systems that are formed through orbital instability followed by planet–planet dynamical tides during their close encounters, based on the results of N-body simulations by Ochiai et al. (Paper I). Paper I showed that the formation probability of a binary is as much as ∼10% for three giant planet systems that undergo orbital instability, and after post-capture long-term tidal evolution, the typical binary separation is three to five times the sum of the physical radii of the planets. The binary planets are stable during the main-sequence lifetime of solar-type stars, if the stellarcentric semimajor axis of the binary is larger than 0.3 AU. We show that detecting modulations of transit light curves is the most promising observational method to detect binary planets. Since the likely binary separations are comparable to the stellar diameter, the shape of the transit light curve is different from transit to transit, depending on the phase of the binary’s orbit. The transit durations and depth for binary planet transits are generally longer and deeper than those for the single planet case. We point out that binary planets could exist among the known inflated gas-giant planets or objects classified as false positive detections at orbital radii ≳0.3 AU, propose a binary planet explanation for the CoRoT candidate SRc01 E2 1066, and show that binary planets are likely to be present in, and could be detected using, Kepler-quality data.

  16. Transiting exoplanets from the CoRoT space mission. XXVII. CoRoT-28b, a planet orbiting an evolved star, and CoRoT-29b, a planet showing an asymmetric transit

    Science.gov (United States)

    Cabrera, J.; Csizmadia, Sz.; Montagnier, G.; Fridlund, M.; Ammler-von Eiff, M.; Chaintreuil, S.; Damiani, C.; Deleuil, M.; Ferraz-Mello, S.; Ferrigno, A.; Gandolfi, D.; Guillot, T.; Guenther, E. W.; Hatzes, A.; Hébrard, G.; Klagyivik, P.; Parviainen, H.; Pasternacki, Th.; Pätzold, M.; Sebastian, D.; Tadeu dos Santos, M.; Wuchterl, G.; Aigrain, S.; Alonso, R.; Almenara, J.-M.; Armstrong, J. D.; Auvergne, M.; Baglin, A.; Barge, P.; Barros, S. C. C.; Bonomo, A. S.; Bordé, P.; Bouchy, F.; Carpano, S.; Chaffey, C.; Deeg, H. J.; Díaz, R. F.; Dvorak, R.; Erikson, A.; Grziwa, S.; Korth, J.; Lammer, H.; Lindsay, C.; Mazeh, T.; Moutou, C.; Ofir, A.; Ollivier, M.; Pallé, E.; Rauer, H.; Rouan, D.; Samuel, B.; Santerne, A.; Schneider, J.

    2015-07-01

    Context. We present the discovery of two transiting extrasolar planets by the satellite CoRoT. Aims: We aim at a characterization of the planetary bulk parameters, which allow us to further investigate the formation and evolution of the planetary systems and the main properties of the host stars. Methods: We used the transit light curve to characterize the planetary parameters relative to the stellar parameters. The analysis of HARPS spectra established the planetary nature of the detections, providing their masses. Further photometric and spectroscopic ground-based observations provided stellar parameters (log g, Teff, v sin i) to characterize the host stars. Our model takes the geometry of the transit to constrain the stellar density into account, which when linked to stellar evolutionary models, determines the bulk parameters of the star. Because of the asymmetric shape of the light curve of one of the planets, we had to include the possibility in our model that the stellar surface was not strictly spherical. Results: We present the planetary parameters of CoRoT-28b, a Jupiter-sized planet (mass 0.484 ± 0.087 MJup; radius 0.955 ± 0.066 RJup) orbiting an evolved star with an orbital period of 5.208 51 ± 0.000 38 days, and CoRoT-29b, another Jupiter-sized planet (mass 0.85 ± 0.20 MJup; radius 0.90 ± 0.16 RJup) orbiting an oblate star with an orbital period of 2.850 570 ± 0.000 006 days. The reason behind the asymmetry of the transit shape is not understood at this point. Conclusions: These two new planetary systems have very interesting properties and deserve further study, particularly in the case of the star CoRoT-29. The CoRoT space mission, launched on December 27th 2006, was developed and is operated by CNES, with the contribution of Austria, Belgium, Brazil, ESA (RSSD and Science Programme), Germany, and Spain. Based on observations obtained with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland

  17. SuPerPiG's Ultra-Short-Period Planets from K2 Campaigns 6 through 8

    Science.gov (United States)

    Jackson, Brian K.; Adams, Elisabeth R.; Endl, Michael

    2017-01-01

    The unexpected discoveries of hundreds of exoplanets very close to their host stars have challenged planet formation theories. The most extreme subset of these are the ultra-short-period planets, or USPs, with orbital periods of less than a day. These planets may provide unprecedented insights into planet formation and evolution and serve as sensitive probes for planet-star interactions and the stellar wind. Given their very short periods, such planets are particularly amenable to discovery by the Kepler, K2, and upcoming TESS missions and follow-up efforts. In this presentation, we will discuss our group’s ongoing search for ultra-short-period planets, the SuPerPiG effort. We will present our follow-up work and an updated list of candidates from our project, including a system with two small candidate planets, one with a period of about 13 hours and the other with a period of about 13 days.

  18. The effect of a strong stellar flare on the atmospheric chemistry of an earth-like planet orbiting an M dwarf.

    Science.gov (United States)

    Segura, Antígona; Walkowicz, Lucianne M; Meadows, Victoria; Kasting, James; Hawley, Suzanne

    2010-09-01

    Main sequence M stars pose an interesting problem for astrobiology: their abundance in our galaxy makes them likely targets in the hunt for habitable planets, but their strong chromospheric activity produces high-energy radiation and charged particles that may be detrimental to life. We studied the impact of the 1985 April 12 flare from the M dwarf AD Leonis (AD Leo), simulating the effects from both UV radiation and protons on the atmospheric chemistry of a hypothetical, Earth-like planet located within its habitable zone. Based on observations of solar proton events and the Neupert effect, we estimated a proton flux associated with the flare of 5.9 × 10⁸ protons cm⁻² sr⁻¹ s⁻¹ for particles with energies >10 MeV. Then we calculated the abundance of nitrogen oxides produced by the flare by scaling the production of these compounds during a large solar proton event called the Carrington event. The simulations were performed with a 1-D photochemical model coupled to a 1-D radiative/convective model. Our results indicate that the UV radiation emitted during the flare does not produce a significant change in the ozone column depth of the planet. When the action of protons is included, the ozone depletion reaches a maximum of 94% two years after the flare for a planet with no magnetic field. At the peak of the flare, the calculated UV fluxes that reach the surface, in the wavelength ranges that are damaging for life, exceed those received on Earth during less than 100 s. Therefore, flares may not present a direct hazard for life on the surface of an orbiting habitable planet. Given that AD Leo is one of the most magnetically active M dwarfs known, this conclusion should apply to planets around other M dwarfs with lower levels of chromospheric activity.

