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1

WASP-34b: a near-grazing transiting sub-Jupiter-mass exoplanet in a hierarchical triple system  

CERN Document Server

We report the discovery of WASP-34b, a sub-Jupiter-mass exoplanet transiting its 10.4-magnitude solar-type host star (1SWASP J110135.89-235138.4; TYC 6636-540-1) every 4.3177 days in a slightly eccentric orbit (e = 0.038 +/- 0.012). We find a planetary mass of 0.59 +/- 0.01 M_Jup and radius of 1.22 ^{+0.11}_{-0.08} R_Jup. There is a linear trend in the radial velocities of 55+/-4 m/s/y indicating the presence of a long-period third body in the system with a mass > 0.45 M_Jup at a distance of >1.2 AU from the host star. This third-body is either a low-mass star, white dwarf, or another planet. The transit depth ((R_P/R_*)^2 = 0.0126) and high impact parameter (b = 0.90) suggest that this could be the first known transiting exoplanet expected to undergo grazing transits, but with a confidence of only ~80%.

Smalley, B; Cameron, A Collier; Hellier, C; Lendl, M; Maxted, P F L; Queloz, D; Triaud, A H M J; West, R G; Bentley, S J; Enoch, B; Gillon, M; Lister, T A; Pepe, F; Pollacco, D; Segransan, D; Smith, A M S; Southworth, J; Udry, S; Wheatley, P J; Wood, P L; Bento, J

2010-01-01

2

A SHORT-PERIOD CENSOR OF SUB-JUPITER MASS EXOPLANETS WITH LOW DENSITY  

International Nuclear Information System (INIS)

Despite the existence of many short-period hot Jupiters, there is not one hot Neptune with an orbital period less than 2.5 days. Here, we discuss a cluster analysis of the currently known 106 transiting exoplanets to investigate a possible explanation for this observation. We find two distinct clusters in the mass-density space, one with hot Jupiters with a wide range of orbital periods (0.8-114 days) and a narrow range of planet radii (1.2 ± 0.2 RJ ) and another one with a mixture of super-Earths, hot Neptunes, and hot Jupiters, exhibiting a surprisingly narrow period distribution (3.7 ± 0.8 days). These two clusters follow strikingly different distributions in the period-radius parameter plane. The branch of sub-Jupiter mass exoplanets is censored by the orbital period at the large-radius end: no planets with mass between 0.02 and 0.8 MJ or with radius between 0.25 and 1.0 RJ are known with Porb < 2.5 days. This clustering is not predicted by current theories of planet formation and evolution, which we also review briefly.

3

WASP-78b and WASP-79b: Two highly-bloated hot Jupiter-mass exoplanets orbiting F-type stars in Eridanus  

CERN Document Server

We report the discovery of WASP-78b and WASP-79b, two highly-bloated Jupiter-mass exoplanets orbiting F-type host stars. WASP-78b orbits its V=12.0 host star (TYC 5889-271-1) every 2.175 days and WASP-79b orbits its V=10.1 host star (CD-30 1812) every 3.662 days. A simultaneous fit to WASP and TRAPPIST transit photometry and CORALIE radial-velocity measurements yields planetary masses of 0.89 +/- 0.08 M_Jup and 0.90 +/- 0.08 M_Jup, and radii of 1.70 +/- 0.11 R_Jup and 2.09 +/- 0.14 R_Jup, for WASP-78b and WASP-79b, respectively. The planetary equilibrium temperature of T_P = 2350 +/- 80 K for WASP-78b makes it one of the hottest of the currently known exoplanets. The radius of WASP-79b suggests that it is potentially the largest known exoplanet.

Smalley, B; Collier-Cameron, A; Doyle, A P; Gillon, M; Hellier, C; Jehin, E; Lendl, M; Maxted, P F L; Pepe, F; Pollacco, D; Queloz, D; Segransan, D; Smith, A M S; Southworth, J; Triaud, A H M J; Udry, S; West, R G

2012-01-01

4

Exoplanet Detection: Transit Method  

Science.gov (United States)

The Exoplanet Detection: Transit Method model simulates the detection of exoplanets by using the transit method of detecting exoplanets. In this method, the light curve from a star, and how it changes over time due to exoplanet transits, is observed and then analyzed. In this simulation the exoplanet orbits the star (sun-sized) in circular motion via Kepler's third law.  When the exoplanet passes in front of the star (transits), it blocks part of the starlight. This decrease in starlight is shown on the graph.  If the exoplanet is close enough to the central star, and has sufficient reflectivity, or albedo, it can reflect enough of the starlight to be seen on the light curve. In the simulation the star-exoplanet system is shown as seen from Earth (edge on view) but magnified greatly, and with the star and planet sizes not shown to the scale of the orbit. The radius of the central star (relative to the radius of Sun),semi-major axis of the exoplanet (in AU), radius of the exoplanet (relative to the radius of Jupiter), the exoplanet's albedo (reflectivity), and the inclination of the system relative to Earth can be changed. The simulation uses Java 3D, if installed, to render the view the star and exoplanet. If Java 3D is not installed, the simulation will default to simple 3D using Java.

Belloni, Mario

2010-06-29

5

Transiting Exoplanets with JWST  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The era of exoplanet characterization is upon us. For a subset of exoplanets -- the transiting planets -- physical properties can be measured, including mass, radius, and atmosphere characteristics. Indeed, measuring the atmospheres of a further subset of transiting planets, the hot Jupiters, is now routine with the Spitzer Space Telescope. The James Webb Space Telescope (JWST) will continue Spitzer's legacy with its large mirror size and precise thermal stability. JWST is p...

Seager, S.; Deming, D.; Valenti, J. A.

2008-01-01

6

Transiting Exoplanets with JWST  

CERN Document Server

The era of exoplanet characterization is upon us. For a subset of exoplanets -- the transiting planets -- physical properties can be measured, including mass, radius, and atmosphere characteristics. Indeed, measuring the atmospheres of a further subset of transiting planets, the hot Jupiters, is now routine with the Spitzer Space Telescope. The James Webb Space Telescope (JWST) will continue Spitzer's legacy with its large mirror size and precise thermal stability. JWST is poised for the significant achievement of identifying habitable planets around bright M through G stars--rocky planets lacking extensive gas envelopes, with water vapor and signs of chemical disequilibrium in their atmospheres. Favorable transiting planet systems, are, however, anticipated to be rare and their atmosphere observations will require tens to hundreds of hours of JWST time per planet. We review what is known about the physical characteristics of transiting planets, summarize lessons learned from Spitzer high-contrast exoplanet m...

Seager, S; Valenti, J A

2008-01-01

7

DISCOVERY OF A PROBABLE 4-5 JUPITER-MASS EXOPLANET TO HD 95086 BY DIRECT IMAGING  

International Nuclear Information System (INIS)

Direct imaging has only begun to inventory the population of gas giant planets on wide orbits around young stars in the solar neighborhood. Following this approach, we carried out a deep imaging survey in the near-infrared using VLT/NaCo to search for substellar companions. Here we report the discovery of a probable companion orbiting the young (10-17 Myr), dusty, early-type (A8) star HD 95086 at 56 AU in L' (3.8 ?m) images. This discovery is based on observations with more than a year time lapse. Our first epoch clearly revealed the source at ? 10?, while our second epoch lacks good observing conditions, yielding a ? 3? detection. Various tests were thus made to rule out possible artifacts. This recovery is consistent with the signal at the first epoch but requires cleaner confirmation. Nevertheless, our astrometric precision suggests that the companion is comoving with the star with a 3? confidence level. The planetary nature of the source is reinforced by a non-detection in the Ks-band (2.18 ?m) images according to its possible extremely red Ks-L' color. Conversely, background contamination is rejected with good confidence level. The luminosity yields a predicted mass of about 4-5 MJup (at 10-17 Myr) using ''hot-start'' evolutionary models, making HD 95086 b the exoplanet with the lowest mass ever imaged around a star

8

DISCOVERY OF A PROBABLE 4-5 JUPITER-MASS EXOPLANET TO HD 95086 BY DIRECT IMAGING  

Energy Technology Data Exchange (ETDEWEB)

Direct imaging has only begun to inventory the population of gas giant planets on wide orbits around young stars in the solar neighborhood. Following this approach, we carried out a deep imaging survey in the near-infrared using VLT/NaCo to search for substellar companions. Here we report the discovery of a probable companion orbiting the young (10-17 Myr), dusty, early-type (A8) star HD 95086 at 56 AU in L' (3.8 {mu}m) images. This discovery is based on observations with more than a year time lapse. Our first epoch clearly revealed the source at {approx_equal} 10{sigma}, while our second epoch lacks good observing conditions, yielding a {approx_equal} 3{sigma} detection. Various tests were thus made to rule out possible artifacts. This recovery is consistent with the signal at the first epoch but requires cleaner confirmation. Nevertheless, our astrometric precision suggests that the companion is comoving with the star with a 3{sigma} confidence level. The planetary nature of the source is reinforced by a non-detection in the Ks-band (2.18 {mu}m) images according to its possible extremely red Ks-L' color. Conversely, background contamination is rejected with good confidence level. The luminosity yields a predicted mass of about 4-5 M{sub Jup} (at 10-17 Myr) using ''hot-start'' evolutionary models, making HD 95086 b the exoplanet with the lowest mass ever imaged around a star.

Rameau, J.; Chauvin, G.; Lagrange, A.-M.; Delorme, P. [UJF-Grenoble 1/CNRS-INSU, Institut de Planetologie et d' Astrophysique de Grenoble (IPAG) UMR 5274, Grenoble F-38041 (France); Boccaletti, A. [LESIA, Observatoire de Paris, CNRS, University Pierre et Marie Curie Paris 6 and University Denis Diderot Paris 7, 5 place Jules Janssen, F-92195 Meudon (France); Quanz, S. P. [Institute for Astronomy, ETH Zurich, Wolfgang-Pauli-Strasse 27, 8093 Zurich (Switzerland); Bonnefoy, M.; Klahr, H.; Mordasini, C. [Max Planck Institute for Astronomy, Koenigsthul 17, D-69117 Heidelberg (Germany); Girard, J. H.; Dumas, C. [European Southern Observatory, Casilla 19001, Santiago 19 (Chile); Desidera, S.; Bonavita, M., E-mail: julien.rameau@obs.ujf-grenoble.fr [INAF-Osservatorio Astronomico di Padova, Vicolo dell' Osservatorio 5, I-35122 Padova (Italy)

2013-08-01

9

Three sub-Jupiter-mass planets: WASP-69b & WASP-84b transit active K dwarfs and WASP-70Ab transits the evolved primary of a G4+K3 binary  

CERN Document Server

We report the discovery of the transiting exoplanets WASP-69b, WASP-70Ab and WASP-84b, each of which orbits a bright star (V~10). WASP-69b is a bloated Saturn-mass planet (0.26 M$_{\\rm Jup}$, 1.06 R$_{\\rm Jup}$) in a 3.868-d period around an active mid-K dwarf. We estimate a stellar age of 1 Gyr from both gyrochronological and age-activity relations, though an alternative gyrochronological relation suggests an age of 3 Gyr. ROSAT detected X-rays at a distance of 60$\\pm$27 arcsec from WASP-69. If the star is the source then the planet could be undergoing mass-loss at a rate of ~10$^{12}$ g s$^{-1}$. This is 1-2 orders of magnitude higher than the evaporation rate estimated for HD 209458b and HD 189733b, both of which have exhibited anomalously-large Lyman-{\\alpha} absorption during transit. WASP-70Ab is a sub-Jupiter-mass planet (0.59 M$_{\\rm Jup}$, 1.16R$_{\\rm Jup}$) in a 3.713-d orbit around the primary of a spatially-resolved G4+K3 binary, with a separation of 3.3 arcsec ($\\geq$800 AU). We exploit the binar...

Anderson, D R; Delrez, L; Doyle, A P; Faedi, F; Fumel, A; Gillon, M; Chew, Y Gómez Maqueo; Hellier, C; Jehin, E; Lendl, M; Maxted, P F L; Pepe, F; Pollacco, D; Queloz, D; Ségransan, D; Skillen, I; Smalley, B; Smith, A M S; Southworth, J; Triaud, A H M J; Turner, O D; Udry, S; West, R G

2013-01-01

10

High precision transit observations of the exoplanet WASP-13b with the RISE instrument  

Digital Repository Infrastructure Vision for European Research (DRIVER)

WASP-13b is a sub-Jupiter mass exoplanet orbiting a G1V type star with a period of 4.35 days. The current uncertainty in its impact parameter (0 < b < 0.46) resulted in poorly defined stellar and planetary radii. To better constrain the impact parameter we have obtained high precision transit observations with the RISE instrument mounted on 2.0 m Liverpool Telescope. We present four new transits which are fitted with an MCMC routine to derive accurate system parameters. We f...

Barros, S. C. C.; Pollacco, D. L.; Gibson, N. P.; Keenan, F. P.; Skillen, I.; Steele, I. A.

2011-01-01

11

Transiting Exoplanet Survey Satellite (TESS)  

Science.gov (United States)

The Transiting Exoplanet Survey Satellite (TESS) will discover thousands of exoplanets in orbit around the brightest stars in the sky. In a two-year survey, TESS will monitor more than 500,000 stars for temporary drops in brightness caused by planetary transits. This first-ever spaceborne all-sky transit survey will identify planets ranging from Earth-sized to gas giants, around a wide range of stellar types and orbital distances. No ground-based survey can achieve this feat. A large fraction of TESS target stars will be 30-100 times brighter than those observed by Kepler satellite, and therefore TESS . planets will be far easier to characterize with follow-up observations. TESS will make it possible to study the masses, sizes, densities, orbits, and atmospheres of a large cohort of small planets, including a sample of rocky worlds in the habitable zones of their host stars. TESS will provide prime targets for observation with the James Webb Space Telescope (JWST), as well as other large ground-based and space-based telescopes of the future. TESS data will be released with minimal delay (no proprietary period), inviting immediate community-wide efforts to study the new planets. The TESS legacy will be a catalog of the very nearest and brightest main-sequence stars hosting transiting exoplanets, thus providing future observers with the most favorable targets for detailed investigations.

Ricker, G. R.; Clampin, M.; Latham, D. W.; Seager, S.; Vanderspek, R. K.; Villasenor, J. S.; Winn, J. N.

2012-01-01

12

Factors Affecting the Radii of Close-in Transiting Exoplanets  

CERN Document Server

The radius of an exoplanet may be affected by various factors, including irradiation, planet mass and heavy element content. A significant number of transiting exoplanets have now been discovered for which the mass, radius, semi-major axis, host star metallicity and stellar effective temperature are known. We use multivariate regression models to determine the dependence of planetary radius on planetary equilibrium temperature T_eq, planetary mass M_p, stellar metallicity [Fe/H], orbital semi-major axis a, and tidal heating rate H_tidal, for 119 transiting planets in three distinct mass regimes. We determine that heating leads to larger planet radii, as expected, increasing mass leads to increased or decreased radii of low-mass (2.0R_J) planets, respectively (with no mass effect on Jupiter-mass planets), and increased host-star metallicity leads to smaller planetary radii, indicating a relationship between host-star metallicity and planet heavy element content. For Saturn-mass planets, a good fit to the radii...

Enoch, B; Horne, K

2012-01-01

13

Young Exoplanet Transit Initiative (YETI)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present the Young Exoplanet Transit Initiative (YETI), in which we use several 0.2 to 2.6m telescopes around the world to monitor continuously young (< 100 Myr), nearby (< 1 kpc) stellar clusters mainly to detect young transiting planets (and to study other variability phenomena on time-scales from minutes to years). The telescope network enables us to observe the targets continuously for several days in order not to miss any transit. The runs are typically one to two wee...

Neuha?user, R.; Errmann, R.; Berndt, A.; Maciejewski, G.; Takahashi, H.; Chen, W. P.; Dimitrov, D. P.; Pribulla, T.; Nikogossian, E. H.; Jensen, E. L. N.; Marschall, L.; Wu, Z. -y; Kellerer, A.; Walter, F. M.; Bricen?o, C.

2011-01-01

14

Exoplanets  

... Exoplanets exoplanets, planets, sun, topic, physics, moment Extra-solar planets (or exoplanets) are planets orbiting stars other than ...Careers Policy Resources You are here Resources Topic of the moment Archive Exoplanets Topic of the moment Archive Antimatter The Apollo programme Archeology Astronaut ... Reaching for the stars Exoplanets Fiction to fact Fuel cells Geolocation Graphene The career of Stephen Hawking Artificial heart Herschel Space Observatory Higgs ...and sport Television Transit of Venus Volcanic ash Weights and measures cryptography Exoplanets Extra-solar planets (or exoplanets) are planets orbiting stars other ...

15

Transiting Exoplanet Survey Satellite (TESS)  

Science.gov (United States)

The Transiting Exoplanet Survey Satellite (TESS) is a low cost, SMEX-class planet finder. In a two year all-sky survey, TESS will observe more than two million bright, nearby stars, searching for temporary drops in brightness that are caused by planetary transits. Such transits not only provide the means of identifying the planet, but also provide knowledge of the planet's diameter, mass density, surface gravity, temperature, and other key properties. TESS is expected to detect more than 1000 transiting exoplanet candidates. These detections will include a sample of 100 Super Earths -- small rock-and-ice planets with masses in the range 1 to 10 Earth masses -- orbiting nearby stars with spectral types spanning a broad range, including F, G, K, and M dwarfs. No ground-based survey can achieve this feat. TESS's "wide-shallow" survey complements the "narrow-deep" Corot and Kepler mission surveys. The resulting TESS Transit Catalog of the nearest and brightest stars in the sky will constitute a unique scientific legacy for followup observations. TESS will identify Super Earths orbiting IR-bright stars, ideal for JWST searches for planetary water and carbon dioxide. The TESS mission is a collaborative effort led by researchers at the Massachusetts Institute of Technology, the Harvard-Smithsonian Center for Astrophysics, and the NASA Ames Research Center. Additional TESS partners include ATK Space Systems, the Las Cumbres Observatory Global Telescope Network, Lowell Observatory, the NASA Goddard Space Flight Center, the Infrared Processing and Analysis Center at the California Institute of Technology, the University of California (Berkeley and Santa Cruz), the SETI Institute, Espace Incorporated, the Geneva Observatory (Switzerland), the Tokyo Institute of Technology (Japan), and Institut Supérieur de l'Aéronautique et de l'Espace (France). TESS is currently completing a NASA-funded Phase A study, and is proposed for launch in December 2012.

Ricker, George R.; Latham, D. W.; Vanderspek, R. K.; Ennico, K. A.; Bakos, G.; Brown, T. M.; Burgasser, A. J.; Charbonneau, D.; Clampin, M.; Deming, L. D.; Doty, J. P.; Dunham, E. W.; Elliot, J. L.; Holman, M. J.; Ida, S.; Jenkins, J. M.; Jernigan, J. G.; Kawai, N.; Laughlin, G. P.; Lissauer, J. J.; Martel, F.; Sasselov, D. D.; Schingler, R. H.; Seager, S.; Torres, G.; Udry, S.; Villasenor, J. S.; Winn, J. N.; Worden, S. P.

2009-05-01

16

Young Exoplanet Transit Initiative (YETI)  

CERN Document Server

We present the Young Exoplanet Transit Initiative (YETI), in which we use several 0.2 to 2.6m telescopes around the world to monitor continuously young (< 100 Myr), nearby (< 1 kpc) stellar clusters mainly to detect young transiting planets (and to study other variability phenomena on time-scales from minutes to years). The telescope network enables us to observe the targets continuously for several days in order not to miss any transit. The runs are typically one to two weeks long, about three runs per year per cluster in two or three subsequent years for about ten clusters. There are thousands of stars detectable in each field with several hundred known cluster members, e.g. in the first cluster observed, Tr-37, a typical cluster for the YETI survey, there are at least 469 known young stars detected in YETI data down to R=16.5 mag with sufficient precision of 50 milli-mag rms (5 mmag rms down to R=14.5 mag) to detect transits, so that we can expect at least about one young transiting object in this cl...

Neuhäuser, R; Berndt, A; Maciejewski, G; Takahashi, H; Chen, W P; Dimitrov, D P; Pribulla, T; Nikogossian, E H; Jensen, E L N; Marschall, L; Wu, Z -Y; Kellerer, A; Walter, F M; Briceño, C; Chini, R; Fernandez, M; Raetz, St; Torres, G; Latham, D W; Quinn, S N; Niedzielski, A; Bukowiecki, ?; Nowak, G; Tomov, T; Tachihara, K; Hu, S C -L; Hung, L W; Radeva, D P Kjurkchieva \\and V S; Mihov, B M; Slavcheva-Mihova, L; Bozhinova, I N; Budaj, J; Va?ko, M; Kundra, E; Hambálek, ?; Krushevska, V; Movsessian, T; Harutyunyan, H; Downes, J J; Hernandez, J; Hoffmeister, V H; Cohen, D H; Abel, I; Ahmad, R; Chapman, S; Eckert, S; Goodman, J; Guerard, A; Kim, H M; Koontharana, A; Sokol, J; Trinh, J; Wang, Y; Zhou, X; Redmer, R; Kramm, U; Nettelmann, N; Mugrauer, M; Schmidt, J; Moualla, M; Ginski, C; Marka, C; Adam, C; Seeliger, M; Baar, S; Roell, T; Schmidt, T O B; Trepl, L; Eisenbei\\ss, T; Fiedler, S; Tetzlaff, N; Schmidt, E; Hohle, M M; Kitze, M; Chakrova, N; Gräfe, C; Schreyer, K; Hambaryan, V V; Broeg, C H; Koppenhoefer, J; Pandey, A K

2011-01-01

17

Transiting Exoplanet Survey Satellite (TESS)  

DEFF Research Database (Denmark)

The Transiting Exoplanet Survey Satellite (TESS ) will search for planets transiting bright and nearby stars. TESS has been selected by NASA for launch in 2017 as an Astrophysics Explorer mission. The spacecraft will be placed into a highly elliptical 13.7-day orbit around the Earth. During its two-year mission, TESS will employ four wide-field optical CCD cameras to monitor at least 200,000 main-sequence dwarf stars with IC (approximately less than) 13 for temporary drops in brightness caused by planetary transits. Each star will be observed for an interval ranging from one month to one year, depending mainly on the star's ecliptic latitude. The longest observing intervals will be for stars near the ecliptic poles, which are the optimal locations for follow-up observations with the James Webb Space Telescope. Brightness measurements of preselected target stars will be recorded every 2 min, and full frame images will be recorded every 30 min. TESS stars will be 10-100 times brighter than those surveyed by thepioneering Kepler mission. This will make TESS planets easier to characterize with follow-up observations. TESS is expected to find more than a thousand planets smaller than Neptune, including dozens that are comparable in size to the Earth. Public data releases will occur every four months, inviting immediate community-wide efforts to study the new planets. The TESS legacy will be a catalog of the nearest and brightest stars hosting transiting planets, which will endure as highly favorable targets for detailed investigations.

Ricker, George R.; Winn, Joshua N.

2014-01-01

18

Nightside Pollution of Exoplanet Transit Depths  

CERN Document Server

Out of the known transiting extrasolar planets, the majority are gas giants orbiting their host star at close proximity. Both theoretical and observational studies support the hypothesis that such bodies emit significant amounts of flux, especially at mid-infrared wavelengths. For the dayside of the exoplanet, this phenomenon typically permits detectable secondary eclipses at such wavelengths, which may be used to infer atmospheric composition. In this paper, we explore the effects of emission from the nightside of the exoplanet on the primary transit lightcurve. Allowing for nightside emission, an exoplanet's transit depth is no longer exclusively a function of the ratio-of-radii. The nightside of an exoplanet is emitting flux and the contrast to the star's emission is of the order of ~10^(-3) for hot-Jupiters. Consequently, we show that the transit depth in the mid-infrared will be attenuated due to flux contribution from the nightside emission by ~10^(-4). We show how this effect can be compensated for in ...

Kipping, David M

2009-01-01

19

Transit timing variation in exoplanet WASP-3b  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Photometric follow-ups of transiting exoplanets may lead to discoveries of additional, less massive bodies in extrasolar systems. This is possible by detecting and then analysing variations in transit timing of transiting exoplanets. We present photometric observations gathered in 2009 and 2010 for exoplanet WASP-3b during the dedicated transit-timing-variation campaign. The observed transit timing cannot be explained by a constant period but by a periodic variation in the o...

Maciejewski, G.; Dimitrov, D.; Neuhaeuser, R.; Niedzielski, A.; Raetz, St; Ginski, Ch; Adam, Ch; Marka, C.; Moualla, M.; Mugrauer, M.

2010-01-01

20

Searching for transit timing variations in transiting exoplanet systems  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Searching for transit timing variations in the known transiting exoplanet systems can reveal the presence of other bodies in the system. Here we report such searches for two transiting exoplanet systems, TrES-1 and WASP-2. Their new transits were observed with the 4.2m William Herschel Telescope located on La Palma, Spain. In a continuing programme, three consecutive transits were observed for TrES-1, and one for WASP-2 during September 2007. We used the Markov Chain Monte C...

Hrudkova?, Marie; Skillen, Ian; Benn, Chris; Pollacco, Don; Gibson, Neale; Joshi, Yogesh; Harmanec, Petr; Tulloch, Simon

2008-01-01

 
 
 
 
21

WASP-26b: A 1-Jupiter-mass planet around an early-G-type star  

CERN Document Server

We report the discovery of WASP-26b, a moderately over-sized Jupiter-mass exoplanet transiting its 11.3-magnitude early-G-type host star (1SWASP J001824.70-151602.3; TYC 5839-876-1) every 2.7566 days. A simultaneous fit to transit photometry and radial-velocity measurements yields a planetary mass of 1.02 +/- 0.03 M_Jup and radius of 1.32 +/- 0.08 R_Jup. The host star, WASP-26, has a mass of 1.12 +/- 0.03 M_sun and a radius of 1.34 +/- 0.06 R_sun and is in a visual double with a fainter K-type star. The two stars are at least a common-proper motion pair with a common distance of around 250 +/- 15 pc and an age of 6 +/- 2 Gy.

Smalley, B; Cameron, A Collier; Gillon, M; Hellier, C; Lister, T A; Maxted, P F L; Queloz, D; Triaud, A H M J; West, R G; Bentley, S J; Enoch, B; Pepe, F; Pollacco, D L; Segransan, D; Smith, A M S; Southworth, J; Udry, S; Wheatley, P J; Wood, P L; Bento, J

2010-01-01

22

Modeling transiting exoplanet and spots For interferometric study  

Science.gov (United States)

Up to now, many techniques have been developed to detect and observe exoplanets, the radial velocity (RV) method being the most prolific one. However, stellar magnetic spots can mimic an exoplanet transit signal and lead to a false detection. A few models have already been developed to constrain the different signature of exoplanets and spots, but they only concern RV measurements or photometry. An interferometric approach, with high angular resolution capabilities, could resolve this problem. Optical interferometry is a powerful method to measure accurate stellar diameters, and derive fundamental parameters of stars and exoplanets minimum masses. We have built an analytical code able to calculate visibility moduli and closure phases of stars with a transiting exoplanet, to be compared with a star with no exoplanet. From the difference of interferometric signal, we can derive the presence of the exoplanet, but this requires that the star is resolved enough. We have tested this code with current available facilities like VEGA/CHARA and determined which already discovered exoplanets systems can be resolved enough to test this method. To make a more general study, we also tested different parameters (exoplanet and stellar diameters, exoplanet position) that can lead to a variation of the minimum baseline length required to see the exoplanet signal on the visibility modulus and the phase. Stellar spots act in the same way, but the difference of local intensity between an exoplanet transit and a spot can easily be studied thanks to the interferometric measurements.

Ligi, Roxanne; Mourard, Denis; Perraut, Karine; Bério, Philippe; Bigot, Lionel; Chiavassa, Andrea; Lagrange, Anne-Marie; Nardetto, Nicolas

2014-08-01

23

The Transiting Exoplanet Survey Satellite: Mission Status  

Science.gov (United States)

The Transiting Exoplanet Survey Satellite (TESS) will discover thousands of exoplanets in orbit around the brightest stars in the sky. In a two-year survey of the solar neighborhood, TESS will monitor more than 200,000 bright stars for temporary drops in brightness caused by planetary transits. This first-ever spaceborne all-sky transit survey will identify planets ranging from Earth-sized to gas giants, around a wide range of stellar types and orbital distances.TESS stars will typically be 30-100 times brighter than those surveyed by the Kepler satellite; thus, TESS planets will be far easier to characterize with follow-up observations. For the first time it will be possible to study the masses, sizes, densities, orbits, and atmospheres of a large cohort of small planets, including a sample of rocky worlds in the habitable zones of their host stars. Full frame images with a cadence of 30 minutes or less will provide precise photometric information for more than 20 million stars during observation sessions of several weeks. The brighter TESS stars will potentially yield valuable asteroseismic information as a result of monitoring at a rapid cadence of 2 minute or less. An extended survey by TESS of regions surrounding the North and South Ecliptic Poles will provide prime exoplanet targets for characterization with the James Webb Space Telescope (JWST), as well as other large ground-based and space-based telescopes of the future.TESS will issue data releases every 4 months, inviting immediate community-wide efforts to study the new planets. The TESS legacy will be a catalog of the nearest and brightest main-sequence stars hosting transiting exoplanets, which will endure as the most favorable targets for detailed future investigations.TESS has a planned launch date in 2017 as a NASA Astrophysics Explorer mission.

Ricker, George R.; TESS Team

2015-01-01

24

The Transiting Exoplanet Survey Satellite Mission  

Science.gov (United States)

(Abstract only) The Transiting Exoplanet Survey Satellite (TESS) will discover thousands of exoplanets in orbit around the brightest stars in the sky. In a two-year survey of the solar neighborhood, TESS will monitor more than 500,000 stars for temporary drops in brightness caused by planetary transits. This first-ever spaceborne all-sky transit survey will identify planets ranging from Earth-sized to gas giants, around a wide range of stellar types and orbital distances. TESS stars will typically be 30 to 100 times brighter than those surveyed by the Kepler satellite; thus,TESS planets will be far easier to characterize with follow-up observations. For the first time it will be possible to study the masses, sizes, densities, orbits, and atmospheres of a large cohort of small planets, including a sample of rocky worlds in the habitable zones of their host stars. All of the half-million plus TESS targets will be observed at a rapid cadence (1 minute or less). Hence, the brighter TESS stars will potentially yield valuable asteroseismic information. TESS will provide prime exoplanet targets for characterization with the James Webb Space Telescope (JWST), as well as other large ground-based and space-based telescopes of the future. TESS will serve as the "People's Telescope," with data releases every 4 months, inviting immediate community-wide efforts to study the new planets. The TESS legacy will be a catalog of the nearest and brightest main-sequence stars hosting transiting exoplanets, which will endure as the most favorable targets for detailed future investigations. TESS has been selected by NASA for launch in 2017 as an Astrophysics Explorer mission.

Ricker, G. R.

2014-06-01

25

Mass-loss rates for transiting exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Exoplanets at small orbital distances from their host stars are submitted to intense levels of energetic radiations, X-rays and extreme ultraviolet (EUV). Depending on the masses and densities of the planets and on the atmospheric heating efficiencies, the stellar energetic inputs can lead to atmospheric mass loss. These evaporation processes are observable in the ultraviolet during planetary transits. The aim of the present work is to quantify the mass-loss rates (dm/dt), h...

Ehrenreich, David; De?sert, Jean-michel

2011-01-01

26

TERMS PHOTOMETRY OF KNOWN TRANSITING EXOPLANETS  

International Nuclear Information System (INIS)

The Transit Ephemeris Refinement and Monitoring Survey conducts radial velocity and photometric monitoring of known exoplanets in order to refine planetary orbits and predictions of possible transit times. This effort is primarily directed toward planets not known to transit, but a small sample of our targets consists of known transiting systems. Here we present precision photometry for six WASP (Wide Angle Search for Planets) planets acquired during their transit windows. We perform a Markov Chain Monte Carlo analysis for each planet and combine these data with previous measurements to redetermine the period and ephemerides for these planets. These observations provide recent mid-transit times which are useful for scheduling future observations. Our results improve the ephemerides of WASP-4b, WASP-5b, and WASP-6b and reduce the uncertainties on the mid-transit time for WASP-29b. We also confirm the orbital, stellar, and planetary parameters of all six systems.

27

TERMS and Conditions of Transiting Exoplanets  

Science.gov (United States)

Photometric follow-up of planets discovered by the radial velocity technique have yielded known transiting extra-solar planets, especially for those with the brightest host stars (e.g., HD 209458b). The only limitation to photometric precision is determined by the chosen telescope/instrument and small uncertainties in the timing of the transit. We have conducted follow-up observations of numerous known exoplanets, such as HD 37605 and HD 6434, using the updated Transit Ephemeris Refinement and Monitoring Survey (TERMS) pipeline. We have calculated the transit ephemerides via optimal observing windows and are able to fully characterize the planetary system and possible transit. While the field of exoplanets has expanded to include characterization, these are typically limited to shorter period orbits. Our program extends characterization to a much more diverse range of planetary orbits both in terms of longer periods and higher eccentricities. In the case of a null detection, our photometry is used to place constraints on orbital and astrophysical parameters of the planet.

Hinkel, Natalie R.; Ciardi, D.; Dragomir, D.; Fischer, D.; Henry, G. W.; Howard, A.; Jensen, E. L.; Kane, S. R.; Laughlin, G.; Mahadevan, S.; Pilyavsky, G.; von Braun, K.; Wang, X.; Wright, J.

2013-01-01

28

The WASP-South search for transiting exoplanets  

Directory of Open Access Journals (Sweden)

Full Text Available Since 2006 WASP-South has been scanning the Southern sky for transiting exoplanets. Combined with Geneva Observatory radial velocities we have so far found over 30 transiting exoplanets around relatively bright stars of magnitude 9–13. We present a status report for this ongoing survey.

Queloz D.

2011-02-01

29

The WASP-South search for transiting exoplanets  

CERN Document Server

Since 2006 WASP-South has been scanning the Southern sky for transiting exoplanets. Combined with Geneva Observatory radial velocities we have so far found over 30 transiting exoplanets around relatively bright stars of magnitude 9--13. We present a status report for this ongoing survey.

Hellier, Coel; Cameron, A Collier; Gillon, M; Lendl, M; Lister, T A; Maxted, P F L; Pollacco, D; Queloz, D; Smalley, B; Triaud, A H M J; West, R G

2010-01-01

30

Exoplanets  

Science.gov (United States)

This is a unique time in human history - for the first time, we are on the technological brink of being able to answer questions that have been around for thousands of years: Are there other planets like Earth? Are they common? Do any have signs of life? The field of exoplanets is rapidly moving toward answering these questions with the discovery of hundreds of exoplanets now pushing toward lower and lower masses; the Kepler Space Telescope with its yield of small planets; plans to use the James Webb Space Telescope (launch date 2014) to study atmospheres of a subset of super Earths; and ongoing development for technology to directly image true Earth analogs. Theoretical studies in dynamics, planet formation, and physical characteristics provide the needed framework for prediction and interpretation. People working outside of exoplanets often ask if the field of exoplanets is like a dot.com bubble that will burst, deflating excitement and progress. In my opinion, exciting discoveries and theoretical advances will continue indefinitely in the years ahead, albeit at a slower pace than in the first decade. The reason is that observations uncover new kinds and new populations of exoplanets -- and these observations rely on technological development that usually takes over a decade to mature. For example, in the early 2000s all but one exoplanet was discovered by the radial velocity technique. At that time, many groups around the world were working on wide-field transit surveys. But it was not until recently, a decade into the twenty-first century, that the transit technique is responsible for almost one-quarter of known exoplanets. The planet discovery techniques astrometry (as yet to find a planet) and direct imaging have not yet matured; when they do, they will uncover planets within a new parameter space of planet mass and orbital characteristics. In addition, people are working hard to improve the precision for existing planet discovery techniques to detect lower-mass planets and those further from the star. All in all, technology enables slow but sure progress, and this fuels ongoing discovery. Theory, like observations, also takes time to unfold and mature. We can anticipate an "ultimate" planet formation model similar to the "millenimum simulation" for galaxy formation and evolution. In time, incorporating detailed physics as well as being able to reproduce the generic outcome of planet populations (mass, radius, and orbital characteristics, including period) will enable a deeper understanding of planet formation and migration. Similarly, the ideal exoplanet atmosphere code of the future could be a three-dimensional Monte Carlo code that includes radiative transfer with inhomogeneous cloud coverage and surface features, a code that also solves for the temperature structure and combines with a hydrodynamical simulation to calculate the three-dimensional temperature and wind structure. Classical orbital mechanics, already reinvigorated by interesting exoplanet systems (e.g., planets in resonant orbits, hot Jupiter exoplanets that orbit in the direction opposite to the stellar rotation), also has a role to play in explaining fundamental mechanisms of how planetary system configurations came to be. Orbital dynamics modeling is driving the search for moons and other unseen planet companions by their perturbations on transiting planet signatures. Exoplanets is a unique science because it involves so many disciplines within and beyond planetary science and astrophysics. The other disciplines include geophysics, high-pressure mineral physics, quantum mechanics, chemistry, and even microbiology. While exoplanet observations clearly belong under the branch of astronomy, for many years the whole discipline of exoplanets lacked a true home. Physics departments have said "Exoplanets: It's interesting, but is it physics?" Planetary and Earth science departments used to collecting real data in their hands from Earth and in situ measurements from solar system planets were, in the early 2000s, reluctant t

Seager, S.

31

TASTE: The Asiago Survey for Timing transit variations of Exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A promising method to detect earth-sized exoplanets is the timing analysis of a known transit. The technique allows a search for variations in transit duration or center induced by the perturbation of a third body, e.g. a second planet or an exomoon. To this aim, TASTE (The Asiago Survey for Timing transit variations of Exoplanets) project will collect high-precision, short-cadence light curves for a selected sample of transits by using imaging differential photometry at the...

Nascimbeni, V.; Piotto, G.; Bedin, L. R.; Damasso, M.

2010-01-01

32

Characterization of Transiting Exoplanets by Way of Differential Photometry  

Science.gov (United States)

This paper describes a simple activity for plotting and characterizing the light curve from an exoplanet transit event by way of differential photometry analysis. Using free digital imaging software, participants analyse a series of telescope images with the goal of calculating various exoplanet parameters, including size, orbital radius and…

Cowley, Michael; Hughes, Stephen

2014-01-01

33

High precision transit observations of the exoplanet WASP-13b with the RISE instrument  

CERN Document Server

WASP-13b is a sub-Jupiter mass exoplanet orbiting a G1V type star with a period of 4.35 days. The current uncertainty in its impact parameter (0 < b < 0.46) resulted in poorly defined stellar and planetary radii. To better constrain the impact parameter we have obtained high precision transit observations with the RISE instrument mounted on 2.0 m Liverpool Telescope. We present four new transits which are fitted with an MCMC routine to derive accurate system parameters. We found an orbital inclination of 85.2 \\pm 0.3 degrees resulting in stellar and planetary radii of 1.56 \\pm 0.04 R\\odot and 1.39 \\pm 0.05 RJup, respectively. This suggests that the host star has evolved off the main-sequence and is in the shell hydrogen-burning phase. We also discuss how the limb darkening affects the derived system parameters. With a density of 0.17{\\rho}J, WASP-13b joins the group of low density planets whose radii are too large to be explained by standard irradiation models. We derive a new ephemeris for the system, ...

Barros, S C C; Gibson, N P; Keenan, F P; Skillen, I; Steele, I A

2011-01-01

34

The observation of exoplanet transit events in China  

Directory of Open Access Journals (Sweden)

Full Text Available We have carried out a research project on the exoplanet transit events at Yunnan Observatory. By using CCD cameras attached to 1m telescope of Yunnan Observatory and 85cm telescope of Xinglong station, NAOC, a group of exoplanet systems with transit events have been observed photometrically. By means of MCMC method, the preliminary results of the systems WASP-11 and XO-2 are derived. Finally, we give out the future plan on this research topic in China.

Fang X.-S.

2011-07-01

35

Carbon monoxide and water vapor in the atmosphere of the non-transiting exoplanet HD 179949 b  

CERN Document Server

(Abridged) In recent years, ground-based high-resolution spectroscopy has become a powerful tool for investigating exoplanet atmospheres. It allows the robust identification of molecular species, and it can be applied to both transiting and non-transiting planets. Radial-velocity measurements of the star HD 179949 indicate the presence of a giant planet companion in a close-in orbit. Here we present the analysis of spectra of the system at 2.3 micron, obtained at a resolution of R~100,000, during three nights of observations with CRIRES at the VLT. We targeted the system while the exoplanet was near superior conjunction, aiming to detect the planet's thermal spectrum and the radial component of its orbital velocity. We detect molecular absorption from carbon monoxide and water vapor with a combined S/N of 6.3, at a projected planet orbital velocity of K_P = (142.8 +- 3.4) km/s, which translates into a planet mass of M_P = (0.98 +- 0.04) Jupiter masses, and an orbital inclination of i = (67.7 +- 4.3) degrees, ...

Brogi, M; Birkby, J L; Schwarz, H; Snellen, I A G

2014-01-01

36

Transiting exoplanets and magnetic spots characterized with optical interferometry  

Science.gov (United States)

Context. Stellar activity causes difficulties in the characterization of transiting exoplanets. In particular, the magnetic spots present on most exoplanet host stars can lead to false detections with radial velocity, photometry, or astrometry techniques. Studies have been performed to quantify their impact on infrared interferometry, but no such studies have been performed in the visible domain. This wavelength domain, however, allows reaching better angular resolution than in the infrared and is also the wavelength most often used for spectroscopic and photometric measurements. Aims: We use a standard case to completely analyse the impact of an exoplanet and a spot on interferometric observables and relate it to current instrument capabilities, taking into account realistic achievable precisions. Methods: We built a numerical code called COMETS using analytical formulae to perform a simple comparison of exoplanet and spot signals. We explored instrumental specificities needed to detect them, such as the required baseline length, the accuracy, and signal-to-noise ratio. We also discuss the impact of exoplanet and spot parameters on squared visibility and phase: exoplanet diameter and size, exoplanet position, spot temperature, star diameter. Results: According to our study, the main improvement to achieve is the instrument sensitivity. The accuracy on squared visibilities has to be improved by a factor 10 to detect an exoplanet of 0.10 mas, leading to <0.5% precision, along with phase measurements of ~5° accuracy beyond the first null of visibility. For an exoplanet of 0.05 mas, accuracies of ~0.1% and ~1° from the first null are required on squared visibilities and phases. Magnetic spots can mimic these signals, leading to false exoplanet characterization. Phase measurements from the third lobe are needed to distinguish between the spot and the exoplanet if they have the same radius. Conclusions: By increasing interferometer sensitivity, more objects will become common between interferometric and photometric targets. Furthermore, new missions such as PLATO, CHEOPS, or TESS will provide bright exoplanet host stars. Measurements will thus overlap and provide a better characterization of stellar activity and exoplanet.

Ligi, R.; Mourard, D.; Lagrange, A.-M.; Perraut, K.; Chiavassa, A.

2015-02-01

37

Transiting exoplanets: From planet statistics to their physical nature  

Directory of Open Access Journals (Sweden)

Full Text Available The colloquium "Detection and Dynamics of Transiting Exoplanets" was held at the Observatoire de Haute-Provence and discussed the status of transiting exoplanet investigations in a 4.5 day meeting. Topics addressed ranged from planet detection, a discussion on planet composition and interior structure, atmospheres of hot-Jupiter planets, up to the e?ect of tides and the dynamical evolution of planetary systems. Here, I give a summary of the recent developments of transiting planet detections and investigations discussed at this meeting.

Rauer H.

2011-02-01

38

Characterizing Transiting Exoplanet Atmospheres with Gemini/GMOS: First Results  

Science.gov (United States)

We present the first results from a 4-year ground-based survey of nine transiting exoplanet atmospheres. The program uses the Multi-Object Spectrograph (GMOS) on both Gemini north and south to repetitively measure transit lightcurves of individual exoplanets at high spectrophotometric precision. I will present the first results from this program. We attain photometric precisions per spectral bin of 200-600 ppm. Such precision enables us to construct transmission spectra of hot Jupiters. These transmission spectra reveal the dominant upper-atmosphere absorbers in the optical bandpass. Our overarching goal is to understand the prevalence and formation of high altitude clouds and hazes, and other important atmospheric constituents.

Huitson, Catherine; Desert, Jean-Michel; Bean, Jacob; Fortney, Jonathan J.; Stevenson, Kevin B.; Bergmann, Marcel

2015-01-01

39

Exoplanets with LSST: Period Recoverability of Transiting Hot Jupiters  

Science.gov (United States)

The Large Synoptic Survey Telescope (LSST) will generate light curves for an unprecedented one billion stars across the night sky. While the LSST was not conceived or designed to find exoplanets, the data can nevertheless be exploited for that purpose. Although the LSST will have a much lower observing cadence compared to dedicated exoplanet surveys, the sheer number of stars that LSST will survey could result in a very large number of transiting exoplanet detections. In particular, LSST will probe stellar populations currently undersampled in most transit surveys, including out to extragalactic distances. Since period detection is one of the necessary criteria for transit detection, here we report on a test of the efficiency of a standard boxed-least-squares (BLS) algorithm at accurately recovering the periods of exoplanets using simulated LSST data. Specifically, we test the case of a 1 solar mass star at 7000 pc from Earth, transited by an 8-, 10-, and 12- Earth radius planet at input periods ranging from 0.5 to 20 days. At short periods, BLS was highly accurate at recovering the input period, with accuracy trailing off quickly for LSST regular cadence observation but much more gradually for "deep drilling" cadence observation. For example, in the 10-Earth radius case, we find that the transits are correctly recovered at least 50% of the time for planet periods up to 2.5 days in the regular cadence mode, and 15 days in the deep-drilling mode.

Jacklin, Savannah; Lund, Michael; Pepper, Joshua; Stassun, Keivan

2015-01-01

40

Placing Limits On The Transit Timing Variations Of Circumbinary Exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present an efficient analytical method to predict the maximum transit timing variations of a circumbinary exoplanet, given some basic parameters of the host binary. We derive an analytical model giving limits on the potential location of transits for coplanar planets orbiting eclipsing binaries, then test it against numerical N-body simulations of a distribution of binaries and planets. We also show the application of the analytic model to Kepler-16b, -34b and -35b. The r...

Armstrong, D.; Martin, D. V.; Brown, G.; Faedi, F.; Chew, Y. Go?mez Maqueo; Mardling, R.; Pollacco, D.; Triaud, A. H. M. J.; Udry, S.

2013-01-01

 
 
 
 
41

The NStED Exoplanet Transit Survey Service  

CERN Document Server

The NASA Star and Exoplanet Database (NStED) is a general purpose stellar archive with the aim of providing support for NASA's planet finding and characterization goals, stellar astrophysics, and the planning of NASA and other space missions. There are two principal components of NStED: a database of (currently) 140,000 nearby stars and exoplanet-hosting stars, and an archive dedicated to high-precision photometric surveys for transiting exoplanets. We present a summary of the latter component: the NStED Exoplanet Transit Survey Service (NStED-ETSS), along with its content, functionality, tools, and user interface. NStED-ETSS currently serves data from the TrES Survey of the Kepler Field as well as dedicated photometric surveys of four stellar clusters. NStED-ETSS aims to serve both the surveys and the broader astronomical community by archiving these data and making them available in a homogeneous format. Examples of usability of ETSS include investigation of any time-variable phenomena in data sets not stud...

Von Braun, K; Ali, B; Baker, R; Berriman, G B; Chiu, N-M; Ciardi, D R; Good, J; Kane, S R; Laity, A C; McElroy, D L; Monkewitz, S; Payne, A N; Ramírez, S; Schmitz, M; Stauffer, J R; Wyatt, P L; Zhang, A

2008-01-01

42

A Search for Photometric Variability Towards M71 with the Near-Infrared Transiting ExoplanetS Telescope  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present the results of a high-cadence photometric survey of an $11'\\times11'$ field centred on the globular cluster M71, with the Near-Infrared Transiting ExoplanetS Telescope. The aim of our survey is to search for stellar variability and transiting giant exoplanets. This survey differs from previous photometric surveys of M71 in that it is more sensitive to lower amplitude ($\\Delta M\\leq0.02$ mag) and longer period ($P>2$ d) variability than previous work on this cluste...

Mccormac, J.; Skillen, I.; Pollacco, D.; Faedi, F.; Ramsay, G.; Dhillon, V. S.; Todd, I.; Gonzalez, A.

2013-01-01

43

Transiting Planets With LSST. I. Potential for LSST Exoplanet Detection  

Science.gov (United States)

The Large Synoptic Survey Telescope (LSST) is designed to meet several scientific objectives over a 10 year synoptic sky survey. Beyond its primary goals, the large amount of LSST data can be exploited for additional scientific purposes. We show that LSST data are sufficient to detect the transits of exoplanets, including planets orbiting stars that are members of stellar populations that have so far been largely unexplored. Using simulated LSST light curves, we find that existing transit detection algorithms can identify the signatures of Hot Jupiters around solar-type stars, Hot Neptunes around K-dwarfs, and (in favorable cases) Super-Earths in habitable-zone orbits of M-dwarfs. We also find that LSST may identify Hot Jupiters orbiting stars in the Large Magellanic Cloud—a remarkable possibility that would advance exoplanet science into the extragalactic regime.

Lund, Michael B.; Pepper, Joshua; Stassun, Keivan G.

2015-01-01

44

Refining Exoplanet Ephemerides and Transit Observing Strategies  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Transiting planet discoveries have yielded a plethora of information regarding the internal structure and atmospheres of extra-solar planets. These discoveries have been restricted to the low-periastron distance regime due to the bias inherent in the geometric transit probability. Monitoring known radial velocity planets at predicted transit times is a proven method of detecting transits, and presents an avenue through which to explore the mass-radius relationship of exoplan...

Kane, Stephen R.; Mahadevan, Suvrath; Von Braun, Kaspar; Laughlin, Gregory; Ciardi, David R.