  19. Ultra-Short-Period Planets in K2: New Results From SuPerPiG

    Science.gov (United States)

    Adams, Elisabeth; Jackson, Brian; Endl, Michael

    2016-10-01

    Ultra-short-period planets, with orbital periods of less than 1 day, are a challenge to theories of planet formation. The SuPerPiG collaboration (Short-Period Planet Group) reports on 19 candidates identified in Campaigns 0-5 of the K2 mission. Planet candidates range in size from 0.7-16 Earth radii and in orbital period from 4.2 to 23.5 hours. One candidate (EPIC 203533312, Kp=12.5) is among the shortest-period planet candidates discovered to date (P=4.2 hours), and, if confirmed as a planet, must have a density of at least rho=8.9 g/cm^3 in order to not be tidally disrupted. Five candidates have nominal radius values in the sub-Jovian desert (R_P=3-11 R_E and P<=1.5 days) where theoretical models do not favor their long-term stability; the only confirmed planet in this range is thought to be disintegrating (EPIC 201637175). Based on an assessment of our survey's completeness, we estimate an occurrence rate for ultra-short-period planets among K2 target stars that is about half that estimated from the Kepler sample, raising questions as to whether K2 systems are intrinsically different from Kepler systems, possibly as a result of their different galactic location.

  20. Tidal dissipation in rotating low-mass stars and implications for the orbital evolution of close-in massive planets. II. Effect of stellar metallicity

    Science.gov (United States)

    Bolmont, E.; Gallet, F.; Mathis, S.; Charbonnel, C.; Amard, L.; Alibert, Y.

    2017-08-01

    Observations of hot-Jupiter exoplanets suggest that their orbital period distribution depends on the metallicity of the host stars. We investigate here whether the impact of the stellar metallicity on the evolution of the tidal dissipation inside the convective envelope of rotating stars and its resulting effect on the planetary migration might be a possible explanation for this observed statistical trend. We use a frequency-averaged tidal dissipation formalism coupled to an orbital evolution code and to rotating stellar evolution models in order to estimate the effect of a change of stellar metallicity on the evolution of close-in planets. We consider here two different stellar masses: 0.4 M⊙ and 1.0 M⊙ evolving from the early pre-main sequence phase up to the red-giant branch. We show that the metallicity of a star has a strong effect on the stellar parameters, which in turn strongly influence the tidal dissipation in the convective region. While on the pre-main sequence, the dissipation of a metal-poor Sun-like star is higher than the dissipation of a metal-rich Sun-like star; on the main sequence it is the opposite. However, for the 0.4 M⊙ star, the dependence of the dissipation with metallicity is much less visible. Using an orbital evolution model, we show that changing the metallicity leads to different orbital evolutions (e.g., planets migrate farther out from an initially fast-rotating metal-rich star). Using this model, we qualitatively reproduced the observational trends of the population of hot Jupiters with the metallicity of their host stars. However, more steps are needed to improve our model to try to quantitatively fit our results to the observations. Specifically, we need to improve the treatment of the rotation evolution in the orbital evolution model, and ultimately we need to consistently couple the orbital model to the stellar evolution model.

  1. Orbits

    CERN Document Server

    Xu, Guochang

    2008-01-01

    This is the first book of the satellite era which describes orbit theory with analytical solutions of the second order with respect to all possible disturbances. Based on such theory, the algorithms of orbits determination are completely revolutionized.

  2. Climate of Earth-Like Planets With and Without Ocean Heat Transport Orbiting a Range of M and K Stars

    Science.gov (United States)

    Kiang, N. Y.; Jablonski, Emma R.; Way, Michael J.; Del Genio, Anthony; Roberge, Aki

    2015-01-01

    The mean surface temperature of a planet is now acknowledged as insufficient to surmise its full potential habitability. Advancing our understanding requires exploration with 3D general circulation models (GCMs), which can take into account how gradients and fluxes across a planet's surface influence the distribution of heat, clouds, and the potential for heterogeneous distribution of liquid water. Here we present 3D GCM simulations of the effects of alternative stellar spectra, instellation, model resolution, and ocean heat transport, on the simulated distribution of heat and moisture of an Earth-like planet (ELP).

  3. Architecture of Kepler's multi-transiting systems. II. New investigations with twice as many candidates

    Energy Technology Data Exchange (ETDEWEB)

    Fabrycky, Daniel C. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Lissauer, Jack J.; Rowe, Jason F.; Barclay, Thomas; Batalha, Natalie; Borucki, William; Jenkins, Jon M.; Li, Jie; Morris, Robert L.; Smith, Jeffrey C. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Ragozzine, Darin; Geary, John C.; Holman, Matthew J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Steffen, Jason H. [Fermilab Center for Particle Astrophysics, P.O. Box 500, MS 127, Batavia, IL 60510 (United States); Agol, Eric [Department of Astronomy, University of Washington, P.O. Box 351580, Seattle, WA 98195 (United States); Ciardi, David R. [NASA Exoplanet Science Institute/Caltech, 770 South Wilson Avenue, MC 100-2, Pasadena, CA 91125 (United States); Ford, Eric B.; Morehead, Robert C. [Center for Exoplanets and Habitable Worlds, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA 16802 (United States); Gautier, Thomas N.; Shporer, Avi, E-mail: fabrycky@uchicago.edu [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); and others

    2014-08-01

    We report on the orbital architectures of Kepler systems having multiple-planet candidates identified in the analysis of data from the first six quarters of Kepler data and reported by Batalha et al. (2013). These data show 899 transiting planet candidates in 365 multiple-planet systems and provide a powerful means to study the statistical properties of planetary systems. Using a generic mass-radius relationship, we find that only two pairs of planets in these candidate systems (out of 761 pairs total) appear to be on Hill-unstable orbits, indicating ∼96% of the candidate planetary systems are correctly interpreted as true systems. We find that planet pairs show little statistical preference to be near mean-motion resonances. We identify an asymmetry in the distribution of period ratios near first-order resonances (e.g., 2:1, 3:2), with an excess of planet pairs lying wide of resonance and relatively few lying narrow of resonance. Finally, based upon the transit duration ratios of adjacent planets in each system, we find that the interior planet tends to have a smaller transit impact parameter than the exterior planet does. This finding suggests that the mode of the mutual inclinations of planetary orbital planes is in the range 1.°0-2.°2, for the packed systems of small planets probed by these observations.

  4. The Effect of Star-Planet Interactions on Planetary Climate

    Science.gov (United States)

    Shields, Aomawa; Meadows, Victoria; Bitz, Cecilia; Pierrehumbert, Raymond; Joshi, Manoj; Robinson, Tyler; Agol, Eric; Barnes, Rory; Charnay, Benjamin; Virtual Planetary Laboratory

    2015-01-01

    In this work I explored the effect on planetary climate and habitability of interactions between a host star, an orbiting planet and additional planets in a stellar system. I developed and tested models that include both radiative and gravitational effects, and simulated planets covered by ocean, land and water ice, with incident stellar radiation from stars of different spectral types. These simulations showed that ice-covered conditions occurred on an F-dwarf planet with a much smaller decrease in stellar flux than planets orbiting stars with less near-UV radiation, due to ice reflecting strongly in the visible and near-UV. The surface ice-albedo feedback effect is less important at the outer edge of the habitable zone, where ˜3-10 bars of CO2 could entirely mask the climatic effect of ice and snow, leaving the traditional outer limit of the habitable zone unaffected by the spectral dependence of water ice and snow albedo. The exit out of global ice cover was also sensitive to host star spectral energy distribution. A planet orbiting an M-dwarf star exhibited a smaller resistance to melting out of a frozen state, requiring a smaller stellar flux to initiate deglaciation than planets orbiting hotter, brighter stars. Given their greater climate stability, planets orbiting cooler, lower-mass stars may be the best candidates for long-term habitability and life beyond the Solar System. A specific case was explored—that of Kepler-62f, a potentially habitable planet in a five-planet system orbiting a K-dwarf star. Simulations using a 3-D Global Climate Model indicated that Kepler-62f would have areas of the planet with surface temperatures above the freezing point of water with 1 bar or more of CO2 in its atmosphere. In a low-CO2 case, increases in planetary obliquity and orbital eccentricity coupled with an orbital configuration that places the summer solstice at or near pericenter generated regions of the planet with above-freezing surface temperatures, which may

  5. ALMA observations of the nearby AGB star L2 Puppis - I. Mass of the central star and detection of a candidate planet

    CERN Document Server

    Kervella, P; Richards, A M S; Decin, L; McDonald, I; Montargès, M; Ohnaka, K

    2016-01-01

    Six billion years from now, while evolving on the asymptotic giant branch (AGB), the Sun will metamorphose from a red giant into a beautiful planetary nebula. This spectacular evolution will impact the Solar System planets, but observational confirmations of the predictions of evolution models are still elusive as no planet orbiting an AGB star has yet been discovered. The nearby AGB red giant L2 Puppis (d = 64 pc) is surrounded by an almost edge-on circumstellar dust disk. We report new observations with ALMA at very high angular resolution (18 x 15 mas) in band 7 (f ~ 350 GHz) that allow us to resolve the velocity profile of the molecular disk. We establish that the gas velocity profile is Keplerian within the central cavity of the dust disk, allowing us to derive the mass of the central star L2 Pup A, mA = 0.659 +/- 0.011 +/- 0.041 Msun (+/- 6.6%). From evolutionary models, we determine that L2 Pup A had a near-solar main sequence mass, and is therefore a close analog of the future Sun in 5 to 6 Gyr. The c...

  6. Habitable-zone super-Earth candidate in a six-planet system around the K2.5V star HD 40307

    CERN Document Server

    Tuomi, Mikko; Gerlach, Enrico; Jones, Hugh R R; Reiners, Ansgar; Rivera, Eugenio J; Vogt, Steven S; Butler, R Paul

    2012-01-01

    The K2.5 dwarf HD 40307 has been reported to host three super-Earths. The system lacks massive planets and is therefore a potential candidate for having additional low-mass planetary companions. We re-derive Doppler measurements from public HARPS spectra of HD 40307 to confirm the significance of the reported signals using independent data analysis methods. We also investigate these measurements for additional low-amplitude signals. We used Bayesian analysis of our radial velocities to estimate the probability densities of different model parameters. We also estimated the relative probabilities of models with differing numbers of Keplerian signals and verified their significance using periodogram analyses. We investigated the relation of the detected signals with the chromospheric emission of the star. As previously reported for other objects, we found that radial velocity signals correlated with the S-index are strongly wavelength dependent. We identify two additional clear signals with periods of 34 and 51 ...

  7. Why 400 Years to Discover Countless Planets?

    Science.gov (United States)

    Carr, Paul H.

    2011-04-01

    In 1584, Dominican monk Giordano Bruno envisioned the stars as "countless suns with countless earths, all rotating around their suns." Searching for intellectual freedom, he fled his native Italy to Protestant Switzerland and Germany, but in 1600 the Roman Inquisition condemned him for heresy. He was burned at the stake. Fast-forwarding to 1995, the Swiss astronomers Michel Mayor and Didier Queloz announced the discovery of a planet orbiting a star similar to our sun (51 Pegasi). In 2010, 500 planets had been found orbiting 421 stars. On Feb 2, 2011, NASA announced 1200 planet candidates. It took 400 years for telescope technology to advance and for Copernicus, Galileo, Newton, Bradley, and Foucault to make major contributions, culminating in today's astrophysics with digital imaging and processing. Contrasting with Bruno, in 2010 Dominican Francisco Ayala, who had been president of the Sigma Xi and AAAS, won the 1.6M Templeton Prize for affirming life's spiritual dimension.

  8. Surface properties of the Mars Science Laboratory candidate landing sites: characterization from orbit and predictions

    Science.gov (United States)

    Fergason, R.L.; Christensen, P.R.; Golombek, M.P.; Parker, T.J.

    2012-01-01

    This work describes the interpretation of THEMIS-derived thermal inertia data at the Eberswalde, Gale, Holden, and Mawrth Vallis Mars Science Laboratory (MSL) candidate landing sites and determines how thermophysical variations correspond to morphology and, when apparent, mineralogical diversity. At Eberswalde, the proportion of likely unconsolidated material relative to exposed bedrock or highly indurated surfaces controls the thermal inertia of a given region. At Gale, the majority of the landing site region has a moderate thermal inertia (250 to 410 J m-2 K-1 s-1/2), which is likely an indurated surface mixed with unconsolidated materials. The primary difference between higher and moderate thermal inertia surfaces may be due to the amount of mantling material present. Within the mound of stratified material in Gale, layers are distinguished in the thermal inertia data; the MSL rover could be traversing through materials that are both thermophysically and compositionally diverse. The majority of the Holden ellipse has a thermal inertia of 340 to 475 J m-2 K-1 s-1/2 and consists of bed forms with some consolidated material intermixed. Mawrth Vallis has a mean thermal inertia of 310 J m-2 K-1 s-1/2 and a wide variety of materials is present contributing to the moderate thermal inertia surfaces, including a mixture of bedrock, indurated surfaces, bed forms, and unconsolidated fines. Phyllosilicates have been identified at all four candidate landing sites, and these clay-bearing units typically have a similar thermal inertia value (400 to 500 J m-2 K-1 s-1/2), suggesting physical properties that are also similar.