2009-01-01

45

Five kepler target stars that show multiple transiting exoplanet candidates  

DEFF Research Database (Denmark)

We present and discuss five candidate exoplanetary systems identified with the Kepler spacecraft. These five systems show transits from multiple exoplanet candidates. Should these objects prove to be planetary in nature, then these five systems open new opportunities for the field of exoplanets and provide new insights into the formation and dynamical evolution of planetary systems. We discuss the methods used to identify multiple transiting objects from the Kepler photometry as well as the false-positive rejection methods that have been applied to these data. One system shows transits from three distinct objects while the remaining four systems show transits from two objects. Three systems have planet candidates that are near mean motion commensurabilities—two near 2:1 and one just outside 5:2. We discuss the implications that multi-transiting systems have on the distribution of orbital inclinations in planetary systems, and hence their dynamical histories, as well as their likely masses and chemical compositions. A Monte Carlo study indicates that, with additional data, most of these systems should exhibit detectable transit timing variations (TTVs) due to gravitational interactions, though none are apparent in these data. We also discuss new challenges that arise in TTV analyses due to the presence of more than two planets in a system.

Steffen..[], Jason H.; Batalha, N. M.

2010-01-01

46

Space-based Search for Transiting Exoplanets Orbiting Bright Stars  

Science.gov (United States)

At the current stage of research transiting planets hold the key to advancing our knowledge of exoplanets as they are the only targets that allow determination of many of the key plane-tary parameters. Because the employed techniques are differential (either photometry or spec-troscopy) and the planet is significantly fainter the host star the dominant limitation is simply the number of photons. This puts a very high premium on transiting planets with bright parent stars. The ExoPlanet Task Force recognized the high value of planets transiting bright stars and identified the need to perform a wide area space-based transit survey. In this presentation I will describe a program that addresses the ExoPTF recommendation by using the output of one of the instruments on the currently operating space mission STEREO. STEREO is the third mission in NASA's Solar Terrestrial Probes program. It uses two nearly identical spacecrafts -one on an Earth-leading orbit and one on an Earth-trailing orbit -each equipped with a suit of five small telescopes to provide a stereoscopic view of the coronal mass ejections (CME) as they propagate away from the Sun. As each of these telescopes observes a portion of the heliospehre, they also image the star field in the background. For the purposes of this study we will consider only the images obtained by the HI-1 instruments. Other instruments, although showing the stellar background as well, do not have the data output suitable for a search for transiting exoplanets. This project described here has the potential of delivering a number of very high value targets for follow-up studies with a wide range of facilities, both ground-based and space-based. It will provide a complete survey of all bright stars (<10m) for 18% of the sky. The photometric data series have the sensitivity to detect all transiting hot-Jupiters and other gas giants with periods up to ˜20 days and even some Neptune size planets orbiting bright and/or late type stars. On the extreme bright end, the survey is sensitive to some super-Earth size planets, but the available number of target stars is small. In my presentation I will describe the capabilities and limitations of the project, will demon-strate the utility of the HI-1 images for searching for transiting exoplanets, and will describe the existing data for several RV discovered planets.

Tsvetanov, Zlatan

47

TRANSIT TIMING VARIATIONS FOR ECCENTRIC AND INCLINED EXOPLANETS  

International Nuclear Information System (INIS)

The Transit Timing Variation (TTV) method relies on monitoring changes in timing of transits of known exoplanets. Nontransiting planets in the system can be inferred from TTVs by their gravitational interactions with the transiting planet. The TTV method is sensitive to low-mass planets that cannot be detected by other means. Inferring the orbital elements and mass of the nontransiting planets from TTVs, however, is more challenging than for other planet detection schemes. It is a difficult inverse problem. Here, we extended the new inversion method proposed by Nesvorny and Morbidelli to eccentric transiting planets and inclined orbits. We found that the TTV signal can be significantly amplified for hierarchical planetary systems with substantial orbital inclinations and/or for an eccentric transiting planet with anti-aligned orbit of the planetary companion. Thus, a fortuitous orbital setup of an exoplanetary system may significantly enhance our chances of TTV detection. We also showed that the detailed shape of the TTV signal is sensitive to the orbital inclination of the nontransiting planetary companion. The TTV detection method may thus provide important constraints on the orbital inclination of exoplanets and be used to test theories of planetary formation and evolution.

48

Placing Limits On The Transit Timing Variations Of Circumbinary Exoplanets  

CERN Document Server

We present an efficient analytical method to predict the maximum transit timing variations of a circumbinary exoplanet, given some basic parameters of the host binary. We derive an analytical model giving limits on the potential location of transits for coplanar planets orbiting eclipsing binaries, then test it against numerical N-body simulations of a distribution of binaries and planets. We also show the application of the analytic model to Kepler-16b, -34b and -35b. The resulting method is fast, efficient and is accurate to approximately 1% in predicting limits on possible times of transits over a three-year observing campaign. The model can easily be used to, for example, place constraints on transit timing while performing circumbinary planet searches on large datasets. It is adaptable to use in situations where some or many of the planet and binary parameters are unknown.

Armstrong, D; Brown, G; Faedi, F; Chew, Y Gómez Maqueo; Mardling, R; Pollacco, D; Triaud, A H M J; Udry, S

2013-01-01

49

H? Absorption in Transiting Exoplanet Atmospheres  

Science.gov (United States)

Recent observations by Jensen et al. of H? absorption by the upper atmosphere of HD189733b have motivated the need for a theoretical understanding of the distribution of n=2 hydrogen within hot Jupiter atmospheres. With this in mind, we model the n=2 state of atomic hydrogen in a hydrostatic atmosphere in thermal and photoionization equilibrium. Both collisional and radiative transitions are included in the calculation of the n = 2 state level population. In our model, the H? absorption is dominated by a ? ~ 1 shell composed of metastable 2s hydrogen located within the neutral atomic layer, with the contribution coming roughly uniformly throughout the layer instead of from a specific impact parameter. An ionization rate an order of magnitude over the expected value can reproduce the observed transit depth.

Christie, Duncan; Arras, Phil; Li, Zhi-Yun

2014-01-01

50

WASP-29b: A Saturn-sized transiting exoplanet  

CERN Document Server

We report the discovery of a Saturn-sized planet transiting a V = 11.3, K4 dwarf star every 3.9 d. WASP-29b has a mass of 0.24+/-0.02 M_Jup and a radius of 0.79+/-0.05 R_Jup, making it the smallest planet so far discovered by the WASP survey, and the exoplanet most similar in mass and radius to Saturn. The host star WASP-29 has an above-Solar metallicity and fits a possible correlation for Saturn-mass planets such that planets with higher-metallicity host stars have higher core masses and thus smaller radii.

Hellier, Coel; Cameron, A Collier; Gillon, M; Lendl, M; Maxted, P F L; Queloz, D; Smalley, B; Triaud, A H M J; West, R G; Brown, D J A; Enoch, B; Lister, T A; Pepe, F; Pollacco, D; Segransan, D; Udry, S

2010-01-01

51

RISE: a fast-readout imager for exoplanet transit timing  

Digital Repository Infrastructure Vision for European Research (DRIVER)

By the precise timing of the low amplitude (0.005 - 0.02 magnitude) transits of exoplanets around their parent star it should be possible to infer the presence of other planetary bodies in the system down to Earth-like masses. We describe the design and construction of RISE, a fast-readout frame transfer camera for the Liverpool Telescope designed to carry out this experiment. The results of our commissioning tests are described as well as the data reduction procedure necess...

Steele, I. A.; Bates, S. D.; Gibson, N.; Keenan, F.; Meaburn, J.; Mottram, C. J.; Pollacco, D.; Todd, I.

2008-01-01

52

Transiting Planets with LSST I: Potential for LSST Exoplanet Detection  

CERN Document Server

The Large Synoptic Survey Telescope (LSST) has been designed in order to satisfy several different scientific objectives that can be addressed by a ten-year synoptic sky survey. However, LSST will also provide a large amount of data that can then be exploited for additional science beyond its primary goals. We demonstrate the potential of using LSST data to search for transiting exoplanets, and in particular to find planets orbiting host stars that are members of stellar populations that have been less thoroughly probed by current exoplanet surveys. We find that existing algorithms can detect in simulated LSST light curves the transits of Hot Jupiters around solar-type stars, Hot Neptunes around K dwarfs, and planets orbiting stars in the Large Magellanic Cloud. We also show that LSST would have the sensitivity to potentially detect Super-Earths orbiting red dwarfs, including those in habitable zone orbits, if they are present in some fields that LSST will observe. From these results, we make the case that LS...

Lund, Michael B; Stassun, Keivan G

2014-01-01

53

Transiting exoplanets from the CoRoT space mission XVI. CoRoT-14b: an unusually dense very hot Jupiter  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper, the CoRoT ExoplanetScience Team announces its 14th discovery. Herein, we discuss the observations and analyses that allowed us to derive the parameters of this system: a hot Jupiter with a mass of 7.6 ± 0.6 Jupiter masses orbiting a solar-type star (F9V) with a period of only 1.5 d, less than 5 stellar radii from its parent star. It is unusual for such a massive planet to have such a small orbit: only one other known higher mass exoplanet orbits with a shorter period. The CoR...

Tingley, B.; Endl, M.; Gazzano, J-c; Alonso, R.; Mazeh, T.; Jorda, L.; Aigrain, S.; Almenara, J-m; Auvergne, M.; Baglin, A.; Barge, P.; Bonomo, As; Borde, P.; Bouchy, F.; Bruntt, H.

2011-01-01

54

Transiting exoplanets from the CoRoT space mission: XIII. CoRoT-14b: an unusually dense very hot Jupiter  

CERN Document Server

In this paper, the CoRoT Exoplanet Science Team announces its 14th discovery. Herein, we discuss the observations and analyses that allowed us to derive the parameters of this system: a hot Jupiter with a mass of $7.6 \\pm 0.6$ Jupiter masses orbiting a solar-type star (F9V) with a period of only 1.5 d, less than 5 stellar radii from its parent star. It is unusual for such a massive planet to have such a small orbit: only one other known exoplanet with a higher mass orbits with a shorter period.

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

2011-01-01

55

The role of space telescopes in the characterization of transiting exoplanets.  

Science.gov (United States)

Characterization studies now have a dominant role in the field of exoplanets. Such studies include the measurement of an exoplanet's bulk density, its brightness temperature and the chemical composition of its atmosphere. The use of space telescopes has played a key part in the characterization of transiting exoplanets. These facilities offer astronomers data of exquisite precision and temporal sampling as well as access to wavelength regions of the electromagnetic spectrum that are inaccessible from the ground. Space missions such as the Hubble Space Telescope, Microvariability and Oscillations of Stars (MOST), Spitzer Space Telescope, Convection, Rotation and Planetary Transits (CoRoT), and Kepler have rapidly advanced our knowledge of the physical properties of exoplanets and have blazed a trail for a series of future space missions that will help us to understand the observed diversity of exoplanets. PMID:25230657

Hatzes, Artie P

2014-09-18

56

RISE: a fast-readout imager for exoplanet transit timing  

CERN Document Server

By the precise timing of the low amplitude (0.005 - 0.02 magnitude) transits of exoplanets around their parent star it should be possible to infer the presence of other planetary bodies in the system down to Earth-like masses. We describe the design and construction of RISE, a fast-readout frame transfer camera for the Liverpool Telescope designed to carry out this experiment. The results of our commissioning tests are described as well as the data reduction procedure necessary. We present light curves of two objects, showing that the desired timing and photometric accuracy can be obtained providing that autoguiding is used to keep the target on the same detector pixel for the entire (typically 4 hour) observing run.

Steele, I A; Gibson, N; Keenan, F; Meaburn, J; Mottram, C J; Pollacco, D; Todd, I

2008-01-01

57

Simulating Exoplanet Transit and Eclipse Observations with JWST  

Science.gov (United States)

The James Webb Space Telescope (JWST) will be a nearly ideal machine for acquiring the transmission and emission spectra of transiting exoplanets over its large wavelength range 0.7 - 28 microns. The NIRSpec, NIRCam, nTFI, and MIRI instruments will have spectroscopic capabilities that span spectral resolutions from 20 - 3000 and can cover up to 2 - 3 octaves in wavelength simultaneously. This will allow observing multiple molecular features at once, facilitating the separation of atmospheric temperature and abundance effects on spectra. Many transiting planets will also be able to be observed with both transmission and eclipse spectroscopy, providing further insights and constraints on planetary thermal structures and energy transport. Simulated JWST spectra of planets ranging from mini-Neptunes to gas giants will be presented. These simulations include planets ranging from mini-Neptunes to gas giants will be presented. These simulations include current best estimates of actual instrument throughput, resolution, spectral range, systematic noise, and random noise terms. They show that JWST will be able to determine the atmospheric parameters of a wide variety of planets, often when observing only one or a few transit or eclipse event sequences. The thermal emissions of rocky super-Earths will also be quickly detectable via mid-IR eclipse observations if such planets are found around nearby M star hosts beforehand.

Greene, Tom

2011-01-01

58

Transmission spectrum of Venus as a transiting exoplanet  

CERN Document Server

On 5-6 June 2012, Venus will be transiting the Sun for the last time before 2117. This event is an unique opportunity to assess the feasibility of the atmospheric characterisation of Earth-size exoplanets near the habitable zone with the transmission spectroscopy technique and provide an invaluable proxy for the atmosphere of such a planet. In this letter, we provide a theoretical transmission spectrum of the atmosphere of Venus that could be tested with spectroscopic observations during the 2012 transit. This is done using radiative transfer across Venus' atmosphere, with inputs from in-situ missions such as Venus Express and theoretical models. The transmission spectrum covers a range of 0.1-5 {\\mu}m and probes the limb between 70 and 150 km in altitude. It is dominated in UV by carbon dioxide absorption producing a broad transit signal of ~20 ppm as seen from Earth, and from 0.2 to 2.7 {\\mu}m by Mie extinction (~5 ppm at 0.8 {\\mu}m) caused by droplets of sulfuric acid composing an upper haze layer above th...

Ehrenreich, David; Widemann, Thomas; Gronoff, Guillaume; Tanga, Paolo; Barthélemy, Mathieu; Lilensten, Jean; Etangs, Alain Lecavelier des; Arnold, Luc

2011-01-01

59

Updates to the Exoplanet Orbit Database and Transit&Secondary Eclipse Ephemerides  

Science.gov (United States)

We report a series of updates and enhancements on the Exoplanet Orbit Database (EOD), which contains peer reviewed orbital and transit parameters of exoplanets and stellar parameters of their host stars. Since December 2010, the EOD expanded from 427 planets to 640 planets, as of September 2012. The EOD can be explored through the Exoplanet Data Explorer Plotter and Table, available at http://exoplanets.org. We have written a program called boottran which uses radial velocity data to calculate transit times and secondary eclipse times with robust bootstrapped uncertainties, which we have made publicly available at exoplanets.org. boottran calculates robust predicted transit dates with uncertainties for the next 10 years for long period planets not known to transit. We use data taken from published peer reviewed papers and new data from the California Planet Survey for our ephmerides and for radial velocity plots on exoplanets.org. TERMS uses these ephemerides to plan photometric observations of the stars. To improve the EOD, we have added fields for surface gravity, transit duration (T14), impact parameter (b) and their uncertainties. We also have added transit parameters including secondary eclipse depth at multiple bands and Rossiter-McLaughlin spin orbit misalignment measurements.

Han, Eunkyu; Feng, Y.; Wright, J.; Zhao, M.; Wang, X.; Fakhouri, O.; Kane, S. R.; Dragomir, D.

2013-01-01

60

A Search for Photometric Variability Towards M71 with the Near-Infrared Transiting ExoplanetS Telescope  

CERN Document Server

We present the results of a high-cadence photometric survey of an $11'\\times11'$ field centred on the globular cluster M71, with the Near-Infrared Transiting ExoplanetS Telescope. The aim of our survey is to search for stellar variability and transiting giant exoplanets. This survey differs from previous photometric surveys of M71 in that it is more sensitive to lower amplitude ($\\Delta M\\leq0.02$ mag) and longer period ($P>2$ d) variability than previous work on this cluster. We have discovered $17$ new variable stars towards M71 and confirm the nature of $13$ previously known objects, for which the orbital periods of $7$ are refined or newly determined. Given the photometric precision of our high-cadence survey on the horizontal branch of M71, we confirm the cluster is devoid of RR Lyrae variable stars within the area surveyed. We present new $B$ and $V$ band photometry of the stars in our sample from which we estimate spectral types of the variable objects. We also search our survey data for transiting hot...

McCormac, J; Pollacco, D; Faedi, F; Ramsay, G; Dhillon, V S; Todd, I; Gonzalez, A

2013-01-01

 
 
 
 
61

AN EFFICIENT AUTOMATED VALIDATION PROCEDURE FOR EXOPLANET TRANSIT CANDIDATES  

International Nuclear Information System (INIS)

Surveys searching for transiting exoplanets have found many more candidates than they have been able to confirm as true planets. This situation is especially acute with the Kepler survey, which has found over 2300 candidates but has to date confirmed only a small fraction of them as planets. I present here a general procedure that can quickly be applied to any planet candidate to calculate its false positive probability. This procedure takes into account the period, depth, duration, and shape of the signal; the colors of the target star; arbitrary spectroscopic or imaging follow-up observations; and informed assumptions about the populations and distributions of field stars and multiple-star properties. Applying these methods to a sample of known Kepler planets, I demonstrate that many signals can be validated with very limited follow-up observations: in most cases with only a spectrum and an adaptive optics image. Additionally, I demonstrate that this procedure can reliably identify false positive signals. Because of the computational efficiency of this analysis, it is feasible to apply it to all Kepler planet candidates in the near future, and it will streamline the follow-up efforts for Kepler and other current and future transit surveys.

62

AN EFFICIENT AUTOMATED VALIDATION PROCEDURE FOR EXOPLANET TRANSIT CANDIDATES  

Energy Technology Data Exchange (ETDEWEB)

Surveys searching for transiting exoplanets have found many more candidates than they have been able to confirm as true planets. This situation is especially acute with the Kepler survey, which has found over 2300 candidates but has to date confirmed only a small fraction of them as planets. I present here a general procedure that can quickly be applied to any planet candidate to calculate its false positive probability. This procedure takes into account the period, depth, duration, and shape of the signal; the colors of the target star; arbitrary spectroscopic or imaging follow-up observations; and informed assumptions about the populations and distributions of field stars and multiple-star properties. Applying these methods to a sample of known Kepler planets, I demonstrate that many signals can be validated with very limited follow-up observations: in most cases with only a spectrum and an adaptive optics image. Additionally, I demonstrate that this procedure can reliably identify false positive signals. Because of the computational efficiency of this analysis, it is feasible to apply it to all Kepler planet candidates in the near future, and it will streamline the follow-up efforts for Kepler and other current and future transit surveys.

Morton, Timothy D., E-mail: tdm@astro.caltech.edu [Department of Astrophysics, California Institute of Technology, MC 249-17, Pasadena, CA 91125 (United States)

2012-12-10

63

Emulating JWST Exoplanet Transit Observations in a Testbed laboratory experiment  

Science.gov (United States)

The transit technique is used for the detection and characterization of exoplanets. The combination of transit and radial velocity (RV) measurements gives information about a planet's radius and mass, respectively, leading to an estimate of the planet's density (Borucki et al. 2011) and therefore to its composition and evolutionary history. Transit spectroscopy can provide information on atmospheric composition and structure (Fortney et al. 2013). Spectroscopic observations of individual planets have revealed atomic and molecular species such as H2O, CO2 and CH4 in atmospheres of planets orbiting bright stars, e.g. Deming et al. (2013). The transit observations require extremely precise photometry. For instance, Jupiter transit results to a 1% brightness decrease of a solar type star while the Earth causes only a 0.0084% decrease (84 ppm). Spectroscopic measurements require still greater precision science images. At PPL we have developed a testbed to project simulated spectra and other images onto a HgCdTe array in order to assess precision photometry for transits, weak lensing etc. for Explorer concepts like JWST, WFIRST, EUCLID. In our controlled laboratory experiment, the goal is to demonstrate ability to extract weak transit spectra as expected for NIRCam, NIRIS and NIRSpec. Two lamps of variable intensity, along with spectral line and photometric simulation masks emulate the signals from a star-only, from a planet-only and finally, from a combination of a planet + star. Three masks have been used to simulate spectra in monochromatic light. These masks, which are fabricated at JPL, have a length of 1000 pixels and widths of 2 pixels, 10 pixels and 1 pixel to correspond respectively to the noted above JWST instruments. From many-hour long observing sequences, we obtain time series photometry with deliberate offsets introduced to test sensitivity to pointing jitter and other effects. We can modify the star-planet brightness contrast by factors up to 10^4:1. With cross correlation techniques we calculate positional shifts which are then used to decorrelate the effects of vertical and lateral offsets due to turbulence and instrumental vibrations on the photometry. Using Principal Component Analysis (PCA), we reject correlated temporal noise to achieve a precision lower than 50 ppm (Clanton et al. 2012). In our current work, after decorrelation of vertical and lateral offsets along with PCA, we achieve a precision of sim20 ppm. To assess the photometric precision we use the Allan variance (Allan 1987). This statistical method is used to characterize noise and stability as it indicates shot noise limited performance. Testbed experiments are ongoing to provide quantitative information on the achievable spectroscopic precision using realistic exoplanet spectra with the goal to define optimized data acquisition sequences for use, for example, with the James Webb Space Telescope.

Touli, D.; Beichman, C. A.; Vasisht, G.; Smith, R.; Krist, J. E.

2014-12-01

64

Disentangling degenerate solutions from primary transit and secondary eclipse spectroscopy of exoplanets  

CERN Document Server

Infrared transmission and emission spectroscopy of exoplanets, recorded from primary transit and secondary eclipse measurements, indicate the presence of the most abundant carbon and oxygen molecular species (H2O, CH4, CO, and CO2) in a few exoplanets. However, efforts to constrain the molecular abundances to within several orders of magnitude are thwarted by the broad range of degenerate solutions that fit the data. Here we explore, with radiative transfer models and analytical approximations, the nature of the degenerate solution sets resulting from the sparse measurements of "hot Jupiter" exoplanets. As demonstrated with simple analytical expressions, primary transit measurements probe roughly 4 atmospheric scale heights at each wavelength band. Derived mixing ratios from these data are highly sensitive to errors in the radius in planet (at a reference pressure), which are approximately a few percent. For example, an uncertainty of 1% in the radius of a 1000 K and H2-based exoplanet with Jupiter's radius a...

Griffith, Caitlin A

2013-01-01

65

Microlensing Constraints on the Frequency of Jupiter Mass Planets  

CERN Document Server

Microlensing is the only technique likely, within the next 5 years, to constrain the frequency of Jupiter-analogs. The PLANET collaboration has monitored nearly 100 microlensing events of which more than 20 have sensitivity to the perturbations that would be caused by a Jovian-mass companion to the primary lens. No clear signatures of such planets have been detected. These null results indicate that Jupiter mass planets with separations of 1.5-3 AU occur in less than 1/3 of systems. A similar limit applies to planets of 3 Jupiter masses between 1-4 AU.

Gaudi, B S; An Jun Hong; Beaulieu, J P; Caldwell, J A R; De Poy, D L; Dominik, M; Gould, A; Greenhill, J; Hill, K; Kane, S; Martin, R D; Menzies, J; Pogge, R W; Pollard, K R; Sackett, P D; Sahu, K C; Vermaak, P; Watson, R; Williams, A

2000-01-01

66

Disentangling degenerate solutions from primary transit and secondary eclipse spectroscopy of exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Infrared transmission and emission spectroscopy of exoplanets, recorded from primary transit and secondary eclipse measurements, indicate the presence of the most abundant carbon and oxygen molecular species (H2O, CH4, CO, and CO2) in a few exoplanets. However, efforts to constrain the molecular abundances to within several orders of magnitude are thwarted by the broad range of degenerate solutions that fit the data. Here we explore, with radiative transfer models and analyt...

Griffith, Caitlin A.

2013-01-01

67

C/O Ratios of Stars with Transiting Hot Jupiter Exoplanets  

CERN Document Server

The relative abundances of carbon and oxygen have long been recognized as fundamental diagnostics of stellar chemical evolution. Now, the growing number of exoplanet observations enable estimation of these elements in exoplanetary atmospheres. In hot Jupiters, the C/O ratio affects the partitioning of carbon in the major observable molecules, making these elements diagnostic of temperature structure and composition. Here we present measurements of carbon and oxygen abundances in 16 stars that host transiting hot Jupiter exoplanets, and compare our C/O ratios to those measured in larger samples of host stars, as well as those estimated for the corresponding exoplanet atmospheres. With standard stellar abundance analysis we derive stellar parameters as well as [C/H] and [O/H] from multiple abundance indicators, including synthesis fitting of the [O I] 6300 {\\AA} line and NLTE corrections for the O I triplet. Our results, in agreement with recent suggestions, indicate that previously-measured exoplanet host star...

Teske, Johanna K; Smith, Verne V; Schuler, Simon C; Griffith, Caitlin A

2014-01-01

68

Exoplanet Atmospheres  

CERN Document Server

At the dawn of the first discovery of exoplanets orbiting sun-like stars in the mid-1990s, few believed that observations of exoplanet atmospheres would ever be possible. After the 2002 Hubble Space Telescope detection of a transiting exoplanet atmosphere, many skeptics discounted it as a one-object, one-method success. Nevertheless, the field is now firmly established, with over two dozen exoplanet atmospheres observed today. Hot Jupiters are the type of exoplanet currently most amenable to study. Highlights include: detection of molecular spectral features; observation of day-night temperature gradients; and constraints on vertical atmospheric structure. Atmospheres of giant planets far from their host stars are also being studied with direct imaging. The ultimate exoplanet goal is to answer the enigmatic and ancient question, "Are we alone?" via detection of atmospheric biosignatures. Two exciting prospects are the immediate focus on transiting super Earths orbiting in the habitable zone of M-dwarfs, and u...

Seager, S

2010-01-01

69

The Transit Ingress and the Tilted Orbit of the Extraordinarily Eccentric Exoplanet HD 80606b  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present the results of a transcontinental campaign to observe the 2009 June 5 transit of the exoplanet HD 80606b. We report the first detection of the transit ingress, revealing the transit duration to be 11.64 ± 0.25 hr and allowing more robust determinations of the system parameters. Keck spectra obtained at midtransit exhibit an anomalous blueshift, giving definitive evidence that the stellar spin axis and planetary orbital axis are misaligned. The Keck data show that the projected spi...

Winn, Joshua N.; Howard, Andrew W.; Johnson, John Asher; Marcy, Geoffrey W.; Gazak, J. Zachary; Starkey, Donn; Ford, Eric B.; Colon, Knicole D.; Reyes, Francisco; Nortmann, Lisa; Dreizler, Stefan; Odewahn, Stephen; Welsh, William F.; Kadakia, Shimonee; Vanderbei, Robert J.

2009-01-01

70

Photometric and Spectral Signatures of 3D Models of Transiting Giant Exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Using a 3D GCM, we create dynamical model atmospheres of a representative transiting giant exoplanet, HD 209458b. We post-process these atmospheres with an opacity code to obtain transit radius spectra during the primary transit. Using a spectral atmosphere code, we integrate over the face of the planet seen by an observer at various orbital phases and calculate light curves as a function of wavelength and for different photometric bands. The products of this study are gener...

Burrows, Adam; Rauscher, Emily; Spiegel, David; Menou, Kristen

2010-01-01

71

Hubble/WFC3 Spectroscopy of the Transiting Exoplanets WASP-19b and WASP-17b  

Science.gov (United States)

Measurements of transiting exoplanets that target extremes in parameter space offer the best chance to disentangle the structure and composition of the atmospheres of hot Jupiters. WASP-19b is one of the hottest exoplanets discovered to date, while WASP-17b has a much lower equilibrium temperature but has one of the largest atmospheric radii of known transiting planets. We discuss results from HST/WFC3 grism 1.1-1.7 micron spectroscopy of these planets during transit. We compare our integrated-light transit depths to previous IR transit photometry, and derive the 1.4-micron water absorption spectrum. We discuss implications for the atmospheric composition and structure of these hot Jupiters, and outline future observations that will further expand on these results.

Mandell, A.; Haynes, K.; Sinukoff, E.; Deming, D.; Wlikins, A.; Madhusudhan, N.; Agol, E.; Burrows, A.; Charbonneau, D.; Gilliland, R.; Knutson, H.; Ranjan, S.; Seager, S.; Showman, A.

2012-01-01

72

Observations of Mass Loss from the Transiting Exoplanet HD 209458b  

CERN Document Server

Using the new Cosmic Origins Spectrograph (COS) on the {\\it Hubble Space Telescope (HST)}, we obtained moderate-resolution, high signal/noise ultraviolet spectra of HD 209458 and its exoplanet HD 209458b during transit, both orbital quadratures, and secondary eclipse. We compare transit spectra with spectra obtained at non-transit phases to identify spectral features due to the exoplanet's expanding atmosphere. We find that the mean flux decreased by $7.8\\pm 1.3$\\% for the C~II 1334.5323~\\AA\\ and 1335.6854~\\AA\\ lines and by $8.2\\pm 1.4$\\% for the Si~III 1206.500~\\AA\\ line during transit compared to non-transit times in the velocity interval --50 to +50 km~s$^{-1}$. Comparison of the C~II and Si~III line depths and transit/non-transit line ratios shows deeper absorption features near --10 and +15 km~s$^{-1}$ and less certain features near --40 and +30--70 km~s$^{-1}$, but future observations are needed to verify this first detection of velocity structure in the expanding atmosphere of an exoplanet. Our results...

Linsky, Jeffrey L; France, Kevin; Froning, Cynthia S; Green, James C; Stocke, John T; Osterman, Steven N

2010-01-01

73

Photometric measurements of a Transit of Exoplanet TrES 3b  

Science.gov (United States)

Using the 0.6 m Ritchey-Chretien telescope at the Paul and Jane Meyer Observatory (PJMO), light curves from a transit of exoplanet TReS 3b were produced from images made with a Roper 1300B camera. Light curves from both V and R bands will be presented. Analysis using AstroImageJ software will be discussed. Planet properties determined using the Czech Astronomical Society's transit fitting routines will be presented.

Russell, Dwight; Shannon, Lydia; Campbell, Richard; Strickland, Willie

2012-10-01

74

DETECTION OF TRANSITING JOVIAN EXOPLANETS BY GAIA PHOTOMETRY-EXPECTED YIELD  

Energy Technology Data Exchange (ETDEWEB)

Several attempts have been made in the past to assess the expected number of exoplanetary transits that the Gaia space mission will detect. In this Letter, we use the updated design of Gaia and its expected performance and apply recent empirical statistical procedures to provide a new assessment. Depending on the extent of the follow-up effort that will be devoted, we expect Gaia to detect from a few hundreds to a few thousands of transiting exoplanets.

Dzigan, Yifat; Zucker, Shay, E-mail: yifatdzigan@gmail.com, E-mail: shayz@post.tau.ac.il [Department of Geophysical, Atmospheric, and Planetary Sciences, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel)

2012-07-01

75

DETECTION OF TRANSITING JOVIAN EXOPLANETS BY GAIA PHOTOMETRY—EXPECTED YIELD  

International Nuclear Information System (INIS)

Several attempts have been made in the past to assess the expected number of exoplanetary transits that the Gaia space mission will detect. In this Letter, we use the updated design of Gaia and its expected performance and apply recent empirical statistical procedures to provide a new assessment. Depending on the extent of the follow-up effort that will be devoted, we expect Gaia to detect from a few hundreds to a few thousands of transiting exoplanets.

76

THE TRANSIT LIGHT CURVE PROJECT. XII. SIX TRANSITS OF THE EXOPLANET XO-2b  

International Nuclear Information System (INIS)

We present photometry of six transits of the exoplanet XO-2b. By combining the light-curve analysis with theoretical isochrones to determine the stellar properties, we find the planetary radius to be 0.996+0.031 -0.018 R Jup and the planetary mass to be 0.565 ± 0.054 M Jup. These results are consistent with those reported previously, and are also consistent with theoretical models for gas giant planets. The midtransit times are accurate to within 1 minute and are consistent with a constant period. However, the period we derive differs by 2.5? from the previously published period. More data are needed to tell whether the period is actually variable (as it would be in the presence of an additional body) or if the timing errors have been underestimated.

77

A Hazy Situation: Using exoplanet retrieval techniques to characterize Titan's atmosphere from a Cassini transit spectrum  

Science.gov (United States)

One of the main discoveries in exoplanet atmosphere characterization over the past several years is the dramatic role of clouds in shaping the transit spectra of close-in planets. High altitude clouds/hazes obscure molecular absorption features, leading to detrimental effects in studying transiting planet atmospheres. To investigate these effects with a "ground truth" solar system example, we utilize a transit spectrum obtained using NASA's Cassini spacecraft of Saturn's moon Titan. Titan, with its well-studied atmosphere and high-altitude hydrocarbon haze layer gives insight into how hazes affect exoplanetary transit spectra. To test how well current exoplanet atmosphere models can account for and extract information from hazy planets, we use the Bayesian CHIMERA transit spectrum model and a Markov-Chain Monte Carlo affiant-invariable ensemble technique to retrieve well-known atmospheric and planetary parameters for Titan. These include the CH4, C2H2, and CO abundances, haze scattering parameters, temperature, pressure, and gravity. We discuss how our findings compare to in situ and other Cassini remote sensing measurements, and the implications of our results for the accuracy of exoplanet retrievals for hazy bodies.

Teal, Dillon J.; Line, Michael R.; Morley, Caroline V.; Fortney, Jonathan J.

2015-01-01

78

The Transit Light Curve (TLC) Project. I. Four Consecutive Transits of the Exoplanet XO-1b  

CERN Document Server

We present RIz photometry of four consecutive transits of the newly discovered exoplanet XO-1b. We improve upon the estimates of the transit parameters, finding the planetary radius to be R_P = 1.184 +0.028/-0.018 R_Jupiter and the stellar radius to be R_S = 0.928 +0.018/-0.013 R_Sun, assuming a stellar mass of M_S = 1.00 +/- 0.03 M_Sun. The uncertainties in the planetary and stellar radii are dominated by the uncertainty in the stellar mass. These uncertainties increase by a factor of 2-3 if a more conservative uncertainty of 0.10 M_Sun is assumed for the stellar mass. Our estimate of the planetary radius is smaller than that reported by McCullough et al. (2006) and yields a mean density that is comparable to that of TrES-1 and HD 189733b. The timings of the transits have an accuracy ranging from 0.2 to 2.5 minutes, and are marginally consistent with a uniform period.

Holman, M J; Latham, D W; O'Donovan, F T; Charbonneau, D; Bakos, G A; Esquerdo, G A; Hergenrother, C; Everett, M E; Pal, A; Holman, Matthew J.; Winn, Joshua N.; Latham, David W.; Donovan, Francis T. O'; Charbonneau, David; Bakos, Gaspar A.; Esquerdo, Gilbert A.; Hergenrother, Carl; Everett, Mark E.; Pal, Andras

2006-01-01

79

C/O Ratios of Stars with Transiting Hot Jupiter Exoplanets  

Science.gov (United States)

The relative abundances of carbon and oxygen have long been recognized as fundamental diagnostics of stellar chemical evolution. Now, the growing number of exoplanet observations enable estimation of these elements in exoplanetary atmospheres. In hot Jupiters, the C/O ratio affects the partitioning of carbon in the major observable molecules, making these elements diagnostic of temperature structure and composition. Here we present measurements of carbon and oxygen abundances in 16 stars that host transiting hot Jupiter exoplanets, and we compare our C/O ratios to those measured in larger samples of host stars, as well as those estimated for the corresponding exoplanet atmospheres. With standard stellar abundance analysis we derive stellar parameters as well as [C/H] and [O/H] from multiple abundance indicators, including synthesis fitting of the [O I] ?6300 line and non-LTE corrections for the O I triplet. Our results, in agreement with recent suggestions, indicate that previously measured exoplanet host star C/O ratios may have been overestimated. The mean transiting exoplanet host star C/O ratio from this sample is 0.54 (C/O? = 0.54), versus previously measured C/Ohost star means of ~0.65-0.75. We also observe the increase in C/O with [Fe/H] expected for all stars based on Galactic chemical evolution; a linear fit to our results falls slightly below that of other exoplanet host star studies but has a similar slope. Though the C/O ratios of even the most-observed exoplanets are still uncertain, the more precise abundance analysis possible right now for their host stars can help constrain these planets' formation environments and current compositions. Based on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

Teske, Johanna K.; Cunha, Katia; Smith, Verne V.; Schuler, Simon C.; Griffith, Caitlin A.

2014-06-01

80

Community College Non-Science Undergraduates Observe Exoplanet Transits with 8-inch Observatory in Glendale, Arizona  

Science.gov (United States)

Using the 8-inch Celestron telescopes at the Glendale Community College North Observatory in Glendale, Arizona, a group of undergraduate students, most of whom are non-science majors, observed exoplanet transits during the Fall 2014 semester. These students, members of the Glendale Community College's Astronomy Students for Telescope Research and Outreach (A.S.T.R.O.) Club, selected targets observable with telescopes of this size and the conditions of the sky. With these observations and using concepts and skills learned in introductory astronomy courses for non-science majors, the co-authors recorded detections of exoplanet transits consistent with published professional results. These results demonstrate that post-secondary institutions can teach hands-on, practical astronomy experience given equipment that is readily available and affordable, regardless of the size of the student body majoring in the physical sciences.

Gleim, Brian; Esteban, Henry; Lincoln, Connor; Price, Jason; Giroux, Elizabeth; Lentowski, Noreen; Valencia, Leslie; Morris, Bryce; Smith, Blake; Leffler, Chris; Bonilla, Matt; Watt, Sara D.

2015-01-01

 
 
 
 
81

Wideband Infrared Spectrometer for Characterization of Transiting Exoplanets with Space Telescopes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper presents a conceptual design for a spectrometer designed specifically for characterizing transiting exoplanets with space-borne infrared telescopes. The design adopting cross-dispersion is intended to be simple, compact, highly stable, and has capability of simultaneous coverage over a wide wavelength region with high throughput. Typical wavelength coverage and spectral resolving power is 1-13 micron with a spectral resolving power of ~ a few hundred, respectively...

Enya, Keigo

2012-01-01

82

Estimations of orbital parameters of exoplanets from transit photometry by using dynamical constraints  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The probability of the detection of Earth-like exoplanets may increase in the near future after the launch of the space missions using the transit photometry as observation method. By using this technique only the semi-major axis of the detected planet can be determined, and there will be no information on the upper limit of its orbital eccentricity. However, the orbital eccentricity is a very important parameter, not only from a dynamical point of view, since it gives also ...

Sandor, Zsolt

2006-01-01

83

The Exoplanet Orbit Database II: Updates to exoplanets.org  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Exoplanet Orbit Database (EOD) compiles orbital, transit, host star, and other parameters of robustly detected exoplanets reported in the peer-reviewed literature. The EOD can be navigated through the Exoplanet Data Explorer (EDE) Plotter and Table, available on the World Wide Web at exoplanets.org. The EOD contains data for 1492 confirmed exoplanets as of July 2014. The EOD descends from a table in Butler et al. (2002) and the Catalog of Nearby Exoplanets (Butler et al....

Han, Eunkyu; Wang, Sharon X.; Wright, Jason T.; Feng, Y. Katherina; Zhao, Ming; Brown, Jacob I.; Hancock, Colin

2014-01-01

84

Improving Transit Predictions of Known Exoplanets with TERMS  

Directory of Open Access Journals (Sweden)

Full Text Available Transiting planet discoveries have largely been restricted to the short-period or low-periastron distance regimes due to the bias inherent in the geometric transit probability. Through the re?nement of planetary orbital parameters, and hence reducing the size of transit windows, long-period planets become feasible targets for photometric follow-up. Here we describe the TERMS project that is monitoring these host stars at predicted transit times.

Mahadevan S.

2011-02-01

85

OBSERVATIONS OF MASS LOSS FROM THE TRANSITING EXOPLANET HD 209458b  

International Nuclear Information System (INIS)

Using the new Cosmic Origins Spectrograph on the Hubble Space Telescope, we obtained moderate-resolution, high signal/noise ultraviolet spectra of HD 209458 and its exoplanet HD 209458b during transit, both orbital quadratures, and secondary eclipse. We compare transit spectra with spectra obtained at non-transit phases to identify spectral features due to the exoplanet's expanding atmosphere. We find that the mean flux decreased by 7.8% ± 1.3% for the C II 1334.5323 A and 1335.6854 A lines and by 8.2% ± 1.4% for the Si III 1206.500 A line during transit compared to non-transit times in the velocity interval -50 to +50 km s-1. Comparison of the C II and Si III line depths and transit/non-transit line ratios shows deeper absorption features near -10 and +15 km s-1 and less certain features near -40 and +30-70 km s-1, but future observations are needed to verify this first detection of velocity structure in the expanding atmosphere of an exoplanet. Our results for the C II lines and the non-detection of Si IV 1394.76 A absorption are in agreement with Vidal-Madjar et al., but we find absorption during transit in the Si III line contrary to the earlier result. The 8% ± 1% obscuration of the star during transit is far larger than the 1.5% obscuration by the exoplanet's disk. Absorption during transit at velocities between -50 and +50 km s-1 in the C II and Si III lines requires high-velocity ion absorbers. Assuming hydrodynamcity ion absorbers. Assuming hydrodynamic model values for the gas temperature and outflow velocity at the limb of the outflow as seen in the C II lines, we find mass-loss rates in the range (8-40)x1010 g s-1. These rates assume that the carbon abundance is solar, which is not the case for the giant planets in the solar system. Our mass-loss rate estimate is consistent with theoretical hydrodynamic models that include metals in the outflowing gas.

86

EVIDENCE OF POSSIBLE SPIN-ORBIT MISALIGNMENT ALONG THE LINE OF SIGHT IN TRANSITING EXOPLANET SYSTEMS  

International Nuclear Information System (INIS)

Of the 26 transiting exoplanet systems with measurements of the Rossiter-McLaughlin (RM) effect, eight have now been found to be significantly spin-orbit misaligned in the plane of the sky (i.e., RM misalignment angle |?| ?> 300 and inconsistent with ? = 00). Unfortunately, the RM effect does not constrain the complement misalignment angle between the orbit of the planet and the spin of its host star along the line of sight (LOS). I use a simple model of stellar rotation benchmarked with observational data to statistically identify 10 exoplanet systems from a sample of 75 for which there is likely a significant degree of spin-orbit misalignment along the LOS: HAT-P-7, HAT-P-14, HAT-P-16, HD 17156, Kepler-5, Kepler-7, TrES-4, WASP-1, WASP-12, and WASP-14. All 10 systems have host stellar masses M * in the range 1.2 M sun ?* ?sun, and the probability of this occurrence by chance is less than one in ten thousand. In addition, the planets in the candidate-misaligned systems are preferentially massive and eccentric. The coupled distribution of misalignment from the RM effect and from this analysis suggests that transiting exoplanets are more likely to be spin-orbit aligned than expected given predictions for a transiting planet population produced entirely by planet-planet scattering or Kozai cycles and tidal friction. For that reason, there are likely two populations of close-in exoplaneo populations of close-in exoplanet systems: a population of aligned systems and a population of apparently misaligned systems in which the processes that lead to misalignment or to the survival of misaligned systems operate more efficiently in systems with massive stars and planets.

87

A high dynamic-range instrument for SPICA for coronagraphic observation of exoplanets and monitoring of transiting exoplanets  

CERN Document Server

This paper, first, presents introductory reviews of the Space Infrared Telescope for Cosmology and Astrophysics (SPICA) mission and the SPICA Coronagraph Instrument (SCI). SPICA will realize a 3m class telescope cooled to 6K in orbit. The launch of SPICA is planned to take place in FY2018. The SPICA mission provides us with a unique opportunity to make high dynamic-range observations because of its large telescope aperture, high stability, and the capability for making infrared observations from deep space. The SCI is a high dynamic-range instrument proposed for SPICA. The primary objectives for the SCI are the direct coronagraphic detection and spectroscopy of Jovian exoplanets in the infrared region, while the monitoring of transiting planets is another important target owing to the non-coronagraphic mode of the SCI. Then, recent technical progress and ideas in conceptual studies are presented, which can potentially enhance the performance of the instrument: the designs of an integral 1-dimensional binary-s...

Enya, K; Takeuchi, S; Kotani, T; Yamamuro, T

2011-01-01

88

Influence of stellar variability on the determination of the radius during a transit of an exoplanet  

Directory of Open Access Journals (Sweden)

Full Text Available Stellar variability can affect the estimate of an exoplanet radius measured during a transit. We developed a transit light curve model which includes stellar spots. It appears that, if spectro-photometric technique is used, spots and faculae have to be considered to conclude on atmospheric detection and characterization. When using a model including spots, characterization of Hot-Jupiter atmosphere around active stars is possible with this technique, provided a signal to noise ratio up to 105. For Earth-size planets a long-term parallel photometric follow up monitoring the stellar activity is required to compensate the error due to the stellar variability.

Désert J.-M.

2011-07-01

89

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

Science.gov (United States)

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.

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

2010-02-01

90

Exoplanet Transit Variability: Bow Shocks and Winds Around HD 189733b  

CERN Document Server

By analogy with the solar system, it is believed that stellar winds will form bow shocks around exoplanets. For hot Jupiters the bow shock will not form directly between the planet and the star, causing an asymmetric distribution of mass around the exoplanet and hence an asymmetric transit. As the planet orbits thorough varying wind conditions, the strength and geometry of its bow shock will change, thus producing transits of varying shape. We model this process using magnetic maps of HD 189733 taken one year apart, coupled with a 3D stellar wind model, to determine the local stellar wind conditions throughout the orbital path of the planet. We predict the time-varying geometry and density of the bow shock that forms around the magnetosphere of the planet and simulate transit light curves. Depending on the nature of the stellar magnetic field, and hence its wind, we find that both the transit duration and ingress time can vary when compared to optical light curves. We conclude that consecutive near-UV transit...

Llama, J; Jardine, M; Wood, K; Fares, R; Gombosi, T I

2013-01-01

91

Toward the Detection of Exoplanet Transits with Polarimetry  

CERN Document Server

In contrast to photometric transits, whose peak signal occurs at mid-transit due to occultation of the brightest region of the disk, polarimetric transits provide a signal upon ingress and egress due to occultation of the polarized stellar limb. Limb polarization, the bright corollary to limb darkening, arises from the $90^\\circ$ scattering angle and low optical depth experienced by photons at the limb. In addition to the ratio $R_{\\rm p} / R_*$, the amplitude of a polarimetric transit is expected to be controlled by the strength and width of the stellar limb polarization profile, which depend on the scattering-to-total opacity ratio at the stellar limb. We present a short list of the systems providing the highest expected signal-to-noise ratio for detection of this effect, and we draw particular attention to HD 80606b. This planet is spin/orbit misaligned, has a three-hour ingress, and has a bright parent star, which make it an attractive target. We report on test observations of an HD 80606b ingress with th...

Wiktorowicz, Sloane J

2014-01-01

92

Catalog of Nearby Exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present a catalog of nearby exoplanets, available at http://exoplanets.org and ApJ 646, 505 (published version available at the link above). It contains the 172 known low mass companions with orbits established through radial velocity and transit measurements around stars within 200 pc. We include 5 previously unpublished exoplanets orbiting the stars HD 11964, HD 66428, HD 99109, HD 107148, and HD 164922. We update orbits for 90 additional exoplanets including many whose...

Butler, R. P.; Wright, J. T.; Marcy, G. W.; Fischer, D. A.; Vogt, S. S.; Tinney, C. G.; Jones, H. R. A.; Carter, B. D.; Johnson, J. A.; Mccarthy, C.; Penny, A. J.

2006-01-01

93

GTC OSIRIS Transiting Exoplanet Atmospheric Survey: Detection of potassium in XO-2b from spectrophotometry  

CERN Document Server

We present Gran Telescopio Canarias (GTC) optical transit narrow-band photometry of the hot-Jupiter exoplanet XO-2b using the OSIRIS instrument. This unique instrument has the capabilities to deliver high cadence narrow-band photometric lightcurves, allowing us to probe the atmospheric composition of hot Jupiters from the ground. The observations were taken during three transit events which cover four wavelengths at spectral resolutions near 500, necessary for observing atmospheric features, and have near-photon limited sub-mmag precisions. Precision narrow-band photometry on a large aperture telescope allows for atmospheric transmission spectral features to be observed for exoplanets around much fainter stars than those of the well studied targets HD209458b and HD189733b, providing access to the majority of known transiting planets. For XO-2b, we measure planet-to-star radius contrasts of R_pl/R_star=0.10508+/-0.00052 at 6792 Ang, 0.10640+/-0.00058 at 7582 Ang, and 0.10686+/-0.00060 at 7664.9 Ang, and 0.1036...

Sing, D K; Fortney, J J; Etangs, A Lecavelier des; Ballester, G E; Cepa, J; Ehrenreich, D; Lopez-Morales, M; Pont, F; Shabram, M; Vidal-Madjar, A

2010-01-01

94

How Close are the Nearest Transiting Exoplanet Systems? Updated Planet Occurrence Rates from Kepler & Implications for TESS  

Science.gov (United States)

Here we consider the most likely distances and apparent magnitudes of the nearest transiting exoplanet systems. In preparation for the next-generation of exoplanet surveys, we would like to know the properties of these systems in order to optimize survey strategies and plan follow-up observations. We begin by populating a catalog of nearby stars with planets using occurrence rates estimated from Kepler. For FGK stars, we rely on previously published estimates of the planet occurrence rate. For smaller stars, we determine the planet occurrence rate by using our own planet detection pipeline to search for additional planets around small Kepler target stars. We empirically measure the planet detection threshold of our pipeline by injecting and recovering transits. After assigning planets to stars, we query the resulting planet catalog to determine the properties of the nearest and brightest transiting exoplanets. We will discuss the implications of this simulated planet population for exoplanet surveys such as TESS, PLATO, MEarth, CARMENES, CHEOPS, ExoplanetSat, ExTrA, HPF, SPECULOOS, and SPIROU. We also consider the observing resources that will be required to follow up these systems with extremely large ground-based telescopes like the GMT, TMT, and E-ELT.

Dressing, Courtney D.; Charbonneau, David; Sullivan, Peter; Winn, Joshua N.

2014-06-01

95

Venus transit 2004: Illustrating the capability of exoplanet transmission spectroscopy  

CERN Document Server

The transit of Venus in 2004 offered the rare possibility to remotely sense a well-known planetary atmosphere using ground-based observations for absorption spectroscopy. Transmission spectra of Venus' atmosphere were obtained in the near infrared using the Vacuum Tower Telescope (VTT) in Tenerife. Since the instrument was designed to measure the very bright photosphere of the Sun, extracting Venus' atmosphere was challenging. CO_2 absorption lines could be identified in the upper Venus atmosphere. Moreover, the relative abundance of the three most abundant CO_2 isotopologues could be determined. The observations resolved Venus' limb, showing Doppler-shifted absorption lines that are probably caused by high-altitude winds. This paper illustrates the ability of ground-based measurements to examine atmospheric constituents of a terrestrial planet atmosphere which might be applied in future to terrestrial extrasolar planets.