  9. Kepler constraints on planets near hot Jupiters

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, Jason H.; /Fermilab; Ragozzine, Darin; /Harvard-Smithsonian Ctr. Astrophys.; Fabrycky, Daniel C.; /UC, Santa Cruz, Astron. Astrophys.; Carter, Joshua A.; /Harvard-Smithsonian Ctr. Astrophys.; Ford, Eric B.; /Florida U.; Holman, Matthew J.; /Harvard-Smithsonian Ctr. Astrophys.; Rowe, Jason F.; /NASA, Ames; Welsh, William F.; /San Diego State U., Astron. Dept.; Borucki, William J.; /NASA, Ames; Boss, Alan P.; /Carnegie Inst., Wash., D.C., DTM; Ciardi, David R.; /Caltech /Harvard-Smithsonian Ctr. Astrophys.

    2012-05-01

    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.

  10. Kepler constraints on planets near hot Jupiters

    CERN Document Server

    Steffen, Jason H; 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 days) 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 2/3 to 5 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 or TTVs) 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.

  11. 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.

  12. Planetary Candidates Observed by Kepler, III: Analysis of the First 16 Months of Data

    Energy Technology Data Exchange (ETDEWEB)

    Batalha, Natalie M.; /San Jose State U.; Rowe, Jason F.; /NASA, Ames; Bryson, Stephen T.; /NASA, Ames; Barclay, Thomas; /NASA, Ames; Burke, Christopher J.; /NASA, Ames; Caldwell, Douglas A.; /NASA, Ames; Christiansen, Jessie L.; /NASA, Ames; Mullally, Fergal; /NASA, Ames; Thompson, Susan E.; /NASA, Ames; Brown, Timothy M.; /Las Cumbres Observ.; Dupree, Andrea K.; /Harvard-Smithsonian Ctr. Astrophys. /UC, Santa Cruz

    2012-02-01

    New transiting planet candidates are identified in sixteen months (May 2009 - September 2010) of data from the Kepler spacecraft. Nearly five thousand periodic transit-like signals are vetted against astrophysical and instrumental false positives yielding 1091 viable new planet candidates, bringing the total count up to over 2,300. Improved vetting metrics are employed, contributing to higher catalog reliability. Most notable is the noise-weighted robust averaging of multiquarter photo-center offsets derived from difference image analysis which identifies likely background eclipsing binaries. Twenty-two months of photometry are used for the purpose of characterizing each of the new candidates. Ephemerides (transit epoch, T{sub 0}, and orbital period, P) are tabulated as well as the products of light curve modeling: reduced radius (R{sub P}/R{sub {star}}), reduced semi-major axis (d/R{sub {star}}), and impact parameter (b). The largest fractional increases are seen for the smallest planet candidates (197% for candidates smaller than 2R{sub {circle_plus}} compared to 52% for candidates larger than 2R{sub {circle_plus}}) and those at longer orbital periods (123% for candidates outside of 50 day orbits versus 85% for candidates inside of 50 day orbits). The gains are larger than expected from increasing the observing window from thirteen months (Quarter 1 - Quarter 5) to sixteen months (Quarter 1 - Quarter 6). This demonstrates the benefit of continued development of pipeline analysis software. The fraction of all host stars with multiple candidates has grown from 17% to 20%, and the paucity of short-period giant planets in multiple systems is still evident. The progression toward smaller planets at longer orbital periods with each new catalog release suggests that Earth-size planets in the Habitable Zone are forthcoming if, indeed, such planets are abundant.

  13. March of the Planets

    Science.gov (United States)

    Thompson, Bruce

    2007-01-01

    The motion of the planets in their orbits can be demonstrated to students by using planetarium software programs. These allow time to be sped up so that the relative motions are readily observed. However, it is also valuable to have the students understand the real speed of the planets in their orbits. This paper describes an exercise that gives…

  14. RECOVERY OF THE CANDIDATE PROTOPLANET HD 100546 b WITH GEMINI/NICI AND DETECTION OF ADDITIONAL (PLANET-INDUCED?) DISK STRUCTURE AT SMALL SEPARATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Currie, Thayne; Kudo, Tomoyuki [NAOJ, Subaru Telescope, 650 N' Aohoku Pl., Hilo, HI 96720 (United States); Muto, Takayuki [Division of Liberal Arts, Kogashin University, 1-24-2, Nishi-Shinjuku, Shinijuku-ku, Tokyo 163-8677 (Japan); Honda, Mitsuhiko [Department of Mathematics and Physics, Kanagawa University, 2946 Tsuchiya, Hiratsuka 259-1293 (Japan); Brandt, Timothy D. [Astrophysics Department, Institute for Advanced Study, Princeton, NJ 08540 (United States); Grady, Carol [Eureka Scientific, 2452 Delmer, Suite 100, Oakland, CA96002 (United States); Fukagawa, Misato [Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Burrows, Adam [Department of Astrophysical Sciences, Princeton University, 7 Ivy Lane, Princeton, NJ 08544-1001 (United States); Janson, Markus [Stockholm University, SE-106 91 Stockholm (Sweden); Kuzuhara, Masayuki [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); McElwain, Michael W. [Exoplanets and Stellar Astrophysics Laboratory, Code 667, Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Follette, Katherine [Department of Astronomy, Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721-0065 (United States); Hashimoto, Jun [H. L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W. Brooks St Norman, OK 73019 (United States); Henning, Thomas [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Kandori, Ryo; Kusakabe, Nobuhiko; Morino, Jun-ichi; Nishikawa, Jun [National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo 181-8588 (Japan); Kwon, Jungmi; Mede, Kyle, E-mail: currie@naoj.org [Department of Astronomy, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); and others

    2014-12-01

    We report the first independent, second epoch (re-)detection of a directly imaged protoplanet candidate. Using L' high-contrast imaging of HD 100546 taken with the Near-Infrared Coronagraph and Imager on Gemini South, we recover ''HD 100546 b'' with a position and brightness consistent with the original Very Large Telescope/NAos-COnica detection from Quanz et al., although data obtained after 2013 will be required to decisively demonstrate common proper motion. HD 100546 b may be spatially resolved, up to ≈12-13 AU in diameter, and is embedded in a finger of thermal IR-bright, polarized emission extending inward to at least 0.''3. Standard hot-start models imply a mass of ≈15 M{sub J} . However, if HD 100546 b is newly formed or made visible by a circumplanetary disk, both of which are plausible, its mass is significantly lower (e.g., 1-7 M{sub J} ). Additionally, we discover a thermal IR-bright disk feature, possibly a spiral density wave, at roughly the same angular separation as HD 100546 b but 90° away. Our interpretation of this feature as a spiral arm is not decisive, but modeling analyses using spiral density wave theory implies a wave launching point exterior to ≈0.''45 embedded within the visible disk structure: plausibly evidence for a second, hitherto unseen, wide-separation planet. With one confirmed protoplanet candidate and evidence for one to two others, HD 100546 is an important evolutionary precursor to intermediate-mass stars with multiple super-Jovian planets at moderate/wide separations like HR 8799.