Hedelt, P; Brown, T; Vera, M Collados; Rauer, H; Schleicher, H; Schmidt, W; Schreier, F; Titz, R

2011-01-01

96

Venus transit 2004: Illustrating the capability of exoplanet transmission spectroscopy  

Science.gov (United States)

The transit of Venus in 2004 offered the rare possibility to remotely sense a well-known planetary atmosphere using ground-based absorption spectroscopy. Transmission spectra of Venus' atmosphere were obtained in the near infrared using the Vacuum Tower Telescope (VTT) in Tenerife. Since the instrument was designed to measure the very bright photosphere of the Sun, extracting Venus' atmosphere was challenging. We were able to identify CO2 absorption lines in the upper Venus atmosphere. Moreover, the relative abundance of the three most abundant CO2 isotopologues could be determined. The observations resolved Venus' limb, showing Doppler-shifted absorption lines that are probably caused by high-altitude winds. We demonstrate the utility of ground-based measurements in analyzing the atmospheric constituents of a terrestrial planet atmosphere using methods that might be applied in future to terrestrial extrasolar planets.

Hedelt, P.; Alonso, R.; Brown, T.; Collados Vera, M.; Rauer, H.; Schleicher, H.; Schmidt, W.; Schreier, F.; Titz, R.

2011-09-01

97

Bayesian mass and age estimates for transiting exoplanet host stars  

CERN Document Server

The mean density of a star transited by a planet, brown dwarf or low mass star can be accurately measured from its light curve. This measurement can be combined with other observations to estimate its mass and age by comparison with stellar models. Our aim is to calculate the posterior probability distributions for the mass and age of a star given its density, effective temperature, metallicity and luminosity. We computed a large grid of stellar models that densely sample the appropriate mass and metallicity range. The posterior probability distributions are calculated using a Markov-chain Monte-Carlo method. The method has been validated by comparison to the results of other stellar models and by applying the method to stars in eclipsing binary systems with accurately measured masses and radii. We have explored the sensitivity of our results to the assumed values of the mixing-length parameter, $\\alpha_{\\rm MLT}$, and initial helium mass fraction, Y. For a star with a mass of 0.9 solar masses and an age of 4...

Maxted, P F L; Southworth, J

2014-01-01

98

The Transit Light Curve (TLC) Project. II. Two Transits of the Exoplanet OGLE-TR-111b  

CERN Document Server

As part of our ongoing effort to measure exoplanet sizes and transit times with greater accuracy, we present I band observations of two transits of OGLE-TR-111b. The photometry has an accuracy of 0.15-0.20% and a cadence of 1-2 minutes. We derive a planetary radius of 1.067 +/- 0.054 Jupiter radii and a stellar radius of 0.831 +/- 0.031 solar radii. The uncertainties are dominated by errors in the photometry, rather than by systematic errors arising from uncertainties in the limb darkening function or the stellar mass. Both the stellar radius and the planetary radius are in agreement with theoretical expectations. The transit times are accurate to within 30 seconds, and allow us to refine the estimate of the mean orbital period: 4.0144479 +/- 0.0000041 days.

Winn, J N; Fuentes, C I; Winn, Joshua N.; Holman, Matthew J.; Fuentes, Cesar I.

2006-01-01

99

K-band transit and secondary eclipse photometry of exoplanet OGLE-TR-113b  

CERN Document Server

We present high precision K-band photometry of the transit and secondary eclipse of extrasolar planet OGLE-TR-113, using the SOFI near-infrared instrument on ESO's NTT. Data were taken in 5 second exposures over two periods of 3-4 hours, using random jitter position offsets. In this way, a relative photometric precision of ~1% per frame was achieved, avoiding systematic effects that seem to become dominant at precisions exceeding this level, and resulting in an overall accuracy of 0.1% per ~10 minutes. The observations of the transit show a flat bottom light-curve indicative of a significantly lower stellar limb-darkening at near-infrared than at optical wavelengths. The observations of the secondary eclipse result in a 3 sigma detection of emission from the exoplanet at 0.17+-0.05%. However, residual systematic errors make this detection rather tentative.

Snellen, I

2006-01-01

100

Transiting Planets with LSST: Assessing the Potential for LSST Exoplanet Detection  

Science.gov (United States)

Over its decade-long run, the Large Scale Synoptic Survey (LSST) will gather several hundred multi-band photometric observations of approximately ten billion stars. We demonstrate that while LSST will have a much lower cadence than most transiting planet surveys, a significant number of transiting planets will yet have sufficient photometric signal for detection. We also show that due to LSST's multiple filters and sensitivity to faint stars, LSST opens the door to detecting planets in stellar populations that have not been thoroughly searched by past surveys, including planets around red dwarfs, in star clusters, and even in the Large Magellanic Cloud. While these regimes will have very limited follow-up possibilities, LSST can provide a statistical picture of exoplanet frequencies in interesting stellar environments.

Lund, Michael; Pepper, Joshua; Stassun, Keivan; Jacklin, Savannah

2015-01-01

 
 
 
 
101

Stellar Spectroscopy during Exoplanet Transits: Dissecting fine structure across stellar surfaces  

CERN Document Server

Differential spectroscopy during exoplanet transits permits to reconstruct spectra of small stellar surface portions that successively become hidden behind the planet. The center-to-limb behavior of stellar line shapes, asymmetries and wavelength shifts will enable detailed tests of 3-dimensional hydrodynamic models of stellar atmospheres, such that are required for any precise determination of abundances or seismic properties. Such models can now be computed for widely different stars but have been feasible to test in detail only for the Sun with its resolved surface structure. Although very high quality spectra are required, already current data permit reconstructions of line profiles in the brightest transit host stars such as HD209458 (G0 V).

Dravins, Dainis; Dahlén, Erik; Pazira, Hiva

2014-01-01

102

Thermal phase curves of non-transiting terrestrial exoplanets 2. Characterizing airless planets  

CERN Document Server

Context. The photometric signal we receive from a star hosting a planet is modulated by the variation of the planet signal with its orbital phase. Such phase variations are observed for transiting hot Jupiters with current instrumentation, and have also been measured for one transiting terrestrial planet (Kepler 10 b) and one non-transiting gas giant (Ups A b). Future telescopes (JWST and EChO) will have the capability to measure thermal phase curves of exoplanets including hot rocky planets in transiting and non-transiting configurations, and at different wavelengths. Short-period planets with a mass below 10 R_EARTH are indeed frequent and nearby targets (within 10 pc) are already known and more are to be found. Aims. To test the possibility to use multi-wavelengths infrared phase curves to constrain the radius, the albedo and the orbital inclination of a non-transiting planet with no atmosphere and on a 1:1 spin orbit resonance. Methods. We model the thermal emission of a synchronous rocky planet with no a...

Maurin, A S; Hersant, F; Belu, A

2011-01-01

103

The Qatar Exoplanet Survey  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Qatar Exoplanet Survey (QES) is discovering hot Jupiters and aims to discover hot Saturns and hot Neptunes that transit in front of relatively bright host stars. QES currently operates a robotic wide-angle camera system to identify promising transiting exoplanet candidates among which are the confirmed exoplanets Qatar 1b and 2b. This paper describes the first generation QES instrument, observing strategy, data reduction techniques, and follow-up procedures. The QES came...

Alsubai, K. A.; Parley, N. R.; Bramich, D. M.; Horne, K.; Cameron, A. Collier; West, R. G.; Sorensen, P. M.; Pollacco, D.; Smith, J. C.; Fors, O.

2014-01-01

104

TRANSMISSION SPECTRUM OF EARTH AS A TRANSITING EXOPLANET FROM THE ULTRAVIOLET TO THE NEAR-INFRARED  

International Nuclear Information System (INIS)

Transmission spectroscopy of exoplanets is a tool to characterize rocky planets and explore their habitability. Using the Earth itself as a proxy, we model the atmospheric cross section as a function of wavelength, and show the effect of each atmospheric species, Rayleigh scattering, and refraction from 115 to 1000 nm. Clouds do not significantly affect this picture because refraction prevents the lowest 12.75 km of the atmosphere, in a transiting geometry for an Earth-Sun analog, to be sampled by a distant observer. We calculate the effective planetary radius for the primary eclipse spectrum of an Earth-like exoplanet around a Sun-like star. Below 200 nm, ultraviolet (UV) O2 absorption increases the effective planetary radius by about 180 km, versus 27 km at 760.3 nm, and 14 km in the near-infrared (NIR) due predominantly to refraction. This translates into a 2.6% change in effective planetary radius over the UV-NIR wavelength range, showing that the UV is an interesting wavelength range for future space missions

105

Directly Imaged L-T Transition Exoplanets in the Mid-Infrared  

CERN Document Server

Gas-giant planets emit a large fraction of their light in the mid-infrared ($\\gtrsim$3$\\mu \\rm m$), where photometry and spectroscopy are critical to our understanding of the bulk properties of extrasolar planets. Of particular importance are the L and M-band atmospheric windows (3-5$\\mu \\rm m$), which are the longest wavelengths currently accessible to ground-based, high-contrast imagers. We present binocular LBT AO images of the HR 8799 planetary system in six narrow-band filters from 3-4$\\mu \\rm m$, and a Magellan AO image of the 2M1207 planetary system in a broader 3.3$\\mu \\rm m$ band. These systems encompass the five known exoplanets with luminosities consistent with L$\\rightarrow$T transition brown dwarfs. Our results show that the exoplanets are brighter and have shallower spectral slopes than equivalent temperature brown dwarfs in a wavelength range that contains the methane fundamental absorption feature. For 2M1207 b, we find that thick clouds and non-equilibrium chemistry caused by vertical mixing ...

Skemer, Andrew J; Hinz, Philip M; Morzinski, Katie M; Skrutskie, Michael F; Leisenring, Jarron M; Close, Laird M; Saumon, Didier; Bailey, Vanessa P; Briguglio, Runa; Defrere, Denis; Esposito, Simone; Follette, Katherine B; Hill, John M; Males, Jared R; Puglisi, Alfio; Rodigas, Timothy J; Xompero, Marco

2013-01-01

106

TRANSMISSION SPECTRUM OF EARTH AS A TRANSITING EXOPLANET FROM THE ULTRAVIOLET TO THE NEAR-INFRARED  

Energy Technology Data Exchange (ETDEWEB)

Transmission spectroscopy of exoplanets is a tool to characterize rocky planets and explore their habitability. Using the Earth itself as a proxy, we model the atmospheric cross section as a function of wavelength, and show the effect of each atmospheric species, Rayleigh scattering, and refraction from 115 to 1000 nm. Clouds do not significantly affect this picture because refraction prevents the lowest 12.75 km of the atmosphere, in a transiting geometry for an Earth-Sun analog, to be sampled by a distant observer. We calculate the effective planetary radius for the primary eclipse spectrum of an Earth-like exoplanet around a Sun-like star. Below 200 nm, ultraviolet (UV) O{sub 2} absorption increases the effective planetary radius by about 180 km, versus 27 km at 760.3 nm, and 14 km in the near-infrared (NIR) due predominantly to refraction. This translates into a 2.6% change in effective planetary radius over the UV-NIR wavelength range, showing that the UV is an interesting wavelength range for future space missions.

Betremieux, Y. [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany); Kaltenegger, L., E-mail: betremieux@mpia.de, E-mail: kaltenegger@mpia.de [Harvard-Smithsonian Center for Astrophysics, 60 Garden street, Cambridge MA 02138 (United States)

2013-08-01

107

Photometric and Spectral Signatures of 3D Models of Transiting Giant Exoplanets  

CERN Document Server

Using a 3D GCM, we create dynamical model atmospheres of a representative transiting giant exoplanet, HD 209458b. We post-process these atmospheres with an opacity code to obtain transit radius spectra during the primary transit. Using a spectral atmosphere code, we integrate over the face of the planet seen by an observer at various orbital phases and calculate light curves as a function of wavelength and for different photometric bands. The products of this study are generic predictions for the phase variations of a zero-eccentricity giant planet's transit spectrum and of its light curves. We find that for these models the temporal variations in all quantities and the ingress/egress contrasts in the transit radii are small ($< 1.0$\\%). Moreover, we determine that the day/night contrasts and phase shifts of the brightness peaks relative to the ephemeris are functions of photometric band. The $J$, $H$, and $K$ bands are shifted most, while the IRAC bands are shifted least. Therefore, we verify that the mag...

Burrows, Adam; Spiegel, David; Menou, Kristen

2010-01-01

108

Gran Telescopio Canarias OSIRIS Transiting Exoplanet Atmospheric Survey: Detection of potassium in XO-2b from narrowband spectrophotometry  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present Gran Telescopio Canarias (GTC) optical transit narrow-band photometry of the hot-Jupiter exoplanet XO-2b using the OSIRIS instrument. This unique instrument has the capabilities to deliver high cadence narrow-band photometric lightcurves, allowing us to probe the atmospheric composition of hot Jupiters from the ground. The observations were taken during three transit events which cover four wavelengths at spectral resolutions near 500, necessary for observing atmo...

Sing, David K.; De?sert, Jean-michel; Fortney, Jonathan J.; Lecavalier Des Etangs, Alain; Ballester, Gilda E.; Cepa, Jordi; Ehrenreich, David; Lo?pez-morales, Mercedes; Pont, Fre?de?ric; Shabram, Megan; Vidal-madjar, Alfred

2010-01-01

109

Colour-magnitude diagrams of transiting Exoplanets - II. A larger sample from photometric distances  

CERN Document Server

Colour-magnitude diagrams form a traditional way of presenting luminous objects in the Universe and compare them to each others. Here, we estimate the photometric distance of 44 transiting exoplanetary systems. Parallaxes for seven systems confirm our methodology. Combining those measurements with fluxes obtained while planets were occulted by their host stars, we compose colour-magnitude diagrams in the near and mid-infrared. When possible, planets are plotted alongside very low-mass stars and field brown dwarfs, who often share similar sizes and equilibrium temperatures. They offer a natural, empirical, comparison sample. We also include directly imaged exoplanets and the expected loci of pure blackbodies. Irradiated planets do not match blackbodies; their emission spectra are not featureless. For a given luminosity, hot Jupiters' daysides show a larger variety in colour than brown dwarfs do and display an increasing diversity in colour with decreasing intrinsic luminosity. The presence of an extra absorben...

Triaud, Amaury H M J; Smalley, Barry; Gillon, Michael

2014-01-01

110

The secondary eclipse of the transiting exoplanet CoRoT-2b  

CERN Document Server

We present a study of the light curve of the transiting exoplanet CoRoT-2b, aimed at detecting the secondary eclipse and measuring its depth. The data were obtained with the CoRoT satellite during its first run of more than 140 days. After filtering the low frequencies with a pre-whitening technique, we detect a 0.0060$\\pm$0.0020% secondary eclipse centered on the orbital phase 0.494$\\pm$0.006. Assuming a black-body emission of the planet, we estimate a surface brightness temperature of T$_{\\rm p,CoRoT}$=1910$^{+90}_{-100}$ K. We provide the planet's equilibrium temperature and re-distribution factors as a function of the unknown amount of reflected light. The upper limit for the geometric albedo is 0.12. The detected secondary is the shallowest ever found.

Alonso, R; Mazeh, T; Aigrain, S; Alapini, A; Barge, P; Hatzes, A; Pont, F

2009-01-01

111

The 2012 Transit of Venus for Cytherean Atmospheric Studies and as an Exoplanet Analog  

Science.gov (United States)

We worked to assemble as complete a dataset as possible for the Cytherean atmosphere in collaboration with Venus Express in situ and to provide an analog of spectral and total irradiance exoplanet measurements. From Haleakala, the whole transit was visible in coronal skies; our B images showed the evolution of the visibility of Venus's atmosphere and of the black-drop effect, as part of the Venus Twilight Experiment's 9 coronagraphs distributed worldwide with BVRI. We imaged the Cytherean atmosphere over two minutes before first contact, with subarcsecond resolution, with the coronagraph and a separate refractor. The IBIS imaging spectrometer at Sacramento Peak Observatory at H-alpha and carbon-dioxide also provided us high-resolution imaging. The NST of Big Bear Solar Observatory also provided high-resolution vacuum observations of the Cytherean atmosphere and black drop evolution. Our liaison with UH's Mees Solar Observatory scientists provided magneto-optical imaging at calcium and potassium. Spaceborne observations included the Solar Dynamics Observatory's AIA and HMI, and the Solar Optical Telescope (SOT) and X-ray Telescope (XRT) on Hinode, and total-solar-irradiance measurements with ACRIMSAT and SORCE/TIM, to characterize the event as an exoplanet-transit analog. Our expedition was sponsored by the Committee for Research and Exploration/National Geographic Society. Some of the funds for the carbon-dioxide filter for IBIS were provided by NASA through AAS's Small Research Grant Program. We thank Rob Lucas, Aram Friedman, and Eric Pilger '82 for assistance with Haleakala observing, Rob Ratkowski of Haleakala Amateur Astronomers for assistance with equipment and with the site, Stan Truitt for the loan of his Paramount ME, and Steve Bisque/Software Bisque for TheSky X controller. We thank Joseph Gangestad '06 of Aerospace Corp., a veteran of our 2004 expedition, for assistance at Big Bear. We thank the Lockheed Martin Solar and Astrophysics Laboratory and Hinode science and operations teams for planning and support.

Pasachoff, Jay M.; Schneider, G.; Babcock, B. A.; Lu, M.; Reardon, K. P.; Widemann, T.; Tanga, P.; Dantowitz, R.; Willson, R.; Kopp, G.; Yurchyshyn, V.; Sterling, A.; Scherrer, P.; Schou, J.; Golub, L.; Reeves, K.

2012-10-01

112

Recent Transits of the Super-Earth Exoplanet GJ 1214b  

CERN Document Server

We report recent ground-based photometry of the transiting super-Earth exoplanet GJ1214b at several wavelengths, including the infrared near 1.25 microns (J-band). We observed a J-band transit with the FLAMINGOS infrared imager and the 2.1-meter telescope on Kitt Peak, and we observed several optical transits using a 0.5-meter telescope on Kitt Peak and the 0.36-meter Universidad de Monterrey Observatory telescope. Our high-precision J-band observations exploit the brightness of the M-dwarf host star at this infrared wavelength as compared to the optical, as well as being significantly less affected by stellar activity and limb darkening. We fit the J-band transit to obtain an independent determination of the planetary and stellar radii. Our radius for the planet (2.61^+0.30_-0.11 Earth radii) is in excellent agreement with the discovery value reported by Charbonneau et al. based on optical data. We demonstrate that the planetary radius is insensitive to degeneracies in the fitting process. We use all of our ...

Sada, Pedro V; Jackson, Brian; Jennings, Donald E; Peterson, Steven W; Haase, Flynn; Bays, Kevin; O'Gorman, Eamon; Lundsford, Alan

2010-01-01

113

THE TRANSIT INGRESS AND THE TILTED ORBIT OF THE EXTRAORDINARILY ECCENTRIC EXOPLANET HD 80606b  

International Nuclear Information System (INIS)

We present the results of a transcontinental campaign to observe the 2009 June 5 transit of the exoplanet HD 80606b. We report the first detection of the transit ingress, revealing the transit duration to be 11.64 ± 0.25 hr and allowing more robust determinations of the system parameters. Keck spectra obtained at midtransit exhibit an anomalous blueshift, giving definitive evidence that the stellar spin axis and planetary orbital axis are misaligned. The Keck data show that the projected spin-orbit angle ? is between 32 deg. and 87 deg. with 68.3% confidence and between 14 deg. and 142 deg. with 99.73% confidence. Thus, the orbit of this planet is not only highly eccentric (e = 0.93) but is also tilted away from the equatorial plane of its parent star. A large tilt had been predicted, based on the idea that the planet's eccentric orbit was caused by the Kozai mechanism. Independently of the theory, it is worth noting that all three exoplanetary systems with known spin-orbit misalignments have massive planets on eccentric orbits, suggesting that those systems migrate through a different channel than lower mass planets on circular orbits.

114

Molecular opacities for exoplanets.  

Science.gov (United States)

Spectroscopic observations of exoplanets are now possible by transit methods and direct emission. Spectroscopic requirements for exoplanets are reviewed based on existing measurements and model predictions for hot Jupiters and super-Earths. Molecular opacities needed to simulate astronomical observations can be obtained from laboratory measurements, ab initio calculations or a combination of the two approaches. This discussion article focuses mainly on laboratory measurements of hot molecules as needed for exoplanet spectroscopy. PMID:24664921

Bernath, Peter F

2014-04-28

115

Line-profile tomography of exoplanet transits -- II. A gas-giant planet transiting a rapidly-rotating A5 star  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Most of our knowledge of extrasolar planets rests on precise radial-velocity measurements, either for direct detection or for confirmation of the planetary origin of photometric transit signals. This has limited our exploration of the parameter space of exoplanet hosts to solar- and later-type, sharp-lined stars. Here we extend the realm of stars with known planetary companions to include hot, fast-rotating stars. Planet-like transits have previously been reported in the lig...

Cameron, A. Collier; Guenther, E.; Smalley, B.; Mcdonald, I.; Hebb, L.; Andersen, J.; Augusteijn, Th; Barros, S. C. C.; Brown, D. J. A.; Cochran, W. D.; Endl, M.; Fossey, S. J.; Hartmann, M.; Maxted, P. F. L.; Pollacco, D.

2010-01-01

116

Finding the Nearest Extrasolar Planets with the Transiting Exoplanet Survey Satellite  

Science.gov (United States)

The Transiting Exoplanet Survey Satellite (TESS) is under development for NASA's Explorers Program with a planned launch in 2017. Over a two-year mission, TESS will conduct an all-sky survey to find transiting planets around dwarf stars in the solar neighborhood using four wide-angle optical cameras. TESS will spend between 27 and 350 days covering each of several hundred thousand target stars. In order to predict its yield, we have developed a detailed simulation of the TESS mission. We model the selection of target stars and adopt a planet population from the Kepler results. Next, we calculate the photometric signal-to-noise ratio TESS will achieve, accounting for photon shot noise, instrumental artifacts, and the background from zodiacal light and unresolved stars. We will present the yields of detected planets from the latest simulations, which currently show that TESS should discover over 200 super-Earths and over 400 sub-Neptunes with host stars brighter than I=12. We will also estimate the false-positive rate from blended binary stars. These results will allow the community to prepare for follow-up observations using photometric and radial-velocity techniques.

Sullivan, Peter; Winn, Joshua N.; Dressing, Courtney D.; Charbonneau, David; Morton, Tim; Levine, Alan M.; Vanderspek, Roland Kraft; Ricker, George R.

2014-06-01

117

A New Look at Spitzer Primary Transit Observations of the Exoplanet HD 189733b  

Science.gov (United States)

Blind source separation techniques are used to reanalyze two exoplanetary transit light curves of the exoplanet HD 189733b recorded with the IR camera IRAC on board the Spitzer Space Telescope at 3.6 ?m during the "cold" era. These observations, together with observations at other IR wavelengths, are crucial to characterize the atmosphere of the planet HD 189733b. Previous analyses of the same data sets reported discrepant results, hence the necessity of the reanalyses. The method we used here is based on the Independent Component Analysis (ICA) statistical technique, which ensures a high degree of objectivity. The use of ICA to detrend single photometric observations in a self-consistent way is novel in the literature. The advantage of our reanalyses over previous work is that we do not have to make any assumptions on the structure of the unknown instrumental systematics. Such "admission of ignorance" may result in larger error bars than reported in the literature, up to a factor 1.6. This is a worthwhile tradeoff for much higher objectivity, necessary for trustworthy claims. Our main results are (1) improved and robust values of orbital and stellar parameters, (2) new measurements of the transit depths at 3.6 ?m, (3) consistency between the parameters estimated from the two observations, (4) repeatability of the measurement within the photometric level of ~2 × 10-4 in the IR, and (5) no evidence of stellar variability at the same photometric level within one year.

Morello, G.; Waldmann, I. P.; Tinetti, G.; Peres, G.; Micela, G.; Howarth, I. D.

2014-05-01

118

ASTEROSEISMOLOGY OF THE TRANSITING EXOPLANET HOST HD 17156 WITH HUBBLE SPACE TELESCOPE FINE GUIDANCE SENSOR  

International Nuclear Information System (INIS)

Observations conducted with the Fine Guidance Sensor on the Hubble Space Telescope (HST) providing high cadence and precision time-series photometry were obtained over 10 consecutive days in 2008 December on the host star of the transiting exoplanet HD 17156b. During this time, 1.0 x 1012 photons (corrected for detector dead time) were collected in which a noise level of 163 parts per million per 30 s sum resulted, thus providing excellent sensitivity to the detection of the analog of the solar 5-minute p-mode oscillations. For HD 17156, robust detection of p modes supports the determination of the stellar mean density of (?*) = 0.5301 ± 0.0044 g cm-3 from a detailed fit to the observed frequencies of modes of degree l = 0, 1, and 2. This is the first star for which the direct determination of (?*) has been possible using both asteroseismology and detailed analysis of a transiting planet light curve. Using the density constraint from asteroseismology, and stellar evolution modeling results in M* = 1.285 ± 0.026 Msun, R* = 1.507 ± 0.012 Rsun, and a stellar age of 3.2 ± 0.3 Gyr.

119

Asteroseismology of the Transiting Exoplanet Host HD 17156 with HST FGS  

CERN Document Server

Observations conducted with the Fine Guidance Sensor on Hubble Space Telescope (HST) providing high cadence and precision time-series photometry were obtained over 10 consecutive days in December 2008 on the host star of the transiting exoplanet HD 17156b. During this time 10^12 photons (corrected for detector deadtime) were collected in which a noise level of 163 parts per million per 30 second sum resulted, thus providing excellent sensitivity to detection of the analog of the solar 5-minute p-mode oscillations. For HD 17156 robust detection of p-modes supports determination of the stellar mean density of 0.5301 +/- 0.0044 g/cm^3 from a detailed fit to the observed frequencies of modes of degree l = 0, 1, and 2. This is the first star for which direct determination of the mean stellar density has been possible using both asteroseismology and detailed analysis of a transiting planet light curve. Using the density constraint from asteroseismology, and stellar evolution modeling results in M_star = 1.285 +/- 0...

Gilliland, Ronald L; Nelan, Edmund P; Brown, Timothy M; Charbonneau, David; Nutzman, Philip; Christensen-Dalsgaard, Joergen; Kjeldsen, Hans

2010-01-01

120

TASTE: The Asiago Search for Transit timing variations of Exoplanets. I. Overview and improved parameters for HAT-P-3b and HAT-P-14b  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A promising method for detecting earth-sized exoplanets is the timing analysis of a known transit. The technique allows a search for variations in either the transit duration or the center induced by the perturbation of a third body, e.g. a second planet or an exomoon. By applying this method, the TASTE (The Asiago Search for Transit Timing variations of Exoplanets) project will collect high-precision, short-cadence light curves for a selected sample of transits by using ima...

Nascimbeni, V.; Piotto, G.; Bedin, L. R.; Damasso, M.

2010-01-01

 
 
 
 
121

High-precision ground-based observations of transiting exoplanets to detect their magnetic fields and undiscovered companions  

Science.gov (United States)

Here we present U and B band photometric light curves of several bright transiting exoplanets observed with the University of Arizona's 61''/Mont4k in order to better determine their physical parameters and search for their magnetic fields and undiscovered planetary companions. Recent studies suggest that it is possible to determine the presence and constrain the strength of a magnetic field by observing an exoplanet's bow shock. The shock would be detected via asymmetries in the UV and optical light curves, specifically if the ingress in the near-UV occurs earlier than in the optical. The size of this offset indicates the planet's magnetic field strength. In addition, our photometry, which spans multiple nights, is used to more precisely measure the radius of these exoplanets and determine any transit timing variations that could potentially indicate a nearby companion. The data are reduced via an in-house, publicly available pipeline, ExoDRPL. Our research group, AzGOE, is made primarily of undergraduate students from the University of Arizona in cooperation with the University of Arizona Astronomy Club, and gives these students the ability to take, reduce, and publish their own ground based observations.

Ryleigh Fitzpatrick, Morgan; Watson, Zachary; Zellem, Robert; Pearson, Kyle; Griffith, Caitlin Ann; AzGOE

2015-01-01

122

A new look at Spitzer primary transit observations of the exoplanet HD189733b  

CERN Document Server

Blind source separation techniques are used to reanalyse two exoplanetary transit lightcurves of the exoplanet HD189733b recorded with the IR camera IRAC on board the Spitzer Space Telescope at 3.6$\\mu$m during the "cold" era. These observations, together with observations at other IR wavelengths, are crucial to characterise the atmosphere of the planet HD189733b. Previous analyses of the same datasets reported discrepant results, hence the necessity of the reanalyses. The method we used here is based on the Independent Component Analysis (ICA) statistical technique, which ensures a high degree of objectivity. The use of ICA to detrend single photometric observations in a self-consistent way is novel in the literature. The advantage of our reanalyses over previous work is that we do not have to make any assumptions on the structure of the unknown instrumental systematics. Such "admission of ignorance" may result in larger error bars than reported in the literature, up to a factor $1.6$. This is a worthwhile t...

Morello, Giuseppe; Tinetti, Giovanna; Peres, Giovanni; Micela, Giuseppina; Howarth, Ian D

2014-01-01

123

The centre-to-limb variations of solar Fraunhofer lines imprinted upon lunar eclipse spectra. Implications for exoplanet transit observations  

Science.gov (United States)

The atmospheres of exoplanets are commonly studied by observing the transit of the planet passing in front of its parent star. The obscuration of part of the stellar disk during a transit will reveal aspects of its surface structure resulting from general centre-to-limb variations (CLVs). These become apparent when forming the ratio between the stellar light in and out of transit. These phenomena can be seen particularly clearly during the progress of a penumbral lunar eclipse, where the Earth transits the solar disk and masks different regions of the solar disk as the eclipse progresses. When inferring the properties of the planetary atmosphere, it is essential that this effect originating at the star is properly accounted for. Using the data observed from the 2014-April-15 lunar eclipse with the ESPaDOnS spectrograph mounted on the Canada France Hawaii Telescope (CFHT), we have obtained for the first time a time sequence of the penumbral spectra. These penumbral spectra enable us to study the centre-to-limb variations of solar Fraunhofer lines when the Earth is transiting Sun. The Na i and Ca ii absorption features reported from previous lunar eclipse observations are demonstrated to be CLV features, which dominate the corresponding line profiles and mask possible planetary signal. Detecting atmospheric species in exoplanets via transit spectroscopy must account for the CLV effect.

Yan, F.; Fosbury, R. A. E.; Petr-Gotzens, M. G.; Zhao, G.; Pallé, E.

2015-02-01

124

Transit Observations of Venus's Atmosphere in 2012 from Terrestrial and Space Telescopes as Exoplanet Analogs  

Science.gov (United States)

We extensively observed the 8 June 2012 transit of Venus from several sites on Earth; we provide this interim status report about this and about two subsequent ToVs observed from space. From Haleakala Obs., we observed the entire June transit over almost 7 h with a coronagraph of the Venus Twilight Experiment B filter) and with a RED Epic camera to compare with simultaneous data from ESA's Venus Express, to study the Cytherean mesosphere; from Kitt Peak, we have near-IR spectropolarimetry at 1.6 µm from the aureole and during the disk crossing that compare well with carbon dioxide spectral models; from Sac Peak/IBIS we have high-resolution imaging of the Cytherean aureole for 22 min, starting even before 1st contact; from Big Bear, we have high-resolution imaging of Venus's atmosphere and the black-drop effect through 2nd contact; and we had 8 other coronagraphs around the world. For the Sept 21 ToV as seen from Jupiter, we had 14 orbits of HST to use Jupiter's clouds as a reflecting surface to search for an 0.01% diminution in light and a differential drop that would result from Venus's atmosphere by observing in both IR/UV, for which we have 170 HST exposures. As of this writing, preliminary data reduction indicates that variations in Jovian clouds and the two periods of Jupiter's rotation will be too great to allow extraction of the transit signal. For the December 20 ToV as seen from Saturn, we had 22 hours of observing time with VIMS on Cassini, for which we are looking for a signal of the 10-hr transit in total solar irradiance and of Venus's atmosphere in IR as an exoplanet-transit analog. Our Maui & Sac Peak expedition was sponsored by National Geographic Society's Committee for Research and Exploration; HST data reduction by NASA: HST-GO-13067. Some of the funds for the carbon dioxide filter for Sac Peak provided by NASA through AAS's Small Research Grant Program. We thank Rob Ratkowski of Haleakala Amateur Astronomers; Rob Lucas, Aram Friedman, Eric Pilger, Stan Truitt, and Steve Bisque/Software Bisque for Haleakala support/operations; Vasyl Yurchyshyn and Joseph Gangestad '06 of The Aerospace Corp. at Big Bear Solar Obs; LMSAL and Hinode science/operations team.

Pasachoff, Jay M.; Schneider, G.; Babcock, B. A.; Lu, M.; Penn, M. J.; Jaeggli, S. A.; Galayda, E.; Reardon, K. P.; Widemann, T.; Tanga, P.; Ehrenreich, D.; Vidal-Madjar, A.; Nicholson, P. D.; Dantowitz, R.

2013-06-01

125

Directed follow-up strategy of low-cadence photometric surveys in Search of Transiting Exoplanets - II. application to Gaia  

CERN Document Server

In a previous paper we presented the Directed Follow-Up (DFU) approach, which we suggested can be used to efficiently augment low-cadence photometric surveys in a way that will optimize the chances to detect transiting exoplanets. In this paper we present preliminary tests of applying the DFU approach to the future ESA space mission Gaia. We demonstrate the strategy application to Gaia photometry through a few simulated cases of known transiting planets, using Gaia expected performance and current design. We show that despite the low cadence observations DFU, when tailored for Gaia's scanning law, can facilitate detection of transiting planets with ground-based observations, even during the lifetime of the mission. We conclude that Gaia photometry, although not optimized for transit detection, should not be ignored in the search of transiting planets. With a suitable ground-based follow-up network it can make an important contribution to this search.

Dzigan, Yifat

2012-01-01

126

Accretion of Jupiter-mass Planets in the Limit of Vanishing Viscosity  

CERN Document Server

In the core-accretion model the nominal runaway gas-accretion phase brings most planets to multiple Jupiter masses. However, known giant planets are predominantly Jupiter-mass. Obtaining longer timescales for gas accretion may require using realistic equations of states, or accounting for the dynamics of the circumplanetary disk (CPD) in low-viscosity regime, or both. Here we explore the second way using global, three-dimensional isothermal hydrodynamical simulations with 8 levels of nested grids around the planet. In our simulations the vertical inflow from the circumstellar disk (CSD) to the CPD determines the shape of the CPD and its accretion rate. Even without prescribed viscosity Jupiter's mass-doubling time is $\\sim 10^4$ years, assuming the planet at 5.2 AU and a Minimum Mass Solar Nebula. However, we show that this high accretion rate is due to resolution-dependent numerical viscosity. Furthermore, we consider the scenario of a layered CSD, viscous only in its surface layer, and an inviscid CPD. We i...

Szulágyi, J; Crida, A; Masset, F

2013-01-01

127

GTC OSIRIS transiting exoplanet atmospheric survey: detection of sodium in XO-2b from differential long-slit spectroscopy  

CERN Document Server

We present two transits of the hot-Jupiter exoplanet XO-2b using the Gran Telescopio Canarias (GTC). The time series observations were performed using long-slit spectroscopy of XO-2 and a nearby reference star with the OSIRIS instrument, enabling differential specrophotometric transit lightcurves capable of measuring the exoplanet's transmission spectrum. Two optical low-resolution grisms were used to cover the optical wavelength range from 3800 to 9300{\\AA}. We find that sub-mmag level slit losses between the target and reference star prevent full optical transmission spectra from being constructed, limiting our analysis to differential absorption depths over ~1000{\\AA} regions. Wider long slits or multi-object grism spectroscopy with wide masks will likely prove effective in minimising the observed slit-loss trends. During both transits, we detect significant absorption in the planetary atmosphere of XO-2b using a 50{\\AA} bandpass centred on the Na I doublet, with absorption depths of Delta(R_pl/R_star)^2=0...

Sing, D K; Lopez-Morales, M; Pont, F; Désert, J -M; Ehrenreich, D; Wilson, P A; Ballester, G E; Fortney, J J; Etangs, A Lecavelier des; Vidal-Madjar, A

2012-01-01

128

The Transit Light Curve Project. VII. The Not-So-Bloated Exoplanet HAT-P-1b  

CERN Document Server

We present photometry of the G0 star HAT-P-1 during six transits of its close-in giant planet, and we refine the estimates of the system parameters. Relative to Jupiter's properties, HAT-P-1b is 1.20 +/- 0.05 times larger and its surface gravity is 2.7 +/- 0.2 times weaker. Although it remains the case that HAT-P-1b is among the least dense of the known sample of transiting exoplanets, its properties are in accord with previously published models of strongly irradiated, coreless, solar-composition giant planets. The times of the transits have a typical accuracy of 1 min and do not depart significantly from a constant period.

Winn, Joshua N; Bakos, Gaspar A; Pal, Andras; Johnson, John Asher; Williams, Peter K G; Shporer, Avi; Mazeh, Tsevi; Fernandez, Jose; Latham, David W

2007-01-01

129

Confirmation of an exoplanet using the transit color signature: Kepler-418b, a blended giant planet in a multiplanet system  

Science.gov (United States)

Aims: We announce confirmation of Kepler-418b, one of two proposed planets in this system. This is the first confirmation of an exoplanet based primarily on the transit color signature technique. Methods: We used the Kepler public data archive combined with multicolor photometry from the Gran Telescopio de Canarias and radial velocity follow-up using FIES at the Nordic Optical Telescope for confirmation. Results: We report a confident detection of a transit color signature that can only be explained by a compact occulting body, entirely ruling out a contaminating eclipsing binary, a hierarchical triple, or a grazing eclipsing binary. Those findings are corroborated by our radial velocity measurements, which put an upper limit of ~1 MJup on the mass of Kepler-418b. We also report that the host star is significantly blended, confirming the ~10% light contamination suspected from the crowding metric in the Kepler light curve measured by the Kepler team. We report detection of an unresolved light source that contributes an additional ~30% to the target star, which would not have been detected without multicolor photometric analysis. The resulting planet-star radius ratio is 0.110 ± 0.0025, more than 25% more than the 0.087 measured by Kepler leading to a radius of 1.20 ± 0.16 RJup instead of the 0.94 RJup measured by the Kepler team. Conclusions: This is the first confirmation of an exoplanet candidate based primarily on the transit color signature, demonstrating that this technique is viable from ground for giant planets. It is particularly useful for planets with long periods such as Kepler-418b, which tend to have long transit durations. While this technique is limited to candidates with deep transits from the ground, it may be possible to confirm earth-like exoplanet candidates with a few hours of observing time with an instrument like the James Webb Space Telescope. Additionally, multicolor photometric analysis of transits can reveal unknown stellar neighbors and binary companions that do not affect the classification of the transiting object but can have a very significant effect on the perceived planetary radius. GTC g' and z' photometry and NOT-FIES spectroscopy 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/567/A14

Tingley, B.; Parviainen, H.; Gandolfi, D.; Deeg, H. J.; Palle, E.; Montañés Rodriguez, P.; Murgas, F.; Alonso, R.; Bruntt, H.; Fridlund, M.

2014-07-01

130

The MEarth project: an all-sky survey for transiting Earth-like exoplanets orbiting nearby M-dwarfs  

Science.gov (United States)

The MEarth project is an operational all-sky survey searching for transiting Earth-like exoplanets around 3,000 of the closest mid-to-late M-dwarfs. These will be among the best planets in their size class for atmospheric characterization using present day and near-future instruments such as HST, JWST and ground-based Extremely Large Telescopes (ELTs), by virtue of the large observational signal sizes afforded by their small and bright host stars. We present an update on the status and recent scientific results of the survey from our two observing stations: MEarth-North at Fred Lawrence Whipple Observatory, Mount Hopkins, Arizona, and MEarth-South at Cerro Tololo Inter-American Observatory, Chile. MEarth-North discovered the transiting mini-Neptune exoplanet GJ 1214b, which currently has the best-studied atmosphere of any exoplanet in its size class. In addition to searching for planets, we actively pursue stellar astrophysics topics and characterization of the target star sample using MEarth data and supplementary spectroscopic follow-up. This has included measuring astrometric parallaxes for more than 1500 nearby stars, the discovery of 6 new low-mass eclipsing binaries amenable to direct measurement of the masses and radii of their components, and rotation periods, spectral classifications, metallicities and activity indices for hundreds of stars. The MEarth light curves themselves also provide a detailed record of the photometric behavior of the target stars, which include the most favorable and interesting targets to search for small and potentially habitable planets. This will be a valuable resource for all future surveys searching for planets around these stars. All light curves gathered during the survey are made publicly available after one year.The MEarth project gratefully acknowledges funding from the David and Lucile Packard Fellowship for Science and Engineering, the National Science Foundation under grants AST-0807690, AST-1109468, and AST-1004488, and the John Templeton Foundation.

Irwin, Jonathan; Berta-Thompson, Zachory K.; Charbonneau, David; Dittmann, Jason; Newton, Elisabeth R.

2015-01-01

131

Observations of Transiting Exoplanets with the James Webb Space Telescope (JWST), Publications of the Astronomical Society of the Pacific (PASP), December 2014  

CERN Document Server

This article summarizes a workshop held on March, 2014, on the potential of the James Webb Space Telescope (JWST) to revolutionize our knowledge of the physical properties of exoplanets through transit observations. JWST's unique combination of high sensitivity and broad wavelength coverage will enable the accurate measurement of transits with high signal-to-noise. Most importantly, JWST spectroscopy will investigate planetary atmospheres to determine atomic and molecular compositions, to probe vertical and horizontal structure, and to follow dynamical evolution, i.e. exoplanet weather. JWST will sample a diverse population of planets of varying masses and densities in a wide variety of environments characterized by a range of host star masses and metallicities, orbital semi-major axes and eccentricities. A broad program of exoplanet science could use a substantial fraction of the overall JWST mission.

Beichman, Charles; Knutson, Heather; Smith, Roger; Dressing, Courtney; Latham, David; Deming, Drake; Lunine, Jonathan; Lagage, Pierre-Olivier; Sozzetti, Alessandro; Beichman, Charles; Sing, David; Kempton, Eliza; Ricker, George; Bean, Jacob; Kreidberg, Laura; Bouwman, Jeroen; Crossfield, Ian; Christiansen, Jessie; Ciardi, David; Fortney, Jonathan; Albert, Loïc; Doyon, René; Rieke, Marcia; Rieke, George; Clampin, Mark; Greenhouse, Matt; Goudfrooij, Paul; Hines, Dean; Keyes, Tony; Lee, Janice; McCullough, Peter; Robberto, Massimo; Stansberry, John; Valenti, Jeff; Deroo, Pieter D; Mandell, Avi; Ressler, Michael E; Shporer, Avi; Swain, Mark; Vasisht, Gautam; Carey, Sean; Krick, Jessica; Birkmann, Stephan; Ferruit, Pierre; Giardino, Giovanna; Greene, Tom; Howell, Steve

2014-01-01

132

On the (im)possibility of testing new physics in exoplanets using transit timing variations: deviation from inverse-square law of gravity  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Ground-based and space-borne observatories studying exoplanetary transits now and in the future will considerably increase the number of known exoplanets and the precision of the measured times of transit minima. Variations in the transit times can not only be used to infer the presence of additional planets, but might also provide opportunities for testing new physics in the places beyond the Solar system. In this work, we take deviation from the inverse-square law of gravi...

Xie, Yi; Deng, Xue-mei

2014-01-01

133

CFBDSIR2149-0403: a 4-7 Jupiter-mass free-floating planet in the young moving group AB Doradus?  

Science.gov (United States)

Using the CFBDSIR wide field survey for brown dwarfs, we identified CFBDSIRJ214947.2-040308.9, a late T dwarf with an atypically red J - KS colour. We obtained an X-Shooter spectra, with signal detectable from 0.8 ?m to 2.3 ?m, which confirmed a T7 spectral type with an enhanced Ks-band flux indicative of a potentially low-gravity, young object. The comparison of our near infrared spectrum with atmosphere models for solar metallicity shows that CFBDSIRJ214947.2-040308.9 is probably a 650-750 K, log g = 3.75-4.0 substellar object. Using evolution models, this translates into a planetary mass object with an age in the 20-200 Myr range. An independent Bayesian analysis from proper motion measurements results in a 87% probability that this free-floating planet is a member of the 50-120 Myr-old AB Doradus moving group, which strengthens the spectroscopic diagnosis of youth. By combining our atmospheric characterisation with the age and metallicity constraints arising from the probable membership to the AB Doradus moving group, we find that CFBDSIRJ214947.2-040308.9 is probably a 4-7 Jupiter mass, free-floating planet with an effective temperature of ~700 K and a log g of ~4.0, typical of the late T-type exoplanets that are targeted by direct imaging. We stress that this object could be used as a benchmark for understanding the physics of the similar T-type exoplanets that will be discovered by the upcoming high-contrast imagers. Based on observations obtained with SOFI on the NTT at ESO-La Silla (run 086.C-0655(A)). Based on observations obtained with X-Shooter on VLT-UT2 at ESO-Paranal (run 087.C-0562(A)). Based on observations obtained with WIRCAM at CFHT (programmes 09AF21, 10BF26, and 11BD86).

Delorme, P.; Gagné, J.; Malo, L.; Reylé, C.; Artigau, E.; Albert, L.; Forveille, T.; Delfosse, X.; Allard, F.; Homeier, D.

2012-12-01

134

The centre-to-limb variations of solar Fraunhofer lines imprinted upon lunar eclipse spectra - Implications for exoplanet transit observations  

CERN Document Server

The atmospheres of exoplanets are commonly studied by observing the transit of the planet passing in front of its parent star. The obscuration of part of the stellar disk during a transit will reveal aspects of its surface structure resulting from general centre-to-limb variations (CLVs). These become apparent when forming the ratio between the stellar light in and out of transit. These phenomena can be seen particularly clearly during the progress of a penumbral lunar eclipse, where the Earth transits the solar disk and masks different regions of the solar disk as the eclipse progresses. When inferring the properties of the planetary atmosphere, it is essential that this effect originating at the star is properly accounted for. Using the data observed from the 2014-April-15 lunar eclipse with the ESPaDOnS spectrograph mounted on the Canada France Hawaii Telescope (CFHT), we have obtained for the first time a time sequence of the penumbral spectra. These penumbral spectra enable us to study the centre-to-limb...

Yan, Fei; Petr-Gotzens, Monika G; Zhao, Gang; Pallé, Enric

2015-01-01

135

Discovery of a probable 4-5 Jupiter-mass exoplanet to HD 95086 by direct-imaging  

CERN Document Server

Direct imaging has just started the inventory of the population of gas giant planets on wide-orbits around young stars in the solar neighborhood. Following this approach, we carried out a deep imaging survey in the near-infrared using VLT/NaCo to search for substellar companions. We report here the discovery in L' (3.8 microns) images of a probable companion orbiting at 56 AU the young (10-17 Myr), dusty, and early-type (A8) star HD 95086. This discovery is based on observations with more than a year-time-lapse. Our first epoch clearly revealed the source at 10 sigma while our second epoch lacked good observing conditions hence yielding a 3 sigma detection. Various tests were thus made to rule out possible artifacts. This recovery is consistent with the signal at the first epoch but requires cleaner confirmation. Nevertheless, our astrometric precision suggests the companion to be comoving with the star, with a 3 sigma confidence level. The planetary nature of the source is reinforced by a non-detection in Ks...

Rameau, J; Lagrange, A -M; Boccaletti, A; Quanz, S P; Bonnefoy, M; Girard, J H; Delorme, P; Desidera, S; Klahr, H; Mordasini, C; Dumas, C; Bonavita, M; Meshkat, T; Bailey, V; Kenworthy, M

2013-01-01

136

Analysis of Secondary Eclipse Observations of Exoplanet WASP-34b  

Science.gov (United States)

WASP-34b is a short-period exoplanet with a mass of 0.59 +/- 0.01 Jupiter masses orbiting a sun-like star with a period of 4.3177 days and an eccentricity of 0.038 +/- 0.012 (Smalley, 2010). We observed WASP-34b using the 3.6 and 4.5 micron channels of the InfraredArray Camera aboard the Spitzer Space Telescope in 2010 (Program 60003). We present eclipse-depth measurements, estimates of infrared brightness temperatures, and refine the orbit using our secondary eclipse measurements.

Challener, Ryan; Harrington, Joseph; Garland, Justin; Cubillos, Patricio; Blecic, Jasmina; Smalley, Barry

2015-01-01

137

Exoplanet properties from Lick, Keck and AAT  

Energy Technology Data Exchange (ETDEWEB)

Doppler-shift measurements with a remarkable precision of {delta}{lambda}/{lambda}=3x10{sup -9}, corresponding to velocities of 1 m s{sup -1}, have been made repeatedly of 2500 stars located within 300 light years. The observed gravitational perturbations of the stars have revealed 250 orbiting planets, with 27 that cross in front of the host star, blocking a fraction of the starlight to allow measurement of the planet's mass, radius and density. Two new discoveries are the first good analog of Jupiter (HD 154345b) and the first system of five planets (55 Cancri). The predominantly eccentric orbits of exoplanets probably result from planet-planet gravitational interactions or angular momentum exchange by mean-motion resonances. The planet mass distribution ranges from {approx}15 M{sub JUP} to as low as {approx}5 M{sub Earth} and rises toward lower masses as dN/dM{approx}M{sup -1.1}. The distribution with orbital distance, a, rises (in logarithmic intervals) as dN/d log a{approx}a{sup +0.4}. Extrapolation and integration suggests that 19% of all Sun-like stars harbor a gas-giant planet within 20 AU, but there remains considerable incompleteness for large orbits. Beyond 20 AU, the occurrence of gas-giant planets may be less than a few per cent as protoplanetary disk material there has lower densities and is vulnerable to destruction. Jupiter-mass planets occur more commonly around more massive stars than low mass stars. The transit of the Neptune-mass planet, Gliese 436b, yields a density of 1.55 g cm{sup -3} suggesting that its interior has an iron-silicate core surrounded by an envelope of water-ice and an outer H-He shell. Planets with masses as low as five Earth-masses may be commonly composed of iron-nickel, rock and water along with significant amounts of H and He, making the term 'super-Earth' misleading. The transiting planet HD147506b has high orbital eccentricity but no significant orbital inclination to the line of sight, presenting a puzzle about its history. Its orbit together with the mean motion resonances of 4 of the 22 multi-planet systems provides further evidence for the role of planet-planet interactions in shaping planetary architectures.