  15. A survey for very short-period planets in the Kepler data

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Brian; Stark, Christopher C.; Chambers, John [Carnegie Institution for Science, 5241 Broad Branch Road NW, Washington, DC 20015 (United States); Adams, Elisabeth R. [Planetary Science Institute, 1700 East Fort Lowell, Suite 106, Tucson, AZ 85719 (United States); Deming, Drake, E-mail: bjackson@dtm.ciw.edu [Department of Astronomy, University of Maryland at College Park, College Park, MD 20742 (United States)

    2013-12-20

    We conducted a search for very short-period transiting objects in the publicly available Kepler data set. Our preliminary survey has revealed four planetary candidates, all with orbital periods less than 12 hr. We have analyzed the data for these candidates using photometric models that include transit light curves, ellipsoidal variations, and secondary eclipses to constrain the candidates' radii, masses, and effective temperatures. Even with masses of only a few Earth masses, the candidates' short periods mean that they may induce stellar radial velocity signals (a few m s{sup –1}) detectable by currently operating facilities. The origins of such short-period planets are unclear, but we discuss the possibility that they may be the remnants of disrupted hot Jupiters. Whatever their origins, if confirmed as planets, these candidates would be among the shortest-period planets ever discovered. Such planets would be particularly amenable to discovery by the planned TESS mission.

  16. Planet hunters. VII. Discovery of a new low-mass, low-density planet (PH3 C) orbiting Kepler-289 with mass measurements of two additional planets (PH3 B and D)

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, Joseph R.; Fischer, Debra A.; Wang, Ji; Margossian, Charles; Brewer, John M.; Giguere, Matthew J. [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Agol, Eric [Department of Astronomy, Box 351580, University of Washington, Seattle, WA 98195 (United States); Deck, Katherine M. [Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Rogers, Leslie A. [Department of Astronomy and Division of Geological and Planetary Sciences, California Institute of Technology, MC249-17, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Gazak, J. Zachary [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Holman, Matthew J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Jek, Kian J.; Omohundro, Mark R.; Winarski, Troy; Lintott, Chris; Simpson, Robert [Oxford Astrophysics, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Lynn, Stuart; Parrish, Michael [Adler Planetarium, 1300 South Lake Shore Drive, Chicago, IL 60605 (United States); Schawinski, Kevin [Institute for Astronomy, Department of Physics, ETH Zurich, Wolfgang-Pauli-Strasse 16, CH-8093 Zurich (Switzerland); Schwamb, Megan E., E-mail: joseph.schmitt@yale.edu [Institute of Astronomy and Astrophysics, Academia Sinica: 11F Astronomy-Mathematics Building, National Taiwan University. No.1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan (China); and others

    2014-11-10

    We report the discovery of one newly confirmed planet (P = 66.06 days, R {sub P} = 2.68 ± 0.17 R {sub ⊕}) and mass determinations of two previously validated Kepler planets, Kepler-289 b (P = 34.55 days, R {sub P} = 2.15 ± 0.10 R {sub ⊕}) and Kepler-289-c (P = 125.85 days, R {sub P} = 11.59 ± 0.10 R {sub ⊕}), through their transit timing variations (TTVs). We also exclude the possibility that these three planets reside in a 1:2:4 Laplace resonance. The outer planet has very deep (∼1.3%), high signal-to-noise transits, which puts extremely tight constraints on its host star's stellar properties via Kepler's Third Law. The star PH3 is a young (∼1 Gyr as determined by isochrones and gyrochronology), Sun-like star with M {sub *} = 1.08 ± 0.02 M {sub ☉}, R {sub *} = 1.00 ± 0.02 R {sub ☉}, and T {sub eff} = 5990 ± 38 K. The middle planet's large TTV amplitude (∼5 hr) resulted either in non-detections or inaccurate detections in previous searches. A strong chopping signal, a shorter period sinusoid in the TTVs, allows us to break the mass-eccentricity degeneracy and uniquely determine the masses of the inner, middle, and outer planets to be M = 7.3 ± 6.8 M {sub ⊕}, 4.0 ± 0.9M {sub ⊕}, and M = 132 ± 17 M {sub ⊕}, which we designate PH3 b, c, and d, respectively. Furthermore, the middle planet, PH3 c, has a relatively low density, ρ = 1.2 ± 0.3 g cm{sup –3} for a planet of its mass, requiring a substantial H/He atmosphere of 2.1{sub −0.3}{sup +0.8}% by mass, and joins a growing population of low-mass, low-density planets.

  17. PLANET HUNTERS: ASSESSING THE KEPLER INVENTORY OF SHORT-PERIOD PLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Schwamb, Megan E. [Yale Center for Astronomy and Astrophysics, Yale University, P.O. Box 208121, New Haven, CT 06520 (United States); Lintott, Chris J.; Lynn, Stuart; Smith, Arfon M.; Simpson, Robert J. [Oxford Astrophysics, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Fischer, Debra A.; Giguere, Matthew J.; Brewer, John M. [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Parrish, Michael [Adler Planetarium, 1300 S. Lake Shore Drive, Chicago, IL 60605 (United States); Schawinski, Kevin, E-mail: megan.schwamb@yale.edu [Department of Physics, Yale University, New Haven, CT 06511 (United States)

    2012-08-01

    We present the results from a search of data from the first 33.5 days of the Kepler science mission (Quarter 1) for exoplanet transits by the Planet Hunters citizen science project. Planet Hunters enlists members of the general public to visually identify transits in the publicly released Kepler light curves via the World Wide Web. Over 24,000 volunteers reviewed the Kepler Quarter 1 data set. We examine the abundance of {>=}2 R{sub Circled-Plus} planets on short-period (<15 days) orbits based on Planet Hunters detections. We present these results along with an analysis of the detection efficiency of human classifiers to identify planetary transits including a comparison to the Kepler inventory of planet candidates. Although performance drops rapidly for smaller radii, {>=}4 R{sub Circled-Plus} Planet Hunters {>=}85% efficient at identifying transit signals for planets with periods less than 15 days for the Kepler sample of target stars. Our high efficiency rate for simulated transits along with recovery of the majority of Kepler {>=}4 R{sub Circled-Plus} planets suggests that the Kepler inventory of {>=}4 R{sub Circled-Plus} short-period planets is nearly complete.

  18. Planet Hunters VII. Discovery of a New Low-Mass, Low-Density Planet (PH3 c) Orbiting Kepler-289 with Mass Measurements of Two Additional Planets (PH3 b and d)

    CERN Document Server

    Schmitt, Joseph R; Deck, Katherine M; Rogers, Leslie A; Gazak, J Zachary; Fischer, Debra A; Wang, Ji; Holman, Matthew J; Jek, Kian J; Margossian, Charles; Omohundro, Mark R; Winarski, Troy; Brewer, John M; Giguere, Matthew J; Lintott, Chris; Lynn, Stuart; Parrish, Michael; Schawinski, Kevin; Schwamb, Megan E; Simpson, Robert; Smith, Arfon M

    2014-01-01

    We report the discovery of one newly confirmed planet ($P=66.06$ days, $R_{\\rm{P}}=2.68\\pm0.17R_\\oplus$) and mass determinations of two previously validated Kepler planets, Kepler-289 b ($P=34.55$ days, $R_{\\rm{P}}=2.15\\pm0.10R_\\oplus$) and Kepler-289-c ($P=125.85$ days, $R_{\\rm{P}}=11.59\\pm0.10R_\\oplus$), through their transit timing variations (TTVs). We also exclude the possibility that these three planets reside in a $1:2:4$ Laplace resonance. The outer planet has very deep ($\\sim1.3%$), high signal-to-noise transits, which puts extremely tight constraints on its host star's stellar properties via Kepler's Third Law. The star PH3 is a young ($\\sim1$ Gyr as determined by isochrones and gyrochronology), Sun-like star with $M_*=1.08\\pm0.02M_\\odot$, $R_*=1.00\\pm0.02R_\\odot$, and $T_{\\rm{eff}}=5990\\pm38$ K. The middle planet's large TTV amplitude ($\\sim5$ hours) resulted either in non-detections or inaccurate detections in previous searches. A strong chopping signal, a shorter period sinusoid in the TTVs, allo...

  19. The theory of globulettes: candidate precursors of brown dwarfs and free floating planets in H II regions

    CERN Document Server

    Haworth, Thomas J; Clarke, Cathie J

    2014-01-01

    Large numbers of small opaque dust clouds - termed 'globulettes' by Gahm et al - have been observed in the H II regions surrounding young stellar clusters. With masses typically in the planetary (or low mass brown dwarf) regime, these objects are so numerous in some regions (e.g. the Rosette) that, if only a small fraction of them could ultimately collapse, then they would be a very significant source of free floating planets. Here we review the properties of globulettes and present a theoretical framework for their structure and evolution. We demonstrate that their interior structure is well described by a pressure confined isothermal Bonnor-Ebert sphere and that the observed mass-radius relation (mass approximately proportional to the radius squared) is a systematic consequence of a column density threshold below which components of the globulette are not identified. We also find that globulettes with this interior structure are very stable against collapse within H II regions. We follow Gahm et al in assum...

  20. Discovery of a Companion Candidate in the HD169142 Transition Disk and the Possibility of Multiple Planet Formation

    CERN Document Server

    Reggiani, Maddalena; Meyer, Michael R; Pueyo, Laurent; Absil, Olivier; Amara, Adam; Anglada, Guillem; Avenhaus, Henning; Girard, Julien H; Gonzalez, Carlos Carrasco; James, Graham; Mawet, Dimitri; Meru, Farzana; Milli, Julien; Osorio, Mayra; Wolff, Schuyler; Torrelles, Jose-Maria

    2014-01-01

    We present L' and J-band high-contrast observations of HD169142, obtained with the VLT/NACO AGPM vector vortex coronagraph and the Gemini Planet Imager, respectively. A source located at 0".156+/-0".032 north of the host star (PA=7.4+/-11.3 degrees) appears in the final reduced L' image. At the distance of the star (~145 pc), this angular separation corresponds to a physical separation of 22.7+/-4.7 AU, locating the source within the recently resolved inner cavity of the transition disk. The source has a brightness of L'=12.2+/-0.5 mag, whereas it is not detected in the J band (J>13.8 mag). If its L' brightness arose solely from the photosphere of a companion and given the J-L' color constraints, it would correspond to a 28-32 MJupiter object at the age of the star, according to the COND models. Ongoing accretion activity of the star suggests, however, that gas is left in the inner disk cavity from which the companion could also be accreting. In this case the object could be lower in mass and its luminosity e...

  1. Naming the extrasolar planets

    CERN Document Server

    Lyra, W

    2009-01-01

    Extrasolar planets are not named and are referred to only by their assigned scientific designation. The reason given by the IAU to not name the planets is that it is considered impractical as planets are expected to be common. I advance some reasons as to why this logic is flawed, and suggest names for the 403 extrasolar planet candidates known as of Oct 2009, based on the continued tradition of names from Roman-Greek mythology.

  2. 太阳系外行星系统轨道参数的统计研究%A Statistical Survey of Orbital Parameters of Extra-Solar Planets System

    Institute of Scientific and Technical Information of China (English)

    赵佳; 赵刚

    2012-01-01

    Since the first extra-solar planet around a Sun-like star was detected in 1995,the number of known extra-solar planets has been growing,which makes statistical surveys of characteristics of extra-solar planets and their host stars very important. By February 18 of 2011,527 planets had been discovered. In this paper, major techniques used for detections of extra-solar planets are introduced.Based on the physical and orbital parameters of these extra-solar planets, a statistical analysis has been carried out to investigate their properties, obtaining a number of meaningful conclusions.(1) The minimum mass of planets ranges from 0 to 25 Mjup, with a peak around 1 Mjup. There are very few planets beyond 12 Mjup.(2) A bimodality is shown in the period of extra-solar planets with peaks at 3 days and 300 days and a " flat" distribution in between.(3) There are very few large-mass planets beyond 0.03 AU and the proportion of large-mass planets become larger as the orbital semi-major axis increases.(4) The orbital semi-major axis and planet mass are two key factors that affect the orbital eccentricity of the planet. The orbital eccentricity decreases as the orbital semi-major axis and planet mass decreases.(5) For F-G-K stars, planets tend to be detected around metal-rich stars. When the star is more massive than the Sun, the mass of its planet is in direct proportion to the star's mass.(6) We have discussed the properties of low-mass ( M < 20 M⊕ ) planets and found that their orbital eccentricities are lower than 0.4.In this paper, we briefly introduce current models of planet formation and evolution and test the models with the derived statistical properties of planets. It therefore provides a reference for future detections of extra-solar planets.%自1995年第一颗类太阳恒星周围的系外行星发现以来,随着已发现的系外行星数目的增多,对系外行星性质的统计分析变得重要和有意义.截至2011年6月9日,共发现系外行星555

  3. Synthesizing Exoplanet Demographics from Radial Velocity and Microlensing Surveys, II: The Frequency of Planets Orbiting M Dwarfs

    CERN Document Server

    Clanton, Christian

    2014-01-01

    In contrast to radial velocity surveys, results from microlensing surveys indicate that giant planets with masses greater than the critical mass for core accretion ($\\sim 0.1~M_{\\rm Jup}$) are relatively common around low-mass stars. Using the methodology developed in the first paper, we predict the sensitivity of M-dwarf radial velocity (RV) surveys to analogs of the population of planets inferred by microlensing. We find that RV surveys should detect a handful of super-Jovian ($>M_{\\rm Jup}$) planets at the longest periods being probed. These planets are indeed found by RV surveys, implying that the demographic constraints inferred from these two methods are consistent. We combine the results from both methods to estimate planet frequencies spanning wide regions of parameter space. We find that the frequency of Jupiters and super-Jupiters ($1\\lesssim m_p\\sin{i}/M_{\\rm Jup}\\lesssim 13$) with periods $1\\leq P/{\\rm days}\\leq 10^4$ is $f_{\\rm J}=0.029^{+0.013}_{-0.015}$, a median factor of 4.3 ($1.5-14$ at 95% ...