Marcy, G W; Wright, J T; Upadhyay, S [Department of Astronomy, MS3411, University of California, Berkeley, CA 94720 (United States); Butler, R P [Department of Terrestrial Magnetism, Carnegie Institute of Washington, 5241 Broad Branch Road NW, Washington, DC 20015 (United States); Vogt, S S [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Fischer, D A [Department of Physics and Astronomy, San Francisco State University, CA, 94132 (United States); Johnson, J A [Institute for Astronomy, Honolulu, HI 96822 (United States); Tinney, C G [Department of Astrophysics, University of New South Wales (Australia); Jones, H R A [Department of Astrophysics, University of Hertfordshire, Hatfield, AL10 9AB (United Kingdom); Carter, B D [Faculty of Sciences, University of Southern Queensland, Toowoomba, Queensland 4350 (Australia); Bailey, J [Australian Centre for Astrobiology, Macquarie University, Sydney, NSW 2109 (Australia); O' Toole, S J [Anglo-Australian Observatory, PO Box 296, Epping 1710 (Australia)], E-mail: gmarcy@berkeley.edu

2008-08-15

138

Confirmation of an exoplanet using the transit color signature: Kepler-418b, a blended giant planet in a multiplanet system  

CERN Document Server

We announce confirmation of Kepler-418b, one of two proposed planets in this system. This is the first confirmation of an exoplanet based primarily on the transit color signature technique. We used the Kepler public data archive combined with multicolor photometry from the Gran Telescopio de Canarias and radial velocity follow-up using FIES at the Nordic Optical Telescope for confirmation. We report a confident detection of a transit color signature that can only be explained by a compact occulting body, entirely ruling out a contaminating eclipsing binary, a hierarchical triple, or a grazing eclipsing binary. Those findings are corroborated by our radial velocity measurements, which put an upper limit of ~1 Mjup on the mass of Kepler-418b. We also report that the host star is significantly blended, confirming the ~10% light contamination suspected from the crowding metric in the Kepler light curve measured by the Kepler team. We report detection of an unresolved light source that contributes an additional ~4...

Tingley, B; Gandolfi, D; Deeg, H J; Pallé, E; Rodriguez, P Montañés; Murgas, F; Alonso, R; Bruntt, H; Fridlund, M

2014-01-01

139

Transiting exoplanets from the CoRoT space mission. XXIII. CoRoT-21b: a doomed large Jupiter around a faint subgiant star  

DEFF Research Database (Denmark)

CoRoT-21, a F8IV star of magnitude V = 16 mag, was observed by the space telescope CoRoT during the Long Run 01 (LRa01) in the first winter field (constellation Monoceros) from October 2007 to March 2008. Transits were discovered during the light curve processing. Radial velocity follow-up observations, however, were performed mainly by the 10-m Keck telescope in January 2010. The companion CoRoT-21b is a Jupiter-like planet of 2.26 ± 0.33 Jupiter masses and 1.30 ± 0.14 Jupiter radii in an circular orbit of semi-major axis 0.0417 ± 0.0011 AU and an orbital period of 2.72474 ± 0.00014 days. The planetary bulk density is (1.36 ? ± ? 0.48) × 103 kg m-3, very similar to the bulk density of Jupiter, and follows an M1/3 ? R relation like Jupiter. The F8IV star is a sub-giant star of 1.29 ± 0.09 solar masses and 1.95 ± 0.2 solar radii. The star and the planet exchange extremetidal forces that will lead to orbital decay and extreme spin-up of the stellar rotation within 800 Myr if the stellar dissipation is Q?/k2? ? 107.

Pätzold, M.; Endl, M.

2012-01-01

140

Long-lived Chaotic Orbital Evolution of Exoplanets in Mean Motion Resonances with Mutual Inclinations  

Science.gov (United States)

Mean motion resonances, in which two orbital frequencies are close to an integer multiple of each other, are common throughout the Solar System and exoplanetary systems. We present N-body simulations of resonant planets with inclined orbits and show that orbital eccentricities and inclinations can evolve chaotically for at least 10 Gyr. A wide range of behavior is possible, ranging from fast, low amplitude variations to a complete sampling of all parameter space, i.e. eccentricities reach 0.999 and inclinations 179.9 degrees. While the orbital elements evolve chaotically, at least one resonant argument librates, the traditional metric for identifying resonant behavior. This chaotic evolution is possible in the 2:1, 3:1 and 3:2 resonances, and for a range of planetary masses from lunar- to Jupiter-mass. In some cases, orbital disruption occurs after several Gyr, implying the mechanism is not rigorously stable, just long-lived relative to the main sequence lifetimes of solar type stars. We also re-examine simulations of planet-planet scattering and find that they produce planets in inclined resonances that evolve chaotically in about 0.5% of cases. Our results suggest that 1) approximate methods for identifying unstable orbital architectures may have limited applicability, 2) some short-period exoplanets may be formed during tidal circularization when the eccentricity is large, 3) those exoplanets' orbital planes may be misaligned with the host star spin axis, 4) on average, systems with resonances may be systematically younger than those without, 5) the distribution of period ratios of adjacent planets detected via transit may be skewed, and 6) potentially habitable planets may have dramatically different climatic evolution than the Earth. We show that the known systems HD 73526, HD 45364 and HD 60532 system may be in chaotically-evolving resonances. The GAIA spacecraft is capable of discovering giant planets in these types of planetary systems.

Barnes, Rory; Deitrick, Russell; Greenberg, Richard; Quinn, Thomas R.; Raymond, Sean N.

2015-01-01

 
 
 
 
141

The Effect of Conjunctions on the Transit Timing Variations of Exoplanets  

CERN Document Server

We develop an analytic model for transit timing variations produced by orbital conjunctions between gravitationally interacting planets. If the planetary orbits have tight orbital spacing, which is a common case among the Kepler planets, the effect of a single conjunction can be best described as: (1) a step-like change of the transit timing ephemeris with subsequent transits of the inner planet being delayed and those of the outer planet being sped up, and (2) a discrete change in sampling of the underlying oscillations from eccentricity-related interaction terms. In the limit of small orbital eccentricities, our analytic model gives explicit equations for these effects as a function of the mass and orbital separation of planets. We point out that a detection of the conjunction effect in real data is of crucial importance for the physical characterization of planetary systems from transit timing variations.

Nesvorny, David

2014-01-01

142

The NASA EPOXI mission of opportunity to gather ultraprecise photometry of known transiting exoplanets  

CERN Document Server

The NASA Discovery mission EPOXI, utilizing the Deep Impact flyby spacecraft, comprises two phases: EPOCh (Extrasolar Planet Observation and Characterization) and DIXI (Deep Impact eXtended Investigation). With EPOCh, we use the 30-cm high resolution visible imager to obtain ultraprecise photometric light curves of known transiting planet systems. We will analyze these data for evidence of additional planets, via transit timing variations or transits; for planetary moons or rings; for detection of secondary eclipses and the constraint of geometric planetary albedos; and for refinement of the system parameters. Over a period of four months, EPOCh observed four known transiting planet systems, with each system observed continuously for several weeks. Here we present an overview of EPOCh, including the spacecraft and science goals, and preliminary photometry results.

Christiansen, Jessie L; A'Hearn, Michael F; Deming, Drake; Holman, Matthew J; Ballard, Sarah; Weldrake, David T F; Barry, Richard K; Kuchner, Marc J; Livengood, Timothy A; Pedelty, Jeffrey; Schultz, Alfred; Hewagama, Tilak; Sunshine, Jessica M; Wellnitz, Dennis D; Hampton, Don L; Lisse, Carey M; Seager, Sara; Veverka, Joseph F

2008-01-01

143

Exoplanet Orbit Database. II. Updates to Exoplanets.org  

Science.gov (United States)

The Exoplanet Orbit Database (EOD) compiles orbital, transit, host star, and other parameters of robustly-detected exoplanets reported in the peer-reviewed literature. The EOD can be navigated through the Exoplanet Data Explorer (EDE) plotter and table, available on the World Wide Web at http://exoplanets.org. The EOD contains data for 1492 confirmed exoplanets as of 2014 July. The EOD descends from a table provided by Butler and coworkers in 2002 and the Catalog of Nearby Exoplanets (Butler and coworkers in 2006), and the first complete documentation for the EOD and the EDE was presented by Wright and coworkers in 2011. In this work, we describe our work since then. We have expanded the scope of the EOD to include secondary eclipse parameters and asymmetric uncertainties and expanded the EDE to include the sample of over 3000 Kepler Objects of Interest (KOIs) and other real planets without good orbital parameters (such as many of those detected by microlensing and imaging). Users can download the latest version of the entire EOD as a single comma separated value file from the front page of http://exoplanets.org.

Han, Eunkyu; Wang, Sharon X.; Wright, Jason T.; Feng, Y. Katherina; Zhao, Ming; Fakhouri, Onsi; Brown, Jacob I.; Hancock, Colin

2014-11-01

144

HAT-P-14b: A 2.2 MJ EXOPLANET TRANSITING A BRIGHT F STAR  

International Nuclear Information System (INIS)

We report the discovery of HAT-P-14b, a fairly massive transiting extrasolar planet orbiting the moderately bright star GSC 3086-00152 (V = 9.98), with a period of P = 4.627669 ± 0.000005 days. The transit is close to grazing (impact parameter 0.891+0.007-0.008) and has a duration of 0.0912 ± 0.0017 days, with a reference epoch of mid-transit of Tc = 2, 454, 875.28938 ± 0.00047 (BJD). The orbit is slightly eccentric (e = 0.107 ± 0.013), and the orientation is such that occultations are unlikely to occur. The host star is a slightly evolved mid-F dwarf with a mass of 1.386 ± 0.045 Msun, a radius of 1.468 ± 0.054 Rsun, effective temperature 6600 ± 90 K, and a slightly metal-rich composition corresponding to [Fe/H] = +0.11 ± 0.08. The planet has a mass of 2.232 ± 0.059 MJ and a radius of 1.150 ± 0.052 RJ, implying a mean density of 1.82 ± 0.24 g cm-3. Its radius is well reproduced by theoretical models for the 1.3 Gyr age of the system if the planet has a heavy-element fraction of about 50 M+ (7% of its total mass). The brightness, near-grazing orientation, and other properties of HAT-P-14 make it a favorable transiting system to look for changes in the orbital elements or transit timing variations induced by a possible second planet, and also to place meaningful constraints on the presence of sub-Earth mass or Earth-mass exomoons, by monitoring it for transit duby monitoring it for transit duration variations.

145

Evolution of Exoplanets and their Parent Stars  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Studying exoplanets with their parent stars is crucial to understand their population, formation and history. We review some of the key questions regarding their evolution with particular emphasis on giant gaseous exoplanets orbiting close to solar-type stars. For masses above that of Saturn, transiting exoplanets have large radii indicative of the presence of a massive hydrogen-helium envelope. Theoretical models show that this envelope progressively cools and contracts wit...

Guillot, Tristan; Lin, Douglas; Morel, Pierre; Havel, Mathieu; Parmentier, Vivien

2013-01-01

146

What asteroseismology can do for exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We describe three useful applications of asteroseismology in the context of exoplanet science: (1) the detailed characterisation of exoplanet host stars; (2) the measurement of stellar inclinations; and (3) the determination of orbital eccentricity from transit duration making use of asteroseismic stellar densities. We do so using the example system Kepler-410 (Van Eylen et al. 2014). This is one of the brightest (V = 9.4) Kepler exoplanet host stars, containing a small (2.8...

Eylen, Vincent; Lund, Mikkel N.; Aguirre, Victor Silva; Arentoft, Torben; Kjeldsen, Hans; Albrecht, Simon; Chaplin, William J.; Isaacson, Howard; Pedersen, May G.; Jessen-hansen, Jens; Tingley, Brandon; Christensen-dalsgaard, Joergen; Aerts, Conny; Campante, Tiago L.; Bryson, Steve T.

2014-01-01

147

Exoplanet Transit Spectroscopy Using WFC3: WASP-12 b, WASP-17 b, and WASP-19 b  

CERN Document Server

We report analysis of transit spectroscopy of the extrasolar planets WASP-12 b, WASP-17 b, and WASP-19 b using the Wide Field Camera 3 on the HST. We analyze the data for a single transit for each planet using a strategy similar in certain aspects to the techniques used by Berta et al. (2012), but we extend their methodology to allow us to correct for channel- or wavelength-dependent instrumental effects by utilizing the band-integrated time series and measurements of the drift of the spectrum on the detector over time. We achieve almost photon-limited results for individual spectral bins, but the uncertainties in the transit depth for the the band-integrated data are exacerbated by the uneven sampling of the light curve imposed by the orbital phasing of HST's observations. Our final transit spectra for all three objects are consistent with the presence of a broad absorption feature at 1.4 microns potentially due to water. However, the amplitude of the absorption is less than that expected based on previous o...

Mandell, Avi; Sinukoff, Evan; Madhusudhan, Nikku; Burrows, Adam; Deming, Drake

2013-01-01

148

FIVE NEW TRANSIT EPOCHS OF THE EXOPLANET OGLE-TR-111b  

International Nuclear Information System (INIS)

We report five new transit epochs of the extrasolar planet OGLE-TR-111b, observed in the v-HIGH and Bessell I bands with the FORS1 and FORS2 at the ESO Very Large Telescope between 2008 April and May. The new transits have been combined with all previously published transit data for this planet to provide a new transit timing variations (TTVs) analysis of its orbit. We find no TTVs with amplitudes larger than 1.5 minutes over a four-year observation time baseline, in agreement with the recent result by Adams et al. Dynamical simulations fully exclude the presence of additional planets in the system with masses greater than 1.3, 0.4, and 0.5 M+ at the 3:2, 1:2, and 2:1 resonances, respectively. We also place an upper limit of about 30 M+ on the mass of potential second planets in the region between the 3:2 and 1:2 mean-motion resonances.

149

Radial velocity follow-up of CoRoT transiting exoplanets  

Directory of Open Access Journals (Sweden)

Full Text Available We report on the results from the radial-velocity follow-up program performed to establish the planetary nature and to characterize the transiting candidates discovered by the space mission CoRoT. We use the SOPHIE at OHP, HARPS at ESO and the HIRES at Keck spectrographs to collect spectra and high-precision radial velocity (RV measurements for several dozens di?erent candidates from CoRoT. We have measured the Rossiter-McLaughlin e?ect of several con?rmed planets, especially CoRoT-1b which revealed that it is another highly inclined system. Such high-precision RV data are necessary for the discovery of new transiting planets. Furthermore, several low mass planet candidates have emerged from our Keck and HARPS data.

Deleuil M.

2011-02-01

150

New approach for modeling of transiting exoplanets for arbitrary limb-darkening law  

CERN Document Server

We present a new solution of the direct problem of planet transits based on transformation of double integrals to single ones. On the basis of our direct problem solution we created the code TAC-maker for rapid and interactive calculation of synthetic planet transits by numerical computations of the integrals. The validation of our approach was made by comparison with the results of the wide-spread Mandel & Agol (2002) method for the cases of linear, quadratic and squared root limb-darkening laws and various combinations of model parameters. For the first time our approach allows the use of arbitrary limb-darkening law of the host star. This advantage together with the practically arbitrary precision of the calculations make the code a valuable tool that faces the challenges of the continuously increasing photometric precision of the ground-based and space observations.

Kjurkchieva, D; Vladev, A; Yotov, V

2013-01-01

151

K-band transit and secondary eclipse photometry of exoplanet OGLE-TR-113b  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present high precision K-band photometry of the transit and secondary eclipse of extrasolar planet OGLE-TR-113, using the SOFI near-infrared instrument on ESO's NTT. Data were taken in 5 second exposures over two periods of 3-4 hours, using random jitter position offsets. In this way, a relative photometric precision of ~1% per frame was achieved, avoiding systematic effects that seem to become dominant at precisions exceeding this level, and resulting in an overall accur...

Snellen, I. A. G.; Covino, E.

2006-01-01

152

Three WASP-South transiting exoplanets: WASP-74b, WASP-83b & WASP-89b  

CERN Document Server

We report the discovery of three new transiting hot Jupiters by WASP-South together with the TRAPPIST photometer and the Euler/CORALIE spectrograph. WASP-74b orbits a star of V = 9.7, making it one of the brighter systems accessible to Southern telescopes. It is a 0.95 M_Jup planet with a moderately bloated radius of 1.5 R_Jup in a 2-d orbit around a slightly evolved F9 star. WASP-83b is a Saturn-mass planet at 0.3 M_Jup with a radius of 1.0 R_Jup. It is in a 5-d orbit around a fainter (V = 12.9) G8 star. WASP-89b is a 6 M_Jup planet in a 3-d orbit with an eccentricity of e = 0.2. It is thus similar to massive, eccentric planets such as XO-3b and HAT-P-2b, except that those planets orbit F stars whereas WASP-89 is a K star. The V = 13.1 host star is magnetically active, showing a rotation period of 20.2 d, while star spots are visible in the transits. There are indications that the planet's orbit is aligned with the stellar spin. WASP-89 is a good target for an extensive study of transits of star spots.

Hellier, Coel; Cameron, A Collier; Delrez, L; Gillon, M; Jehin, E; Lendl, M; Maxted, P F L; Pepe, F; Pollacco, D; Queloz, D; Segransan, D; Smalley, B; Smith, A M S; Southworth, J; Triaud, A H M J; Turner, O D; Udry, S; West, R G

2014-01-01

153

Search for Carbon Monoxide in the Atmosphere of the Transiting Exoplanet HD 189733b  

Science.gov (United States)

Water, methane, and carbon monoxide are expected to be among the most abundant molecules besides molecular hydrogen in the hot atmosphere of close-in extrasolar giant planets. Atmospheric models for these planets predict that the strongest spectrophotometric features of those molecules are located at wavelengths ranging from 1 to 10 ?m making this region of particular interest. Consequently, transit observations in the mid-infrared (mid-IR) allow the atmospheric content of transiting planets to be determined. We present new primary transit observations of the hot-Jupiter HD 189733b, obtained simultaneously at 4.5 and 8 ?m with the Infrared Array Camera onboard the Spitzer Space Telescope. Together with a new refined analysis of previous observations at 3.6 and 5.8 ?m using the same instrument, we are able to derive the system parameters, including planet-to-star radius ratio, impact parameter, scale of the system, and central time of the transit from fits of the transit light curves at these four wavelengths. We measure the four planet-to-star radius ratios, to be (Rp /R sstarf)3.6 ?m = 0.1545 ± 0.0003, (Rp /R sstarf)4.5 ?m = 0.1557 ± 0.0003, (Rp /R sstarf)5.8 ?m = 0.1547 ± 0.0005, and (Rp /R sstarf)8 ?m = 0.1544 ± 0.0004. The high accuracy of the planet radii measurement allows the search for atmospheric molecular absorbers. Contrary to a previous analysis of the same data set, our study is robust against systematics and reveals that water vapor absorption at 5.8 ?m is not detected in this photometric data set. Furthermore, in the band centered around 4.5 ?m we find a hint of excess absorption with an apparent planetary radius ?Rp /R * = 0.00128 ± 0.00056 larger (2.3?) than the one measured simultaneously at 8 ?m. This value is 4? above what would be expected for an atmosphere where water vapor is the only absorbing species in the near-IR. This shows that an additional species absorbing around 4.5 ?m could be present in the atmosphere. Carbon monoxide (CO) being a strong absorber at this wavelength is a possible candidate and this may suggest a large CO/H2O ratio between 5 and 60.

Désert, Jean-Michel; Lecavelier des Etangs, Alain; Hébrard, Guillaume; Sing, David K.; Ehrenreich, David; Ferlet, Roger; Vidal-Madjar, Alfred

2009-07-01

154

Transiting exoplanets from the CoRoT space mission. XIII. CoRoT-13b: a dense hot Jupiter in transit around a star with solar metallicity and super-solar lithium content  

CERN Document Server

We announce the discovery of the transiting planet CoRoT-13b. Ground based follow-up in CFHT and IAC80 confirmed CoRoT's observations. The mass of the planet was measured with the HARPS spectrograph and the properties of the host star were obtained analyzing HIRES spectra from the Keck telescope. It is a hot Jupiter-like planet with an orbital period of 4.04 days, 1.3 Jupiter masses, 0.9 Jupiter radii, and a density of 2.34 g cm-3. It orbits a G0V star with Teff=5945K, M*=1.09 Msun, R*=1.01 Rsun, solar metallicity, a lithium content of +1.45 dex, and an estimated age between 0.12 and 3.15 Gyr. The lithium abundance of the star is consistent with its effective temperature, activity level, and age range derived from the stellar analysis. The density of the planet is extreme for its mass. It implies the existence of an amount of heavy elements with a mass between about 140 and 300 Mearth.

Cabrera, J; Ollivier, M; Diaz, R F; Csizmadia, Sz; Aigrain, S; Alonso, R; Almenara, J -M; Auvergne, M; Baglin, A; Barge, P; Bonomo, A S; Borde, P; Bouchy, F; Carone, L; Carpano, S; Deleuil, M; Deeg, H J; Dvorak, R; Erikson, A; Ferraz-Mello, S; Fridlund, M; Gandolfi, D; Gazzano, J -C; Gillon, M; Guenther, E W; Guillot, T; Hatzes, A; Havel, M; Hebrard, G; Jorda, L; Leger, A; Llebaria, A; Lammer, H; Lovis, C; Mazeh, T; Moutou, C; Ofir, A; von Paris, P; Patzold, M; Queloz, D; Rauer, H; Rouan, D; Santerne, A; Schneider, J; Tingley, B; Titz-Weider, R; Wuchterl, G

2010-01-01

155

Radial velocity follow-up of CoRoT transiting exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We report on the results from the radial-velocity follow-up program performed to establish the planetary nature and to characterize the transiting candidates discovered by the space mission CoRoT. We use the SOPHIE at OHP, HARPS at ESO and the HIRES at Keck spectrographs to collect spectra and high- precision radial velocity (RV) measurements for several dozens dif- ferent candidates from CoRoT. We have measured the Rossiter- McLaughlin effect of several confirmed planets, e...

Deleuil M.; Moutou C.; Bouchy F.; Hatzes A.; Santerne A.; Endl M.

2011-01-01

156

The Effects of Refraction on Transit Transmission Spectroscopy: Application to Earth-like Exoplanets  

CERN Document Server

We quantify the effects of refraction in transit transmission spectroscopy on spectral absorption features and on temporal variations that could be used to obtain altitude-dependent spectra for planets orbiting stars of different stellar types. We validate our model against altitude-dependent transmission spectra of the Earth from ATMOS and against lunar eclipse spectra from Palle et al. (2009). We perform detectability studies to show the potential effects of refraction on hypothetical observations of Earth analogs with the James Webb Space Telescope (JWST) Near-Infrared Spectrograph (NIRSPEC). Due to refraction, there will be a maximum tangent pressure level that can be probed during transit for each given planet-star system. We show that because of refraction, for an Earth-analog planet orbiting in the habitable zone of a Sun-like star only the top 0.3 bars of the atmosphere can be probed, leading to a decrease in the signal to noise ratio (SNR) of absorption features by 60%, while for an Earth-analog plan...

Misra, Amit; Crisp, Dave

2014-01-01

157

The Qatar Exoplanet Survey  

CERN Document Server

The Qatar Exoplanet Survey (QES) is discovering hot Jupiters and aims to discover hot Saturns and hot Neptunes that transit in front of relatively bright host stars. QES currently operates a robotic wide-angle camera system to identify promising transiting exoplanet candidates among which are the confirmed exoplanets Qatar 1b and 2b. This paper describes the first generation QES instrument, observing strategy, data reduction techniques, and follow-up procedures. The QES cameras in New Mexico complement the SuperWASP cameras in the Canary Islands and South Africa, and we have developed tools to enable the QES images and light curves to be archived and analysed using the same methods developed for the SuperWASP datasets. With its larger aperture, finer pixel scale, and comparable field of view, and with plans to deploy similar systems at two further sites, the QES, in collaboration with SuperWASP, should help to speed the discovery of smaller radius planets transiting bright stars in northern skies.

Alsubai, K A; Bramich, D M; Horne, K; Cameron, A Collier; West, R G; Sorensen, P M; Pollacco, D; Smith, J C; Fors, O

2014-01-01

158

Exoplanet habitability.  

Science.gov (United States)

The search for exoplanets includes the promise to eventually find and identify habitable worlds. The thousands of known exoplanets and planet candidates are extremely diverse in terms of their masses or sizes, orbits, and host star type. The diversity extends to new kinds of planets, which are very common yet have no solar system counterparts. Even with the requirement that a planet's surface temperature must be compatible with liquid water (because all life on Earth requires liquid water), a new emerging view is that planets very different from Earth may have the right conditions for life. The broadened possibilities will increase the future chances of discovering an inhabited world. PMID:23641111

Seager, Sara

2013-05-01

159

Improved Modeling of the Rossiter-McLaughlin Effect for Transiting Exoplanets  

CERN Document Server

We present an improved formula for the anomalous radial velocity of the star during planetary transits due to the Rossiter-McLaughlin (RM) effect. The improvement comes from a more realistic description of the stellar absorption line profiles, taking into account stellar rotation, macroturbulence, thermal broadening, pressure broadening, and instrumental broadening. Although the formula is derived for the case in which radial velocities are measured by cross-correlation, we show through numerical simulations that the formula accurately describes the cases where the radial velocities are measured with the iodine absorption-cell technique. The formula relies on prior knowledge of the parameters describing macroturbulence, instrumental broadening and other broadening mechanisms, but even 30% errors in those parameters do not significantly change the results in typical circumstances. We show that the new analytic formula agrees with previous ones that had been computed on a case-by-case basis via numerical simula...

Hirano, Teruyuki; Winn, Joshua N; Taruya, Atsushi; Narita, Norio; Albrecht, Simon; Sato, Bun'ei

2011-01-01

160

Three WASP-South transiting exoplanets: WASP-74b, WASP-83b & WASP-89b  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We report the discovery of three new transiting hot Jupiters by WASP-South together with the TRAPPIST photometer and the Euler/CORALIE spectrograph. WASP-74b orbits a star of V = 9.7, making it one of the brighter systems accessible to Southern telescopes. It is a 0.95 M_Jup planet with a moderately bloated radius of 1.5 R_Jup in a 2-d orbit around a slightly evolved F9 star. WASP-83b is a Saturn-mass planet at 0.3 M_Jup with a radius of 1.0 R_Jup. It is in a 5-d orbit a...

Hellier, Coel; Anderson, D. R.; Cameron, A. Collier; Delrez, L.; Gillon, M.; Jehin, E.; Lendl, M.; Maxted, P. F. L.; Pepe, F.; Pollacco, D.; Queloz, D.; Segransan, D.; Smalley, B.; Smith, A. M. S.; Southworth, J.

2014-01-01

 
 
 
 
161

Radial velocity follow-up of CoRoT transiting exoplanets  

CERN Document Server

We report on the results from the radial-velocity follow-up program performed to establish the planetary nature and to characterize the transiting candidates discovered by the space mission CoRoT. We use the SOPHIE at OHP, HARPS at ESO and the HIRES at Keck spectrographs to collect spectra and high- precision radial velocity (RV) measurements for several dozens dif- ferent candidates from CoRoT. We have measured the Rossiter- McLaughlin effect of several confirmed planets, especially CoRoT- 1b which revealed that it is another highly inclined system. Such high-precision RV data are necessary for the discovery of new tran- siting planets. Furthermore, several low mass planet candidates have emerged from our Keck and HARPS data.

Santerne, A; Hatzes, A; Bouchy, F; Moutou, C; Deleuil, M

2011-01-01

162

The Exoplanet Orbit Database II: Updates to exoplanets.org  

CERN Document Server

The Exoplanet Orbit Database (EOD) compiles orbital, transit, host star, and other parameters of robustly detected exoplanets reported in the peer-reviewed literature. The EOD can be navigated through the Exoplanet Data Explorer (EDE) Plotter and Table, available on the World Wide Web at exoplanets.org. The EOD contains data for 1492 confirmed exoplanets as of July 2014. The EOD descends from a table in Butler et al. (2002) and the Catalog of Nearby Exoplanets (Butler et al. 2006), and the first complete documentation for the EOD and the EDE was presented in Wright et al. (2011). In this work, we describe our work since then. We have expanded the scope of the EOD to include secondary eclipse parameters, asymmetric uncertainties, and expanded the EDE to include the sample of over 3000 Kepler Objects of Interest (KOIs), and other real planets without good orbital parameters (such as many of those detected by microlensing and imaging). Users can download the latest version of the entire EOD as a single comma sep...

Han, Eunkyu; Wright, Jason T; Feng, Y Katherina; Zhao, Ming; Brown, Jacob I; Hancock, Colin

2014-01-01

163

The transiting exoplanet CoRoT-11b and its peculiar tidal evolution  

Directory of Open Access Journals (Sweden)

Full Text Available CoRoT-11b is a fairly massive hot-Jupiter (Mp = 2.33 ± 0.34 MJup in a 3 days orbit around a F6 V star with an age of 2 ± 1 Gyr. The relatively high projected rotational velocity of the star (v sin i? = 40 ± 5 km/s places CoRoT-11 among the most rapidly rotating planet hosting stars discovered so far. Assuming that the star is seen equator-on, the v sin i? and the star radius (R? = 1.37±0.03 R? translate into a stellar rotation period of 1.73±0.26 days. This peculiar planet/star con?guration o?ers an unique opportunity to study the tidal evolution of the system. Owing to the strong tidal interaction, the planet would have moved outwards, from a starting semi-major axis corresponding to an orbital period almost synchronized with the stellar rotation. We found that the present value of the tidal quality factor Q?s could be measured by a timing of the mid-epoch of the transits to be observed with an accuracy of about 0.5 ? 1 seconds over a time baseline of about 25 years.

Damiani C.

2011-02-01

164

Fluctuations and Flares in the Ultraviolet Line Emission of Cool Stars: Implications for Exoplanet Transit Observations  

CERN Document Server

Variations in stellar flux can potentially overwhelm the photometric signal of a transiting planet. Such variability has not previously been well-characterized in the ultraviolet lines used to probe the inflated atmospheres surrounding hot Jupiters. Therefore, we surveyed 38 F-M stars for intensity variations in four narrow spectroscopic bands: two enclosing strong lines from species known to inhabit hot Jupiter atmospheres, CII $\\lambda\\lambda$1334,1335 and SiIII $\\lambda$1206; one enclosing SiIV $\\lambda\\lambda$1393,1402; and 36.5 \\AA\\ of interspersed continuum. For each star/band combination, we generated 60 s cadence lightcurves from archival HST COS and STIS time-tagged photon data. Within these lightcurves, we characterized flares and stochastic fluctuations as separate forms of variability. Flares: We used a cross-correlation approach to detect 116 flares. These events occur in the time-series an average of once per 2.5 h, over 50% last 4 min or less, and most produce the strongest response in SiIV. If...

Loyd, R O Parke

2014-01-01

165

Near-UV and optical observations of the transiting exoplanet TrES-3b  

CERN Document Server

We observed nine primary transits of the hot Jupiter TrES-3b in several optical and near-UV photometric bands from 2009 June to 2012 April in an attempt to detect its magnetic field. Vidotto, Jardine and Helling suggest that the magnetic field of TrES-3b can be constrained if its near-UV light curve shows an early ingress compared to its optical light curve, while its egress remains unaffected. Predicted magnetic field strengths of Jupiter-like planets should range between 8 G and 30 G. Using these magnetic field values and an assumed B_star of 100 G, the Vidotto et al. method predicts a timing difference of 5-11 min. We did not detect an early ingress in our three nights of near-UV observations, despite an average cadence of 68 s and an average photometric precision of 3.7 mmag. However, we determined an upper limit of TrES-3b's magnetic field strength to range between 0.013 and 1.3 G (for a 1-100 G magnetic field strength range for the host star, TrES-3) using a timing difference of 138 s derived from the N...

Turner, Jake D; Hardegree-Ullman, Kevin K; Carleton, Timothy M; Walker-LaFollette, Amanda M; Crawford, Benjamin E; Smith, Carter-Thaxton W; McGraw, Allison M; Small, Lindsay C; Rocchetto, Marco; Cunningham, Kathryn I; Towner, Allison P M; Zellem, Robert; Robertson, Amy N; Guvenen, Blythe C; Schwarz, Kamber R; Hardegree-Ullman, Emily E; Collura, Daniel; Henz, Triana N; Lejoly, Cassandra; Richardson, Logan L; Weinand, Michael A; Taylor, Joanna M; Daugherty, Michael J; Wilson, Ashley A; Austin, Carmen L

2012-01-01

166

Constraining High Speed Winds in Exoplanet Atmospheres Through Observations of Anomalous Doppler Shifts During Transit  

CERN Document Server

Three-dimensional (3-D) dynamical models of hot Jupiter atmospheres predict very strong wind speeds. For tidally locked hot Jupiters, winds at high altitude in the planet's atmosphere advect heat from the day side to the cooler night side of the planet. Net wind speeds on the order of 1-10 km/s directed towards the night side of the planet are predicted at mbar pressures, which is the approximate pressure level probed by transmission spectroscopy. These winds should result in an observed blue shift of spectral lines in transmission on the order of the wind speed. Indeed, Snellen et al. (2010) recently observed a 2 +/- 1 km/s blue shift of CO transmission features for HD 209458b, which has been interpreted as a detection of the day-to-night winds that have been predicted by 3-D atmospheric dynamics modeling. Here we present the results of a coupled 3-D atmospheric dynamics and transmission spectrum model, which predicts the Doppler-shifted spectrum of a hot Jupiter during transit resulting from winds in the pl...

Kempton, Eliza Miller-Ricci

2011-01-01

167

INDEPENDENT DISCOVERY OF THE TRANSITING EXOPLANET HAT-P-14b  

International Nuclear Information System (INIS)

We present SuperWASP observations of HAT-P-14b, a hot Jupiter discovered by Torres et al. The planet was found independently by the SuperWASP team and named WASP-27b after follow-up observations had secured the discovery, but prior to the publication by Torres et al. Our analysis of HAT-P-14/WASP-27 is in good agreement with the values found by Torres et al. and we provide additional evidence against astronomical false positives. Due to the brightness of the host star, Vmag = 10, HAT-P-14b is an attractive candidate for further characterization observations. The planet has a high impact parameter and the primary transit is close to grazing. This could readily reveal small deviations in the orbital parameters indicating the presence of a third body in the system, which may be causing the small but significant orbital eccentricity. Our results suggest that the planet may undergo a grazing secondary eclipse. However, even a non-detection would tightly constrain the system parameters.

168

CONSTRAINING HIGH-SPEED WINDS IN EXOPLANET ATMOSPHERES THROUGH OBSERVATIONS OF ANOMALOUS DOPPLER SHIFTS DURING TRANSIT  

International Nuclear Information System (INIS)

Three-dimensional (3D) dynamical models of hot Jupiter atmospheres predict very strong wind speeds. For tidally locked hot Jupiters, winds at high altitude in the planet's atmosphere advect heat from the day side to the cooler night side of the planet. Net wind speeds on the order of 1-10 km s–1 directed towards the night side of the planet are predicted at mbar pressures, which is the approximate pressure level probed by transmission spectroscopy. These winds should result in an observed blueshift of spectral lines in transmission on the order of the wind speed. Indeed, Snellen et al. recently observed a 2 ± 1 km s–1 blueshift of CO transmission features for HD 209458b, which has been interpreted as a detection of the day-to-night (substellar to anti-stellar) winds that have been predicted by 3D atmospheric dynamics modeling. Here, we present the results of a coupled 3D atmospheric dynamics and transmission spectrum model, which predicts the Doppler-shifted spectrum of a hot Jupiter during transit resulting from winds in the planet's atmosphere. We explore four different models for the hot Jupiter atmosphere using different prescriptions for atmospheric drag via interaction with planetary magnetic fields. We find that models with no magnetic drag produce net Doppler blueshifts in the transmission spectrum of ?2 km s–1 and that lower Doppler shifts of ?1 km s–1 are found for the higher drag cases, results consiser drag cases, results consistent with—but not yet strongly constrained by—the Snellen et al. measurement. We additionally explore the possibility of recovering the average terminator wind speed as a function of altitude by measuring Doppler shifts of individual spectral lines and spatially resolving wind speeds across the leading and trailing terminators during ingress and egress.

169

TRANSIT AND ECLIPSE ANALYSES OF THE EXOPLANET HD 149026b USING BLISS MAPPING  

International Nuclear Information System (INIS)

The dayside of HD 149026b is near the edge of detectability by the Spitzer Space Telescope. We report on 11 secondary-eclipse events at 3.6, 4.5, 3 × 5.8, 4 × 8.0, and 2 × 16 ?m plus three primary-transit events at 8.0 ?m. The eclipse depths from jointly fit models at each wavelength are 0.040% ± 0.003% at 3.6 ?m, 0.034% ± 0.006% at 4.5 ?m, 0.044% ± 0.010% at 5.8 ?m, 0.052% ± 0.006% at 8.0 ?m, and 0.085% ± 0.032% at 16 ?m. Multiple observations at the longer wavelengths improved eclipse-depth signal-to-noise ratios by up to a factor of two and improved estimates of the planet-to-star radius ratio (Rp /R* = 0.0518 ± 0.0006). We also identify no significant deviations from a circular orbit and, using this model, report an improved period of 2.8758916 ± 0.0000014 days. Chemical-equilibrium models find no indication of a temperature inversion in the dayside atmosphere of HD 149026b. Our best-fit model favors large amounts of CO and CO2, moderate heat redistribution (f = 0.5), and a strongly enhanced metallicity. These analyses use BiLinearly-Interpolated Subpixel Sensitivity (BLISS) mapping, a new technique to model two position-dependent systematics (intrapixel variability and pixelation) by mapping the pixel surface at high resolution. BLISS mapping outperforms previous methods in both speed and goodness of fit. We also present an orthogonalization technique for linearly correlated parameters that accelerates the convergt accelerates the convergence of Markov chains that employ the Metropolis random walk sampler. The electronic supplement contains light-curve files.

170

Notes on exoplanets  

International Nuclear Information System (INIS)

Our knowledge about exoplanets evolves rapidly. Here I give a short overview of some aspects of the exoplanet research and I also introduce shortly the reader to the Hungarian activities in the exoplanet field.

171

A new view on exoplanet transits: Transit of Venus described using three-dimensional solar atmosphere Stagger-grid simulations  

CERN Document Server

Stellar activity and, in particular, convection-related surface structures, potentially cause fluctuations that can affect the transit light curves. Surface convection simulations can help the interpretation of ToV. We used realistic three-dimensional radiative hydrodynamical simulation of the Sun from the Stagger-grid and synthetic images computed with the radiative transfer code Optim3D to provide predictions for the transit of Venus in 2004 observed by the satellite ACRIMSAT. We computed intensity maps from RHD simulation of the Sun and produced synthetic stellar disk image. We computed the light curve and compared it to the ACRIMSAT observations and also to the light curves obtained with solar surface representations carried out using radial profiles with different limb-darkening laws. We also applied the same spherical tile imaging method to the observations of center-to-limb Sun granulation with HINODE. We managed to explain ACRIMSAT observations of 2004 ToV and showed that the granulation pattern cause...

Chiavassa, A; Faurobert, M; Ricort, G; Tanga, P; Magic, Z; Collet, R; Asplund, M

2015-01-01

172

Exoplanet plenitude  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The main aim of the present paper is to give a brief overview of the revolution in exoplanet discoveries which started about two decades ago and the new concepts and perspectives that these observational findings have brought about. The level of the text is simple, as deemed suitable for reading by young scientists with different levels of expertise. The paper is organized in the following sections: 1) Historical background. 2) Basic concepts and definitions of what is a planet. 3) Observatio...

Marti?n, E. L.

2012-01-01

173

Water in exoplanets.  

Science.gov (United States)

Exoplanets--planets orbiting around stars other than our own Sun--appear to be common. Significant research effort is now focused on the observation and characterization of exoplanet atmospheres. Species such as water vapour, methane, carbon monoxide and carbon dioxide have been observed in a handful of hot, giant, gaseous planets, but cooler, smaller planets such as Gliese 1214b are now analysable with current telescopes. Water is the key chemical dictating habitability. The current observations of water in exoplanets from both space and the ground are reviewed. Controversies surrounding the interpretation of these observations are discussed. Detailed consideration of available radiative transfer models and linelists are used to analyse these differences in interpretation. Models suggest that there is a clear need for data on the pressure broadening of water transitions by H(2) at high temperatures. The reported detections of water appear to be robust, although final confirmation will have to await the better quality observational data provided by currently planned dedicated space missions. PMID:22547242

Tinetti, Giovanna; Tennyson, Jonathan; Griffith, Caitlin A; Waldmann, Ingo

2012-06-13

174

On the (im)possibility of testing new physics in exoplanets using transit timing variations: deviation from inverse-square law of gravity  

CERN Document Server

Ground-based and space-borne observatories studying exoplanetary transits now and in the future will considerably increase the number of known exoplanets and the precision of the measured times of transit minima. Variations in the transit times can not only be used to infer the presence of additional planets, but might also provide opportunities for testing new physics in the places beyond the Solar system. In this work, we take deviation from the inverse-square law of gravity as an example, focus on the fifth-force-like Yukawa-type correction to the Newtonian gravitational force which parameterizes this deviation, investigate its effects on the secular transit timing variations and analyze their observability in exoplanetary systems. It is found that the most optimistic values of Yukawa-type secular transit timing variations are at the level of $\\sim 0.1$ seconds per year. Those values unfortunately appear only in rarely unique cases and, most importantly, they are still at least two orders of magnitude belo...

Xie, Yi

2014-01-01

175

The NASA Exoplanet Archive: Data and Tools for Exoplanet Research  

CERN Document Server

We describe the contents and functionality of the NASA Exoplanet Archive, a database and tool set funded by NASA to support astronomers in the exoplanet community. The current content of the database includes interactive tables containing properties of all published exoplanets, Kepler planet candidates, threshold-crossing events, data validation reports and target stellar parameters, light curves from the Kepler and CoRoT missions and from several ground-based surveys, and spectra and radial velocity measurements from the literature. Tools provided to work with these data include a transit ephemeris predictor, both for single planets and for observing locations, light curve viewing and normalization utilities, and a periodogram and phased light curve service. The archive can be accessed at http://exoplanetarchive.ipac.caltech.edu.

Akeson, R L; Ciardi, D; Crane, M; Good, J; Harbut, M; Jackson, E; Kane, S R; Laity, A C; Leifer, S; Lynn, M; McElroy, D L; Papin, M; Plavchan, P; Ramirez, S V; Rey, R; von Braun, K; Wittman, M; Abajian, M; Ali, B; Beichman, C; Beekley, A; Berriman, G B; Berukoff, S; Bryden, G; Chan, B; Groom, S; Lau, C; Payne, A N; Regelson, M; Saucedo, M; Schmitz, M; Stauffer, J; Wyatt, P; Zhang, A

2013-01-01

176

The Fabra-ROA Baker-Nunn Camera at Observatori Astron\\`omic del Montsec: a wide-field imaging facility for exoplanet transit detection  

CERN Document Server

A number of Baker-Nunn Camera (BNC) were manufactured by Smithsonian Institution during the 60s as optical tracking systems for artificial satellites with optimal optical and mechanical specifications. One of them was installed at the Real Instituto y Observatorio de la Armada (ROA). We have conducted a profound refurbishment project of the telescope to be installed at Observatori Astron\\`omic del Montsec (OAdM). As a result, the BNC offers the largest combination of a huge FOV (4.4$\\deg$x4.4$\\deg$) and aperture (leading to a limiting magnitude of V$\\sim$20). These specifications, together with their remote and robotic natures, allows this instrument to face an observational program of exoplanets detection by means of transit technique with high signal-to-noise ratio in the appropiate magnitude range.

Fors, O; Muiños, J L; Montojo, F J; Baena, R; Merino, M; Morcillo, R; Blanco, V

2009-01-01

177

The Fabra-ROA Baker-Nunn Camera at Observatori Astronòmic del Montsec: A Wide-field Imaging Facility for Exoplanet Transit Detection  

Science.gov (United States)

A number of Baker-Nunn Camera (BNC) were manufactured by Smithsonian Institution during the 60’s as optical tracking systems for artificial satellites with optimal optical and mechanical specifications. One of them was installed at the Real Instituto y Observatorio de la Armada (ROA). We have conducted a profound refurbishment project of the telescope to be installed at Observatori Astronòmic del Montsec (OAdM) (Fors 2009). As a result, the BNC offers the largest combination of a huge FOV (4.4°×4.4°) and aperture (leading to a limiting magnitude of V˜20). These specifications, together with their remote and robotic natures, allows this instrument to face an observational program of exoplanets detection by means of transit technique with high signal-to-noise ratio in the appropiate magnitude range.

Fors, O.; Núñez, J.; Muiños, J. L.; Montojo, F. J.; Baena, R.; Merino, M.; Morcillo, R.; Blanco, V.

2010-10-01

178

Stellar diameters and temperatures - VI. High angular resolution measurements of the transiting exoplanet host stars HD 189733 and HD 209458 and implications for models of cool dwarfs  

Science.gov (United States)

We present direct radii measurements of the well-known transiting exoplanet host stars HD 189733 and HD 209458 using the CHARA Array interferometer. We find the limb-darkened angular diameters to be ?LD = 0.3848 ± 0.0055 and 0.2254 ± 0.0072 mas for HD 189733 and HD 209458, respectively. HD 189733 and HD 209458 are currently the only two transiting exoplanet systems where detection of the respective planetary companion's orbital motion from high-resolution spectroscopy has revealed absolute masses for both star and planet. We use our new measurements together with the orbital information from radial velocity and photometric time series data, Hipparcos distances, and newly measured bolometric fluxes to determine the stellar effective temperatures (Teff = 4875 ± 43, 6092 ± 103 K), stellar linear radii (R* = 0.805 ± 0.016, 1.203 ± 0.061 R?), mean stellar densities (?* = 1.62 ± 0.11, 0.58 ± 0.14 ??), planetary radii (Rp = 1.216 ± 0.024, 1.451 ± 0.074 RJup), and mean planetary densities (?p = 0.605 ± 0.029, 0.196 ± 0.033 ?Jup) for HD 189733b and HD 209458b, respectively. The stellar parameters for HD 209458, an F9 dwarf, are consistent with indirect estimates derived from spectroscopic and evolutionary modelling. However, we find that models are unable to reproduce the observational results for the K2 dwarf, HD 189733. We show that, for stellar evolutionary models to match the observed stellar properties of HD 189733, adjustments lowering the solar-calibrated mixing-length parameter to ?MLT =1.34 need to be employed.

Boyajian, Tabetha; von Braun, Kaspar; Feiden, Gregory A.; Huber, Daniel; Basu, Sarbani; Demarque, Pierre; Fischer, Debra A.; Schaefer, Gail; Mann, Andrew W.; White, Timothy R.; Maestro, Vicente; Brewer, John; Lamell, C. Brooke; Spada, Federico; López-Morales, Mercedes; Ireland, Michael; Farrington, Chris; van Belle, Gerard T.; Kane, Stephen R.; Jones, Jeremy; ten Brummelaar, Theo A.; Ciardi, David R.; McAlister, Harold A.; Ridgway, Stephen; Goldfinger, P. J.; Turner, Nils H.; Sturmann, Laszlo

2015-02-01

179

Observation of the full 12-hour-long transit of the exoplanet HD80606b. Warm-Spitzer photometry and SOPHIE spectroscopy  

CERN Document Server

We present new observations of a transit of the 111-day-period exoplanet HD80606b. Using the Spitzer Space Telescope and its IRAC camera on the post-cryogenic mission, we performed a 19-hour-long photometric observation of HD80606 that covers the full transit of 13-14 January 2010. We complement this photometric data by new spectroscopic observations that we simultaneously performed with SOPHIE at Haute-Provence Observatory. This provides radial velocity measurements of the first half of the transit that was previously uncovered with spectroscopy. This new data set allows the parameters of this singular planetary system to be significantly refined. We obtained a planet-to-star radius ratio R_p/R_* = 0.1001 +/- 0.0006 that is slightly lower than the one measured from previous ground observations. We detected a feature in the Spitzer light curve that could be due to a stellar spot. We also found a transit timing about 20 minutes earlier than the ephemeris prediction; this could be caused by actual TTVs due to a...

Hebrard, G; Diaz, R F; Boisse, I; Bouchy, F; Etangs, A Lecavelier des; Moutou, C; Ehrenreich, D; Arnold, L; Bonfils, X; Delfosse, X; Desort, M; Eggenberger, A; Forveille, T; Gregorio, J; Lagrange, A -M; Lovis, C; Pepe, F; Perrier, C; Pont, F; Queloz, D; Santerne, A; Santos, N C; Segransan, D; Sing, D K; Udry, S; Vidal-Madjar, A

2010-01-01

180

Exoplanet Peer-Learning Exercises for Introductory Astronomy Courses  

Science.gov (United States)

While exoplanet research has witnessed explosive growth over the past decade with over 350 exoplanets identified to date (http://exoplanet.eu), few education and public outreach tools capable of bringing the techniques and results of exoplanet science into the classroom have been developed. To help reduce this shortcoming, we have been developing and implementing a series of exoplanet-related active-learning exercises to be used in non-astronomy major introductory settings, including think-pair-share questions and peer-learning activities. We discuss some of these activities which we have field tested in undergraduate classes at the University of Washington. We also discuss our efforts to engage students in these classes in obtaining and analyzing astronomical observations of exoplanet host stars to identify and characterize exoplanet transit events. JPW acknowledges support from NSF Astronomy & Astrophysics Postdoctoral Fellowship AST 08-02230.

Wisniewski, John P.; Larson, A.

2010-01-01

 
 
 
 
181

What asteroseismology can do for exoplanets  

CERN Document Server

We describe three useful applications of asteroseismology in the context of exoplanet science: (1) the detailed characterisation of exoplanet host stars; (2) the measurement of stellar inclinations; and (3) the determination of orbital eccentricity from transit duration making use of asteroseismic stellar densities. We do so using the example system Kepler-410 (Van Eylen et al. 2014). This is one of the brightest (V = 9.4) Kepler exoplanet host stars, containing a small (2.8 Rearth) transiting planet in a long orbit (17.8 days), and one or more additional non-transiting planets as indicated by transit timing variations. The validation of Kepler-410 (KOI-42) was complicated due to the presence of a companion star, and the planetary nature of the system was confirmed after analyzing a Spitzer transit observation as well as ground-based follow-up observations.

Van Eylen, Vincent; Aguirre, Victor Silva; Arentoft, Torben; Kjeldsen, Hans; Albrecht, Simon; Chaplin, William J; Isaacson, Howard; Pedersen, May G; Jessen-Hansen, Jens; Tingley, Brandon; Christensen-Dalsgaard, Joergen; Aerts, Conny; Campante, Tiago L; Bryson, Steve T

2014-01-01

182

Pulsation Frequencies and Modes of Giant Exoplanets  

CERN Document Server

We calculate the eigenfrequencies and eigenfunctions of the acoustic oscillations of giant exoplanets and explore the dependence of the characteristic frequency and the eigenfrequencies on several parameters: the planet mass, the planet radius, the core mass, and the heavy element mass fraction in the envelope. We provide the eigenvalues for degree l up to 8 and radial order n up to 12. For the selected values of l and n, we find that the pulsation eigenfrequencies depend strongly on the planet mass and radius, especially at high frequency. We quantify this dependence through the calculation of the characteristic frequency which gives us an estimate of the scale of the eigenvalue spectrum at high frequency. For the mass range ~0.5 \\leq M_P \\leq 15 M_J, and fixing the planet radius to the Jovian value, we find that the characteristic frequency is ~164.0 (M_P/M_J)^{0.48} microHz, where M_P is the planet mass and M_J is Jupiter's mass. For the radius range from 0.9 to 2.0 R_J, and fixing the planet's mass to the...

Bihan, Bastien Le

2012-01-01

183

PULSATION FREQUENCIES AND MODES OF GIANT EXOPLANETS  

International Nuclear Information System (INIS)

We calculate the eigenfrequencies and eigenfunctions of the acoustic oscillations of giant exoplanets and explore the dependence of the characteristic frequency ?0 and the eigenfrequencies on several parameters: the planet mass, the planet radius, the core mass, and the heavy element mass fraction in the envelope. We provide the eigenvalues for degree l up to 8 and radial order n up to 12. For the selected values of l and n, we find that the pulsation eigenfrequencies depend strongly on the planet mass and radius, especially at high frequency. We quantify this dependence through the calculation of the characteristic frequency ?0 which gives us an estimate of the scale of the eigenvalue spectrum at high frequency. For the mass range 0.5 MJ ? MP ? 15 MJ , and fixing the planet radius to the Jovian value, we find that ?0 ? 164.0 × (MP /MJ )0.48?Hz, where MP is the planet mass and MJ is Jupiter's mass. For the radius range from 0.9 to 2.0 RJ , and fixing the planet's mass to the Jovian value, we find that ?0 ? 164.0 × (RP /RJ )–2.09?Hz, where RP is the planet radius and RJ is Jupiter's radius. We explore the influence of the presence of a dense core on the pulsation frequencies and on the characteristic frequency of giant exoplanets. We find that the presence find that the presence of heavy elements in the envelope affects the eigenvalue distribution in ways similar to the presence of a dense core. Additionally, we apply our formalism to Jupiter and Saturn and find results consistent with both the observational data of Gaulme et al. and previous theoretical work.

184

Thermal phase curves of nontransiting terrestrial exoplanets 1. Characterizing atmospheres  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Although transit spectroscopy is a powerful method for studying the composition, thermal properties and dynamics of exoplanet atmospheres, only a few transiting terrestrial exoplanets will be close enough to allow significant transit spectroscopy. Thermal phase curves (variations of the apparent infrared emission of the planet with its orbital phase) have been observed for hot Jupiters in both transiting and nontransiting configurations, and could be observed for hot terrest...

Selsis, Franck; Wordsworth, Robin; Forget, Franc?ois

2011-01-01

185

Spectra as windows into exoplanet atmospheres.  

Science.gov (United States)

Understanding a planet's atmosphere is a necessary condition for understanding not only the planet itself, but also its formation, structure, evolution, and habitability. This requirement puts a premium on obtaining spectra and developing credible interpretative tools with which to retrieve vital planetary information. However, for exoplanets, these twin goals are far from being realized. In this paper, I provide a personal perspective on exoplanet theory and remote sensing via photometry and low-resolution spectroscopy. Although not a review in any sense, this paper highlights the limitations in our knowledge of compositions, thermal profiles, and the effects of stellar irradiation, focusing on, but not restricted to, transiting giant planets. I suggest that the true function of the recent past of exoplanet atmospheric research has been not to constrain planet properties for all time, but to train a new generation of scientists who, by rapid trial and error, are fast establishing a solid future foundation for a robust science of exoplanets. PMID:24613929

Burrows, Adam S

2014-09-01

186

Evolution of Exoplanets and their Parent Stars  

CERN Document Server

Studying exoplanets with their parent stars is crucial to understand their population, formation and history. We review some of the key questions regarding their evolution with particular emphasis on giant gaseous exoplanets orbiting close to solar-type stars. For masses above that of Saturn, transiting exoplanets have large radii indicative of the presence of a massive hydrogen-helium envelope. Theoretical models show that this envelope progressively cools and contracts with a rate of energy loss inversely proportional to the planetary age. The combined measurement of planetary mass, radius and a constraint on the (stellar) age enables a global determination of the amount of heavy elements present in the planet interior. The comparison with stellar metallicity shows a correlation between the two, indicating that accretion played a crucial role in the formation of planets. The dynamical evolution of exoplanets also depends on the properties of the central star. We show that the lack of massive giant planets a...

Guillot, Tristan; Morel, Pierre; Havel, Mathieu; Parmentier, Vivien

2014-01-01

187

Transiting exoplanets from the CoRoT space mission. XX. CoRoT-18b: a massive hot jupiter on a prograde, nearly aligned orbit  

CERN Document Server

We report the detection of CoRoT-18b, a massive hot jupiter transiting in front of its host star with a period of 1.9000693 +/- 0.0000028 days. This planet was discovered thanks to photometric data secured with the CoRoT satellite combined with spectroscopic and photometric follow-up ground-based observations. The planet has a mass M_p = 3.47 +/- 0.38 M_Jup, a radius R_p = 1.31 +/- 0.18 R_Jup, and a density rho_p = 2.2 +/- 0.8 g/cm3. It orbits a G9V star with a mass M_* = 0.95 +/- 0.15 M_Sun, a radius R_* = 1.00 +/- 0.13 R_Sun, and a rotation period P_rot = 5.4 +/- 0.4 days. The age of the system remains uncertain, stellar evolution models pointing either to a few tens Ma or several Ga, while gyrochronology and lithium abundance point towards ages of a few hundred Ma. This mismatch potentially points to a problem in our understanding of the evolution of young stars, with possible significant implications for stellar physics and the interpretation of inferred sizes of exoplanets around young stars. We detected...

Hebrard, G; Alonso, R; Fridlund, M; Ofir, A; Aigrain, S; Guillot, T; Almenara, J M; Auvergne, M; Baglin, A; Barge, P; Bonomo, A S; Borde, P; Bouchy, F; Cabrera, J; Carone, L; Carpano, S; Cavarroc, C; Csizmadia, Sz; Deeg, H J; Deleuil, M; Diaz, R F; Dvorak, R; Erikson, A; Ferraz-Mello, S; Gandolfi, D; Gibson, N; Gillon, M; Guenther, E; Hatzes, A; Havel, M; Jorda, L; Lammer, H; Leger, A; Llebaria, A; Mazeh, T; Moutou, C; Ollivier, M; Parviainen, H; Patzold, M; Queloz, D; Rauer, H; Rouan, D; Santerne, A; Schneider, J; Tingley, B; Wuchterl, G

2011-01-01

188

The GTC exoplanet transit spectroscopy survey I: OSIRIS transmission spectroscopy of the short period planet WASP-43b  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We used GTC instrument OSIRIS to obtain long-slit spectra in the optical range (520-1040 nm) of the planetary host star WASP-43 (and a reference star) during a full primary transit event and four partial transit observations. We integrated the stellar flux of both stars in different wavelength regions producing several light curves. We fitted transit models to these curves to measure the star-to-planet radius ratio, Rp/Rs, across wavelength among other physical parameters. W...

Murgas, F.; Palle, E.; Osorio, M. R. Zapatero; Nortmann, L.; Hoyer, S.; Cabrera-lavers, A.

2014-01-01

189

WARM SPITZER PHOTOMETRY OF THE TRANSITING EXOPLANETS CoRoT-1 AND CoRoT-2 AT SECONDARY ECLIPSE  

International Nuclear Information System (INIS)

We measure secondary eclipses of the hot giant exoplanets CoRoT-1 at 3.6 and 4.5 ?m, and CoRoT-2 at 3.6 ?m, both using Warm Spitzer. We find that the Warm Spitzer mission is working very well for exoplanet science. For consistency of our analysis we also re-analyze archival cryogenic Spitzer data for secondary eclipses of CoRoT-2 at 4.5 and 8 ?m. We compare the total data for both planets, including optical eclipse measurements by the CoRoT mission, and ground-based eclipse measurements at 2 ?m, to existing models. Both planets exhibit stronger eclipses at 4.5 than at 3.6 ?m, which is often indicative of an atmospheric temperature inversion. The spectrum of CoRoT-1 is best reproduced by a 2460 K blackbody, due either to a high altitude layer that strongly absorbs stellar irradiance, or an isothermal region in the planetary atmosphere. The spectrum of CoRoT-2 is unusual because the 8 ?m contrast is anomalously low. Non-inverted atmospheres could potentially produce the CoRoT-2 spectrum if the planet exhibits line emission from CO at 4.5 ?m, caused by tidal-induced mass loss. However, the viability of that hypothesis is questionable because the emitting region cannot be more than about 30% larger than the planet's transit radius, based on the ingress and egress times at eclipse. An alternative possibility to account for the spectrum of CoRoT-2 is an additional opacity source that acts strongly at wavelengths less than 5 ?m, heating the upper atmosphere while alling the upper atmosphere while allowing the deeper atmosphere seen at 8 ?m to remain cooler. We obtain a similar result as Gillon et al. for the phase of the secondary eclipse of CoRoT-2, implying an eccentric orbit with e cos(?) = -0.0030 ± 0.0004.

190

A TRANSIT TIMING ANALYSIS OF NINE RISE LIGHT CURVES OF THE EXOPLANET SYSTEM TrES-3  

International Nuclear Information System (INIS)

We present nine newly observed transits of TrES-3, taken as part of a transit timing program using the RISE instrument on the Liverpool Telescope. A Markov-Chain Monte Carlo analysis was used to determine the planet-star radius ratio and inclination of the system, which were found to be Rp /R * = 0.1664+0.0011 -0.0018 and i = 81.73+0.13 -0.04, respectively, consistent with previous results. The central transit times and uncertainties were also calculated, using a residual-permutation algorithm as an independent check on the errors. A re-analysis of eight previously published TrES-3 light curves was conducted to determine the transit times and uncertainties using consistent techniques. Whilst the transit times were not found to be in agreement with a linear ephemeris, giving ?2 = 35.07 for 15 degrees of freedom, we interpret this to be the result of systematics in the light curves rather than a real transit timing variation. This is because the light curves that show the largest deviation from a constant period either have relatively little out-of-transit coverage or have clear systematics. A new ephemeris was calculated using the transit times and was found to be Tc (0) = 2454632.62610 ± 0.00006 HJD and P = 1.3061864 ± 0.0000005 days. The transit times were then used to place upper mass limits as a function of the period ratio of a potential perturbing planet, showing that our dl perturbing planet, showing that our data are sufficiently sensitive to have probed sub-Earth mass planets in both interior and exterior 2:1 resonances, assuming that the additional planet is in an initially circular orbit.

191

Distra: a code to find invisible exoplanets  

Science.gov (United States)

Given the transit times of an exoplanet, which will differ from a Keplerian two-body series of transits if a second, non-transiting exoplanet is perturbing it, we solve the inverse problem of finding the six orbital elements and the mass of that second planet. This is equivalent to an optimization problem in seven dimensions, in which the function to minimize is some measure of the differences between the observed transits and the transits obtained with a three-body integration of the transiting planet and the invisible one; the seven dependent variables are the elements and the mass of the latter. We solve this formidable numerical problem in two stages, applying a genetic algorithm as a first step, and then polishing this result with a 7D simplex algorithm. We applied the algorithm to the Kepler-9 system, in which two planets transit and therefore the second planet has known orbital elements and mass.

Carpintero, D. D.; Melita, M. D.; Miloni, O. I.

2014-06-01

192

A transit timing analysis of nine RISE light curves of the exoplanet system TrES-3  

CERN Document Server

We present nine newly observed transits of TrES-3, taken as part of a transit timing program using the RISE instrument on the Liverpool Telescope. A Markov-Chain Monte-Carlo analysis was used to determine the planet-star radius ratio and inclination of the system, which were found to be Rp/Rstar=0.1664^{+0.0011}_{-0.0018} and i = 81.73^{+0.13}_{-0.04} respectively, consistent with previous results. The central transit times and uncertainties were also calculated, using a residual-permutation algorithm as an independent check on the errors. A re-analysis of eight previously published TrES-3 light curves was conducted to determine the transit times and uncertainties using consistent techniques. Whilst the transit times were not found to be in agreement with a linear ephemeris, giving chi^2 = 35.07 for 15 degrees of freedom, we interpret this to be the result of systematics in the light curves rather than a real transit timing variation. This is because the light curves that show the largest deviation from a con...

Gibson, N P; Skillen, I; Simpson, E K; Barros, S; Joshi, Y C; Todd, I; Benn, C; Christian, D; Hrudková, M; Keenan, F P; Steele, I A

2009-01-01

193

Transiting exoplanets from the CoRoT space mission XIV. CoRoT-11b: a transiting massive "hot-Jupiter" in a prograde orbit around a rapidly rotating F-type star  

CERN Document Server

The CoRoT exoplanet science team announces the discovery of CoRoT-11b, a fairly massive hot-Jupiter transiting a V=12.9 mag F6 dwarf star (M*=1.27 +/- 0.05 Msun, R*=1.37 +/- 0.03 Rsun, Teff=6440 +/- 120 K), with an orbital period of P=2.994329 +/- 0.000011 days and semi-major axis a=0.0436 +/- 0.005 AU. The detection of part of the radial velocity anomaly caused by the Rossiter-McLaughlin effect shows that the transit-like events detected by CoRoT are caused by a planet-sized transiting object in a prograde orbit. The relatively high projected rotational velocity of the star (vsini=40+/-5 km/s) places CoRoT-11 among the most rapidly rotating planet host stars discovered so far. With a planetary mass of mp=2.33+/-0.34 Mjup and radius rp=1.43+/-0.03 Rjup, the resulting mean density of CoRoT-11b (rho=0.99+/-0.15 g/cm^3) can be explained with a model for an inflated hydrogen-planet with a solar composition and a high level of energy dissipation in its interior.

Gandolfi, D; Alonso, R; Deleuil, M; Guenther, E W; Fridlund, M; Endl, M; Eigmüller, P; Csizmadia, Sz; Havel, M; Aigrain, S; Auvergne, M; Baglin, A; Barge, P; Bonomo, A S; Bordé, P; Bouchy, F; Bruntt, H; Cabrera, J; Carpano, S; Carone, L; Cochran, W D; Deeg, H J; Dvorak, R; Eislöffel, J; Erikson, A; Ferraz-Mello, S; Gazzano, J -C; Gibson, N P; Gillon, M; Gondoin, P; Guillot, T; Hartmann, M; Hatzes, A; Jorda, L; Kabath, P; Léger, A; Llebaria, A; Lammer, H; MacQueen, P J; Mayor, M; Mazeh, T; Moutou, C; Ollivier, M; Pätzold, M; Pepe, F; Queloz, D; Rauer, H; Rouan, D; Samuel, B; Schneider, J; Stecklum, B; Tingley, B; Udry, S; Wuchterl, G; 10.1051/0004-6361/201015132

2010-01-01

194

DIRECT IMAGING OF A COLD JOVIAN EXOPLANET IN ORBIT AROUND THE SUN-LIKE STAR GJ 504  

International Nuclear Information System (INIS)

Several exoplanets have recently been imaged at wide separations of >10 AU from their parent stars. These span a limited range of ages ( 0.5 mag), implying thick cloud covers. Furthermore, substantial model uncertainties exist at these young ages due to the unknown initial conditions at formation, which can lead to an order of magnitude of uncertainty in the modeled planet mass. Here, we report the direct-imaging discovery of a Jovian exoplanet around the Sun-like star GJ 504, detected as part of the SEEDS survey. The system is older than all other known directly imaged planets; as a result, its estimated mass remains in the planetary regime independent of uncertainties related to choices of initial conditions in the exoplanet modeling. Using the most common exoplanet cooling model, and given the system age of 160+350-60 Myr, GJ 504b has an estimated mass of 4+4.5-1.0 Jupiter masses, among the lowest of directly imaged planets. Its projected separation of 43.5 AU exceeds the typical outer boundary of ?30 AU predicted for the core accretion mechanism. GJ 504b is also significantly cooler (510+30-20 K) and has a bluer color (J – H = –0.23 mag) than previously imaged exoplanets, suggesting a largely cloud-free atmosphere accessible to spectroscopic characterization. Thus, it has the potential of providis, it has the potential of providing novel insights into the origins of giant planets as well as their atmospheric properties

195

WASP-38b: A 6.87 day period exoplanet transiting a bright F-type star  

CERN Document Server

We report the discovery of WASP-38b, a long period transiting planet in an eccentric $6.871815$ day orbit. The transit epoch is $2455335.92050 \\pm 0.00074$ (HJD) and the transit duration is $4.663$ hours. We performed a spectral analysis of the host star HD 146389/BD+10 2980 that yielded $T_{eff} = 6150 \\pm 80 $K, \\logg$=4.3 \\pm 0.1$, \\vsini=$8.6 \\pm 0.4 $\\kms, $M_*=1.16 \\pm 0.04$\\Msun\\ and $R_* =1.36 \\pm 0.05 $\\Rsun, consistent with a dwarf of spectral type F8. The radial velocity variations and the transit light curves were fitted simultaneously to estimate the orbital and planetary parameters. The planet has a mass of $2.71 \\pm 0.07 $ \\Mjup\\ and a radius of $1.08 \\pm 0.05\\, $\\Rjup\\, giving a density, $ \\rho_p = 2.2 \\pm 0.3 \\rho_J$. The high precision of the eccentricity $e=0.032 \\pm 0.0045$ is due to the relative transit timing from the light curves and the RV shape. The planet equilibrium temperature is estimated at $1311 \\pm 45$K. WASP-38b is the longest period planet found by WASP-North and with a brigh...

Barros, S C C; Cameron, A Collier; Lister, T A; McCormac, J; Pollacco, D; Simpson, E K; Smalley, B; Street, R A; Todd, I; Triaud, A H M J; Boisse, I; Bouchy, F; Hebrard, G; Moutou, C; Pepe, F; Queloz, D; Santerne, A; Segransan, D; Udry, S; Bento, J; Butters, O W; Enoch, B; Haswell, C A; Hellier, C; Keenan, F P; Miller, G R M; Moulds, V; Norton, A J; Parley, N; Skillen, I; Watson, C A; West, R G; Wheatley, P J

2010-01-01

196

Atmospheric Circulation of Exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We survey the basic principles of atmospheric dynamics relevant to explaining existing and future observations of exoplanets, both gas giant and terrestrial. Given the paucity of data on exoplanet atmospheres, our approach is to emphasize fundamental principles and insights gained from Solar-System studies that are likely to be generalizable to exoplanets. We begin by presenting the hierarchy of basic equations used in atmospheric dynamics, including the Navier-Stokes, primi...

Showman, Adam P.; Cho, James Y-k; Menou, Kristen

2009-01-01

197

The APACHE survey hardware and software design: Tools for an automatic search of small-size transiting exoplanets  

Directory of Open Access Journals (Sweden)

Full Text Available Small-size ground-based telescopes can effectively be used to look for transiting rocky planets around nearby low-mass M stars using the photometric transit method, as recently demonstrated for example by the MEarth project. Since 2008 at the Astronomical Observatory of the Autonomous Region of Aosta Valley (OAVdA, we have been preparing for the long-term photometric survey APACHE, aimed at finding transiting small-size planets around thousands of nearby early and mid-M dwarfs. APACHE (A PAthway toward the Characterization of Habitable Earths is designed to use an array of five dedicated and identical 40-cm Ritchey-Chretien telescopes and its observations started at the beginning of summer 2012. The main characteristics of the survey final set up and the preliminary results from the first weeks of observations will be discussed.

Lattanzi M.G.

2013-04-01

198

Kepler-447b: a hot-Jupiter with an extremely grazing transit  

CERN Document Server

We present the radial velocity confirmation of the extrasolar planet Kepler-447b, initially detected as a candidate by the Kepler mission. In this work, we analyze its transit signal and the radial velocity data obtained with the Calar Alto Fiber-fed Echelle spectrograph (CAFE). By simultaneously modeling both datasets, we obtain the orbital and physical properties of the system. According to our results, Kepler-447b is a Jupiter-mass planet ($M_p=1.37^{+0.48}_{-0.46} M_{\\rm Jup}$), with an estimated radius of $R_p=1.65^{+0.59}_{-0.56} R_{\\rm Jup}$ (uncertainties provided in this work are $3\\sigma$ unless specified). This translates into a sub-Jupiter density. The planet revolves every $\\sim7.8$ days around a G8V star with detected activity in the Kepler light curve. Kepler-447b transits its host with a large impact parameter ($b=1.076^{+0.112}_{-0.086}$), being one of the few planetary grazing transits confirmed so far and the first in the Kepler large crop of exoplanets. We estimate that only around 20% of ...

Lillo-Box, J; Santos, N C; Mancini, L; Figueira, P; Ciceri, S; Henning, Th

2015-01-01

199

Exoplanets: A New Era of Comparative Planetology  

Science.gov (United States)

We now know of over 1700 planets orbiting other stars, and several thousand additional planetary candidates. These discoveries have the potential to revolutionize our understanding of planet formation and evolution, while providing targets for the search for life beyond the Solar System. Exoplanets display a larger diversity of planetary types than those seen in our Solar System – including low-density, low-mass objects. They are also found in planetary system architectures very different from our own, even for stars similar to our Sun. Over 20 potentially habitable planets are now known, and half of the M dwarfs stars in our Galaxy may harbor a habitable planet. M dwarfs are plentiful, and they are therefore the most likely habitable planet hosts, but their planets will have radiative and gravitational interactions with their star and sibling planets that are unlike those in our Solar System. Observations to characterize the atmospheres and surfaces of exoplanets are extremely challenging, and transit transmission spectroscopy has been used to measure atmospheric composition for a handful of candidates. Frustratingly, many of the smaller exoplanets have flat, featureless spectra indicative of planet-wide haze or clouds. The James Webb Space Telescope and future ground-based telescopes will improve transit transmission characterization, and enable the first search for signs of life in terrestrial exoplanet atmospheres. Beyond JWST, planned next-generation space telescopes will directly image terrestrial exoplanets, allowing surface and atmospheric characterization that is more robust to haze. Until these observations become available, there is a lot that we can do as planetary scientists to inform required measurements and future data interpretation. Solar System planets can be used as validation targets for extrasolar planet observations and models. The rich heritage of planetary science models can also be used to explore the potential diversity of exoplanet environments and star-planet interactions. And planetary remote-sensing can inform new techniques to identify environmental characteristics and biosignatures in exoplanet spectra.

Meadows, Victoria

2014-11-01

200

Transit spectrophotometry of the exoplanet HD189733b. II. New Spitzer observations at 3.6 microns  

CERN Document Server

We present a new primary transit observation of the hot-jupiter HD189733b, obtained at 3.6 microns with the Infrared Array Camera (IRAC) onboard the Spitzer Space Telescope. Previous measurements at 3.6 microns suffered from strong systematics and conclusions could hardly be obtained with confidence on the water detection by comparison of the 3.6 and 5.8 microns observations. We use a high S/N Spitzer photometric transit light curve to improve the precision of the near infrared radius of the planet at 3.6 microns. The observation has been performed using high-cadence time series integrated in the subarray mode. We are able to derive accurate system parameters, including planet-to-star radius ratio, impact parameter, scale of the system, and central time of the transit from the fits of the transit light curve. We compare the results with transmission spectroscopic models and with results from previous observations at the same wavelength. We obtained the following system parameters: R_p/R_\\star=0.15566+0.00011-...

Desert, J -M; Vidal-Madjar, A; Hebrard, G; Ehrenreich, D; Etangs, A Lecavelier des; Parmentier, V; Ferlet, R; Henry, G W

2010-01-01

 
 
 
 
201

Updated parameters for the transiting exoplanet WASP-3b using RISE, a new fast camera for the Liverpool Telescope  

CERN Document Server

Some of the first results are reported from RISE - a new fast camera mounted on the Liverpool Telescope primarily designed to obtain high time resolution light curves of transiting extrasolar planets for the purpose of transit timing. A full and partial transit of WASP-3 are presented, and a Monte Carlo Markov Chain analysis is used to update the parameters from the discovery paper. This results in a planetary radius of 1.29^{+0.05}_{-0.12} R_J and therefore a density of 0.82^{+0.14}_{-0.09} p_J, consistent with previous results. The inclination is 85.07^{+0.15}_{-0.16} deg, in agreement (but with a significant improvement in the precision) with the previously determined value. Central transit times are found to be consistent with the ephemeris given in the discovery paper. However, a new ephemeris calculated using the longer baseline results in T_c(0) = 2454605.55915 +- 0.00023 HJD and P = 1.846835 +- 0.000002 days.

Gibson, N P; Simpson, E K; Joshi, Y C; Todd, I; Benn, C; Christian, D; Hrudková, M; Keenan, F P; Meaburn, J; Skillen, I; Steele, I A

2008-01-01

202

The NASA Exoplanet Archive: Data Inventory Service  

Science.gov (United States)

We present here the latest addition to the NASA Exoplanet Archive - the Data Inventory Service, a tool aimed to provide the user with all the data available within the archive (exoplanet and stellar parameters, time series from ground-based transit surveys (such as Super WASP, XO, HAT-P, KELT), Kepler Pipeline products, CoRoT light curves, etc.) at or near the location of an astronomical object. The NASA Exoplanet Archive is an online service dedicated to compile and to serve public astronomical data sets involved in the search for and characterization of extrasolar planets and their host stars. The data in the archive include stellar parameters (e.g., positions, magnitudes, temperatures, etc.), exoplanet parameters (such as masses and orbital parameters) and discovery/characterization data (e.g., published radial velocity curves, photometric light curves, spectra, etc.). In support of the Kepler Extended Mission, the NASA Exoplanet Archive also hosts data related to Kepler Objects of Interest (KOI), Kepler Pipeline products such as Threshold Crossing Events (TCE) and Data Validation Reports, and Kepler Stellar parameters as used by the Kepler Pipeline. The archive provides tools to work with these data, including interative tables (with plotting capabilities), interactive light curve viewer, periodogram service, transit and ephemeris calculator, and application program interface. To access this information visit us at: http://exoplanetarchive.ipac.caltech.edu

Ramirez, Solange; Akeson, Rachel L.; Ciardi, David R.; Chen, Xi; Christiansen, Jessie; Plavchan, Peter

2014-06-01

203

The atmospheric circulation of ultra-short period exoplanets  

Science.gov (United States)

Even though ultra-short period exoplanets comprise only a small fraction of the total exoplanet population, they present a useful probe into the role of fast rotation rates and small orbital distances on atmospheric dynamics. In this regime, advective timescales are longer than radiative timescales such that the temperature contrasts from dayside to nightside are large (>500 K at photospheric pressures); this strong day-night forcing, coupled with the planet's fast rotation rate (and hence small Rossby deformation radius) yields multiple, narrow (~40 degrees) jets in the atmosphere. Here we will present two cases illustrative of the dynamical regime for ultra-short period exoplanets, and how we can use general circulation models to constrain observations of their atmospheres. First, we will present models of WASP-43b, a Jupiter-mass planet in a 19.5-hour orbit around a K7 star. Because WASP-43b has an equilibrium temperature similar to that of HD 209458b, we can explore the role of rotation rate on the dynamics at a fixed stellar flux. We then compare our models to spectrophotometric observations obtained with HST/WFC3 and show how our 5× solar model provides the best match to the data. Next, we explore the dynamical regime of 55 Cnc e, a 7 Earth-mass, 2 Earth-radius planet in a 0.7 day orbit around a K star. Because smaller planets have a large diversity in possible compositions, we compare hydrogen-, water- and carbon dioxide-dominated models and show how differences in opacity structure lead to differences in temperature structure and circulation. We also demonstrate how future observations can distinguish between these possible compositions of 55 Cnc e, particularly in emission.

Kataria, Tiffany; Showman, Adam P.; Fortney, Jonathan J.; Stevenson, Kevin B.; Lewis, Nikole K.

2015-01-01

204

WASP-40b: independent discovery of the 0.6-Mjup transiting exoplanet HAT-P-27b  

CERN Document Server

From WASP photometry and SOPHIE radial velocities we report the discovery of WASP-40b (= HAT-P-27b), a 0.6-Mjup planet that transits its 12th magnitude host star every 3.04 d. The host star is of late-G or early-K type and likely has an above-Solar metallicity, with [Fe/H] = 0.14 +/- 0.11. The planet's mass and radius are typical of the known hot Jupiters, thus adding another system to the apparent pileup of transiting planets with periods near 3 to 4 d. Our parameters match those of the recent HATnet announcement of the same planet, thus giving confidence in the techniques used. We report a possible indication of stellar activity in the host star.

Anderson, D R; Boisse, I; Bouchy, F; Collier-Cameron, A; Faedi, F; Hebrard, G; Hellier, C; Lendl, M; Moutou, C; Pollacco, D; Santerne, A; Smalley, B; Smith, A M S; Todd, I; Triaud, A H M J; West, R G; Wheatley, P J; Bento, J; Enoch, B; Gillon, M; Maxted, P F L; McCormac, J; Queloz, D; Simpson, E K; Skillen, I

2011-01-01

205

Astrometric Exoplanet Detection with Gaia  

Science.gov (United States)

We provide a revised assessment of the number of exoplanets that should be discovered by Gaia astrometry, extending previous studies to a broader range of spectral types, distances, and magnitudes. Our assessment is based on a large representative sample of host stars from the TRILEGAL Galaxy population synthesis model, recent estimates of the exoplanet frequency distributions as a function of stellar type, and detailed simulation of the Gaia observations using the updated instrument performance and scanning law. We use two approaches to estimate detectable planetary systems: one based on the signal-to-noise ratio of the astrometric signature per field crossing, easily reproducible and allowing comparisons with previous estimates, and a new and more robust metric based on orbit fitting to the simulated satellite data. With some plausible assumptions on planet occurrences, we find that some 21,000 (±6000) high-mass (~1-15M J) long-period planets should be discovered out to distances of ~500 pc for the nominal 5 yr mission (including at least 1000-1500 around M dwarfs out to 100 pc), rising to some 70,000 (±20, 000) for a 10 yr mission. We indicate some of the expected features of this exoplanet population, amongst them ~25-50 intermediate-period (P ~ 2-3 yr) transiting systems.

Perryman, Michael; Hartman, Joel; Bakos, Gáspár Á.; Lindegren, Lennart

2014-12-01

206

Direct Measurement of the Radius and Density of the Transiting Exoplanet HD 189733B with the CHARA Array  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We have measured the angular diameter of the transiting extrasolar planet host star HD 189733 using the CHARA O/IR interferometric array. Combining our new angular diameter of 0.377+/-0.024 mas with the Hipparcos parallax leads to a linear radius for the host star of 0.779+/-0.052 Rsol and a radius for the planet of 1.19+/-0.08 RJup. Adopting the mass of the planet as derived by its discoverers, we derive a mean density of the planet of 0.91+/-0.18 g cm-3. This is the first ...

Baines, E. K.; Belle, G. T.; Brummelaar, T. A. Ten; Mcalister, H. A.; Swain, M.; Turner, N. H.; Sturmann, L.; Sturmann, J.

2007-01-01

207

Exoplanet Science with TMT  

Science.gov (United States)

TMT will have unparalleled capabilities for characterizing the composition of extrasolar planets and their atmospheres, and for probing the complex interplay between planet formation, evolution, and migration. In this plenary talk I will summarize these science cases and discuss their synergy with other observing facilities. High-resolution imaging with IRIS and PFI/SEIT will study young, hot planets in nearby star-forming regions, complementing JWST and WFIRST/AFTA coronagraphic efforts at larger semimajor axes. The same instruments will flesh out planets detected by radial velocity (RV) by measuring the albedos and bolometric radii of old, cold Jovian planets and a few ~300 K super-Earths. Complementing JWST and HST studies of short-period transiting planets, NIRES and IRMS spectroscopy will reveal atmospheric composition, dynamics, and thermal structure for dozens of hot Jupiters and Neptunes; NIRES will also produce 2D global maps and movies of a few exoplanets and dozens of brown dwarfs. HROS high-dispersion spectroscopy will precisely measure the composition of extrasolar planetesimals in polluted white dwarfs, and RV followup will continue to exploit the legacies of Kepler, K2, TESS, and PLATO to measure the masses, orbits, and bulk compositions of Earth analogues. Most exciting of all, TMT may facilitate the next major step in the study of exobiology by allowing the detection of biosignature gases around the closest habitable transiting planets.

Crossfield, Ian

2014-07-01

208

Precise Estimates of the Physical Parameters for the Exoplanet System HD-17156 Enabled by HST FGS Transit and Asteroseismic Observations  

CERN Document Server

We present observations of three distinct transits of HD 17156b obtained with the Fine Guidance Sensors (FGS) on board the Hubble Space Telescope} (HST). We analyzed both the transit photometry and previously published radial velocities to find the planet-star radius ratio R_p/R_s = 0.07454 +/- 0.00035, inclination i=86.49 +0.24/-0.20 deg, and scaled semi-major axis a/R = 23.19 +0.32/-0.27. This last value translates directly to a mean stellar density determination of 0.522 +0.021/-0.018 g cm^-3. Analysis of asteroseismology observations by the companion paper of Gilliland et al. (2009) provides a consistent but significantly refined measurement of the stellar mean density. We compare stellar isochrones to this density estimate and find M_s = 1.275 +/- 0.018 M_sun and a stellar age of $3.37 +0.20/-0.47 Gyr. Using this estimate of M_s and incorporating the density constraint from asteroseismology, we model both the photometry and published radial velocities to estimate the planet radius R_p= 1.0870 +/- 0.0066 ...

Nutzman, Philip; McCullough, Peter R; Charbonneau, David; Christensen-Dalsgaard, Jørgen; Kjeldsen, Hans; Nelan, Edmund P; Brown, Timothy M; Holman, Matthew J

2010-01-01

209

Spectra as Windows into Exoplanet Atmospheres  

CERN Document Server

Understanding a planet's atmosphere is a necessary condition for understanding not only the planet itself, but also its formation, structure, evolution, and habitability, This puts a premium on obtaining spectra, and developing credible interpretative tools with which to retrieve vital planetary information. However, for exoplanets these twin goals are far from being realized. In this paper, I provide a personal perspective on exoplanet theory and remote sensing via photometry and low-resolution spectroscopy. Though not a review in any sense, this paper highlights the limitations in our knowledge of compositions, thermal profiles, and the effects of stellar irradiation, focussing on, but not restricted to, transiting giant planets. I suggest that the true function of the recent past of exoplanet atmospheric research has been not to constrain planet properties for all time, but to train a new generation of scientists that, by rapid trial and error, is fast establishing a solid future foundation for a robust sc...

Burrows, Adam

2013-01-01

210

Transiting exoplanets from the CoRoT space mission: XXIV. CoRoT-24: A transiting multi-planet system  

CERN Document Server

We present the discovery of a candidate multiply-transiting system, the first one found in the CoRoT mission. Two transit-like features with periods of 5.11 and 11.76d are detected in the CoRoT light curve, around a main sequence K1V star of r=15.1. If the features are due to transiting planets around the same star, these would correspond to objects of 3.7$\\pm$0.4 and 5.0$\\pm$0.5 R_earth respectively. Several radial velocities serve to provide an upper limit of 5.7 M_earth for the 5.11~d signal, and to tentatively measure a mass of 28$^{+11}_{-11}$ M_earth for the object transiting with a 11.76~d period. These measurements imply low density objects, with a significant gaseous envelope. The detailed analysis of the photometric and spectroscopic data serve to estimate the probability that the observations are caused by transiting Neptune-sized planets as $>$26$\\times$ higher than a blend scenario involving only one transiting planet, and $>$900$\\times$ higher than a scenario involving two blends and no planets....

Alonso, R; Endl, M; Almenara, J M; Guenther, E W; Deleuil, M; Hatzes, A; Aigrain, S; Auvergne, M; Baglin, A; Barge, P; Bonomo, A S; Bordé, P; Bouchy, F; Cavarroc, C; Cabrera, J; Carpano, S; Csizmadia, Sz; Cochran, W D; Deeg, H J; Díaz, R F; Dvorak, R; Erikson, A; Ferraz-Mello, S; Fridlund, M; Fruth, T; Gandolfi, D; Gillon, M; Grziwa, S; Guillot, T; Hébrard, G; Jorda, L; Léger, A; Lammer, H; Lovis, C; MacQueen, P J; Mazeh, T; Ofir, A; Ollivier, M; Pasternacki, T; Patzold, M; Queloz, D; Rauer, H; Rouan, D; Santerne, A; Schneider, J; Santos, M Tadeu dos; Tingley, B; Titz-Weider, R; Weingrill, J; Wuchterl, G

2014-01-01

211

The spin-orbit alignment of the transiting exoplanet WASP-3b from Rossiter-McLaughlin observations  

CERN Document Server

We present an observation of the Rossiter-McLaughlin effect for the planetary system WASP-3. Radial velocity measurements were made during transit using the SOPHIE spectrograph at the 1.93m telescope at Haute-Provence Observatory. The shape of the effect shows that the sky-projected angle between the stellar rotation axis and planetary orbital axis (lambda) is small and consistent with zero within 2 sigma; lambda = 15 +10/-9 deg. WASP-3b joins the ~two-thirds of planets with measured spin-orbit angles that are well aligned and are thought to have undergone a dynamically-gentle migration process such as planet-disc interactions. We find a systematic effect which leads to an anomalously high determination of the projected stellar rotational velocity (vsini = 19.6 +2.2/-2.1 km/s) compared to the value found from spectroscopic line broadening (vsini = 13.4 +/- 1.5 km/s). This is thought to be caused by a discrepancy in the assumptions made in the extraction and modelling of the data. Using a model developed by Hi...

Simpson, E K; Hebrard, G; Gibson, N P; Barros, S C C; Bouchy, F; Cameron, A Collier; Boisse, I; Watson, C A; Keenan, F P

2009-01-01

212

Infrared spectroscopy of exoplanets: observational constraints.  

Science.gov (United States)

The exploration of transiting extrasolar planets is an exploding research area in astronomy. With more than 400 transiting exoplanets identified so far, these discoveries have made possible the development of a new research field, the spectroscopic characterization of exoplanets' atmospheres, using both primary and secondary transits. However, these observations have been so far limited to a small number of targets. In this paper, we first review the advantages and limitations of both primary and secondary transit methods. Then, we analyse what kind of infrared spectra can be expected for different types of planets and discuss how to optimize the spectral range and the resolving power of the observations. Finally, we propose a list of favourable targets for present and future ground-based observations. PMID:24664918

Encrenaz, Thérèse

2014-04-28

213

Direct Imaging of a Cold Jovian Exoplanet in Orbit around the Sun-like Star GJ 504  

CERN Document Server

Several exoplanets have recently been imaged at wide separations of >10 AU from their parent stars. These span a limited range of ages ( 0.5 mag), implying thick cloud covers. Furthermore, substantial model uncertainties exist at these young ages due to the unknown initial conditions at formation, which can lead to an order of magnitude of uncertainty in the modeled planet mass. Here, we report the direct imaging discovery of a Jovian exoplanet around the Sun-like star GJ 504, detected as part of the SEEDS survey. The system is older than all other known directly-imaged planets; as a result, its estimated mass remains in the planetary regime independent of uncertainties related to choices of initial conditions in the exoplanet modeling. Using the most common exoplanet cooling model, and given the system age of 160 [+350, -60] Myr, GJ 504 b has an estimated mass of 4 [+4.5, -1.0] Jupiter masses, among the lowest of directly imaged planets. Its projected separation of 43.5 AU exceeds the typical outer boundary ...

Kuzuhara, M; Kudo, T; Janson, M; Kandori, R; Brandt, T D; Thalmann, C; Spiegel, D; Biller, B; Carson, J; Hori, Y; Suzuki, R; Burrows, A; Henning, T; Turner, E L; McElwain, M W; Moro-Martin, A; Suenaga, T; Takahashi, Y H; Kwon, J; Lucas, P; Abe, L; Brandner, W; Egner, S; Feldt, M; Fujiwara, H; Goto, M; Grady, C A; Guyon, O; Hashimoto, J; Hayano, Y; Hayashi, M; Hayashi, S S; Hodapp, K W; Ishii, M; Iye, M; Knapp, G R; Matsuo, T; Mayama, S; Miyama, S; Morino, J -I; Nishikawa, J; Nishimura, T; Kotani, T; Kusakabe, N; Pyo, T -S; Serabyn, E; Suto, H; Takami, M; Takato, N; Terada, H; Tomono, D; Watanabe, M; Wisniewski, J P; Yamada, T; Takami, H; Usuda, T

2013-01-01

214

Transiting exoplanets from the CoRoT space mission III. The spectroscopic transit of CoRoT-Exo-2b with SOPHIE and HARPS  

CERN Document Server

We report on the spectroscopic transit of the massive hot-Jupiter CoRoT-Exo-2b observed with the high-precision spectrographs SOPHIE and HARPS. By modeling the radial velocity anomaly occurring during the transit due to the Rossiter-McLaughlin (RM) effect, we determine the sky-projected angle between the stellar spin and the planetary orbital axis to be close to zero lambda=7.2+-4.5 deg, and we secure the planetary nature of CoRoT-Exo-2b. We discuss the influence of the stellar activity on the RM modeling. Spectral analysis of the parent star from HARPS spectra are presented.

Bouchy, F; Deleuil, M; Loeillet, B; Hatzes, A P; Aigrain, S; Alonso, R; Auvergne, M; Baglin, A; Barge, P; Benz, W; Bordé, P; Deeg, H J; De la Reza, R; Dvorak, R; Erikson, A; Fridlund, M; Gondoin, P; Guillot, T; Hébrard, G; Jorda, L; Lammer, H; Léger, A; Llebaria, A; Magain, P; Mayor, M; Moutou, C; Ollivier, M; Pätzold, M; Pepe, F; Pont, F; Rauer, H; Rouan, D; Schneider, J; Triaud, A H M J; Udry, S; Wuchterl, G

2008-01-01

215

SOPHIE velocimetry of $\\textit{Kepler}$ transit candidates XII. KOI-1257 b: a highly-eccentric 3-month period transiting exoplanet  

CERN Document Server

In this paper we report a new transiting warm giant planet: KOI-1257 b. It was first detected in photometry as a planet-candidate by the $\\textit{Kepler}$ space telescope and then validated thanks to a radial velocity follow-up with the SOPHIE spectrograph. It orbits its host star with a period of 86.647661 d $\\pm$ 3 s and a high eccentricity of 0.772 $\\pm$ 0.045. The planet transits the main star of a metal-rich, relatively old binary system with stars of mass of 0.99 $\\pm$ 0.05 Msun and 0.70 $ \\pm $ 0.07 Msun for the primary and secondary (respectively). This binary system is constrained thanks to a self-consistent modelling of the $\\textit{Kepler}$ transit light curve, the SOPHIE radial velocities, line bisector and full-width half maximum (FWHM) variations as well as the spectral energy distribution. However, future observations are needed to confirm it. The PASTIS fully-Bayesian software was used to validate the nature of the planet and to determine which star of the binary system is the transit host. By...

Santerne, A; Deleuil, M; Havel, M; Correia, A C M; Almenara, J -M; Alonso, R; Arnold, L; Barros, S C C; Behrend, R; Bernasconi, L; Boisse, I; Bonomo, A S; Bouchy, F; Bruno, G; Damiani, C; Díaz, R F; Gravallon, D; Guillot, T; Labrevoir, O; Montagnier, G; Moutou, C; Rinner, C; Santos, N C; Abe, L; Audejean, M; Bendjoya, P; Gillier, C; Gregorio, J; Martinez, P; Michelet, J; Montaigut, R; Poncy, R; Rivet, J -P; Rousseau, G; Roy, R; Suarez, O; Vanhuysse, M; Verilhac, D

2014-01-01

216

Observability of the General Relativistic Precession of Periastra in Exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The general relativistic precession rate of periastra in close-in exoplanets can be orders of magnitude larger than the magnitude of the same effect for Mercury. The realization that some of the close-in exoplanets have significant eccentricities raises the possibility that this precession might be detectable. We explore in this work the observability of the periastra precession using radial velocity and transit light curve observations. Our analysis is independent of the so...

Jordan, Andres; Bakos, Gaspar A.

2008-01-01

217

The distribution of exoplanet masses  

CERN Document Server

The present study derives the distribution of secondary masses M2 for the 67 exoplanets and very low-mass brown dwarf companions of solar-type stars, known as of April 4, 2001. This distribution is related to the distribution of M2 sin i through an integral equation of Abel's type. Although a formal solution exists for this equation, it is known to be ill-behaved, and thus very sensitive to the statistical noise present in the input M2 sin i distribution. To overcome that difficulty, we present two robust, independent approaches: (i) the formal solution of the integral equation is numerically computed after performing an optimal smoothing of the input distribution, (ii) the Lucy-Richardson algorithm is used to invert the integral equation. Both approaches give consistent results. The resulting statistical distribution of exoplanet true masses reveals that there is no reason to ascribe the transition between giant planets and brown dwarfs to the threshold mass for deuterium ignition (about 13 MJ). The M2 distr...

Jorissen, A; Udry, S

2001-01-01

218

The distribution of exoplanet masses  

Science.gov (United States)

The present study derives the distribution of secondary masses M2 for the 67 exoplanets and very low-mass brown-dwarf companions of solar-type stars, known as of April 4, 2001. This distribution is related to the distribution of M2 sin i through an integral equation of Abel's type. Although a formal solution exists for this equation, it is known to be ill-conditioned, and is thus very sensitive to the statistical noise present in the input M2 sin i distribution. To overcome this difficulty, we present two robust, independent approaches: (i) the formal solution of the integral equation is numerically computed after performing an optimal smoothing of the input distribution and (ii) the Lucy-Richardson algorithm is used to invert the integral equation. Both approaches give consistent results. The resulting statistical distribution of exoplanet true masses reveals that there is no reason to ascribe the transition between giant planets and brown dwarfs to the threshold mass for deuterium ignition (about 13.6 MJ). The M2 distribution shows instead that most of the objects have M2 <= 10 MJ, but there is a small tail with a few heavier candidates around 15 MJ.

Jorissen, A.; Mayor, M.; Udry, S.

2001-12-01

219

Evolution of exoplanets and their parent stars  

Science.gov (United States)

Studying exoplanets with their parent stars is crucial to understand their population, formation and history. We review some of the key questions regarding their evolution with particular emphasis on giant gaseous exoplanets orbiting close to solar-type stars. For masses above that of Saturn, transiting exoplanets have large radii indicative of the presence of a massive hydrogen-helium envelope. Theoretical models show that this envelope progressively cools and contracts with a rate of energy loss inversely proportional to the planetary age. The combined measurement of planetary mass, radius and a constraint on the (stellar) age enables a global determination of the amount of heavy elements present in the planet interior. The comparison with stellar metallicity shows a correlation between the two, indicating that accretion played a crucial role in the formation of planets. The dynamical evolution of exoplanets also depends on the properties of the central star. We show that the lack of massive giant planets and brown dwarfs in close orbit around G-dwarfs and their presence around F-dwarfs are probably tied to the different properties of dissipation in the stellar interiors. Both the evolution and the composition of stars and planets are intimately linked.

Guillot, T.; Lin, D. N. C.; Morel, P.; Havel, M.; Parmentier, V.

2014-11-01

220

Exoplanet detection capability of the COROT space mission  

CERN Document Server

COROT will be the first high precision photometric satellite to be launched with the aim of detecting exoplanets by the transit method. In this paper, we present the simulations we have carried out in order to assess the detection capability of COROT. Using the model of stellar population synthesis of the Galaxy developed at Besancon Observatory (Robin & Creze 1986) and a simple cross-correlation technique (Borde et al. 2001), we find that COROT has the capacity to detect numerous exoplanets, not only Jupiter and Uranus-class ones, but also hot terrestrial planets, if they exist. We show that small exoplanets should be mainly gathered around 14-15th magnitude K2-M2 dwarfs and giant exoplanets around 15-16th magnitude F7-G2 dwarfs. We study the effect of crowding and the impact of a high stellar variability noise that both reduce the detection capability of the instrument.

Bordé, P J; Léger, A

2003-01-01

 
 
 
 
221

Spectroscopy of Exoplanet Atmospheres with the FINESSE Explorer  

Science.gov (United States)

FINESSE (Fast INfrared Exoplanet Spectroscopic Survey Explorer) will provide uniquely detailed information on the growing number of newly discovered planets by characterizing their atmospheric composition and temperature structure. This NASA Explorer mission, selected for a competitive Phase A study, is unique in its breath and scope thanks to broad instantaneous spectroscopy from the optical to the mid-IR (0.7 - 5 micron), with a survey of exoplanets measured in a consistent, uniform way. For 200 transiting exoplanets ranging from Terrestrial to Jovians, FINESSE will measure the chemical composition and temperature structure of their atmospheres and trace changes over time with exoplanet longitude. The mission will do so by measuring the spectroscopic time series for a primary and secondary eclipse over the exoplanet orbital phase curve. With spectrophotometric precision being a key enabling aspect for combined light exoplanet characterization, FINESSE is designed to produce spectrophotometric precision of better than 100 parts-per-million per spectral channel without the need for decorrelation. The exceptional stability of FINESSE will even allow the mission to characterize non-transiting planets, potentially as part of FINESSE's Participating Scientist Program. In this paper, we discuss the flow down from the target availability to observations and scheduling to the analysis and calibration of the data and how it enables FINESSE to be the mission that will truly expand the new field of comparative exoplanetology.