  4. Terrestrial Planet Occurrence Rates for the Kepler GK Dwarf Sample

    CERN Document Server

    Burke, Christopher J; Mullally, F; Seader, Shawn; Huber, Daniel; Rowe, Jason F; Coughlin, Jeffrey L; Thompson, Susan E; Catanzarite, Joseph; Clarke, Bruce D; Morton, Timothy D; Caldwell, Douglas A; Bryson, Stephen T; Haas, Michael R; Batalha, Natalie M; Jenkins, Jon M; Tenenbaum, Peter; Twicken, Joseph D; Li, Jie; Quintana, Elisa; Barclay, Thomas; Henze, Christopher E; Borucki, William J; Howell, Steve B; Still, Martin

    2015-01-01

    We measure planet occurrence rates using the planet candidates discovered by the Q1-Q16 Kepler pipeline search. This study examines planet occurrence rates for the Kepler GK dwarf target sample for planet radii, 0.75orbital periods, 50planets per star, with an allowed range of 0.3planet occurrence rates and a steeper increase in planet occurrence rates towards small planets than previous studies of the Kepler GK dwarf sample. Through extrapolation, we find that the one year orbital period terrestrial planet occurrence rate, zeta_1=0.1, with an allowed r...

  5. N-body Simulations of Satellite Formation around Giant Planets: Origin of Orbital Configuration of the Galilean Moons

    CERN Document Server

    Ogihara, Masahiro

    2012-01-01

    As the number of discovered extrasolar planets has been increasing, diversity of planetary systems requires studies of new formation scenarios. It is important to study satellite formation in circumplanetary disks, which is often viewed as analogous to formation of rocky planets in protoplanetary disks. We investigated satellite formation from satellitesimals around giant planets through N-body simulations that include gravitational interactions with a circumplanetary gas disk. Our main aim is to reproduce the observable properties of the Galilean satellites around Jupiter through numerical simulations, as previous N-body simulations have not explained the origin of the resonant configuration. We performed accretion simulations based on the work of Sasaki et al. (2010), in which an inner cavity is added to the model of Canup & Ward (2002, 2006). We found that several satellites are formed and captured in mutual mean motion resonances outside the disk inner edge and are stable after rapid disk gas dissipat...

  6. Kepler-9: A System of Multiple Planets Transiting a Sun-Like Star, Confirmed by Timing Variations

    Science.gov (United States)

    Holman, Matthew J.; Fabrycky, Daniel C.; Ragozzine, Darin; Ford, Eric B.; Steffen, Jason H.; Welsh, William F.; Lissauer, Jack J.; Latham, David W.; Marcy, Geoffrey W.; Walkowicz, Lucianne M.; Batalha, Natalie M.; Jenkins, Jon M.; Rowe, Jason F.; Cochran, William D.; Fressin, Francois; Torres, Guillermo; Buchhave, Lars A.; Sasselov, Dimitar D.; Borucki, William J.; Koch, David G.; Basri, Gibor; Brown, Timothy M.; Caldwell, Douglas A.; Charbonneau, David; Dunham, Edward W.; Gautier, Thomas N.; Geary, John C.; Gilliland, Ronald L.; Haas, Michael R.; Howell, Steve B.; Ciardi, David R.; Endl, Michael; Fischer, Debra; Fürész, Gábor; Hartman, Joel D.; Isaacson, Howard; Johnson, John A.; MacQueen, Phillip J.; Moorhead, Althea V.; Morehead, Robert C.; Orosz, Jerome A.

    2010-10-01

    The Kepler spacecraft is monitoring more than 150,000 stars for evidence of planets transiting those stars. We report the detection of two Saturn-size planets that transit the same Sun-like star, based on 7 months of Kepler observations. Their 19.2- and 38.9-day periods are presently increasing and decreasing at respective average rates of 4 and 39 minutes per orbit; in addition, the transit times of the inner body display an alternating variation of smaller amplitude. These signatures are characteristic of gravitational interaction of two planets near a 2:1 orbital resonance. Six radial-velocity observations show that these two planets are the most massive objects orbiting close to the star and substantially improve the estimates of their masses. After removing the signal of the two confirmed giant planets, we identified an additional transiting super-Earth-size planet candidate with a period of 1.6 days.

  7. Kepler-9: a system of multiple planets transiting a Sun-like star, confirmed by timing variations.

    Science.gov (United States)

    Holman, Matthew J; Fabrycky, Daniel C; Ragozzine, Darin; Ford, Eric B; Steffen, Jason H; Welsh, William F; Lissauer, Jack J; Latham, David W; Marcy, Geoffrey W; Walkowicz, Lucianne M; Batalha, Natalie M; Jenkins, Jon M; Rowe, Jason F; Cochran, William D; Fressin, Francois; Torres, Guillermo; Buchhave, Lars A; Sasselov, Dimitar D; Borucki, William J; Koch, David G; Basri, Gibor; Brown, Timothy M; Caldwell, Douglas A; Charbonneau, David; Dunham, Edward W; Gautier, Thomas N; Geary, John C; Gilliland, Ronald L; Haas, Michael R; Howell, Steve B; Ciardi, David R; Endl, Michael; Fischer, Debra; Fürész, Gábor; Hartman, Joel D; Isaacson, Howard; Johnson, John A; MacQueen, Phillip J; Moorhead, Althea V; Morehead, Robert C; Orosz, Jerome A

    2010-10-01

    The Kepler spacecraft is monitoring more than 150,000 stars for evidence of planets transiting those stars. We report the detection of two Saturn-size planets that transit the same Sun-like star, based on 7 months of Kepler observations. Their 19.2- and 38.9-day periods are presently increasing and decreasing at respective average rates of 4 and 39 minutes per orbit; in addition, the transit times of the inner body display an alternating variation of smaller amplitude. These signatures are characteristic of gravitational interaction of two planets near a 2:1 orbital resonance. Six radial-velocity observations show that these two planets are the most massive objects orbiting close to the star and substantially improve the estimates of their masses. After removing the signal of the two confirmed giant planets, we identified an additional transiting super-Earth-size planet candidate with a period of 1.6 days.