Deroo, Pieter; Swain, Mark R.; Green, Robert O.

2012-01-01

222

Exploring Exoplanet Populations with NASA's Kepler Mission  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Kepler Mission is exploring the diversity of planets and planetary systems. Its legacy will be a catalog of discoveries sufficient for computing planet occurrence rates as a function of size, orbital period, star-type, and insolation flux. The mission has made significant progress toward achieving that goal. Over 3,500 transiting exoplanets have been identified from the analysis of the first three years of data, 100 of which are in the habitable zone. The catalog has a h...

Batalha, Natalie M.

2014-01-01

223

Atmospheric Circulation of Exoplanets  

CERN Document Server

We survey the basic principles of atmospheric dynamics relevant to explaining existing and future observations of exoplanets, both gas giant and terrestrial. Given the paucity of data on exoplanet atmospheres, our approach is to emphasize fundamental principles and insights gained from Solar-System studies that are likely to be generalizable to exoplanets. We begin by presenting the hierarchy of basic equations used in atmospheric dynamics, including the Navier-Stokes, primitive, shallow-water, and two-dimensional nondivergent models. We then survey key concepts in atmospheric dynamics, including the importance of planetary rotation, the concept of balance, and scaling arguments to show how turbulent interactions generally produce large-scale east-west banding on rotating planets. We next turn to issues specific to giant planets, including their expected interior and atmospheric thermal structures, the implications for their wind patterns, and mechanisms to pump their east-west jets. Hot Jupiter atmospheric d...

Showman, Adam P; Menou, Kristen

2009-01-01

224

Warm Spitzer Photometry of the Transiting Exoplanets CoRoT-1 and CoRoT-2 at Secondary Eclipse  

CERN Document Server

We measure secondary eclipses of the hot giant exoplanets CoRoT-1 at 3.6 and 4.5 microns, and CoRoT-2 at 3.6 microns, both using Warm Spitzer. We find that the Warm Spitzer mission is working very well for exoplanet science. For consistency of our analysis we also re-analyze archival cryogenic Spitzer data for secondary eclipses of CoRoT-2 at 4.5 and 8 microns. We compare the total data for both planets, including optical eclipse measurements by the CoRoT mission, and ground-based eclipse measurements at 2 microns, to existing models. Both planets exhibit stronger eclipses at 4.5 than at 3.6 microns, which is often indicative of an atmospheric temperature inversion. The spectrum of CoRoT-1 is best reproduced by a 2460K blackbody, due either to a high altitude layer that strongly absorbs stellar irradiance, or an isothermal region in the planetary atmosphere. The spectrum of CoRoT-2 is unusual because the 8 micron contrast is anomalously low. Non-inverted atmospheres could potentially produce the CoRoT-2 spect...

Deming, Drake; Agol, Eric; Desert, Jean-Michel; Burrows, Adam; Fortney, Jonathan J; Charbonneau, David; Cowan, Nicolas B; Laughlin, Gregory; Langton, Jonathan; Showman, Adam P; Lewis, Nikole K

2010-01-01

225

DIRECT IMAGING OF A COLD JOVIAN EXOPLANET IN ORBIT AROUND THE SUN-LIKE STAR GJ 504  

Energy Technology Data Exchange (ETDEWEB)

Several exoplanets have recently been imaged at wide separations of >10 AU from their parent stars. These span a limited range of ages (<50 Myr) and atmospheric properties, with temperatures of 800-1800 K and very red colors (J - H > 0.5 mag), implying thick cloud covers. Furthermore, substantial model uncertainties exist at these young ages due to the unknown initial conditions at formation, which can lead to an order of magnitude of uncertainty in the modeled planet mass. Here, we report the direct-imaging discovery of a Jovian exoplanet around the Sun-like star GJ 504, detected as part of the SEEDS survey. The system is older than all other known directly imaged planets; as a result, its estimated mass remains in the planetary regime independent of uncertainties related to choices of initial conditions in the exoplanet modeling. Using the most common exoplanet cooling model, and given the system age of 160{sup +350}{sub -60} Myr, GJ 504b has an estimated mass of 4{sup +4.5}{sub -1.0} Jupiter masses, among the lowest of directly imaged planets. Its projected separation of 43.5 AU exceeds the typical outer boundary of {approx}30 AU predicted for the core accretion mechanism. GJ 504b is also significantly cooler (510{sup +30}{sub -20} K) and has a bluer color (J - H = -0.23 mag) than previously imaged exoplanets, suggesting a largely cloud-free atmosphere accessible to spectroscopic characterization. Thus, it has the potential of providing novel insights into the origins of giant planets as well as their atmospheric properties.

Kuzuhara, M. [Department of Earth and Planetary Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Tamura, M.; Kandori, R.; Hori, Y.; Suzuki, R.; Suenaga, T.; Takahashi, Y. H.; Kwon, J. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Kudo, T. [Subaru Telescope, National Astronomical Observatory of Japan, 650 North A' ohoku Place, Hilo, HI 96720 (United States); Janson, M.; Brandt, T. D.; Spiegel, D.; Burrows, A.; Turner, E. L.; Moro-Martin, A. [Department of Astrophysical Sciences, Princeton University, Peyton Hall, Ivy Lane, Princeton, NJ 08544 (United States); Thalmann, C. [Astronomical Institute ' ' Anton Pannekoek' ' , University of Amsterdam, Postbus 94249, 1090 GE, Amsterdam (Netherlands); Biller, B.; Henning, T. [Max Planck Institute for Astronomy, Koenigstuhl 17, D-69117 Heidelberg (Germany); Carson, J. [Department of Physics and Astronomy, College of Charleston, 58 Coming Street, Charleston, SC 29424 (United States); McElwain, M. W., E-mail: m.kuzuhara@nao.ac.jp [Exoplanets and Stellar Astrophysics Laboratory, Code 667, Goddard Space Flight Center, Greenbelt, MD 20771 (United States); and others

2013-09-01

226

The Optical Design of CHARIS: An Exoplanet IFS for the Subaru Telescope  

Science.gov (United States)

High-contrast imaging techniques now make possible both imaging and spectroscopy of planets around nearby stars. We present the optical design for the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS), a lenslet-based, cryogenic integral field spectrograph (IFS) for imaging exoplanets on the Subaru telescope. The IFS will provide spectral information for 138×138 spatial elements over a 2.07 arcsec × 2.07 arcsec field of view (FOV). CHARIS will operate in the near infrared (lambda = 1.15 - 2.5 micrometers) and will feature two spectral resolution modes of R is approximately 18 (low-res mode) and R is approximately 73 (high-res mode). Taking advantage of the Subaru telescope adaptive optics systems and coronagraphs (AO188 and SCExAO), CHARIS will provide sufficient contrast to obtain spectra of young self-luminous Jupiter-mass exoplanets. CHARIS will undergo CDR in October 2013 and is projected to have first light by the end of 2015. We report here on the current optical design of CHARIS and its unique innovations.

Peters-Limbach, Mary; Groff, Tyler; Kasdin, N. Jeremy; Driscoll, Dave; Galvin, Michael; Foster, Allen; Carr, Michael; LeClerc, Dave; Fagan, Rad; McElwain, Michael; Knapp, Gillian; Brandt, Timothy; Janson, Markus; Guyone, Olivier; Jovanovic, Nemanja; Martinache, Frantz; Hayashi, Masahiko; Takato, Naruhisa

2013-01-01

227

The Optical Design of CHARIS: An Exoplanet IFS for the Subaru Telescope  

CERN Document Server

High-contrast imaging techniques now make possible both imaging and spectroscopy of planets around nearby stars. We present the optical design for the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS), a lenslet-based, cryogenic integral field spectrograph (IFS) for imaging exoplanets on the Subaru telescope. The IFS will provide spectral information for 138x138 spatial elements over a 2.07 arcsec x 2.07 arcsec field of view (FOV). CHARIS will operate in the near infrared (lambda = 1.15 - 2.5 microns) and will feature two spectral resolution modes of R = 18 (low-res mode) and R = 73 (high-res mode). Taking advantage of the Subaru telescope adaptive optics systems and coronagraphs (AO188 and SCExAO), CHARIS will provide sufficient contrast to obtain spectra of young self-luminous Jupiter-mass exoplanets. CHARIS will undergo CDR in October 2013 and is projected to have first light by the end of 2015. We report here on the current optical design of CHARIS and its unique innovations.

Peters-Limbach, Mary Anne; Kasdin, N Jeremy; Driscoll, Dave; Galvin, Michael; Foster, Allen; Carr, Michael A; LeClerc, Dave; Fagan, Rad; McElwain, Michael W; Knapp, Gillian; Brandt, Timothy; Janson, Markus; Guyon, Olivier; Jovanovic, Nemanja; Martinache, Frantz; Hayashi, Masahiko; Takato, Naruhisa

2013-01-01

228

Search and characterization of exoplanets by photometry: development and exploitation of the ASTEP project  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The photometry of transits is a powerful method to detect and characterize exoplanets. The Concordia base in Dome C, Antarctica, is an extremely promising site for photometric astronomy due to the 3-month long night during the Antarctic winter and very favorable weather conditions. The ASTEP project (Antarctic Search for Transiting ExoPlanets) is a pilot project to discover and characterize transiting planets and understand the limits of visible photometry from the Concordia site. The project...

Crouzet, Nicolas

2010-01-01

229

Transiting exoplanets from the CoRoT space mission XVII. The hot Jupiter CoRoT-17b: a very old planet  

CERN Document Server

We report on the discovery of a hot Jupiter-type exoplanet, CoRoT-17b, detected by the CoRoT satellite. It has a mass of $2.43\\pm0.30$\\Mjup and a radius of $1.02\\pm0.07$\\Rjup, while its mean density is $2.82\\pm0.38$ g/cm$^3$. CoRoT-17b is in a circular orbit with a period of $3.7681\\pm0.0003$ days. The host star is an old ($10.7\\pm1.0$ Gyr) main-sequence star, which makes it an intriguing object for planetary evolution studies. The planet's internal composition is not well constrained and can range from pure H/He to one that can contain $\\sim$380 earth masses of heavier elements.

Csizmadia, Sz; Deleuil, M; Cabrera, J; Fridlund, M; Gandolfi, D; Aigrain, S; Alonso, R; Almenara, J M; Auvergne, M; Baglin, A; Barge, P; Bonomo, A S; Borde, P; Bouchy, F; Bruntt, H; Carone, L; Carpano, S; Cavarroc, C; Cochran, W; Deeg, H J; Diaz, R F; Dvorak, R; Endl, M; Erikson, A; Ferraz-Mello, S; Fruth, Th; Gazzano, J C; Gillon, M; Guenther, E W; Guillot, T; Hatzes, A; Havel, M; Hebrard, G; Jehin, E; Jorda, L; Leger, A; Llebaria, A; Lammer, H; Lovis, C; MacQueen, P J; Mazeh, T; Ollivier, M; Paetzold, M; Queloz, D; Rauer, H; Rouan, D; Santerne, A; Schneider, J; Tingley, B; Titz-Weider, R; Wuchterl, G

2011-01-01

230

TEST - The Tautenburg Exoplanet Search Telescope  

CERN Document Server

The Tautenburg Exoplanet Search Telescope (TEST) is a robotic telescope system. The telescope uses a folded Schmidt Camera with a 300mm main mirror. The focal length is 940mm and it gives a 2.2 square degree field of view. Dome, mount, and CCD cameras are controlled by a software bundle made by Software Bisque. The automation of the telescope includes selection of the night observing program from a given framework, taking darks and skyflats, field identification, guiding, data taking, and archiving. For the search for transiting exoplanets and variable stars an automated psf photometry based on IRAF and a lightcurve analysis based on ESO-Midas are conducted. The images and the results are managed using a PostgreSQL database.

Eigmüller, Philipp

2008-01-01

231

Light from Exoplanets: Present and Future  

Science.gov (United States)

Measurements using the Spitzer Space Telescope have revealed thermal emission from planets orbiting very close to solar-type stars, primarily transiting "hot Jupiter" exoplanets. The thermal emission spectrum of these worlds has been measured by exploiting their secondary eclipse. Also, during transit of the planet, absorption signatures from atoms and molecules in the planet's atmosphere are imprinted onto the spectrum of the star. Results to date from transit and eclipse studies show that the hot Jupiters often have significant haze and cloud components in their atmospheres, and the temperature structure can often be inverted, i.e. temperature is rising with height. New and very strongly irradiated examples of hot Jupiters have been found that are being stripped of their atmospheres by tidal forces from the star. In parallel, transiting superEarth exoplanets are being discovered, and their atmospheres should also be amenable to study using transit techniques. The 2014 launch of the James Webb Space Telescope will clarify the physical nature of hot Jupiters, and will extend transit and eclipse studies to superEarths orbiting in the habitable zones of lower main sequence stars.

Deming, Leo

2010-01-01

232

Chemical modeling of exoplanet atmospheres  

CERN Document Server

The past twenty years have revealed the diversity of planets that exist in the Universe. It turned out that most of exoplanets are different from the planets of our Solar System and thus, everything about them needs to be explored. Thanks to current observational technologies, we are able to determine some information about the atmospheric composition, the thermal structure and the dynamics of these exoplanets, but many questions remain still unanswered. To improve our knowledge about exoplanetary systems, more accurate observations are needed and that is why the Exoplanet Characterisation Observatory (EChO) is an essential space mission. Thanks to its large spectral coverage and high spectral resolution, EChO will provide exoplanetary spectra with an unprecedented accuracy, allowing to improve our understanding of exoplanets. In this work, we review what has been done to date concerning the chemical modeling of exoplanet atmospheres and what are the main characteristics of warm exoplanet atmospheres, which a...

Venot, Olivia

2014-01-01

233

32 New Exoplanets Found  

Science.gov (United States)

oday, at an international ESO/CAUP exoplanet conference in Porto, the team who built the High Accuracy Radial Velocity Planet Searcher, better known as HARPS, the spectrograph for ESO's 3.6-metre telescope, reports on the incredible discovery of some 32 new exoplanets, cementing HARPS's position as the world's foremost exoplanet hunter. This result also increases the number of known low-mass planets by an impressive 30%. Over the past five years HARPS has spotted more than 75 of the roughly 400 or so exoplanets now known. "HARPS is a unique, extremely high precision instrument that is ideal for discovering alien worlds," says Stéphane Udry, who made the announcement. "We have now completed our initial five-year programme, which has succeeded well beyond our expectations." The latest batch of exoplanets announced today comprises no less than 32 new discoveries. Including these new results, data from HARPS have led to the discovery of more than 75 exoplanets in 30 different planetary systems. In particular, thanks to its amazing precision, the search for small planets, those with a mass of a few times that of the Earth - known as super-Earths and Neptune-like planets - has been given a dramatic boost. HARPS has facilitated the discovery of 24 of the 28 planets known with masses below 20 Earth masses. As with the previously detected super-Earths, most of the new low-mass candidates reside in multi-planet systems, with up to five planets per system. In 1999, ESO launched a call for opportunities to build a high resolution, extremely precise spectrograph for the ESO 3.6-metre telescope at La Silla, Chile. Michel Mayor, from the Geneva Observatory, led a consortium to build HARPS, which was installed in 2003 and was soon able to measure the back-and-forward motions of stars by detecting small changes in a star's radial velocity - as small as 3.5 km/hour, a steady walking pace. Such a precision is crucial for the discovery of exoplanets and the radial velocity method, which detects small changes in the radial velocity of a star as it wobbles slightly under the gentle gravitational pull from an (unseen) exoplanet, has been most prolific method in the search for exoplanets. In return for building the instrument, the HARPS consortium was granted 100 observing nights per year during a five-year period to carry out one of the most ambitious systematic searches for exoplanets so far implemented worldwide by repeatedly measuring the radial velocities of hundreds of stars that may harbour planetary systems. The programme soon proved very successful. Using HARPS, Mayor's team discovered - among others - in 2004, the first super-Earth (around µ Ara; in 2006, the trio of Neptunes around HD 69830; in 2007, Gliese 581d, the first super Earth in the habitable zone of a small star (eso0722); and in 2009, the lightest exoplanet so far detected around a normal star, Gliese 581e (eso0915). More recently, they found a potentially lava-covered world, with density similar to that of the Earth's (eso0933). "These observations have given astronomers a great insight into the diversity of planetary systems and help us understand how they can form," says team member Nuno Santos. The HARPS consortium was very careful in their selection of targets, with several sub-programmes aimed at looking for planets around solar-like stars, low-mass dwarf stars, or stars with a lower metal content than the Sun. The number of exoplanets known around low-mass stars - so-called M dwarfs - has also dramatically increased, including a handful of super Earths and a few giant planets challenging planetary formation theory. "By targeting M dwarfs and harnessing the precision of HARPS we have been able to search for exoplanets in the mass and temperature regime of super-Earths, some even close to or inside the habitable zone around the star," says co-author Xavier Bonfils. The team found three candidate exoplanets around stars that are metal-deficient. Such stars are thought to be less favourable for the formation of planets, which fo

2009-10-01

234

Discriminating Between Cloudy, Hazy and Clearsky Exoplanets Using Refraction  

CERN Document Server

We propose a method to distinguish between cloudy, hazy and clearsky (free of clouds and hazes) exoplanet atmospheres that could be applicable to upcoming large aperture space and ground-based telescopes such as the James Webb Space Telescope (JWST) and the European Extremely Large Telescope (E-ELT). These facilities will be powerful tools for characterizing transiting exoplanets, but only after a considerable amount of telescope time is devoted to a single planet. A technique that could provide a relatively rapid means of identifying haze-free targets (which may be more valuable targets for characterization) could potentially increase the science return for these telescopes. Our proposed method utilizes broadband observations of refracted light in the out-of-transit spectrum. Light refracted through an exoplanet atmosphere can lead to an increase of flux prior to ingress and subsequent to egress. Because this light is transmitted at pressures greater than those for typical cloud and haze layers, the detectio...

Misra, Amit

2014-01-01

235

Dynamical Constraints on Exoplanets  

CERN Document Server

Dynamical studies of new exoplanet systems are a critical component of the discovery and characterisation process. Such studies can provide firmer constraints on the parameters of the newly discovered planets, and may even reveal that the proposed planets do not stand up to dynamical scrutiny. Here, we demonstrate how dynamical studies can assist the characterisation of such systems through two examples: QS Virginis and HD 73526.

Horner, Jonti; Tinney, Chris; Hinse, Tobias C; Marshall, Jonathan P

2013-01-01

236

Signals of exomoons in averaged light curves of exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The increasing number of transiting exoplanets sparked a significant interest in discovering their moons. Most of the methods in the literature utilize timing analysis of the raw light curves. Here we propose a new approach for the direct detection of a moon in the transit light curves via the so called Scatter Peak. The essence of the method is the valuation of the local scatter in the folded light curves of many transits. We test the ability of this method with different s...

Simon, A. E.; Szabo?, Gy M.; Kiss, L. L.; Szatma?ry, K.

2011-01-01

237

WASP-54b, WASP-56b and WASP-57b: Three new sub-Jupiter mass planets from SuperWASP  

CERN Document Server

We present three newly discovered sub-Jupiter mass planets from the SuperWASP survey: WASP-54b is a heavily bloated planet of mass 0.636$^{+0.025}_{-0.024}$ \\mj and radius 1.653$^{+0.090}_{-0.083}$ \\rj. It orbits a F9 star, evolving off the main sequence, every 3.69 days. Our MCMC fit of the system yields a slightly eccentric orbit ($e=0.067^{+0.033}_{-0.025}$) for WASP-54b. We investigated further the veracity of our detection of the eccentric orbit for WASP-54b, and we find that it could be real. However, given the brightness of WASP-54 V=10.42 magnitudes, we encourage observations of a secondary eclipse to draw robust conclusions on both the orbital eccentricity and the thermal structure of the planet. WASP-56b and WASP-57b have masses of 0.571$^{+0.034}_{-0.035}$ \\mj and $0.672^{+0.049}_{-0.046}$ \\mj, respectively; and radii of $1.092^{+0.035}_{-0.033}$ \\rj for WASP-56b and $0.916^{+0.017}_{-0.014}$ \\rj for WASP-57b. They orbit main sequence stars of spectral type G6 every 4.67 and 2.84 days, respectively...

Faedi, F; Barros, S C C; Brown, D; Cameron, A Collier; Doyle, A P; Gillon, M; Chew, Y Gomez Maqueo; Hebrard, G; Lendl, M; Liebig, C; Smalley, B; Triaud, A H M J; West, R G; Wheatley, P J; Alsubai, K A; Anderson, D R; Armstrong, D J; Bento, J; Bochinski, J; Bouchy, F; Busuttil, R; Fossati, L; Fumel, A; Haswell, C A; Hellier, C; Holmes, S; Jehin, E; Kolb, U; McCormac, J; Miller, G R M; Moutou, C; Norton, A J; Parley, N; Queloz, D; Skillen, I; Smith, A M S; Udry, S; Watson, C

2012-01-01

238

Directed follow-up strategy of low-cadence photometric surveys in Search of transiting exoplanets. A Bayesian approach for adaptive scheduling  

Science.gov (United States)

We propose a novel approach to utilize low-cadence photometric surveys for exoplanetary transit search. Even if transits are undetectable in the survey database alone, it can still be useful for finding preferred times for directed follow-up observations that will maximize the chances to detect transits [2].

Dzigan, Y.; Zucker, S.

2011-10-01

239

The CoRoT mission's exoplanet program  

Directory of Open Access Journals (Sweden)

Full Text Available The CoRoT space observatory was launched at the end of 2006 and has been delivering scientific data from early 2007 until its recent interruption, on 2 Nov. 2012, leading to the discovery of over 30 transiting planets. Here we give an overview over the most relevant results from CoRoT's exoplanet detection program.

Deeg H.J.

2013-04-01

240

Directed follow-up strategy of low-cadence photometric surveys in Search of transiting exoplanets - I. Bayesian approach for adaptive scheduling  

CERN Document Server

We propose a novel approach to utilize low-cadence photometric surveys for exoplanetary transit search. Even if transits are undetectable in the survey database alone, it can still be useful for finding preferred times for directed follow-up observations that will maximize the chances to detect transits. We demonstrate the approach through a few simulated cases. These simulations are based on the Hipparcos Epoch Photometry data base, and the transiting planets whose transits were already detected there. In principle, the approach we propose will be suitable for the directed follow-up of the photometry from the planned Gaia mission, and it can hopefully significantly increase the yield of exoplanetary transits detected, thanks to Gaia.

Dzigan, Yifat

2011-01-01

 
 
 
 
241

Directed follow-up strategy of low-cadence photometric surveys in search of transiting exoplanets - I. Bayesian approach for adaptive scheduling  

Science.gov (United States)

We propose a novel approach to utilize low-cadence photometric surveys for exoplanetary transit search. Even if transits are undetectable in the survey data base alone, it can still be useful for finding preferred times for directed follow-up observations that will maximize the chances to detect transits. We demonstrate this approach through a few simulated cases. These simulations are based on the Hipparcos Epoch Photometry data base and on the transiting planets whose transits were already detected there. In principle, the approach we propose will be suitable for the directed follow-up of the photometry from the planned Gaia mission, and it can hopefully significantly increase the yield of exoplanetary transits detected, thanks to Gaia.

Dzigan, Yifat; Zucker, Shay

2011-08-01

242

Transiting exoplanets from the CoRoT space mission. XI. CoRoT-8b: a hot and dense sub-Saturn around a K1 dwarf  

CERN Document Server

We report the discovery of CoRoT-8b, a dense small Saturn-class exoplanet that orbits a K1 dwarf in 6.2 days, and we derive its orbital parameters, mass, and radius. We analyzed two complementary data sets: the photometric transit curve of CoRoT-8b as measured by CoRoT and the radial velocity curve of CoRoT-8 as measured by the HARPS spectrometer. We find that CoRoT-8b is on a circular orbit with a semi-major axis of 0.063 +/- 0.001 AU. It has a radius of 0.57 +/- 0.02 RJ, a mass of 0.22 +/- 0.03 MJ, and therefore a mean density 1.6 +/- 0.1 g/cm^3. With 67 % of the size of Saturn and 72 % of its mass, CoRoT-8b has a density comparable to that of Neptune (1.76 g/cm^3). We estimate its content in heavy elements to be 47-63 Earth masses, and the mass of its hydrogen-helium envelope to be 7-23 Earth masses. At 0.063 AU, the thermal loss of hydrogen of CoRoT-8b should be no more than about 0.1 % over an assumed integrated lifetime of 3~Ga.

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

2010-01-01

243

Exoplanets search and characterization with the SOPHIE spectrograph at OHP  

Directory of Open Access Journals (Sweden)

Full Text Available Several programs of exoplanets search and characterization have been started with SOPHIE at the 1.93-m telescope of Haute-Provence Observatory, France. SOPHIE is an environmentally stabilized echelle spectrograph dedicated to high-precision radial velocity measurements. The objectives of these programs include systematic searches for exoplanets around di?erent types of stars, characterizations of planet-host stars, studies of transiting planets through RossiterMcLaughlin e?ect, follow-up observations of photometric surveys. The instrument SOPHIE and a review of its latest results are presented here.

Hébrard G.

2011-02-01

244

The search for exomoons and the characterization of exoplanet atmospheres  

CERN Document Server

Since planets were first discovered outside our own Solar System in 1992 (around a pulsar) and in 1995 (around a main sequence star), extrasolar planet studies have become one of the most dynamic research fields in astronomy. Now that more than 370 exoplanets have been discovered, focus has moved from finding planets to characterise these alien worlds. As well as detecting the atmospheres of these exoplanets, part of the characterisation process undoubtedly involves the search for extrasolar moons. A review on the current situation of exoplanet characterization is presented in Chapter 3. We focus on the characterization of transiting planets orbiting very close to their parent star since for them we can already probe their atmospheric constituents. By contrast, the second part of the Chapter is dedicated to the search for extraterrestrial life, both within and beyond the Solar System. The characteristics of the Habitable Zone and the markers for the presence of life (biosignatures) are detailed. In Chapter 4 ...

Campanella, Giammarco

2009-01-01

245

DETECTABILITY OF EXOPLANET PERIASTRON PASSAGE IN THE INFRARED  

International Nuclear Information System (INIS)

Characterization of exoplanets has matured in recent years, particularly through studies of exoplanetary atmospheres of transiting planets at infrared wavelengths. The primary source for such observations has been the Spitzer Space Telescope but these studies are anticipated to continue with the James Webb Space Telescope. A relatively unexplored region of exoplanet parameter space is the thermal detection of long-period eccentric planets during periastron passage. Here we describe the thermal properties and albedos of long-period giant planets along with the eccentricities of those orbits which allow them to remain within the habitable zone. We further apply these results to the known exoplanets by calculating temperatures and flux ratios for the IRAC passbands occupied by warm Spitzer, considering both low and high thermal redistribution efficiencies from the perspective of an observer. We conclude with recommendations on which targets are best suited for follow-up observations.

246

A Computational Tool to Interpret the Bulk Composition of Solid Exoplanets based on Mass and Radius Measurements  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The prospects for finding transiting exoplanets in the range of a few to 20 Earth masses is growing rapidly with both ground-based and spaced-based efforts. We describe a publicly available computer code to compute and quantify the compositional ambiguities for differentiated solid exoplanets with a measured mass and radius, including the mass and radius uncertainties.

Zeng, Li; Seager, Sara

2008-01-01

247

EChO's view on gas giant exoplanets atmospheres  

CERN Document Server

The last decade has seen the discovery of more than a thousand exoplanets but, more excitingly, probing their atmospheres has become possible. With current data we caught a glimpse of the diversity of exoplanet atmospheres that will be revealed in the next years. However, numerous questions concerning their chemical composition, thermal structure, and atmospheric dynamics remain to be answered. More observations of higher quality are needed. The Exoplanet Characterisation Observatory (EChO) is a space-based observatory dedicated to the characterization of exoplanets atmospheres proposed to the ESA cosmic vision program. With its large spectral coverage (4-16 {\\mu}m) and high spectral resolution (\\Delta{\\lambda}/{\\lambda}>300 below 5 {\\mu}m and \\Delta{\\lambda}/{\\lambda}>30 above 5 {\\mu}m) EChO will provide spectrally resolved transit lightcurves, secondary eclipses lightcurves, and full phase curves of numerous exoplanets with an unprecedented signal to noise ratio. In this technical note we review some of tod...

Parmentier, Vivien; de Wit, Julien

2014-01-01

248

Exoplanets and their atmospheres  

International Nuclear Information System (INIS)

Full text: A decade of exoplanet search has led to surprising discoveries, from hot giant planets orbiting their star within a few days, to planets orbiting two Suns, extremely hot worlds with potentially permanent lava on their surfaces due to the star's proximity all the way to the first potential rocky worlds in the Habitable Zone of their stars. Observation techniques have now reached the sensitivity to explore the chemical composition of the atmospheres as well as physical structure of some detected planets. Nearly a thousand planets have already been detected around other Suns. The spectral fingerprint of light of planets gives us the key to explore them over light years away. (author)

249

Transiting exoplanets from the CoRoT space mission. XXI. CoRoT-19b: a low density planet orbiting an old inactive F9V-star  

DEFF Research Database (Denmark)

Context. Observations of transiting extrasolar planets are of key importance to our understanding of planets because their mass, radius, and mass density can be determined. These measurements indicate that planets of similar mass can have very different radii. For low-density planets, it is generally assumed that they are inflated owing to their proximity to the host-star. To determine the causes of this inflation, it is necessary to obtain a statistically significant sample of planets with precisely measured masses and radii. Aims. The CoRoT space mission allows us to achieve a very high photometric accuracy. By combining CoRoT data with high-precision radial velocity measurements, we derive precise planetary radii and masses. We report the discovery of CoRoT-19b, a gas-giant planet transiting an old, inactive F9V-type star with a period of four days. Methods. After excluding alternative physical configurations mimicking a planetary transit signal, we determine the radius and mass of the planet by combining CoRoT photometry with high-resolution spectroscopy obtained with the echelle spectrographs SOPHIE, HARPS, FIES, and SANDIFORD. To improve the precision of its ephemeris and the epoch, we observed additional transits with the TRAPPIST and Euler telescopes. Using HARPS spectra obtained during the transit, we then determine the projected angle between the spin of the star and the orbit of the planet. Results. We find that the host star of CoRoT-19b is an inactive F9V-type star close to the end of its main-sequence life. The host star has a mass M? = 1.21 ± 0.05 ?M? and radius R? = 1.65 ?±? 0.04?R?. The planet has a mass of MP = 1.11 ± 0.06?MJup and radius of RP = 1.29 ?± 0.03?RJup. The resulting bulk density is only ? = 0.71 ?± 0.06?g?cm-3, which is much lower than that for Jupiter. Conclusions. The exoplanet CoRoT-19b is an example of a giant planet of almost the same mass as Jupiter but a ?30% larger radius.

Guenther, E. W.; Díaz, R. F.

2012-01-01

250

KEPLER OBSERVATIONS OF THREE PRE-LAUNCH EXOPLANET CANDIDATES: DISCOVERY OF TWO ECLIPSING BINARIES AND A NEW EXOPLANET  

International Nuclear Information System (INIS)

Three transiting exoplanet candidate stars were discovered in a ground-based photometric survey prior to the launch of NASA's Kepler mission. Kepler observations of them were obtained during Quarter 1 of the Kepler mission. All three stars are faint by radial velocity follow-up standards, so we have examined these candidates with regard to eliminating false positives and providing high confidence exoplanet selection. We present a first attempt to exclude false positives for this set of faint stars without high-resolution radial velocity analysis. This method of exoplanet confirmation will form a large part of the Kepler mission follow-up for Jupiter-sized exoplanet candidates orbiting faint stars. Using the Kepler light curves and pixel data, as well as medium-resolution reconnaissance spectroscopy and speckle imaging, we find that two of our candidates are binary stars. One consists of a late-F star with an early M companion, while the other is a K0 star plus a late M-dwarf/brown dwarf in a 19 day elliptical orbit. The third candidate (BOKS-1) is an r = 15 G8V star hosting a newly discovered exoplanet with a radius of 1.12 RJupiter in a 3.9 day orbit.

251

Exoplanet Detection: Radial Velocity Method  

Science.gov (United States)

The Exoplanet Detection: The Radial Velocity Method model simulates the detection of exoplanets by using the radial velocity method and the Doppler effect. In this simulation the exoplanet orbits the star (sun-sized) in circular motion via Kepler's third law.  The radial velocity of the star is determined from the velocity of the exoplanet.  This velocity is then used to calculate the Doppler shift of the Fraunhofer lines of the star.  In practice it is the Doppler shift of the Fraunhofer lines of the star that are detected and from this the radial velocity is inferred.  From this the mass and orbital period and average exoplanet-star separation are determined.  In the simulation the star-exoplanet system is shown as seen from Earth (edge on view) and from space (overhead view), and with the star and exoplanet sizes not shown to the scale of the orbit.  In addition, the Fraunhofer lines are shown.  The radial velocites of stars are such that the Doppler shifts are small, to compensate you may snap to the Na line and use the right-hand side slider to zoom in on that line to see wavelength shift.  The mass of the exoplanet (relative to the mass of Jupiter), the average star-exoplant separation (in AU), and the inclination of the system relative to Earth can be changed. The simulation uses Java 3D, if installed, to render the view the star and exoplanet. If Java 3D is not installed, the simulation will default to simple 3D using Java.

Belloni, Mario

2010-06-29

252

Lightest exoplanet yet discovered  

Science.gov (United States)

Well-known exoplanet researcher Michel Mayor today announced the discovery of the lightest exoplanet found so far. The planet, "e", in the famous system Gliese 581, is only about twice the mass of our Earth. The team also refined the orbit of the planet Gliese 581 d, first discovered in 2007, placing it well within the habitable zone, where liquid water oceans could exist. These amazing discoveries are the outcome of more than four years of observations using the most successful low-mass-exoplanet hunter in the world, the HARPS spectrograph attached to the 3.6-metre ESO telescope at La Silla, Chile. ESO PR Photo 15a/09 Artist's impression of Gliese 581 e ESO PR Photo 15b/09 A planet in the habitable zone ESO PR Video 15a/09 ESOcast 6 ESO PR Video 15b/09 VNR A-roll ESO PR Video 15c/09 Zoom-in on Gliese 581 e ESO PR Video 15d/09 Artist's impression of Gliese 581 e ESO PR Video 15e/09 Artist's impression of Gliese 581 d ESO PR Video 15f/09 Artist's impression of Gliese 581 system ESO PR Video 15g/09 The radial velocity method ESO PR Video 15h/09 Statement in English ESO PR Video 15i/09 Statement in French ESO PR Video 15j/09 La Silla Observatory "The holy grail of current exoplanet research is the detection of a rocky, Earth-like planet in the ‘habitable zone' -- a region around the host star with the right conditions for water to be liquid on a planet's surface", says Michel Mayor from the Geneva Observatory, who led the European team to this stunning breakthrough. Planet Gliese 581 e orbits its host star - located only 20.5 light-years away in the constellation Libra ("the Scales") -- in just 3.15 days. "With only 1.9 Earth-masses, it is the least massive exoplanet ever detected and is, very likely, a rocky planet", says co-author Xavier Bonfils from Grenoble Observatory. Being so close to its host star, the planet is not in the habitable zone. But another planet in this system appears to be. From previous observations -- also obtained with the HARPS spectrograph at ESO's La Silla Observatory and announced two years ago -- this star was known to harbour a system with a Neptune-sized planet (ESO 30/05) and two super-Earths (ESO 22/07). With the discovery of Gliese 581 e, the planetary system now has four known planets, with masses of about 1.9 (planet e), 16 (planet b), 5 (planet c), and 7 Earth-masses (planet d). The planet furthest out, Gliese 581 d, orbits its host star in 66.8 days. "Gliese 581 d is probably too massive to be made only of rocky material, but we can speculate that it is an icy planet that has migrated closer to the star," says team member Stephane Udry. The new observations have revealed that this planet is in the habitable zone, where liquid water could exist. "‘d' could even be covered by a large and deep ocean -- it is the first serious 'water world' candidate," continued Udry. The gentle pull of an exoplanet as it orbits the host star introduces a tiny wobble in the star's motion -- only about 7 km/hour, corresponding to brisk walking speed -- that can just be detected on Earth with today's most sophisticated technology. Low-mass red dwarf stars such as Gliese 581 are potentially fruitful hunting grounds for low-mass exoplanets in the habitable zone. Such cool stars are relatively faint and their habitable zones lie close in, where the gravitational tug of any orbiting planet found there would be stronger, making the telltale wobble more pronounced. Even so, detecting these tiny signals is still a challenge, and the discovery of Gliese 581 e and the refinement of Gliese 581 d's orbit were only possible due to HARPS's unique precision and stability. "It is amazing to see how far we have come since we discovered the first exoplanet around a normal star in 1995 -- the one around 51 Pegasi," says Mayor. "The mass of Gliese 581 e is 80 times less than that of 51 Pegasi b. This is tremendous progress in just 14 years." The astronomers are confident that they can still do better. "With similar observing conditions an E

2009-04-01

253

PRECISE ESTIMATES OF THE PHYSICAL PARAMETERS FOR THE EXOPLANET SYSTEM HD 17156 ENABLED BY HUBBLE SPACE TELESCOPE FINE GUIDANCE SENSOR TRANSIT AND ASTEROSEISMIC OBSERVATIONS  

International Nuclear Information System (INIS)

We present observations of three distinct transits of HD 17156b obtained with the Fine Guidance Sensors on board the Hubble Space Telescope. We analyzed both the transit photometry and previously published radial velocities to find the planet-star radius ratio Rp /R* = 0.07454 ± 0.00035, inclination i = 86.49+0.24-0.20 deg, and scaled semimajor axis a/R* = 23.19+0.32-0.27. This last value translates directly to a mean stellar density determination ?* = 0.522+0.021-0.018 g cm-3. Analysis of asteroseismology observations by the companion paper of Gilliland et al. provides a consistent but significantly refined measurement of ?* = 0.5308 ± 0.0040. We compare stellar isochrones to this density estimate and find M* = 1.275 ± 0.018 Msun and a stellar age of 3.37+0.20-0.47 Gyr. Using this estimate of M* and incorporating the density constraint from asteroseismology, we model both the photometry and published radial velocities to estimate the planet radius Rp = 1.0870 ± 0.0066 RJ and the stellar radius R* = 1.5007 ± 0.0076 Rsun. The planet radius is larger than that found in previous studies and consistent with theoretical models of a solar-composition gas giant of the same mass and equilibrium temperature. For the three transits, we determinFor the three transits, we determine the times of mid-transit to a precision of 6.2 s, 7.6 s, and 6.9 s, and the transit times for HD 17156 do not show any significant departures from a constant period. The joint analysis of transit photometry and asteroseismology presages similar studies that will be enabled by the NASA Kepler Mission.

254

The NASA/IPAC/NExScI Star and Exoplanet Database  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The NASA/IPAC/NExScI Star and Exoplanet Database (NStED) is a general purpose stellar archive which supports NASA planet-finding and planet-characterization goals, stellar astrophysics, and the planning of NASA and other space missions. There are two principal components of NStED: a database of 140,000 nearby stars and exoplanet-hosting stars, and an archive dedicated to high precision photometric surveys for transiting exoplanets (NStED-ETSS). We present summaries of these ...

Berriman, G. B.; Ali, B.; Baker, R; Von Braun, K.; Chiu, N-m; Ciardi, D. R.; Good, J.; Kane, S. R.; Kong, M.; Laity, A. C.; Mcelroy, D. L.; Monkewitz, S.; Payne, A. N.; Ramirez, S.; Schmitz, M.

2009-01-01

255

Precise Estimates of the Physical Parameters for the Exoplanet System HD 17156 Enabled by Hubble Space Telescope Fine Guidance Sensor Transit and Asteroseismic Observations  

DEFF Research Database (Denmark)

We present observations of three distinct transits of HD 17156b obtained with the Fine Guidance Sensors on board the Hubble Space Telescope. We analyzed both the transit photometry and previously published radial velocities to find the planet-star radius ratio Rp /R sstarf = 0.07454 ± 0.00035, inclination i = 86.49+0.24 –0.20 deg, and scaled semimajor axis a/R sstarf = 23.19+0.32 –0.27. This last value translates directly to a mean stellar density determination ?sstarf = 0.522+0.021 –0.018 g cm–3. Analysis of asteroseismology observations by the companion paper of Gilliland et al. provides a consistent but significantly refined measurement of ?sstarf = 0.5308 ± 0.0040. We compare stellar isochrones to this density estimate and find M sstarf = 1.275 ± 0.018 M sun and a stellar age of 3.37+0.20 –0.47 Gyr. Using this estimate of M sstarf and incorporating the density constraint from asteroseismology, we model both the photometry and published radial velocities to estimate the planet radius Rp = 1.0870 ± 0.0066 RJ and the stellar radius R sstarf = 1.5007 ± 0.0076 R sun. The planet radius is larger than that found in previous studies and consistent with theoretical models of a solar-composition gas giant of the same mass and equilibrium temperature. For the three transits, we determine the times of mid-transit to a precision of 6.2 s, 7.6 s, and 6.9 s, and the transit times for HD 17156 do not show any significant departures from a constant period. The joint analysis of transit photometry and asteroseismology presages similar studies that will be enabled by the NASA Kepler Mission.

Nutzman, Philip; Gilliland, Ronald L.

2011-01-01

256

Transiting exoplanets from the CoRoT space mission VIII. CoRoT-7b: the first Super-Earth with measured radius  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Aims. We report the discovery of very shallow (?F/F ? 3.4 × 10-4), periodic dips in the light curve of an active V = 11.7 G9V star observed by the CoRoT satellite, which we interpret as caused by a transiting companion. We describe the 3-colour CoRoT data and complementary ground-based observations that support the planetary nature of the companion. Methods. We used CoRoT colours information, good angular resolution ground-based photometric observations in- and out- of transit, adaptive o...

Leger, A.; Rouan, D.; Schneider, J.; Barge, P.; Fridlund, M.; Samuel, B.; Ollivier, M.; Guenther, E.; Deleuil, M.; Deeg, Hj; Auvergne, M.; Alonso, R.; Aigrain, S.; Alapini, A.; Almenara, Jm

2009-01-01

257

A Cloudy View of Exoplanets  

Science.gov (United States)

The lack of absorption features in the transmission spectrum of exoplanet GJ1214b rules out a hydrogen-rich atmosphere for the planet. It is consistent with an atmosphere rich in water vapour or abundant in clouds.

Deming, Drake

2010-01-01

258

Exploring exoplanet populations with NASA's Kepler Mission.  

Science.gov (United States)

The Kepler Mission is exploring the diversity of planets and planetary systems. Its legacy will be a catalog of discoveries sufficient for computing planet occurrence rates as a function of size, orbital period, star type, and insolation flux. The mission has made significant progress toward achieving that goal. Over 3,500 transiting exoplanets have been identified from the analysis of the first 3 y of data, 100 planets of which are in the habitable zone. The catalog has a high reliability rate (85-90% averaged over the period/radius plane), which is improving as follow-up observations continue. Dynamical (e.g., velocimetry and transit timing) and statistical methods have confirmed and characterized hundreds of planets over a large range of sizes and compositions for both single- and multiple-star systems. Population studies suggest that planets abound in our galaxy and that small planets are particularly frequent. Here, I report on the progress Kepler has made measuring the prevalence of exoplanets orbiting within one astronomical unit of their host stars in support of the National Aeronautics and Space Administration's long-term goal of finding habitable environments beyond the solar system. PMID:25049406

Batalha, Natalie M

2014-09-01

259

Results from the Exoplanet Search Programmes with BEST and TEST  

CERN Document Server

Thueringer Landessternwarte Tautenburg (TLS) has started to operate a small dedicated telescope - the Tautenburg Exoplanet Search Telescope (TEST) - searching for transits of extrasolar planets in photometric time series observations. In a joint effort with the Berlin Exoplanet Search Telescope (BEST) operated by the Institut fuer Planetenforschung of the "Deutsches Zentrum fuer Luft- und Raumfahrt (DLR)" at the Observatoire de Haute-Provence (OHP), France, two observing sites are used to optimise transit search. Here, we give a short overview of these systems and the data analysis. We describe a software pipeline that we have set up to identify transit events of extrasolar planets and variable stars in time series data from these and other telescopes, and report on some first results.

Eislöffel, J; Rauer, H; Voss, H; Erikson, A; Eigmueller, P; Günther, E; Eisloeffel, Jochen; Hatzes, Artie P.; Rauer, Heike; Voss, Holger; Erikson, Anders; Eigmueller, Philipp; Guenther, Eike

2006-01-01

260

Constraints on Secondary Eclipse Probabilities of Long-Period Exoplanets from Orbital Elements  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Long-period transiting exoplanets provide an opportunity to study the mass-radius relation and internal structure of extrasolar planets. Their studies grant insights into planetary evolution akin to the Solar System planets, which, in contrast to hot Jupiters, are not constantly exposed to the intense radiation of their parent stars. Observations of secondary eclipses allow investigations of exoplanet temperatures and large-scale exo-atmospheric properties. In this short pap...

Von Braun, Kaspar; Kane, Stephen R.

2009-01-01

 
 
 
 
261

Coreless Terrestrial Exoplanets  

CERN Document Server

Differentiation in terrestrial planets is expected to include the formation of a metallic iron core. We predict the existence of terrestrial planets that have differentiated but have no metallic core--planets that are effectively a giant silicate mantle. We discuss two paths to forming a coreless terrestrial planet, whereby the oxidation state during planetary accretion and solidification will determine the size or existence of any metallic core. Under this hypothesis, any metallic iron in the bulk accreting material is oxidized by water, binding the iron in the form of iron oxide into the silicate minerals of the planetary mantle. The existence of such silicate planets has consequences for interpreting the compositions and interior density structures of exoplanets based on their mass and radius measurements.

Elkins-Tanton, L

2008-01-01

262

Characterization of exoplanet hosts  

Directory of Open Access Journals (Sweden)

Full Text Available Spectroscopic analysis of exoplanet hosts and the stellar sample from which they are drawn provides abundances and other properties that quantitively constrain models of planet formation. The program Spectroscopy Made Easy (SME determines stellar parameters by fitting observed spectra, though line lists must be selected wisely. For giant planets, it is now well established that stars with higher metallicity are more likely to have detected companions. Stellar metallicity does not seem to affect the formation and/or migration of detectable planets less massive than Neptune, especially when considering only the most massive planet in the system. In systems with at least one planet less than 10 times the mass of Earth, the mass of the most massive planet increases dramatically with host star metallicity. This may reflect metallicity dependent timescales for core formation, envelope accretion, and/or migration into the detection zone.

Valenti Jeff A.

2013-04-01

263

Transiting exoplanets from the CoRoT space mission - XIX. CoRoT-23b: a dense hot Jupiter on an eccentric orbit  

CERN Document Server

We report the detection of CoRoT-23b, a hot Jupiter transiting in front of its host star with a period of 3.6314 \\pm 0.0001 days. This planet was discovered thanks to photometric data secured with the CoRoT satellite, combined with spectroscopic radial velocity (RV) measurements. A photometric search for possible background eclipsing binaries conducted at CFHT and OGS concluded with a very low risk of false positives. The usual techniques of combining RV and transit data simultaneously were used to derive stellar and planetary parameters. The planet has a mass of Mp = 2.8 \\pm 0.3 MJup, a radius of Rpl = 1.05 \\pm 0.13 RJup, a density of \\approx 3 g cm-3. RV data also clearly reveal a non zero eccentricity of e = 0.16 \\pm 0.02. The planet orbits a mature G0 main sequence star of V =15.5 mag, with a mass M\\star = 1.14 \\pm 0.08 M\\odot, a radius R\\star = 1. 61 \\pm 0.18 R\\odot and quasi-solar abundances. The age of the system is evaluated to be 7 Gyr, not far from the transition to subgiant, in agreement with the r...

Rouan, D; Moutou, C; Deleuil, M; Fridlund, M; Ofir, A; Havel, M; Aigrain, S; Alonso, R; Auvergne, M; Baglin, A; Barge, P; Bonomo, A; Bordé, P; Bouchy, F; Cabrera, J; Cavarroc, C; Csizmadia, Sz; Deeg, H; Diaz, R F; Dvorak, R; Erikson, A; Ferraz-Mello, S; Gandolfi, D; Gillon, M; Guillot, T; Hatzes, A; Hébrard, G; Jorda, L; Léger, A; Llebaria, A; Lammer, H; Lovis, C; Mazeh, T; Ollivier, M; Pätzold, M; Queloz, D; Rauer, H; Samuel, B; Santerne, A; Schneider, J; Tingley, B; Wuchterl, G

2011-01-01

264

Transiting exoplanets from the CoRoT space mission: VII. The "hot-Jupiter"-type planet CoRoT-5b  

CERN Document Server

Aims. The CoRoT space mission continues to photometrically monitor about 12 000 stars in its field-of-view for a series of target fields to search for transiting extrasolar planets ever since 2007. Deep transit signals can be detected quickly in the "alarm-mode" in parallel to the ongoing target field monitoring. CoRoT's first planets have been detected in this mode. Methods. The CoRoT raw lightcurves are filtered for orbital residuals, outliers, and low-frequency stellar signals. The phase folded lightcurve is used to fit the transit signal and derive the main planetary parameters. Radial velocity follow-up observations were initiated to secure the detection and to derive the planet mass. Results. We report the detection of CoRoT-5b, detected during observations of the LRa01 field, the first long-duration field in the galactic anticenter direction. CoRoT-5b is a "hot Jupiter-type" planet with a radius of 1.388(+0.046, -0.047) R_Jup, a mass of 0.467(+0.047, -0.024) M_Jup, and therefore, a mean density of 0.21...

Rauer, H; Csizmadia, Sz; Deleuil, M; Alonso, R; Aigrain, S; Almenara, J M; Auvergne, M; Baglin, A; Barge, P; Borde, P; Bouchy, F; Bruntt, H; Cabrera, J; Carone, L; Carpano, S; De la Reza, R; Deeg, H J; Dvorak, R; Erikson, A; Fridlund, M; Gandolfi, D; Gillon, M; Guillot, T; Günther, E; Hatzes, A; Hébrard, G; Kabath, P; Jorda, L; Lammer, H; Léger, A; Llebaria, A; Magain, P; Mazeh, T; Moutou, C; Ollivier, M; Paetzold, M; Pont, F; Rabus, M; Renner, S; Rouan, D; Shporer, A; Samuel, B; Schneider, J; Triaud, A H M J; Wuchterl, G

2009-01-01

265

Transit timing variation and activity in the WASP-10 planetary system  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Transit timing analysis may be an effective method of discovering additional bodies in extrasolar systems which harbour transiting exoplanets. The deviations from the Keplerian motion, caused by mutual gravitational interactions between planets, are expected to generate transit timing variations of transiting exoplanets. In 2009 we collected 9 light curves of 8 transits of the exoplanet WASP-10b. Combining these data with published ones, we found that transit timing cannot b...

Maciejewski, G.; Dimitrov, D.; Neuhaeuser, R.; Tetzlaff, N.; Niedzielski, A.; Raetz, St; Chen, W. P.; Walter, F.; Marka, C.; Baar, S.; Krejcova, T.; Budaj, J.; Krushevska, V.; Tachihara, K.; Takahashi, H.

2010-01-01

266

Minerva: Big Exoplanet Science from Small Telescopes  

Science.gov (United States)

The Kepler mission has identified over 2300 candidate planets in the past two years, adding to the over 500 confirmed exoplanets from radial velocity (RV) surveys. One of the most striking results of these surveys is that the number of planets increases rapidly with decreasing size. There may in fact be more Earth-like planets in the Galaxy than stars. There must be terrestrial planets around nearby stars, though few have yet been discovered. Finding these planets requires high precision RV observations and high cadence transit observing to densely sample the orbital phase. Minerva will surmount these obstacles with a dedicated observatory for detection of super-Earths and close-in Earth-like planets. Our array of four 0.7-m telescopes will operate in two modes: jointly with a high precision fiber-fed spectrometer capable of detecting the RV signal of an Earth orbiting a low mass star, and independently for photometric transit detection surveys.

McCrady, Nate

2012-10-01

267

Overview of past and future space missions dedicated to exoplanet research  

Science.gov (United States)

As more and more exoplanets are being discovered, there is a strong motivation for pushing the limits of current detection methods and atmosphere characterization techniques. The scientific goal is ultimately to discover small rocky exoplanets in the habitable zone of their host star and to determine whether their atmosphere contains any bio-markers. Space observatories play an important role in this field, especially in the IR where ground telescopes are limited by atmospheric absorption and where the star/exoplanet contrast is the lowest. This paper provides an overview of past and current efforts in the field of space telescopes dedicated to exoplanet research, with an emphasis on ESA missions. Spacecraft design drivers, highlighting the impact of exoplanet research requirements on the spacecraft design, are explained when possible. A preliminary mission concept, assessed in the ESA Concurrent Design Facility (CDF), dedicated to spectroscopic measurements of known exoplanets with the capability to observe several transits of a few hundred exoplanets, is outlined and the key design challenges shortly discussed.

Puig, L.; Carpano, S.; Rando, N.; Stankov, A.; Escudero, I.

2010-07-01

268

Transiting exoplanets from the CoRoT space mission. VII. The ``hot-Jupiter''-type planet CoRoT-5b  

Science.gov (United States)

Aims: The CoRoT space mission continues to photometrically monitor about 12 000 stars in its field-of-view for a series of target fields to search for transiting extrasolar planets ever since 2007. Deep transit signals can be detected quickly in the “alarm-mode” in parallel to the ongoing target field monitoring. CoRoT's first planets have been detected in this mode. Methods: The CoRoT raw lightcurves are filtered for orbital residuals, outliers, and low-frequency stellar signals. The phase folded lightcurve is used to fit the transit signal and derive the main planetary parameters. Radial velocity follow-up observations were initiated to secure the detection and to derive the planet mass. Results: We report the detection of CoRoT-5b, detected during observations of the LRa01 field, the first long-duration field in the galactic anti-center direction. CoRoT-5b is a “hot Jupiter-type” planet with a radius of 1.388+0.046-0.047 R_Jup, a mass of 0.467+0.047-0.024 M_Jup, and therefore, a mean density of 0.217+0.031-0.025 g cm-3. The planet orbits an F9V star of 14.0 mag in 4.0378962 ± 0.0000019 days at an orbital distance of 0.04947+0.00026-0.00029 AU. Observations made with SOPHIE spectrograph at the Observatoire de Haute Provence (07B.PNP.MOUT), France, and HARPS spectrograph at ESO La Silla Observatory (072.C-0488(E), 082.C-0312(A)), and partly based on observations made at the Anglo-Australian Telescope. The CoRoT space mission, launched on December 27, 2006, was developed and is operated by CNES, with the contribution of Austria, Belgium, Brasil, ESA, Germany, and Spain.

Rauer, H.; Queloz, D.; Csizmadia, Sz.; Deleuil, M.; Alonso, R.; Aigrain, S.; Almenara, J. M.; Auvergne, M.; Baglin, A.; Barge, P.; Bordé, P.; Bouchy, F.; Bruntt, H.; Cabrera, J.; Carone, L.; Carpano, S.; de La Reza, R.; Deeg, H. J.; Dvorak, R.; Erikson, A.; Fridlund, M.; Gandolfi, D.; Gillon, M.; Guillot, T.; Guenther, E.; Hatzes, A.; Hébrard, G.; Kabath, P.; Jorda, L.; Lammer, H.; Léger, A.; Llebaria, A.; Magain, P.; Mazeh, T.; Moutou, C.; Ollivier, M.; Pätzold, M.; Pont, F.; Rabus, M.; Renner, S.; Rouan, D.; Shporer, A.; Samuel, B.; Schneider, J.; Triaud, A. H. M. J.; Wuchterl, G.

2009-10-01

269

Ammonia, Water Clouds and Methane Abundances of Giant Exoplanets and Opportunities for Super-Earth Exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Future direct-imaging exoplanet missions such as WFIRST/AFTA, Exo-C, and Exo-S will measure the reflectivity of exoplanets at visible wavelengths. The exoplanets to be observed will be located further away from their parent stars than is Earth from the Sun. These "cold" exoplanets have atmospheric environments conducive for the formation of water and/or ammonia clouds, like Jupiter in the Solar System. We study the science return from direct-imaging exoplanet missions, focus...

Hu, Renyu

2014-01-01

270

Transiting exoplanets from the CoRoT space mission. XXIV. CoRoT-25b and CoRoT-26b: two low-density giant planets  

Science.gov (United States)

We report the discovery of two transiting exoplanets, CoRoT-25b and CoRoT-26b, both of low density, one of which is in the Saturn mass-regime. For each star, ground-based complementary observations through optical photometry and radial velocity measurements secured the planetary nature of the transiting body and allowed us to fully characterize them. For CoRoT-25b we found a planetary mass of 0.27 ± 0.04 MJup, a radius of 1.08-0.10+0.3 RJup and hence a mean density of 0.15-0.06+0.15 g cm-3. The planet orbits an F9 main-sequence star in a 4.86-day period, that has a V magnitude of 15.0, solar metallicity, and an age of 4.5-2.0+1.8-Gyr. CoRoT-26b orbits a slightly evolved G5 star of 9.06 ± 1.5-Gyr age in a 4.20-day period that hassolar metallicity and a V magnitude of 15.8. With a mass of 0.52 ± 0.05 MJup, a radius of 1.26-0.07+0.13 RJup, and a mean density of 0.28-0.07+0.09 g cm-3, it belongs to the low-mass hot-Jupiter population. Planetary evolution models allowed us to estimate a core mass of a few tens of Earth mass for the two planets with heavy-element mass fractions of 0.52-0.15+0.08 and 0.26-0.08+0.05, respectively, assuming that a small fraction of the incoming flux is dissipated at the center of the planet. In addition, these models indicate that CoRoT-26b is anomalously large compared with what standard models could account for, indicating that dissipation from stellar heating could cause this size. The CoRoT space mission, launched on December 27th 2006, has been developed and is operated by CNES, with the contribution of Austria, Belgium, Brazil, ESA (RSSD and Science Programme), Germany and Spain. Partly based on observations obtained at the European Southern Observatory at Paranal and La Silla, Chile in programs 083.C-0690(A), 184.C-0639.

Almenara, J. M.; Bouchy, F.; Gaulme, P.; Deleuil, M.; Havel, M.; Gandolfi, D.; Deeg, H. J.; Wuchterl, G.; Guillot, T.; Gardes, B.; Pasternacki, T.; Aigrain, S.; Alonso, R.; Auvergne, M.; Baglin, A.; Bonomo, A. S.; Bordé, P.; Cabrera, J.; Carpano, S.; Cochran, W. D.; Csizmadia, Sz.; Damiani, C.; Diaz, R. F.; Dvorak, R.; Endl, M.; Erikson, A.; Ferraz-Mello, S.; Fridlund, M.; Hébrard, G.; Gillon, M.; Guenther, E.; Hatzes, A.; Léger, A.; Lammer, H.; MacQueen, P. J.; Mazeh, T.; Moutou, C.; Ollivier, M.; Ofir, A.; Pätzold, M.; Parviainen, H.; Queloz, D.; Rauer, H.; Rouan, D.; Santerne, A.; Samuel, B.; Schneider, J.; Tal-Or, L.; Tingley, B.; Weingrill, J.

2013-07-01

271

Transiting exoplanets from the CoRoT space mission VIII. CoRoT-7b: the first Super-Earth with measured radius  

CERN Document Server

We report the discovery of very shallow (DF/F = 3.4 10-4), periodic dips in the light curve of an active V = 11.7 G9V star observed by the CoRoT satellite, which we interpret as due to the presence of a transiting companion. We describe the 3-colour CoRoT data and complementary ground-based observations that support the planetary nature of the companion. Methods. We use CoRoT color information, good angular resolution ground-based photometric observations in- and out- of transit, adaptive optics imaging, near-infrared spectroscopy and preliminary results from Radial Velocity measurements, to test the diluted eclipsing binary scenarios. The parameters of the host star are derived from optical spectra, which were then combined with the CoRoT light curve to derive parameters of the companion. We examine carefully all conceivable cases of false positives, and all tests performed support the planetary hypothesis. Blends with separation larger than 0.40 arcsec or triple systems are almost excluded with a 8 10-4 ris...

Léger, A; Schneider, J; Barge, P; Fridlund, M; Samuel, B; Ollivier, M; Günther, E; Deleuil, M; Deeg, H J; Auvergne, M; Alonso, R; Aigrain, S; Alapini, A; Almenara, J M; Baglin, A; Barbieri, M; Bruntt, H; Borde, P; Bouchy, F; Cabrera, J; Catala, C; Carone, L; Carpano, S; Csizmadia, Sz; Dvorak, R; Erikson, A; Ferraz-Mello, S; Foing, B; Fressin, F; Gandolfi, D; Gillon, M; Gondoin, Ph; Grasset, O; Guillot, T; Hatzes, A; Hébrard, G; Jorda, L; Lammer, H; Llebaria, A; Loeillet, B; Mayor, M; Mazeh, T; Moutou, C; Paetzold, M; Pont, F; Queloz, D; Rauer, H; Renner, S; Samadi, R; Shporer, A; Sotin, Ch; Tingley, B; Wuchterl, G

2009-01-01

272

Doppler tomography of transiting exoplanets: A prograde, low-inclined orbit for the hot Jupiter CoRoT-11b  

CERN Document Server

We report the detection of the Doppler shadow of the transiting hot Jupiter CoRoT-11b. Our analysis is based on line-profile tomography of time-series, Keck/HIRES high-resolution spectra acquired during the transit of the planet. We measured a sky-projected, spin-orbit angle of 0.1 +/- 2.6 degrees, which is consistent with a very low-inclined orbit with respect to the stellar rotation axis. We refined the physical parameters of the system using a Markov chain Monte Carlo simultaneous fitting of the available photometric and spectroscopic data. An analysis of the tidal evolution of the system shows how the currently measured obliquity and its uncertainty translate into an initial absolute value of less than about 10 degrees on the zero-age main sequence, for an expected average modified tidal quality factor of the star Q'* > 4 x 10^6. This is indicative of an inward migration scenario that would not have perturbed the primordial low obliquity of CoRoT-11b. Taking into account the effective temperature and mass...

Gandolfi, Davide; Endl, Michael; Lanza, Antonino F; Damiani, Cilia; Alonso, Roi; Cochran, William D; Deleuil, Magali; Fridlund, Malcolm; Hatzes, Artie P; Guenther, Eike W

2012-01-01

273

Transiting exoplanets from the CoRoT space mission . XIX. CoRoT-23b: a dense hot Jupiter on an eccentric orbit  

DEFF Research Database (Denmark)

We report the detection of CoRoT-23b, a hot Jupiter transiting in front of its host star with a period of 3.6314 ± 0.0001 days. This planet was discovered thanks to photometric data secured with the CoRoT satellite, combined with spectroscopic radial velocity (RV) measurements. A photometric search for possible background eclipsing binaries conducted at CFHT and OGS concluded with a very low risk of false positives. The usual techniques of combining RV and transit data simultaneously were used to derive stellar and planetary parameters. The planet has a mass of Mp = 2.8 ± 0.3 MJup, a radius of Rpl= 1.05 ± 0.13RJup, a density of ? 3 g?cm-3. RV data also clearly reveal a nonzero eccentricity of e = 0.16 ± 0.02. The planet orbits a mature G0 main sequence star of V = 15.5 mag, with a mass M? = 1.14 ± 0.08 M?, a radius R ? = 1. 61 ± 0.18 R?? and quasi-solarabundances. The age of the system is evaluated to be 7 Gyr, not far from the transition to subgiant, in agreement with the rather large stellar radius.The two features of a significant eccentricity of the orbit and of a fairly high density are fairly uncommon for a hot Jupiter. The high density is, however, consistent with a model of contraction of a planet at this mass, given the age of the system. On the other hand, at such an age, circularization is expected to be completed. In fact, we show that for this planetary mass and orbital distance, any initial eccentricity should not totally vanish after 7 Gyr, as long as the tidal quality factor Qp is more than a few 105, a value that is the lower bound of the usually expected range. Even if CoRoT-23b? features a density and an eccentricity that are atypical of a hot Jupiter, it is thus not an enigmatic object.

Rouan, D.; Parviainen, H.

2012-01-01

274

The MEarth-North and MEarth-South transit surveys: searching for habitable super-Earth exoplanets around nearby M-dwarfs  

CERN Document Server

Detection and characterization of potentially habitable Earth-size extrasolar planets is one of the major goals of contemporary astronomy. By applying the transit method to very low-mass M-dwarfs, it is possible to find these planets from the ground with present-day instrumentation and observational techniques. The MEarth project is one such survey with stations in both hemispheres: MEarth-North at the Fred Lawrence Whipple Observatory, Mount Hopkins, Arizona, and MEarth-South at Cerro Tololo Inter-American Observatory, Chile. We present an update on recent results of this survey, for planet occurrence rates, and interesting stellar astrophysics, for which our sample of 3000 nearby mid-to-late M-dwarfs has been very fruitful. All light curves gathered during the survey are made publicly available after one year, and we describe how to access and use these data.

Irwin, Jonathan M; Charbonneau, David; Dittmann, Jason; Falco, Emilio E; Newton, Elisabeth R; Nutzman, Philip

2014-01-01

275

OBSERVATIONAL EVIDENCE FOR TIDAL DESTRUCTION OF EXOPLANETS  

International Nuclear Information System (INIS)

The distribution of the orbits of close-in exoplanets shows evidence for ongoing removal and destruction by tides. Tides raised on a planet's host star cause the planet's orbit to decay, even after the orbital eccentricity has dropped to zero. Comparison of the observed orbital distribution and predictions of tidal theory shows good qualitative agreement, suggesting tidal destruction of close-in exoplanets is common. The process can explain the observed cutoff in small semimajor axis values, the clustering of orbital periods near three days, and the relative youth of transiting planets. Contrary to previous considerations, a mechanism to stop the inward migration of close-in planets at their current orbits is not necessarily required. Planets nearing tidal destruction may be found with extremely small semimajor axes, possibly already stripped of any gaseous envelope. The recently discovered CoroT-7 b may be an example of such a planet and will probably be destroyed by tides within the next few Gyrs. Also, where one or more planets have already been accreted, a star may exhibit an unusual composition and/or spin rate.

276

The Exoplanet Microlensing Survey by the Proposed WFIRST Observatory  

Science.gov (United States)

The New Worlds, New Horizons report released by the Astronomy and Astrophysics Decadal Survey Board in 2010 listed the Wide Field Infrared Survey Telescope (WFIRST) as the highest-priority large space mission for the . coming decade. This observatory will provide wide-field imaging and slitless spectroscopy at near infrared wavelengths. The scientific goals are to obtain a statistical census of exoplanets using gravitational microlensing. measure the expansion history of and the growth of structure in the Universe by multiple methods, and perform other astronomical surveys to be selected through a guest observer program. A Science Definition Team has been established to assist NASA in the development of a Design Reference Mission that accomplishes this diverse array of science programs with a single observatory. In this paper we present the current WFIRST payload concept and the expected capabilities for planet detection. The observatory. with science goals that are complimentary to the Kepler exoplanet transit mission, is designed to complete the statistical census of planetary systems in the Galaxy, from habitable Earth-mass planets to free floating planets, including analogs to all of the planets in our Solar System except Mercury. The exoplanet microlensing survey will observe for 500 days spanning 5 years. This long temporal baseline will enable the determination of the masses for most detected exoplanets down to 0.1 Earth masses.

Barry, Richard; Kruk, Jeffrey; Anderson, Jay; Beaulieu, Jean-Philippe; Bennett, David P.; Catanzarite, Joseph; Cheng, Ed; Gaudi, Scott; Gehrels, Neil; Kane, Stephen; Lunine, Jonathan; Sumi, Takahiro; Tanner, Angelle; Traub, Wesley

2012-01-01

277

Transiting exoplanets from the CoRoT space mission. VIII. CoRoT-7b: the first super-Earth with measured radius  

Science.gov (United States)

Aims: We report the discovery of very shallow (? F/F ? 3.4× 10-4), periodic dips in the light curve of an active V = 11.7 G9V star observed by the CoRoT satellite, which we interpret as caused by a transiting companion. We describe the 3-colour CoRoT data and complementary ground-based observations that support the planetary nature of the companion. Methods: We used CoRoT colours information, good angular resolution ground-based photometric observations in- and out- of transit, adaptive optics imaging, near-infrared spectroscopy, and preliminary results from radial velocity measurements, to test the diluted eclipsing binary scenarios. The parameters of the host star were derived from optical spectra, which were then combined with the CoRoT light curve to derive parameters of the companion. Results: We examined all conceivable cases of false positives carefully, and all the tests support the planetary hypothesis. Blends with separation >0.40´´or triple systems are almost excluded with a 8 × 10-4 risk left. We conclude that, inasmuch we have been exhaustive, we have discovered a planetary companion, named CoRoT-7b, for which we derive a period of 0.853 59 ± 3 × 10-5 day and a radius of Rp = 1.68 ± 0.09 R_Earth. Analysis of preliminary radial velocity data yields an upper limit of 21 M_Earth for the companion mass, supporting the finding. Conclusions: CoRoT-7b is very likely the first Super-Earth with a measured radius. This object illustrates what will probably become a common situation with missions such as Kepler, namely the need to establish the planetary origin of transits in the absence of a firm radial velocity detection and mass measurement. The composition of CoRoT-7b remains loosely constrained without a precise mass. A very high surface temperature on its irradiated face, ?1800-2600 K at the substellar point, and a very low one, ?50 K, on its dark face assuming no atmosphere, have been derived. The CoRoT?space mission, launched on 27 December 2006, has been developed and is operated by CNES, with the contribution of Austria, Belgium, Brazil, ESA, Germany, and Spain. First CoRoT?data are available to the public from the CoRoT?archive: http://idoc-corot.ias.u-psud.fr. The complementary observations were obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT) which is operated by NRC in Canada, INSU-CNRS in France, and the University of Hawaii; ESO Telescopes at the La Silla and Paranal Observatories under programme ID 081.C-0413(C), DDT 282.C-5015; the IAC80 telescope operated by the Instituto de Astrofísica de Tenerife at the Observatorio del Teide; the Isaac Newton Telescope (INT), operated on the island of La Palma by the Isaac Newton group in the Spanish Observatorio del Roque de Los Muchachos of the Instituto de Astrofisica de Canarias; and at the Anglo-Australian Telescope that have been funded by the Optical Infrared Coordination network (OPTICON), a major international collaboration supported by the Research Infrastructures Programme of the European Commissions Sixth Framework Programme; Radial-velocity observations were obtained with the SOPHIE spectrograph at the 1.93m telescope of Observatoire de Haute Provence, France.

Léger, A.; Rouan, D.; Schneider, J.; Barge, P.; Fridlund, M.; Samuel, B.; Ollivier, M.; Guenther, E.; Deleuil, M.; Deeg, H. J.; Auvergne, M.; Alonso, R.; Aigrain, S.; Alapini, A.; Almenara, J. M.; Baglin, A.; Barbieri, M.; Bruntt, H.; Bordé, P.; Bouchy, F.; Cabrera, J.; Catala, C.; Carone, L.; Carpano, S.; Csizmadia, Sz.; Dvorak, R.; Erikson, A.; Ferraz-Mello, S.; Foing, B.; Fressin, F.; Gandolfi, D.; Gillon, M.; Gondoin, Ph.; Grasset, O.; Guillot, T.; Hatzes, A.; Hébrard, G.; Jorda, L.; Lammer, H.; Llebaria, A.; Loeillet, B.; Mayor, M.; Mazeh, T.; Moutou, C.; Pätzold, M.; Pont, F.; Queloz, D.; Rauer, H.; Renner, S.; Samadi, R.; Shporer, A.; Sotin, Ch.; Tingley, B.; Wuchterl, G.; Adda, M.; Agogu, P.; Appourchaux, T.; Ballans, H.; Baron, P.; Beaufort, T.; Bellenger, R.; Berlin, R.; Bernardi, P.; Blouin, D.; Baudin, F.; Bodin, P.; Boisnard, L.; Boit, L.; Bonneau, F.; Borzeix, S.; Briet, R.; Buey, J.-T.; Butler, B.; Cailleau, D.; Cautain, R.; Chabaud, P.-Y.; Chaintreuil, S.; Chiavassa, F.; Costes, V.; Cuna Parrho, V.; de Oliveira Fialho, F.; Decaudin, M.; Defise, J.-M.; Djalal, S.; Epstein, G.; Exil, G.-E.; Fauré, C.; Fenouillet, T.; Gaboriaud, A.; Gallic, A.; Gamet, P.; Gavalda, P.; Grolleau, E.; Gruneisen, R.; Gueguen, L.; Guis, V.; Guivarc'h, V.; Guterman, P.; Hallouard, D.; Hasiba, J.; Heuripeau, F.; Huntzinger, G.; Hustaix, H.; Imad, C.; Imbert, C.; Johlander, B.; Jouret, M.; Journoud, P.; Karioty, F.; Kerjean, L.; Lafaille, V.; Lafond, L.; Lam-Trong, T.; Landiech, P.; Lapeyrere, V.; Larqué, T.; Laudet, P.; Lautier, N.; Lecann, H.; Lefevre, L.; Leruyet, B.; Levacher, P.; Magnan, A.; Mazy, E.; Mertens, F.; Mesnager, J.-M.; Meunier, J.-C.; Michel, J.-P.; Monjoin, W.; Naudet, D.; Nguyen-Kim, K.; Orcesi, J.-L.; Ottacher, H.; Perez, R.; Peter, G.; Plasson, P.; Plesseria, J.-Y.; Pontet, B.; Pradines, A.; Quentin, C.; Reynaud, J.-L.; Rolland, G.; Rollenhagen, F.; Romagnan, R.; Russ, N.; Schmidt, R.; Schwartz, N.; Sebbag, I.; Sedes, G.; Smit, H.; Steller, M. B.; Sunter, W.; Surace, C.; Tello, M.; Tiphène, D.; Toulouse, P.; Ulmer, B.; Vandermarcq, O.; Vergnault, E.; Vuillemin, A.; Zanatta, P.

2009-10-01

278

Direct imaging of exoplanets.  

Science.gov (United States)

Most of the exoplanets known today have been discovered by indirect techniques, based on the study of the host star radial velocity or photometric temporal variations. These detections allowed the study of the planet populations in the first 5-8?AU from the central stars and have provided precious information on the way planets form and evolve at such separations. Direct imaging on 8-10?m class telescopes allows the detection of giant planets at larger separations (currently typically more than 5-10?AU) complementing the indirect techniques. So far, only a few planets have been imaged around young stars, but each of them provides an opportunity for unique dedicated studies of their orbital, physical and atmospheric properties and sometimes also on the interaction with the 'second-generation', debris discs. These few detections already challenge formation theories. In this paper, I present the results of direct imaging surveys obtained so far, and what they already tell us about giant planet (GP) formation and evolution. Individual and emblematic cases are detailed; they illustrate what future instruments will routinely deliver for a much larger number of stars. I also point out the limitations of this approach, as well as the needs for further work in terms of planet formation modelling. I finally present the progress expected in direct imaging in the near future, thanks in particular to forthcoming planet imagers on 8-10?m class telescopes. PMID:24664924

Lagrange, Anne-Marie

2014-04-28

279

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

CERN Document Server

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 ...

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

280

Massive Satellites of Close-In Gas Giant Exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We study the orbits, tidal heating and mass loss from satellites around close-in gas giant exoplanets. The focus is on large satellites which are potentially observable by their transit signature. We argue that even Earth-size satellites around hot Jupiters may be immune to destruction by orbital decay; detection of such a massive satellite would strongly constrain theories of tidal dissipation in gas giants, in a manner complementary to orbital circularization. The star's g...

Cassidy, Timothy A.; Mendez, Rolando; Arras, Phil; Johnson, Robert E.; Skrutskie, Michael F.

2009-01-01

 
 
 
 
281

Evidence for a lost population of close-in exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We investigate the evaporation history of known transiting exoplanets in order to consider the origin of observed correlations between mass, surface gravity and orbital period. We show that the survival of the known planets at their current separations is consistent with a simple model of evaporation, but that many of the same planets would not have survived closer to their host stars. These putative closer-in systems represent a lost population that could account for the ob...

Davis, Timothy A.; Wheatley, Peter J.

2009-01-01

282

Exploring exoplanet populations with NASA’s Kepler Mission  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Kepler Mission is exploring the diversity of planets and planetary systems. Its legacy will be a catalog of discoveries sufficient for computing planet occurrence rates as a function of size, orbital period, star type, and insolation flux. The mission has made significant progress toward achieving that goal. Over 3,500 transiting exoplanets have been identified from the analysis of the first 3 y of data, 100 planets of which are in the habitable zone. The catalog has a high reliability ra...

Batalha, Natalie M.

2014-01-01

283

WASP-33: the first ? Scuti exoplanet host star  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We report the discovery of photometric oscillations in the host star of the exoplanet WASP-33 b (HD 15082). The data were obtained in the R band in both transit and out-of-transit phases from the 0.3-m telescope and the Montcabrer Observatory and the 0.8-m telescope at the Montsec Astronomical Observatory. Proper fitting and subsequent removal of the transit signal reveals stellar photometric variations with a semi-amplitude of about 1 mmag. The detailed analysis of the periodogram yields a s...

Herrero, Enrique; Morales, Juan Carlos; Ribas, Ignasi; Naves, Ramo?n

2011-01-01

284

Transiting exoplanets from the CoRoT space mission IV: CoRoT-Exo-4b: A transiting planet in a 9.2 day synchronous orbit  

CERN Document Server

CoRoT, the first space-based transit search, provides ultra-high precision light curves with continuous time-sampling over periods, of up to 5 months. This allows the detection of transiting planets with relatively long periods, and the simultaneous study of the host star's photometric variability. In this letter, we report on the discovery of the transiting giant planet CoRoT-Exo-4b and use the CoRoT light curve to perform a detailed analysis of the transit and to determine the stellar rotation period. The CoRoT light curve was pre-processed to remove outliers and correct for orbital residuals and artefacts due to hot pixels on the detector. After removing stellar variability around each transit, the transit light curve was analysed to determine the transit parameters. A discrete auto-correlation function method was used to derive the rotation period of the star from the out-of-transit light curve. We derive periods for the planet's orbit and star's rotation of 9.20205 +/- 0.00037 and 8.87 +/- 1.12 days resp...

Aigrain, S; Ollivier, M; Pont, F; Jorda, L; Almenara, J M; Alonso, R; Barge, P; Borde, P; Bouchy, F; Deeg, H; De la Reza, R; Deleuil, M; Dvorak, R; Erikson, A; Fridlund, M; Gondoin, P; Gillon, M; Guillot, T; Hatzes, A; Lammer, H; Lanza, A F; Léger, A; Llebaria, A; Magain, P; Mazeh, T; Moutou, C; Paetzold, M; Pinte, C; Queloz, D; Rauer, H; Rouan, D; Schneider, J; Wuchter, G; Zucker, S

2008-01-01

285

Exoplanet Transmission Spectroscopy in the Near Infrared with Keck/MOSFIRE  

Science.gov (United States)

We present transit transmission spectroscopy of hot sub-Jupiter WASP-6 b with MOSFIRE, a near infrared multi-object spectrograph at W. M. Keck Observatory. These K-band spectra offer a window into exoplanet atmospheres at wavelengths sensitive to absorption by methane and carbon monoxide but not water, providing a potentially valuable perspective on exoplanet atmospheric chemistry for planets that produce featureless spectra in the optical due to water clouds. We use MOSFIRE's Configurable Slit Unit in a wide and long configuration with a 15 arcsecond slit to simultaneously collect spectra from a comparison star and the exoplanet host star during a transit. We perform differential spectrophotometry to obtain a spectrum of the atmosphere of WASP-6 b, providing constraints on its chemical composition. In combination with pending observations, we will use transit transmission spectra from MOSFIRE to better inform our understanding of planet formation.

Morris, Brett; Mandell, Avi; Angerhausen, Daniel; Kassis, Marc; Madhusudhan, Nikku; McElwain, Michael W.

2015-01-01

286

Broadband Eclipse Spectra of Exoplanets are Featureless  

CERN Document Server

Spectral retrieval methods leverage features in emission spectra to constrain the atmospheric composition and structure of transiting exoplanets. Most of the observed emission spectra consist of broadband photometric observations at a small number of wavelengths. We compare the Bayesian Information Criterion (BIC) of blackbody fits and spectral retrieval fits for all planets with eclipse measurements in multiple thermal wavebands, typically hot Jupiters with 2-4 observations. If the published error bars are taken at face value, then eight planets are significantly better fit by a spectral model than by a blackbody. In this under-constrained regime, however, photometric uncertainties directly impact one's ability to constrain atmospheric properties. By considering the handful of planets for which eclipse measurements have been repeated and/or reanalyzed, we obtain an empirical estimate of systematic uncertainties for broadband eclipse depths obtained with the Spitzer Space Telescope: sigma_sys = 5E-4. When thi...

Hansen, C J; Cowan, N B

2014-01-01

287

ASTEP: Towards the detection and characterization of exoplanets from Dome C  

Directory of Open Access Journals (Sweden)

Full Text Available The ASTEP project (Antarctic Search for Transiting ExoPlanets, aims at testing the quality of the Dome C site in Antarctica for photometry in the visible, as well as detecting and characterizing transiting exoplanets. A dedicated telescope, ASTEP400, has been developped and installed at Concordia. The ?rst campaign took place during the winter 2010, and the telescope functionned nominally during all the winter. A ?rst analysis of the data leads to a precision of 189 and 205 ppm for WASP-19 and WASP-18 respectively, for continuous observations during 1 month. This shows that extremely high precision photometry is achievable from Dome C.

Rauer H.

2011-02-01

288

The observational effects and signatures of tidally distorted solid exoplanets  

Science.gov (United States)

Our work examines the detectability of tidally distorted solid exoplanets in synchronous rotation. Previous work has shown that tidally distorted shapes of close-in gas giants can give rise to radius underestimates and subsequently density overestimates for those planets. We examine the assumption that such an effect is too minimal for rocky exoplanets and find that for smaller M Class stars there may be an observationally significant tidal distortion effect at very close-in orbits. We quantify the effect for different stellar types and planetary properties using some basic assumptions. Finally, we develop a simple analytic expression to test if there are detectable bulge signatures in the photometry of a system. We find that close in for smaller M Class stars there may be an observationally significant signature that may manifest itself in both in-transit bulge signatures and ellipsoidal variations.

Saxena, Prabal; Panka, Peter; Summers, Michael

2015-02-01

289

The SPICA coronagraphic instrument (SCI) for the study of exoplanets  

CERN Document Server

We present the SPICA Coronagraphic Instrument (SCI), which has been designed for a concentrated study of extra-solar planets (exoplanets). SPICA mission provides us with a unique opportunity to make high contrast observations because of its large telescope aperture, the simple pupil shape, and the capability for making infrared observations from space. The primary objectives for the SCI are the direct coronagraphic detection and spectroscopy of Jovian exoplanets in infrared, while the monitoring of transiting planets is another important target. The specification and an overview of the design of the instrument are shown. In the SCI, coronagraphic and non-coronagraphic modes are applicable for both an imaging and a spectroscopy. The core wavelength range and the goal contrast of the coronagraphic mode are 3.5--27$\\mu$m, and 10$^{-6}$, respectively. Two complemental designs of binary shaped pupil mask coronagraph are presented. The SCI has capability of simultaneous observations of one target using two channels...

Enya, K; Haze, K; Aono, K; Nakagawa, T; Matsuhara, H; Kataza, H; Wada, T; Kawada, M; Fujiwara, K; Mita, M; Takeuchi, S; Komatsu, K; Sakai, S; Uchida, H; Mitani, S; Yamawaki, T; Miyata, T; Sako, S; Nakamura, T; Asano, K; Yamashita, T; Narita, N; Matsuo, T; Tamura, M; Nishikawa, J; Kokubo, E; Hayano, Y; Oya, S; Fukagawa, M; Shibai, H; Baba, N; Murakami, N; Itoh, Y; Honda, M; Okamoto, B; Ida, S; Takami, M; Abe, L; Guyon, O; Bierden, P; Yamamuro, T; 10.1016/j.asr.2011.03.010

2011-01-01

290

High-temperature measurements of VUV-absorption cross sections of CO2 and their application to exoplanets  

CERN Document Server

UV absorption cross sections are an essential ingredient of photochemical atmosphere models. Exoplanet searches have unveiled a large population of short-period objects with hot atmospheres, very different from what we find in our solar system. Transiting exoplanets whose atmospheres can now be studied by transit spectroscopy receive extremely strong UV fluxes and have typical temperatures ranging from 400 to 2500 K. At these temperatures, UV photolysis cross section data are severely lacking. Aims. Our goal is to provide high-temperature absorption cross sections and their temperature dependency for important atmospheric compounds. This study is dedicated to CO2, which is observed and photodissociated in exoplanet atmospheres. We also investigate the influence of these new data on the photochemistry of some exoplanets. We performed these measurements for the 115 - 200 nm range at 300, 410, 480, and 550 K. In the 195 - 230 nm range, we worked at seven temperatures between 465 and 800 K. We implemented the mea...

Venot, Olivia; Bénilan, Yves; Gazeau, Marie-Claire; Hébrard, Eric; Larcher, Gwenaelle; Schwell, Martin; Dobrijevic, Michel; Selsis, Franck

2013-01-01

291

The Radiation Environment of Exoplanet Atmospheres  

Directory of Open Access Journals (Sweden)

Full Text Available Exoplanets are born and evolve in the radiation and particle environment created by their host star. The host star’s optical and infrared radiation heats the exoplanet’s lower atmosphere and surface, while the ultraviolet, extreme ultraviolet and X-radiation control the photochemistry and mass loss from the exoplanet’s upper atmosphere. Stellar radiation, especially at the shorter wavelengths, changes dramatically as a host star evolves leading to changes in the planet’s atmosphere and habitability. This paper reviews the present state of our knowledge concerning the time-dependent radiation emitted by stars with convective zones, that is stars with spectral types F, G, K, and M, which comprise nearly all of the host stars of detected exoplanets.

Jeffrey L. Linsky

2014-10-01

292

Detection feasability of an early Earth as an exoplanet  

Science.gov (United States)

The search for Earth-like exoplanets has become a tremendous part of planetary research. To date, more than 800 exoplanets have been found, but only a few have been characterized. The main part of an exoplanet that can be studied is obviously its atmosphere. There are two principal ways: transit spectroscopy and secondary transit. The present work aims at evaluating the feasability of detecting non-thermal emissions from an Earth-like exoplanet, due to excitations of species by extreme UV photons and electron impact. In this first step of a larger project, we focus on the primary Earth atmosphere. This atmosphere was inherited from the solar nebula. It was mainly composed of H and H2. As there is no available model of this atmosphere, we rescaled a Jovian atmosphere model to the early Earth conditions. We use a set of codes to compute the excitation and emission rates. The first one is a kinetic transport code. Its inputs are the solar EUV flux, the precipitated electrons, the atmospheric composition and the correlative cross sections. It solves a stationary Boltzmann equation and computes the electron stationary flux, the different ion states productions and excited neutrals. From these outputs, we compute the emission rates through spontaneous deactivation. Finally, we use a radiative transfer code to compute the emission rate of Lyman alpha, which is optically thick. In order to account for the solar emission, we use the prescription proposed by Ribas et al. (2005) out of the Sun in Time program. We find that the contrast between the early Earth and the Young Sun is around 10-8, very unfavorable for detection purpose. This project has been funded by the European FP7 Project ESPAS, Grant agreement no: 283676

Bernard, David; Lilensten, Jean; Gronoff, Guillaume; Barthélémy, Mathieu; Ménager, Hélène

2013-04-01

293

Discriminating between Cloudy, Hazy, and Clear Sky Exoplanets Using Refraction  

Science.gov (United States)

We propose a method to distinguish between cloudy, hazy, and clear sky (free of clouds and hazes) exoplanet atmospheres that could be applicable to upcoming large aperture space- and ground-based telescopes such as the James Webb Space Telescope (JWST) and the European Extremely Large Telescope (E-ELT). These facilities will be powerful tools for characterizing transiting exoplanets, but only after a considerable amount of telescope time is devoted to a single planet. A technique that could provide a relatively rapid means of identifying haze-free targets (which may be more valuable targets for characterization) could potentially increase the science return for these telescopes. Our proposed method utilizes broadband observations of refracted light in the out-of-transit spectrum. Light refracted through an exoplanet atmosphere can lead to an increase of flux prior to ingress and subsequent to egress. Because this light is transmitted at pressures greater than those for typical cloud and haze layers, the detection of refracted light could indicate a cloud- or haze-free atmosphere. A detection of refracted light could be accomplished in <10 hr for Jovian exoplanets with JWST and <5 hr for super-Earths/mini-Neptunes with E-ELT. We find that this technique is most effective for planets with equilibrium temperatures between 200 and 500 K, which may include potentially habitable planets. A detection of refracted light for a potentially habitable planet would strongly suggest the planet was free of a global cloud or haze layer, and therefore a promising candidate for follow-up observations.

Misra, Amit K.; Meadows, Victoria S.

2014-11-01

294

Increasing the sensitivity of Kepler to Earth-like exoplanets  

Science.gov (United States)

Many transiting exoplanets have been discovered using photometry from the Kepler mission but the results are still very incomplete in some of the most interesting parts of parameter space: small planetary radius and long orbital period. We have developed a method for detecting transiting exoplanet signals in stellar light curves that is more sensitive to small planets on long orbits than previously published procedures. It is standard practice to start by "de-trending" the light curves—by filtering—to remove the instrumental systematics and stellar variability from the time series. Instead, we build an flexible model for these effects using a Gaussian Process. We use as inputs to the Gaussian Process not just time but also the light curves of dozens of other stars. This exploits the causal structure of the problem: permitting the noise model to capture spacecraft-induced covariability. Since we know a priori that the other stars are causally unrelated to the star of interest, any information that they share must be due to systematics. A key motivation for our work is that any filtering—no matter how robust—reduces the amplitude of the signals of interest. By marginalizing over the stellar and instrumental variability while simultaneously fitting for the transits, we maintain sensitivity to transit signals and reduce contamination. We apply our method to light curves from the Kepler mission. Using synthetic transits generated by realistic planetary systems injected into raw aperture photometry from the pipeline, we determine the detection efficiency of our method and train a supervised classification algorithm to weed out false signals. Our pipeline returns all of the ingredients needed for studies of exoplanet populations: a catalog of planet candidates, posterior samples for the physical parameters of these planets and their host stars, and an empirical measurement of the detection efficiency as a function of all of these parameters.

Foreman-Mackey, Daniel; Hogg, David W.; Schölkopf, Bernhard; Wang, Dun

2015-01-01

295

Multiplicity-Study of Exoplanet Host Stars  

CERN Document Server

We carry out a systematic search campaign for wide companions of exoplanet host stars to study their multiplicity and its influence on the long-term stability and the orbital parameters of the exoplanets. We have already found 6 wide companions, raising the number of confirmed binaries among the exoplanet host stars to 20 systems. We have also searched for wide companions of Gl86, the first known exoplanet host star with a white dwarf companion. Our Sofi/NTT observations are sensitive to substellar companions with a minimum-mass of 35 Mjup and clearly rule out further stellar companions with projected separations between 40 and 670AU.

Mugrauer, M; Mazeh, T; Günther, E

2005-01-01

296

Balloon exoplanet nulling interferometer (BENI)  

Science.gov (United States)

We evaluate the feasibility of a balloon-borne nulling interferometer to detect and characterize an exosolar planet and the surrounding debris disk. The existing instrument consists of a three-telescope Fizeau imaging interferometer with thre fast steering mirrors and three delay lines operating at 800 Hz for closed-loop control of wavefront errors and fine pointing. A compact visible nulling interferometer would be coupled to the imaging interferometer and in principle, allows deep starlight suppression. Atmospheric simulations of the environment above 100,000 feet show that balloonborne payloads are a possible path towards the direct detection and characterization of a limited set of exoplanets and debris disks. Furthermore, rapid development of lower cost balloon payloads provide a path towards advancement of NASA technology readiness levels for future space-based exoplanet missions. Discussed are the BENI mission and instrument, the balloon environment and the feasibility of such a balloon-borne mission.

Lyon, Richard G.; Clampin, Mark; Woodruff, Robert A.; Vasudevan, Gopal; Ford, Holland; Petro, Larry; Herman, Jay; Rinehart, Stephen; Carpenter, Kenneth; Marzouk, Joe

2009-08-01

297

Atmospheric Circulation of Terrestrial Exoplanets  

CERN Document Server

The investigation of planets around other stars began with the study of gas giants, but is now extending to the discovery and characterization of super-Earths and terrestrial planets. Motivated by this observational tide, we survey the basic dynamical principles governing the atmospheric circulation of terrestrial exoplanets, and discuss the interaction of their circulation with the hydrological cycle and global-scale climate feedbacks. Terrestrial exoplanets occupy a wide range of physical and dynamical conditions, only a small fraction of which have yet been explored in detail. Our approach is to lay out the fundamental dynamical principles governing the atmospheric circulation on terrestrial planets--broadly defined--and show how they can provide a foundation for understanding the atmospheric behavior of these worlds. We first survey basic atmospheric dynamics, including the role of geostrophy, baroclinic instabilities, and jets in the strongly rotating regime (the "extratropics") and the role of the Hadle...

Showman, Adam P; Merlis, Timothy M; Kaspi, Yohai

2013-01-01

298

A Research-Informed Approach to Teaching About Exoplanet Detection in STEM Classrooms  

Science.gov (United States)

JPL’s NASA Exoplanet Exploration Program’s (ExEP) Public Engagement Program, in collaboration with the Center for Astronomy Education (CAE), is engaged in a research and curriculum development program to bring the science of exoplanet detection into STEM classrooms. In recent years, there has been a significant increase in the number of astronomers pursuing research related to exoplanets, along with a significant increase in interest amongst students and the general public regarding the topic of exoplanets. CAE has previously developed a curriculum unit (including Think-Pair-Share questions and a Lecture-Tutorial) to help students develop a deeper understanding of the Doppler method for detecting extrasolar planets. To date, there is a nearly nonexistent research base on students’ conceptual and reasoning difficulties related to the science of the transit and gravitational microlensing methods for detecting extrasolar planets. Appropriate for physical science classrooms from middle school to the introductory college level, the learner-centered active engagement activities we are developing are going through an iterative research and assessment process to ensure that they enable students to achieve increased conceptual understandings and reasoning skills in these areas. In this talk, we will report on our development process for two new Lecture-Tutorials that help students learn about the transit and gravitational microlensing methods for finding exoplanets.

Brissenden, Gina; Wallace, C. S.; Prather, E. E.; Traub, W. A.; Greene, W. M.; Biferno, A. A.

2014-01-01

299

On the Confidence of Molecular Detections in the Atmospheres of Exoplanets from Secondary Eclipse Spectra  

Science.gov (United States)

Armed with a sizable and ever-growing list of confirmed exoplanets we are beginning to face the big question of atmospheric characterization: What are these planets made of? Transit transmission and emission spectroscopy provide a means to probe the composition of exoplanet atmospheres. However, relatively few high-resolution spectra have been obtained for transiting exoplanets leaving attempts at atmospheric characterization to rely heavily on ground and space-based broadband photometric observations. More recently, early claims of molecular detections in exoplanet atmospheres using broadband photometry are called into question as featureless blackbodies can be shown to reproduce the low signal-to-noise observations. In this study, we determine with what confidence we are able to detect spectrally dominant molecules in the atmospheres of nine exoplanets observed in secondary eclipse. Using the Bayesian atmospheric retrieval suite, CHIMERA, we find that the detection of molecules from broadband ground-based and space-based photometry generally fails to breach 3? confidence. However, observations that include spectral data lead to strong molecular detections. Furthermore, we simulate Hubble Space Telescope Wide Field Camera 3 spectral observations from 1.1 to 1.6 microns for a handful of planets to suggest how future observations may lead to molecular detections.

Lustig-Yaeger, Jacob A.; Line, Michael R.; Fortney, Jonathan J.

2015-01-01

300

Abundances in stars with exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Extensive spectroscopic studies of stars with and without planets have concluded that stars hosting planets are significantly more metal-rich than those without planets. More subtle trends of different chemical elements begin to appear as the number of detected extrasolar planetary systems continues to grow. I review our current knowledge concerning the observed abundance trends of various chemical elements in stars with exoplanets and their possible implications.

Israelian, Garik

2003-01-01

 
 
 
 
301

Mapping Directly Imaged Giant Exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

With the increasing number of directly imaged giant exoplanets the current atmosphere models are often not capable of fully explaining the spectra and luminosity of the sources. A particularly challenging component of the atmosphere models is the formation and properties of condensate cloud layers, which fundamentally impact the energetics, opacity, and evolution of the planets. Here we present a suite of techniques that can be used to estimate the level of rotational m...

Kostov, Veselin B.; Apai, Da?niel

2012-01-01

302

Transiting exoplanets from the CoRoT space mission. XII. CoRoT-12b: a short-period low-density planet transiting a solar analog star  

CERN Document Server

We report the discovery by the CoRoT satellite of a new transiting giant planet in a 2.83 days orbit about a V=15.5 solar analog star (M_* = 1.08 +- 0.08 M_sun, R_* = 1.1 +- 0.1 R_sun, T_eff = 5675 +- 80 K). This new planet, CoRoT-12b, has a mass of 0.92 +- 0.07 M_Jup and a radius of 1.44 +- 0.13 R_Jup. Its low density can be explained by standard models for irradiated planets.

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

2010-01-01

303

WASP-33: the first ? Scuti exoplanet host star  

Science.gov (United States)

We report the discovery of photometric oscillations in the host star of the exoplanet WASP-33 b (HD 15082). The data were obtained in the R band in both transit and out-of-transit phases from the 0.3-m telescope and the Montcabrer Observatory and the 0.8-m telescope at the Montsec Astronomical Observatory. Proper fitting and subsequent removal of the transit signal reveals stellar photometric variations with a semi-amplitude of about 1 mmag. The detailed analysis of the periodogram yields a structure of significant signals around a frequency of 21 cyc d-1, which is typical of ? Scuti-type variable stars. An accurate study of the power spectrum reveals a possible commensurability with the planet orbital motion with a factor of 26, but this remains to be confirmed with additional time-series data that will permit the identification of the significant frequencies. These findings make WASP-33 the first transiting exoplanet host star with ? Sct variability and a very interesting candidate to search for star-planet interactions. Photometric data is only available in electronic form at CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/526/L10

Herrero, E.; Morales, J. C.; Ribas, I.; Naves, R.

2011-02-01

304

STELLAR VARIABILITY OF THE EXOPLANET HOSTING STAR HD 63454  

International Nuclear Information System (INIS)

Of the hundreds of exoplanets discovered using the radial velocity (RV) technique, many are orbiting close to their host stars with periods less than 10 days. One of these, HD 63454, is a young active K dwarf which hosts a Jovian planet in a 2.82 day period orbit. The planet has a 14% transit probability and a predicted transit depth of 1.2%. Here we provide a re-analysis of the RV data to produce an accurate transit ephemeris. We further analyze 8 nights of time series data to search for stellar activity both intrinsic to the star and induced by possible interactions of the exoplanet with the stellar magnetospheres. We establish the photometric stability of the star at the 3 mmag level despite strong Ca II emission in the spectrum. Finally, we rule out photometric signatures of both star-planet magnetosphere interactions and planetary transit signatures. From this we are able to place constraints on both the orbital and physical properties of the planet.

305

JWST and Exoplanets  

Science.gov (United States)

The James Webb Space Telescope is on track for a launch in 2013. The author reviews the status and progress on the key hardware. The first primary mirror segments are already at MSFC for cryogenic tests, the mid IR instrument (MIRI) has already had successful tests of the engineering model, and the detectors are showing excellent performance. The author also describes the scientific objectives of the mission, with emphasis on the predicted capabilities for observing planets by the transit technique and through direct imaging. Recent direct observations of planets by HST and by adaptive optics from the ground have shown that, under favorable circumstances, much can be learned.

Mather, John C.