  8. Tidal obliquity evolution of potentially habitable planets

    CERN Document Server

    Heller, René; Barnes, Rory

    2011-01-01

    Stellar insolation has been used as the main constraint on a planet's habitability. However, as more Earth-like planets are discovered around low-mass stars (LMSs), a re-examination of the role of tides on the habitability of exoplanets has begun. Those studies have yet to consider the misalignment between a planet's rotational axis and the orbital plane normal, i.e. the planetary obliquity. We apply two equilibrium tide theories to compute the obliquity evolution of terrestrial planets orbiting in the habitable zones around LMSs. The time for the obliquity to decrease from an Earth-like obliquity of 23.5 deg to 5 deg, the 'tilt erosion time', is compared to the traditional insolation habitable zone (IHZ) as a function of semi-major axis, eccentricity, and stellar mass. We also compute tidal heating and equilibrium rotation caused by obliquity tides. The Super-Earth Gl581d and the planet candidate Gl581g are studied as examples for tidal processes. Earth-like obliquities of terrestrial planets in the IHZ arou...

  9. Probes to the Inferior Planets - A New Dawn for NEO and IEO Detection Technology Demonstration from Heliocentric Orbits Interior to the Earth's?

    Science.gov (United States)

    Grundmann, J. T.; Mottola, S.; Drentschew, M.; Drobczyk, M.; Kahle, R.; Maiwald, V.; Quantius, D.; Zabel, P.; Van Zoest, T.

    2011-11-01

    With the launch of MESSENGER and VENUS EXPRESS, a new wave of exploration of the inner solar system has begun. Noting the growing number of probes to the inner solar system, it is proposed to connect the expertise of the respective spacecraft teams and the NEO and IEO survey community to best utilize the extended cruise phases and to provide additional data return in support of pure science as well as planetary defence. Several missions to Venus and Mercury are planned to follow in this decade. Increased interest in the inferior planets is accompanied by several missions designed to study the Sun and the interplanetary medium (IPM) from a position near or in Earth orbit, such as the STEREO probes and SDO. These augment established solar observation capabilities at the Sun-Earth L1 Lagrangian point such as the SOHO spacecraft. Thus, three distinct classes of spacecraft operate or observe interior to Earth's orbit. All these spacecraft carry powerful multispectral cameras optimized for their respective primary targets. MESSENGER is scheduled to end its six-year interplanetary cruise in March 2011 to enter Mercury orbit, but a similarly extended cruise with several gravity-assists awaits the European Mercury mission BEPICOLOMBO. Unfortunately, the automatic abort of the orbit insertion manoeuvre has also left AKATSUKI (a.k.a. Venus Climate Orbiter (VCO), Planet-C) stranded in heliocentric orbit. After an unintended fly-by, the probe will catch up with Venus in approximately six years. Meanwhile, it stays mostly interior to Venus in a planet-leading orbit. In addition to the study of comets and their interaction with the IPM, observations of small bodies akin to those carried out by outer solar system probes are occasionally attempted with the equipment available. The study of structures in the interplanetary dust (IPD) cloud has been a science objective during the cruise phase of the Japanese Venus probe AKATSUKI from Earth to Venus. IPD observations in the

  10. HAT-P-34b-HAT-P-37b: Four Transiting Planets More Massive than Jupiter Orbiting Moderately Bright Stars

    Science.gov (United States)

    Bakos, G. Á.; Hartman, J. D.; Torres, G.; Béky, B.; Latham, D. W.; Buchhave, L. A.; Csubry, Z.; Kovács, G.; Bieryla, A.; Quinn, S.; Szklenár, T.; Esquerdo, G. A.; Shporer, A.; Noyes, R. W.; Fischer, D. A.; Johnson, J. A.; Howard, A. W.; Marcy, G. W.; Sato, B.; Penev, K.; Everett, M.; Sasselov, D. D.; Fűrész, G.; Stefanik, R. P.; Lázár, J.; Papp, I.; Sári, P.

    2012-07-01

    We report the discovery of four transiting extrasolar planets (HAT-P-34b-HAT-P-37b) with masses ranging from 1.05 to 3.33 M J and periods from 1.33 to 5.45 days. These planets orbit relatively bright F and G dwarf stars (from V = 10.16 to V = 13.2). Of particular interest is HAT-P-34b which is moderately massive (3.33 M J), has a high eccentricity of e = 0.441 ± 0.032 at a period of P = 5.452654 ± 0.000016 days, and shows hints of an outer component. The other three planets have properties that are typical of hot Jupiters. Based in part on observations obtained at the W. M. Keck Observatory, which is operated by the University of California and the California Institute of Technology. Keck time has been granted by NOAO (A289Hr) and NASA (N167Hr and N029Hr). Based in part on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan. Based in part on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias.

  11. Solar system a visual exploration of the planets, moons, and other heavenly bodies that orbit our sun

    CERN Document Server

    Chown, Marcus

    2011-01-01

    Based on the latest ebook sensation developed by Theodore Gray and his company Touch Press, this beautiful print book presents a new and fascinating way to experience the wonders of the solar system Following the stunning success of both the print edition and the app of The Elements, Black Dog & Leventhal and Touch Press have teamed up again. Solar System is something completely new under the sun. Never before have the wonders of our solar system—all its planets, dwarf planets, the sun, moons, rocky Asteroid Belt, and icy Kuiper Belt—been so immediately accessible to readers of all ages. Beginning with a fascinating overview and then organized by planet, in order of its distance from the sun, Solar System takes us on a trip across time and space that includes a front-row seat to the explosive birth of the solar system, a journey to (and then deep inside) each of its eight planets, and even an in-depth exploration of asteroids and comets. With hundreds of gorgeous images produced especially for this...

  12. Influence of Sudden Change of Solar Mass in the PN Stage on the Orbit of Earth-Like Planet

    Indian Academy of Sciences (India)

    Yunfeng Zhu; Caijuan Pan; Dasheng Pan; Hongqiang Huang; Zhi-Fu Chen

    2014-09-01

    Assuming that the terminated mass is confined within the range 0.4551-0.5813⊙ when the sun is going to evolve into a white dwarf, the velocity of the sun projecting the shell in the PN stage is much greater than the revolving velocity of the earth-like planet, therefore, we think that the solar mass change is instantaneous.

  13. Challenges in Planet Formation

    CERN Document Server

    Morbidelli, Alessandro

    2016-01-01

    Over the past two decades, large strides have been made in the field of planet formation. Yet fundamental questions remain. Here we review our state of understanding of five fundamental bottlenecks in planet formation. These are: 1) the structure and evolution of protoplanetary disks; 2) the growth of the first planetesimals; 3) orbital migration driven by interactions between proto-planets and gaseous disk; 4) the origin of the Solar System's orbital architecture; and 5) the relationship between observed super-Earths and our own terrestrial planets. Given our lack of understanding of these issues, even the most successful formation models remain on shaky ground.