2009-01-01

306

Transiting exoplanets from the CoRoT space mission IX. CoRoT-6b: a transiting `hot Jupiter' planet in an 8.9d orbit around a low-metallicity star  

CERN Document Server

The CoRoT satellite exoplanetary team announces its sixth transiting planet in this paper. We describe and discuss the satellite observations as well as the complementary ground-based observations - photometric and spectroscopic - carried out to assess the planetary nature of the object and determine its specific physical parameters. The discovery reported here is a `hot Jupiter' planet in an 8.9d orbit, 18 stellar radii, or 0.08 AU, away from its primary star, which is a solar-type star (F9V) with an estimated age of 3.0 Gyr. The planet mass is close to 3 times that of Jupiter. The star has a metallicity of 0.2 dex lower than the Sun, and a relatively high $^7$Li abundance. While thelightcurveindicatesamuchhigherlevelof activity than, e.g., the Sun, there is no sign of activity spectroscopically in e.g., the [Ca ] H&K lines.

Fridlund, M; Alonso, R; Deleuil, M; Gandolfi, D; Gillon, M; Bruntt, H; Alapini, A; Csizmadia, Sz; Guillot, T; Lammer, H; Aigrain, S; Almenara, J M; Auvergne, M; Baglin, A; Barge, P; Borde, P; Bouchy, F; Cabrera, J; Carone, L; Carpano, S; Deeg, H J; De la Reza, R; Dvorak, R; Erikson, A; Ferraz-Mello, S; Guenther, E; Gondoin, P; Hartog, R den; Hatzes, A; Jorda, L; Leger, A; Llebaria, A; Magain, P; Mazeh, T; Moutou, C; Ollivier, M; Patzold, M; Queloz, D; Rauer, H; Rouan, D; Samuel, B; Schneider, J; Shporer, A; Stecklum, B; Tingley, B; Weingrill, J; Wuchterl, G

2010-01-01

307

Direct Imaging of Radial Velocity Exoplanets with the WFIRST-AFTA Coronagraph  

Science.gov (United States)

The study of exoplanetary systems is an accelerating field as we continue to discover new planets due to advances in detection techniques and instrumentation. However, the majority of planets are detected via indirect methods, such as radial velocity (RV) and transit photometry. These methods rely on observing the effects of exoplanets on the stars they are orbiting, and can therefore limit the planets we can detect and the information we can gather. To further expand the types of planets we can investigate, various direct imaging methods and tools are being developed. One such instrument is a proposed coronagraph for the Wide-Field Infrared Survey Telescope Astrophysics Focused Telescope Assets (WFIRST-AFTA). One science case for this instrument is the direct imaging and spectral characterization of previously discovered exoplanets.In this work, we present a method to find the best times to directly image the subset of RV exoplanets detectable by WFIRST-AFTA. We model the orbits of RV exoplanets using their fit orbital parameters (and error ranges) along with unbiased priors for all unknown parameters. We then map the times (with respect to maximum elongation) when the exoplanet will be geometrically unobscured to the coronagraph to the corresponding radial velocity profiles in order to determine the best times for direct imaging. We find that only 22 out of 534 radial velocity exoplanets are detectable by coronagraph with an inner working angle (IWA) of 200 mas, and 68 using an IWA of 100 mas. These results are folded into a larger instrument model with other factors, such as the coronagraph contrast and throughput, also taken into consideration, to produce a more detailed prediction for the RV exoplanet imaging capabilities of the WFIRST-AFTA coronagraph.

Acharya, Aastha; Savransky, Dmitry

2015-01-01

308

Exoplanet Community Report on Direct Infrared Imaging of Exoplanets  

Science.gov (United States)

Direct infrared imaging and spectroscopy of exoplanets will allow for detailed characterization of the atmospheric constituents of more than 200 nearby Earth-like planets, more than is possible with any other method under consideration. A flagship mission based on larger passively cooled infrared telescopes and formation flying technologies would have the highest angular resolution of any concept under consideration. The 2008 Exoplanet Forum committee on Direct Infrared Imaging of Exoplanets recommends: (1) a vigorous technology program including component development, integrated testbeds, and end-to-end modeling in the areas of formation flying and mid-infrared nulling; (2) a probe-scale mission based on a passively cooled structurally connected interferometer to be started within the next two to five years, for exoplanetary system characterization that is not accessible from the ground, and which would provide transformative science and lay the engineering groundwork for the flagship mission with formation flying elements. Such a mission would enable a complete exozodiacal dust survey (<1 solar system zodi) in the habitable zone of all nearby stars. This information will allow for a more efficient strategy of spectral characterization of Earth-sized planets for the flagship missions, and also will allow for optimization of the search strategy of an astrometric mission if such a mission were delayed due to cost or technology reasons. (3) Both the flagship and probe missions should be pursued with international partners if possible. Fruitful collaboration with international partners on mission concepts and relevant technology should be continued. (4) Research and Analysis (R&A) should be supported for the development of preliminary science and mission designs. Ongoing efforts to characterize the the typical level of exozodiacal light around Sun-like stars with ground-based nulling technology should be continued.

Danchi, William C.; Lawson, Peter R.

2009-01-01

309

Achieving high-precision pointing on ExoplanetSat: Initial feasibility analysis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

ExoplanetSat is a proposed three-unit CubeSat designed to detect down to Earth-sized exoplanets in an orbit out to the habitable zone of Sun-like stars via the transit method. To achieve the required photometric precision to make these measurements, the target star must remain within the same fraction of a pixel, which is equivalent to controlling the pointing of the satellite to the arcsecond level. The satellite will use a two-stage control system: coarse control will be performed by a set ...

Pong, Christopher Masaru; Lim, Sungyung; Smith, Matthew William; Miller, David W.; Villasenor, Jesus Noel Samonte; Seager, Sara

2010-01-01

310

High-precision ground-based photometry of exoplanets  

Directory of Open Access Journals (Sweden)

Full Text Available High-precision photometry of transiting exoplanet systems has contributed significantly to our understanding of the properties of their atmospheres. The best targets are the bright exoplanet systems, for which the high number of photons allow very high signal-to-noise ratios. Most of the current instruments are not optimised for these high-precision measurements, either they have a large read-out overhead to reduce the readnoise and/or their field-of-view is limited, preventing simultaneous observations of both the target and a reference star. Recently we have proposed a new wide-field imager for the Observatoir de Mont-Megantic optimised for these bright systems (PI: Jayawardhana. The instruments has a dual beam design and a field-of-view of 17' by 17'. The cameras have a read-out time of 2 seconds, significantly reducing read-out overheads. Over the past years we have obtained significant experience with how to reach the high precision required for the characterisation of exoplanet atmospheres. Based on our experience we provide the following advice: Get the best calibrations possible. In the case of bad weather, characterise the instrument (e.g. non-linearity, dome flats, bias level, this is vital for better understanding of the science data. Observe the target for as long as possible, the out-of-transit baseline is as important as the transit/eclipse itself. A short baseline can lead to improperly corrected systematic and mis-estimation of the red-noise. Keep everything (e.g. position on detector, exposure time as stable as possible. Take care that the defocus is not too strong. For a large defocus, the contribution of the total flux from the sky-background in the aperture could well exceed that of the target, resulting in very strict requirements on the precision at which the background is measured.

de Mooij Ernst J.W.

2013-04-01

311

The barycentric motion of exoplanet host stars: tests of solar spin-orbit coupling  

CERN Document Server

Empirical evidence suggests a tantalising but unproven link between various indicators of solar activity and the barycentric motion of the Sun. The latter is exemplified by transitions between regular and more disordered motion modulated by the motions of the giant planets, and rare periods of retrograde motion with negative orbital angular momentum. An examination of the barycentric motion of exoplanet host stars, and their stellar activity cycles, has the potential of proving or disproving the Sun's motion as an underlying factor in the complex patterns of short- and long-term solar variability indices, by establishing whether such correlations exist in other planetary systems. A variety of complex patterns of barycentric motions of exoplanet host stars is demonstrated, depending on the number, masses and orbits of the planets. Each of the behavioural types proposed to correlate with solar activity are also evident in exoplanet host stars: repetitive patterns influenced by massive multiple planets, epochs o...

Perryman, M A C

2010-01-01

312

Making FORS2 fit for exoplanet observations (again)  

CERN Document Server

For about three years, it was known that precision spectrophotometry with FORS2 suffered from systematic errors that made quantitative observations of planetary transits impossible. We identified the Longitudinal Atmospheric Dispersion Compensator (LADC) as the most likely culprit, and therefore engaged in a project to exchange the LADC prisms with the uncoated ones from FORS1. This led to a significant improvement in the depth of FORS2 zero points, a reduction in the systematic noise, and should make FORS2 again competitive for transmission spectroscopy of exoplanets.

Boffin, H M J; Gonzalez, O A; Moehler, S; Sedaghati, E; Gibson, N; Ancker, M E van den; Smoker, J; Anderson, J; Hummel, C; Dobrzycka, D; Smette, A; Rupprecht, G

2015-01-01

313

Models of Neptune-Mass Exoplanets: Emergent Fluxes and Albedos  

Digital Repository Infrastructure Vision for European Research (DRIVER)

There are now many known exoplanets with Msin(i) within a factor of two of Neptune's, including the transiting planets GJ436b and HAT-P-11b. Planets in this mass-range are different from their more massive cousins in several ways that are relevant to their radiative properties and thermal structures. By analogy with Neptune and Uranus, they are likely to have metal abundances that are an order of magnitude or more greater than those of larger, more massive planets. This incr...

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

2009-01-01

314

Insolation patterns on eccentric exoplanets  

Science.gov (United States)

Several studies have found that synchronously-rotating Earth-like planets in the habitable zones of M-dwarf stars should exhibit an "eyeball" climate pattern, with a pupil of open ocean facing the parent star, and ice everywhere else. Recent work on eccentric exoplanets by Wang et al. (Wang, Y., Tian, F., Hu, Y. [2014b] Astrophys. J. 791, L12) has extended this conclusion to the 2:1 spin-orbit resonance as well, where the planet rotates twice during one orbital period. However, Wang et al. also found that the 3:2 and 5:2 half-odd resonances produce a zonally-striped climate pattern with polar icecaps instead. Unfortunately, they used incorrect insolation functions for the 3:2 and 5:2 resonances whose long-term time averages are essentially independent of longitude. This paper presents the correct insolation patterns for eccentric exoplanets with negligible obliquities in the 0:1, 1:2, 1:1, 3:2, 2:1, 5:2, 3:1, 7:2, and 4:1 spin-orbit resonances. I confirm that the mean insolation is distributed in an eyeball pattern for integer resonances; but for half-odd resonances, the mean insolation takes a "double-eyeball" pattern, identical over the "eastern" and "western" hemispheres. Presuming that liquids, ices, clouds, albedo, and thermal emission are similarly distributed, this has significant implications for the observation and interpretation of potentially habitable exoplanets. Finally, whether a striped ball, eyeball, or double-eyeball pattern emerges, the possibility exists that long-term build-up of ice (or liquid) away from the hot spots may alter the planet's inertia tensor and quadrupole moments enough to re-orient the planet, ultimately changing the distribution of liquid and ice.

Dobrovolskis, Anthony R.

2015-04-01

315

Thermal Infrared Imaging of Exoplanets  

International Nuclear Information System (INIS)

High-contrast imaging remains the only way to search for and study weakly-irradiated giant exoplanets. We review here in brief a new high-contrast imaging technique that operates in the 3-5 ?m window and show the exquisite sensitivity that can be reached using this technique. The two key advantages of the L-band high-contrast imaging are the superior image quality and the 2-to 4-magnitude gain in sensitivity provided by the red color of giant planets. Most excitingly, this method can be applied to constrain the yet-unexplored giant planet population at radii between 3 and 30 AU.

316

Resource Letter Exo-1: Exoplanets  

CERN Document Server

This Resource Letter gives an introduction to the main topics in exoplanet research. It is intended to serve as a guide to the field for upper-division undergraduate and graduate students, both theoretical and experimental, and for workers in other fields of physics and astronomy who wish learn about this new discipline. Topics include historical background, detection methods, host star properties, theories of planet formation and evolution, their interiors and atmospheres, their relationship to the formation and evolution of our own solar system, and issues of life and habitability.

Perryman, Michael

2013-01-01

317

Resource Letter Exo-1: Exoplanets  

Science.gov (United States)

This Resource Letter gives an introduction to the main topics in exoplanet research. It is intended to serve as a guide to the field for upper-division undergraduate and graduate students, both theoretical and experimental, and for workers in other fields of physics and astronomy who wish learn about this new discipline. Topics include historical background, detection methods, host star properties, theories of planet formation and evolution, their interiors and atmospheres, their relationship to the formation and evolution of our own solar system, and issues of life and habitability.

Perryman, Michael

2014-06-01

318

EMPIRICAL CONSTRAINTS ON THE OBLATENESS OF AN EXOPLANET  

International Nuclear Information System (INIS)

We show that the gas giant exoplanet HD 189733b is less oblate than Saturn, based on Spitzer Space Telescope photometry of seven transits. The observable manifestations of oblateness would have been slight anomalies during the ingress and egress phases, as well as variations in the transit depth due to spin precession. Our nondetection of these effects gives the first empirical constraints on the shape of an exoplanet. The results are consistent with the theoretical expectation that the planetary rotation period and orbital period are synchronized, in which case the oblateness would be an order of magnitude smaller than our upper limits. Conversely, if HD 189733b is assumed to be in a synchronous, zero-obliquity state, then the data give an upper bound on the quadrupole moment of the planet (J2 < 0.068 with 95% confidence) that is too weak to constrain the interior structure of the planet. An Appendix describes a fast algorithm for computing the transit light curve of an oblate planet, which was necessary for our analysis.

319

Highlights in the study of exoplanet atmospheres.  

Science.gov (United States)

Exoplanets are now being discovered in profusion. To understand their character, however, we require spectral models and data. These elements of remote sensing can yield temperatures, compositions and even weather patterns, but only if significant improvements in both the parameter retrieval process and measurements are made. Despite heroic efforts to garner constraining data on exoplanet atmospheres and dynamics, reliable interpretation has frequently lagged behind ambition. I summarize the most productive, and at times novel, methods used to probe exoplanet atmospheres; highlight some of the most interesting results obtained; and suggest various broad theoretical topics in which further work could pay significant dividends. PMID:25230656

Burrows, Adam S

2014-09-18

320

New Exoplanet Surveys in the Canadian High Arctic at 80 Degrees North  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Observations from near the Eureka station on Ellesmere Island, in the Canadian High Arctic at 80 degrees North, benefit from 24-hour darkness combined with dark skies and long cloud-free periods during the winter. Our first astronomical surveys conducted at the site are aimed at transiting exoplanets; compared to mid-latitude sites, the continuous darkness during the Arctic winter greatly improves the survey's detection efficiency for longer-period transiting planets. We det...

Law, Nicholas M.; Sivanandam, Suresh; Murowinski, Richard; Carlberg, Raymond; Ngan, Wayne; Salbi, Pegah; Ahmadi, Aida; Steinbring, Eric; Halman, Mark; Graham, James

2012-01-01

 
 
 
 
321

A Model for Thermal Phase Variations of Circular and Eccentric Exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present a semi-analytic model atmosphere for close-in exoplanets that captures the essential physics of phase curves: orbital and viewing geometry, advection, and re-radiation. We calibrate the model with the well-characterized transiting planet, HD 189733b, then compute light curves for seven of the most eccentric transiting planets. We present phase variations for a variety of different radiative times and wind speeds. In the limit of instant re-radiation, the light cur...

Cowan, Nicolas B.; Agol, Eric

2010-01-01

322

Astrometric exoplanet detection with Gaia  

CERN Document Server

We provide a revised assessment of the number of exoplanets that should be discovered by Gaia astrometry, extending previous studies to a broader range of spectral types, distances, and magnitudes. Our assessment is based on a large representative sample of host stars from the TRILEGAL Galaxy population synthesis model, recent estimates of the exoplanet frequency distributions as a function of stellar type, and detailed simulation of the Gaia observations using the updated instrument performance and scanning law. We use two approaches to estimate detectable planetary systems: one based on the S/N of the astrometric signature per field crossing, easily reproducible and allowing comparisons with previous estimates, and a new and more robust metric based on orbit fitting to the simulated satellite data. With some plausible assumptions on planet occurrences, we find that some 21,000 (+/-6000) high-mass (1-15M_J) long-period planets should be discovered out to distances of ~500pc for the nominal 5-yr mission (incl...

Perryman, Michael; Bakos, Gáspár; Lindegren, Lennart

2014-01-01

323

Exploring exoplanet populations with NASA’s Kepler Mission  

Science.gov (United States)

The Kepler Mission is exploring the diversity of planets and planetary systems. Its legacy will be a catalog of discoveries sufficient for computing planet occurrence rates as a function of size, orbital period, star type, and insolation flux. The mission has made significant progress toward achieving that goal. Over 3,500 transiting exoplanets have been identified from the analysis of the first 3 y of data, 100 planets of which are in the habitable zone. The catalog has a high reliability rate (85–90% averaged over the period/radius plane), which is improving as follow-up observations continue. Dynamical (e.g., velocimetry and transit timing) and statistical methods have confirmed and characterized hundreds of planets over a large range of sizes and compositions for both single- and multiple-star systems. Population studies suggest that planets abound in our galaxy and that small planets are particularly frequent. Here, I report on the progress Kepler has made measuring the prevalence of exoplanets orbiting within one astronomical unit of their host stars in support of the National Aeronautics and Space Administration’s long-term goal of finding habitable environments beyond the solar system. PMID:25049406

Batalha, Natalie M.

2014-01-01

324

Keplerian Orbits and Dynamics of Exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Understanding the consequences of the gravitational interaction between a star and a planet is fundamental to the study of exoplanets. The solution of the two-body problem shows that the planet moves in an elliptical path around the star and that each body moves in an ellipse about the common center of mass. The basic properties of such a system are derived from first principles and described in the context of detecting exoplanets.

Murray, Carl D.; Correia, Alexandre C. M.

2010-01-01

325

Atmospheric Chemistry of Venus-like Exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We use thermodynamic calculations to model atmospheric chemistry on terrestrial exoplanets that are hot enough for chemical equilibira between the atmosphere and lithosphere, as on Venus. The results of our calculations place constraints on abundances of spectroscopically observable gases, the surface temperature and pressure, and the mineralogy of the surface. These results will be useful in planning future observations of the atmospheres of terrestrial-sized exoplanets by ...

Schaefer, Laura; Fegley Jr, Bruce

2010-01-01

326

Observational Evidence for Tidal Destruction of Exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The distribution of the orbits of close-in exoplanets shows evidence for on-going removal and destruction by tides. Tides raised on a planet's host star cause the planet's orbit to decay, even after the orbital eccentricity has dropped to zero. Comparison of the observed orbital distribution and predictions of tidal theory show good qualitative agreement, suggesting tidal destruction of close-in exoplanets is common. The process can explain the observed cut-off in small a-va...

Jackson, Brian; Barnes, Rory; Greenberg, Richard

2009-01-01

327

Light scattering from exoplanet oceans and atmospheres  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Orbital variation in reflected starlight from exoplanets could eventually be used to detect surface oceans. Exoplanets with rough surfaces, or dominated by atmospheric Rayleigh scattering, should reach peak brightness in full phase, orbital longitude = 180 deg, whereas ocean planets with transparent atmospheres should reach peak brightness in crescent phase near OL = 30 deg. Application of Fresnel theory to a planet with no atmosphere covered by a calm ocean predicts a peak ...

Zugger, Michael E.; Kasting, James F.; Williams, Darren M.; Kane, Timothy J.; Philbrick, C. Russell

2010-01-01

328

Balloon Exoplanet Nulling Interferometer (BENI)  

Science.gov (United States)

We evaluate the feasibility of using a balloon-borne nulling interferometer to detect and characterize exosolar planets and debris disks. The existing instrument consists of a 3-telescope Fizeau imaging interferometer with 3 fast steering mirrors and 3 delay lines operating at 800 Hz for closed-loop control of wavefront errors and fine pointing. A compact visible nulling interferometer is under development which when coupled to the imaging interferometer would in-principle allow deep suppression of starlight. We have conducted atmospheric simulations of the environment above 100,000 feet and believe balloons are a feasible path forward towards detection and characterization of a limited set of exoplanets and their debris disks. Herein we will discuss the BENI instrument, the balloon environment and the feasibility of such as mission.

Lyon, Richard G.; Clampin, Mark; Woodruff, Robert A.; Vasudevan, Gopal; Ford, Holland; Petro, Larry; Herman, Jay; Rinehart, Stephen; Carpenter, Kenneth; Marzouk, Joe

2009-01-01

329

Atmospheric mass loss and evolution of short-period exoplanets: the examples of CoRoT-7b and Kepler-10b  

CERN Document Server

Short-period exoplanets potentially lose envelope masses during their evolution because of atmospheric escape caused by the intense XUV radiation from their host stars. We develop a combined model of atmospheric mass loss calculation and thermal evolution calculation of a planet to simulate its evolution and explore the dependences on the formation history of the planet. Thermal atmospheric escape as well as the Roche-lobe overflow contributes to mass loss. The maximum initial planetary model mass depends primarily on the assumed evolution model of the stellar XUV luminosity. We adapt the model to CoRoT-7b and Kepler-10b to explore the evolution of both planets and the maximum initial mass of these planets. We take the recent X-ray observation of CoRoT-7 into account and exploring the effect of different XUV evolution models on the planetary initial mass. Our calculations indicate that both hot super Earths could be remnants of Jupiter mass gas planets.

Kurokawa, Hiroyuki

2013-01-01

330

BIOSIGNATURE GASES IN H2-DOMINATED ATMOSPHERES ON ROCKY EXOPLANETS  

International Nuclear Information System (INIS)

Super-Earth exoplanets are being discovered with increasing frequency and some will be able to retain stable H2-dominated atmospheres. We study biosignature gases on exoplanets with thin H2 atmospheres and habitable surface temperatures, using a model atmosphere with photochemistry and a biomass estimate framework for evaluating the plausibility of a range of biosignature gas candidates. We find that photochemically produced H atoms are the most abundant reactive species in H2 atmospheres. In atmospheres with high CO2 levels, atomic O is the major destructive species for some molecules. In Sun-Earth-like UV radiation environments, H (and in some cases O) will rapidly destroy nearly all biosignature gases of interest. The lower UV fluxes from UV-quiet M stars would produce a lower concentration of H (or O) for the same scenario, enabling some biosignature gases to accumulate. The favorability of low-UV radiation environments to accumulate detectable biosignature gases in an H2 atmosphere is closely analogous to the case of oxidized atmospheres, where photochemically produced OH is the major destructive species. Most potential biosignature gases, such as dimethylsulfide and CH3Cl, are therefore more favorable in low-UV, as compared with solar-like UV, environments. A few promising biosignature gas candidates, including NH3 and N2O, are favorable even in solar-like UV environments, as these gases are destroyed directly by photolysis and not by H (or O). A more subtle finding is that most gases produced by life that are fully hydrogenated forms of an element, such as CH4 and H2S, are not effective signs of life in an H2-rich atmosphere because the dominant atmospheric chemistry will generate such gases abiologically, through photochemistry or geochemistry. Suitable biosignature gases in H2-rich atmospheres for super-Earth exoplanets transiting M stars could potentially be detected in transmission spectra with the James Webb Space Telescope

331

Earth as an Exoplanet: Lessons in Recognizing Planetary Habitability  

Science.gov (United States)

Earth will always be our best-studied example of a habitable world. While extrasolar planets are unlikely to look exactly like Earth, they may share key characteristics, such as oceans, clouds and surface inhomogeneity. Earth's globally-averaged characteristics can therefore help us to recognize planetary habitability in data-limited exoplanet observations. One of the most straightforward ways to detect habitability will be via detection of 'glint', specular reflectance from an ocean (Robinson et al., 2010). Other methods include undertaking a census of atmospheric greenhouse gases, or attempting to measure planetary surface temperature and pressure, to determine if liquid water would be feasible on the planetary surface. Here we present recent research on detecting planetary habitability, led by the NASA Astrobiology Institute's Virtual Planetary Laboratory Team. This work includes a collaboration with the NASA Lunar Science Institute on the detection of ocean glint and ozone absorption using Lunar Crater Observation and Sensing Satellite (LCROSS) Earth observations (Robinson et al., 2014). This data/model comparison provides the first observational test of a technique that could be used to determine exoplanet habitability from disk-integrated observations at visible and near-infrared wavelengths. We find that the VPL spectral Earth model is in excellent agreement with the LCROSS Earth data, and can be used to reliably predict Earth's appearance at a range of phases relevant to exoplanet observations. Determining atmospheric surface pressure and temperature directly for a potentially habitable planet will be challenging due to the lack of spatial-resolution, presence of clouds, and difficulty in spectrally detecting many bulk constituents of terrestrial atmospheres. Additionally, Rayleigh scattering can be masked by absorbing gases and absorption from the underlying surface. However, new techniques using molecular dimers of oxygen (Misra et al., 2014) and nitrogen (Schwieterman et al., 2014) may provide an alternative means to determine terrestrial atmospheric pressure for both transit transmission and direct imaging observations.

Meadows, Victoria; Robinson, Tyler; Misra, Amit; Ennico, Kimberly; Sparks, William B.; Claire, Mark; Crisp, David; Schwieterman, Edward; Bussey, D. Ben J.; Breiner, Jonathan

2015-01-01

332

Observing Exoplanet Atmospheres: Recent Results from ESO and National Facilities  

International Nuclear Information System (INIS)

Full text: Planetary transits and occultations are currently our best windows toward the study of exoplanet atmospheres. Occultations, i.e. passages of the planet behind the star, yield a measure of the planetary spectral energy distribution and thereby allow to investigate the atmospheric temperature structure, heat redistribution efficiency, albedo, and to place constraints on the atmospheric composition. Transits in turn allow to probe for wavelength dependencies in the effective planetary radius that are sensitive to signatures of chemical elements in the planetary atmosphere. We present results of ongoing observing campaigns studying the atmospheres of the very short-period planet WASP-19b and the low-density hot Saturn WASP-49b. (author)

333

Detection and initial characterisation of an exoplanet atmosphere with small aperture telescopes  

Science.gov (United States)

In the recent years atmospheres of exoplanets have been studied with space-based telescopes like the HST or large aperture ground-based telescopes like the Gran Telescopio Canarias. But as the number of suitable exoplanets is rising, comparative studies of atmospheres with a statistically meaningful amount of targets will follow, for which the observational time with large telescopes is limited and expensive. Our aim is to investigate whether it is possible to detect and initially characterise the atmosphere of an exoplanet with small aperture telescopes using chromatic variations in transit depths. We collected multi-color transits in the years 2011 to 2013 using the robotic 1.2m-telescope STELLA on Tenerife as well as the Nordic Optical Telescope and the 70cm-telescope at the Leibniz Institute for Astrophysics Potsdam. The highly inflated Hot Jupiter HAT-P-32 b was chosen as target for our pilot study for its favorable large atmospheric scale height and therefore enhanced atmospheric detectability. Models of the atmospheric spectra of HAT-P-32 b indicate that the STELLA-data can be used to distinguish between a dusty and a cloud-free atmosphere using the gradient in transit depth of the observations in the blue band and in the visible band. Here we want to present our project together with the first results of the transit depth analysis.

Bernt, I.; Müller, M.; Strassmeier, K. G.; Granzer, T.

2013-09-01

334

Ammonia, Water Clouds and Methane Abundances of Giant Exoplanets and Opportunities for Super-Earth Exoplanets  

CERN Document Server

Future direct-imaging exoplanet missions such as WFIRST/AFTA, Exo-C, and Exo-S will measure the reflectivity of exoplanets at visible wavelengths. The exoplanets to be observed will be located further away from their parent stars than is Earth from the Sun. These "cold" exoplanets have atmospheric environments conducive for the formation of water and/or ammonia clouds, like Jupiter in the Solar System. We study the science return from direct-imaging exoplanet missions, focusing on the exoplanet atmospheric compositions. First, the study shows that a low-resolution (R=70) reflection spectrum of a giant exoplanet at 600 - 1000 nm, for a moderate signal-to-noise ratio of 20, will allow measurements of both the pressure of the uppermost cloud deck and the mixing ratio of methane, if the uppermost cloud deck is located at the pressure level of 0.6 - 1.5 bars. Further increasing the signal-to-noise ratio can improve the measurement range of the cloud deck pressure to 0.2 - 4 bars. The strong and the weak absorption...

Hu, Renyu

2014-01-01

335

The Ultraviolet Radiation Environment Around M dwarf Exoplanet Host Stars  

CERN Document Server

The spectral and temporal behavior of exoplanet host stars is a critical input to models of the chemistry and evolution of planetary atmospheres. At present, little observational or theoretical basis exists for understanding the ultraviolet spectra of M dwarfs, despite their critical importance to predicting and interpreting the spectra of potentially habitable planets as they are obtained in the coming decades. Using observations from the Hubble Space Telescope, we present a study of the UV radiation fields around nearby M dwarf planet hosts that covers both FUV and NUV wavelengths. The combined FUV+NUV spectra are publically available in machine-readable format. We find that all six exoplanet host stars in our sample (GJ 581, GJ 876, GJ 436, GJ 832, GJ 667C, and GJ 1214) exhibit some level of chromospheric and transition region UV emission. No "UV quiet" M dwarfs are observed. The bright stellar Ly-alpha emission lines are reconstructed, and we find that the Ly-alpha line fluxes comprise ~37-75% of the tota...

France, Kevin; Linsky, Jeffrey L; Roberge, Aki; Stocke, John T; Tian, Feng; Bushinsky, Rachel; Desert, Jean-Michel; Mauas, Pablo; Vieytes, Mariela; Walkowicz, Lucianne M

2012-01-01

336

Do have nanosatellites a role in detecting exoplanets?  

CERN Document Server

In December 2012, Austria will launch its first two satellites: UniBRITE and BRITE-Austria. This is the first pair of three, forming a network called BRITE-Constellation. The other pairs being contributed by Canada and Poland. The primary goal of BRITE-Constellation is the exploration of short term intensity variations of bright stars (V>6 mag) for a few years. For each satellite pair, one will employ a blue filter and the other a red filter. With the discovery of the first exoplanet in 1992, more than 800 have been detected since. The high-precision photometry from the BRITE instrument will enable a transit search for exoplanets around bright stars. To estimate the capability of BRITE to detect planets, we include in our calculations technical constraints, such as photometric noise levels for stars accessible by BRITE, the duty cycle and duration of observations. The most important parameter is the fraction of stars harboring a planet. Our simulation is based on 2695 stars distributed over the entire sky. Ke...

Weiss, Werner W; Rowe, Jason

2012-01-01

337

Probe-Scale Mission Concepts for Direct Imaging and Spectroscopy of Nearby Exoplanet Systems  

Science.gov (United States)

Two mission concepts are now under study for detecting visible light from exoplanets orbiting nearby stars through high-contrast imaging and for characterizing them through spectroscopy. Exo-S uses a starshade (external occulter) that flies in front of a telescope to block out the central starlight; Exo-C uses a coronagraph with an internal occulter to accomplish the suppression of starlight. Both concepts have the objective of taking optical spectra of nearby exoplanets in reflected light, searching for previously undetected planets, and imaging structure in circumstellar debris disks.The concepts are being developed by two NASA-selected community-led Science and Technology Definition Teams (STDTs), supported by study design teams from NASA's Exoplanet Exploration Program. In addition to developing concepts with an estimated cost ~1B, the Teams are identifying key enabling technologies needed for their designs. These concepts complement existing NASA missions that do exoplanet science (such as transit spectroscopy and debris disk imaging with HST and Spitzer) or are under development or active study (TESS, JWST, WFIRST-AFTA).Final Reports from the two studies will be published in early 2015. This poster serves as an introduction to a series of posters featuring the two studies. At the conclusion of the studies in early 2015, NASA will evaluate them for further technology development and possible development as flight missions. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

Unwin, Stephen C.; Seager, Sara; Stapelfeldt, Karl R.; Warfield, Keith; Dekens, Frank G.; Blackwood, Gary; Exo-S Science; Technology Definition Team, Exo-C Science; Technology Definition Team, JPL Probe Study Design Teams

2015-01-01

338

Generation of an optimal target list for the Exoplanet Characterisation Observatory (EChO)  

CERN Document Server

The Exoplanet Characterisation Observatory EChO is a space mission concept studied by the European Space Agency in the context of the M3 selection process. Through direct measurement of the atmospheric chemical composition of hundreds of exoplanets, EChO would address fundamental questions such as: What are exoplanets made of? How do planets form and evolve? What is the origin of exoplanet diversity? More specifically, EChO is a dedicated survey mission for transit and eclipse spectroscopy capable of observing a large, diverse and well-defined planetary sample within its four to six year mission lifetime. In this paper we use the end-to-end instrument simulator EChOSim to model the currently discovered targets, to gauge which targets are observable and assess the EChO performances obtainable for each observing tier and time. We show that EChO would be capable of observing a large and diverse sample of planets even if it were launched today, and the wealth of optimal targets for EChO expected to be discovered ...

Varley, Ryan; Pascale, Enzo; Tessenyi, Marcell; Hollis, Morgan; Morales, Juan Carlos; Tinetti, Giovanna; Swinyard, Bruce; Deroo, Pieter; Ollivier, Marc; Micela, Giusi

2014-01-01

339

A Semi-Analytical Model of Visible-Wavelength Phase Curves of Exoplanets and Applications to Kepler-7 b and Kepler-10 b  

CERN Document Server

Kepler has detected numerous exoplanet transits by precise measurements of stellar light in a single visible-wavelength band. In addition to detection, the precise photometry provides phase curves of exoplanets, which can be used to study the dynamic processes on these planets. However, the interpretation of these observations can be complicated by the fact that visible-wavelength phase curves can represent both thermal emission and scattering from the planets. Here we present a semi-analytical model framework that can be applied to study Kepler and future visible-wavelength phase curve observations of exoplanets. The model efficiently computes reflection and thermal emission components for both rocky and gaseous planets, considering both homogeneous and inhomogeneous surfaces or atmospheres. We analyze the phase curves of the gaseous planet Kepler-7 b and the rocky planet Kepler-10 b using the model. In general, we find that a hot exoplanet's visible-wavelength phase curve having a significant phase offset c...

Hu, Renyu; Seager, Sara; Lewis, Nikole; Showman, Adam P

2015-01-01

340

Four New Exoplanets and Hints of Additional Substellar Companions to Exoplanet Host Stars  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present four new exoplanets: HIP 14810 b & c, HD 154345 b, and HD 187123 c. The two planets orbiting HIP 14810, from the N2K project, have masses of 3.9 and 0.76 M_jup. We have searched the radial velocity time series of 90 known exoplanet systems and found new residual trends due to additional, long period companions. Two stars known to host one exoplanet have sufficient curvature in the residuals to a one planet fit to constrain the minimum mass of the outer companion t...

Wright, J. T.; Marcy, G. W.; Fischer, D. A.; Butler, R. P.; Vogt, S. S.; Tinney, C. G.; Jones, H. R. A.; Carter, B. D.; Johnson, J. A.; Mccarthy, C.; Apps, K.

2006-01-01

 
 
 
 
341

Planetesimal Compositions in Exoplanet Systems  

CERN Document Server

We have used recent surveys of the composition of exoplanet host stars to investigate the expected composition of condensed material in planetesimals formed beyond the snow line in the circumstellar nebulae of these systems. Of the major solid forming elements, we find that, as for the Sun, the C and O abundances (and particularly the C/O abundance ratio) have the most significant effect on the composition of icy planetesimals formed in these systems. The calculations use a self-consistent model for the condensation sequence of volatile ices from the nebula gas after refractory (silicate and metal) phases have condensed. The resultant proportions of refractory phases and ices were calculated for a range of nebular temperature structure and redox conditions. Planetesimals in systems with sub-solar C/O should be water ice-rich, with lower than solar mass fractions of refractory materials, while in super-solar C/O systems planetesimals should have significantly higher fractions of refractories, in some cases hav...

Johnson, Torrence V; Lunine, Jonathan I; Madhusudhan, Nikku

2012-01-01

342

Temperature-dependent molecular absorption cross sections for exoplanets and other atmospheres  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Exoplanets, and in particular hot ones such as hot Jupiters, require a very significant quantities of molecular spectroscopic data to model radiative transport in their atmospheres or to interpret their spectra. This data is commonly provided in the form of very extensive transition line lists. The size of these line lists is such that constructing a single model may require the consideration of several billion lines. We present a procedure to simplify this process based on ...

Hill, Christian; Yurchenko, Sergei N.; Tennyson, Jonathan

2013-01-01

343

Detecting industrial pollution in the atmospheres of earth-like exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Detecting biosignatures, such as molecular oxygen in combination with a reducing gas, in the atmospheres of transiting exoplanets has been a major focus in the search for alien life. We point out that in addition to these generic indicators, anthropogenic pollution could be used as a novel biosignature for intelligent life. To this end, we identify pollutants in the Earth's atmosphere that have significant absorption features in the spectral range covered by the James Webb S...

Lin, Henry W.; Abad, Gonzalo Gonzalez; Loeb, Abraham

2014-01-01

344

Constraining exoplanet mass from transmission spectroscopy.  

Science.gov (United States)

Determination of an exoplanet's mass is a key to understanding its basic properties, including its potential for supporting life. To date, mass constraints for exoplanets are predominantly based on radial velocity (RV) measurements, which are not suited for planets with low masses, large semimajor axes, or those orbiting faint or active stars. Here, we present a method to extract an exoplanet's mass solely from its transmission spectrum. We find good agreement between the mass retrieved for the hot Jupiter HD 189733b from transmission spectroscopy with that from RV measurements. Our method will be able to retrieve the masses of Earth-sized and super-Earth planets using data from future space telescopes that were initially designed for atmospheric characterization. PMID:24357312

de Wit, Julien; Seager, Sara

2013-12-20

345

Constraining Exoplanet Mass from Transmission Spectroscopy  

CERN Document Server

Determination of an exoplanet's mass is a key to understanding its basic properties, including its potential for supporting life. To date, mass constraints for exoplanets are predominantly based on radial velocity (RV) measurements, which are not suited for planets with low masses, large semi-major axes, or those orbiting faint or active stars. Here, we present a method to extract an exoplanet's mass solely from its transmission spectrum. We find good agreement between the mass retrieved for the hot Jupiter HD189733b from transmission spectroscopy with that from RV measurements. Our method will be able to retrieve the masses of Earth-sized and super-Earth planets using data from future space telescopes that were initially designed for atmospheric characterization.

de Wit, Julien

2014-01-01

346

Discovering the Growth Histories of Exoplanets: The Saturn Analog HD 149026b  

CERN Document Server

The transiting "hot Saturn" HD 149026b, which has the highest mean density of any confirmed planet in the Neptune-Jupiter mass range, has challenged theories of planet formation since its discovery in 2005. Previous investigations could not explain the origin of the planet's 67 Earth-mass solid core without invoking catastrophes such as gas giant collisions or heavy planetesimal bombardment launched by neighboring planets. Here we show that HD 149026b's large core can be successfully explained by the standard core accretion theory of planet formation. The keys to our reconstruction of HD 149026b are (1) applying a model of the solar nebula to describe the protoplanet nursery; (2) placing the planet initially on a long-period orbit at Saturn's heliocentric distance of 9.5 AU; and (3) adjusting the solid mass in the HD 149026 disk to twice that of the solar nebula in accordance with the star's heavy element enrichment. We show that the planet's migration into its current orbit at 0.042 AU is consistent with our...

Dodson-Robinson, Sarah E

2009-01-01

347

DISCOVERING THE GROWTH HISTORIES OF EXOPLANETS: THE SATURN ANALOG HD 149026b  

International Nuclear Information System (INIS)

The transiting 'hot Saturn' HD 149026b, which has the highest mean density of any confirmed planet in the Neptune-Jupiter mass range, has challenged theories of planet formation since its discovery in 2005. Previous investigations could not explain the origin of the planet's 45-110 Earth-mass solid core without invoking catastrophes such as gas giant collisions or heavy planetesimal bombardment launched by neighboring planets. Here we show that HD 149026b's large core can be successfully explained by the standard core accretion theory of planet formation. The keys to our reconstruction of HD 149026b are (1) applying a model of the solar nebula to describe the protoplanet nursery, (2) placing the planet initially on a long-period orbit at Saturn's heliocentric distance of 9.5 AU, and (3) adjusting the solid mass in the HD 149026 disk to twice that of the solar nebula in accordance with the star's heavy element enrichment. We show that the planet's migration into its current orbit at 0.042 AU is consistent with our formation model. Our study of HD 149026b demonstrates that it is possible to discover the growth history of any planet with a well-defined core mass that orbits a solar-type star.

348

The PANOPTES project: discovering exoplanets with low-cost digital cameras  

Science.gov (United States)

The Panoptic Astronomical Networked OPtical observatory for Transiting Exoplanets Survey (PANOPTES, www.projectpanoptes.org) project is aimed at identifying transiting exoplanets using a wide network of low-cost imaging units. Each unit consists of two commercial digital single lens reflex (DSLR) cameras equipped with 85mm F1.4 lenses, mounted on a small equatorial mount. At a few $1000s per unit, the system offers a uniquely advantageous survey eficiency for the cost, and can easily be assembled by amateur astronomers or students. Three generations of prototype units have so far been tested, and the baseline unit design, which optimizes robustness, simplicity and cost, is now ready to be duplicated. We describe the hardware and software for the PANOPTES project, focusing on key challenging aspects of the project. We show that obtaining high precision photometric measurements with commercial DSLR color cameras is possible, using a PSF-matching algorithm we developed for this project. On-sky tests show that percent-level photometric precision is achieved in 1 min with a single camera. We also discuss hardware choices aimed at optimizing system robustness while maintaining adequate cost. PANOPTES is both an outreach project and a scientifically compelling survey for transiting exoplanets. In its current phase, experienced PANOPTES members are deploying a limited number of units, acquiring the experience necessary to run the network. A much wider community will then be able to participate to the project, with schools and citizen scientists integrating their units in the network.

Guyon, Olivier; Walawender, Josh; Jovanovic, Nemanja; Butterfield, Mike; Gee, Wilfred T.; Mery, Rawad

2014-07-01

349

ATMOSPHERIC CHEMISTRY OF VENUS-LIKE EXOPLANETS  

International Nuclear Information System (INIS)

We use thermodynamic calculations to model atmospheric chemistry on terrestrial exoplanets that are hot enough for chemical equilibria between the atmosphere and lithosphere, as on Venus. The results of our calculations place constraints on abundances of spectroscopically observable gases, the surface temperature and pressure, and the mineralogy of the planetary surface. These results will be useful in planning future observations of the atmospheres of terrestrial-sized exoplanets by current and proposed space observatories such as the Hubble Space Telescope, Spitzer, the James Webb Space Telescope, and Darwin.

350

Atmospheric Chemistry of Venus-like Exoplanets  

CERN Document Server

We use thermodynamic calculations to model atmospheric chemistry on terrestrial exoplanets that are hot enough for chemical equilibira between the atmosphere and lithosphere, as on Venus. The results of our calculations place constraints on abundances of spectroscopically observable gases, the surface temperature and pressure, and the mineralogy of the surface. These results will be useful in planning future observations of the atmospheres of terrestrial-sized exoplanets by current and proposed space observatories such as the Hubble Space Telescope (HST), Spitzer, James Webb Space Telescope (JWST), Terrestrial Planet Finder, and Darwin.

Schaefer, Laura

2010-01-01

351

Exoplanet Science with E-ELT/METIS  

Science.gov (United States)

METIS - the Mid-infrared E-ELT Imager and Spectrograph - is foreseen as one of the instruments for the 39-m European Extremely Large Telescope (E-ELT). It will provide diffraction limited imaging and spectroscopy in the L, M and N band. While being a multi-purpose instrument with a broad and diverse science case, exoplanet research is one of the key science topics for METIS. In this talk we will present different observing modes for METIS, how they can be applied for exoplanet research and what results one can expect.

Quanz, S. P.

2014-04-01

352

Characterizing the Parents: Exoplanets Around Cool Stars  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The large majority of stars in the Milky Way are late-type dwarfs, and the frequency of low-mass exoplanets in orbits around these late-type dwarfs appears to be high. In order to characterize the radiation environments and habitable zones of the cool exoplanet host stars, stellar radius and effective temperature, and thus luminosity, are required. It is in the stellar low-mass regime, however, where the predictive power of stellar models is often limited by sparse data volu...

Von Braun, Kaspar; Boyajian, Tabetha S.; Belle, Gerard T.; Mann, Andrew; Kane, Stephen R.

2014-01-01

353

The discovery of a new ELL variable star in Centaurus and possibility of detecting new exoplanets using the FRAM telescope  

Science.gov (United States)

We report on the discovery of a new variable star during the search for new exoplanets in the Centaurus constellation from the archive of the FRAM telescope, operated by the FRAM team at Los Leones, near Malargüe, Argentina. The star is catalogued as GSC 08630-01117 (11h 36m 10s -53° 12' 15.04"). From the light curve, the star should be an ELL-type variable. We computed the period P = 0.6311+/- 0.0002 days. The maximum is 13.07 +/- 0.02 mag and minimum is 13.22 +/-0.02 mag (in the Johnson V filter) with an amplitude of about 0.15 mag. We registered this star in the CzeV catalogue and in the VSX catalogue as new variable star CzeV603. The FRAM telescope observed several transits of known exoplanets. These observations show the ability to detect new exoplanets using the FRAM telescope.

Pintr, Pavel; Vápenka, David; Mašek, Martin

2015-01-01

354

Generation of an optimal target list for the exoplanet characterisation observatory (EChO)  

Science.gov (United States)

The Exoplanet Characterisation Observatory (EChO) has been studied as a space mission concept by the European Space Agency in the context of the M3 selection process. Through direct measurement of the atmospheric chemical composition of hundreds of exoplanets, EChO would address fundamental questions such as: What are exoplanets made of? How do planets form and evolve? What is the origin of exoplanet diversity? More specifically, EChO is a dedicated survey mission for transit and eclipse spectroscopy capable of observing a large, diverse and well-defined planetary sample within its four to six year mission lifetime. In this paper we use the end-to-end instrument simulator EChOSim to model the currently discovered targets, to gauge which targets are observable and assess the EChO performances obtainable for each observing tier and time. We show that EChO would be capable of observing over 170 relativity diverse planets if it were launched today, and the wealth of optimal targets for EChO expected to be discovered in the next 10 years by space and ground-based facilities is simply overwhelming. In addition, we build on previous molecular detectability studies to show what molecules and abundances will be detectable by EChO for a selection of real targets with various molecular compositions and abundances. EChO's unique contribution to exoplanetary science will be in identifying the main constituents of hundreds of exoplanets in various mass/temperature regimes, meaning that we will be looking no longer at individual cases but at populations. Such a universal view is critical if we truly want to understand the processes of planet formation and evolution in various environments. In this paper we present a selection of key results. The full results are available in Online Resource 1.

Varley, R.; Waldmann, I.; Pascale, E.; Tessenyi, M.; Hollis, M.; Morales, J. C.; Tinetti, G.; Swinyard, B.; Deroo, P.; Ollivier, M.; Micela, G.

2015-02-01

355

Jupiter as an exoplanet: UV to NIR transmission spectrum reveals hazes, a Na layer and possibly stratospheric H2O-ice clouds  

CERN Document Server

Currently, the analysis of transmission spectra is the most successful technique to probe the chemical composition of exoplanet atmospheres. But the accuracy of these measurements is constrained by observational limitations and the diversity of possible atmospheric compositions. Here we show the UV-VIS-IR transmission spectrum of Jupiter, as if it were a transiting exoplanet, obtained by observing one of its satellites, Ganymede, while passing through Jupiter's shadow i.e., during a solar eclipse from Ganymede. The spectrum shows strong extinction due to the presence of clouds (aerosols) and haze in the atmosphere, and strong absorption features from CH4. More interestingly, the comparison with radiative transfer models reveals a spectral signature, which we attribute here to a Jupiter stratospheric layer of crystalline H2O ice. The atomic transitions of Na are also present. These results are relevant for the modeling and interpretation of giant transiting exoplanets. They also open a new technique to explore...

Montañes-Rodriguez, P; Palle, E; Lopez-Puertas, M; Garcia-Melendo, E

2015-01-01

356

First Estimate of the Exoplanet Population from Kepler Observations  

Science.gov (United States)

William J. Borucki, David G. Koch, Natalie Batalha, Derek Buzasi , Doug Caldwell, David Charbonneau, Jessie L. Christiansen, David R. Ciardi, Edward Dunham, Eric B. Ford, Steve Thomas N. Gautier III, Steve Howell, Jon M. Jenkins, Jeffery Kolodziejczak, Geoffrey W. Marcy, Jason Rowe, and Andrej Prsa A model was developed to provide a first estimate of the intrinsic frequency of planetary candidates based on the number of detected planetary candidates and the measured noise for each of the 156,000 observed stars. The estimated distributions for the exoplanet frequency are presented with respect to the semi-major axis and the stellar effective temperature and represent values appropriate only to short-period candidates. Improved estimates are expected after a Monte Carlo study of the sensitivity of the data analysis pipeline to transit signals injected at the pixel level is completed.

Borucki, William J.; Koch, D. G.; Batalha, N.; Caldwell, D.; Dunham, E. W.; Gautier, T. N., III; Howell, S. B.; Jenkins, J. M.; Marcy, G. W.; Rowe, J.; Charbonneau, D.; Ciardi, D.; Ford, E. B.; Christiansen, J. L.; Kolodziejczak, J.; Prsa, A.

2011-05-01

357

Possible climates on terrestrial exoplanets.  

Science.gov (United States)

What kind of environment may exist on terrestrial planets around other stars? In spite of the lack of direct observations, it may not be premature to speculate on exoplanetary climates, for instance, to optimize future telescopic observations or to assess the probability of habitable worlds. To begin with, climate primarily depends on (i) the atmospheric composition and the volatile inventory; (ii) the incident stellar flux; and (iii) the tidal evolution of the planetary spin, which can notably lock a planet with a permanent night side. The atmospheric composition and mass depends on complex processes, which are difficult to model: origins of volatiles, atmospheric escape, geochemistry, photochemistry, etc. We discuss physical constraints, which can help us to speculate on the possible type of atmosphere, depending on the planet size, its final distance for its star and the star type. Assuming that the atmosphere is known, the possible climates can be explored using global climate models analogous to the ones developed to simulate the Earth as well as the other telluric atmospheres in the solar system. Our experience with Mars, Titan and Venus suggests that realistic climate simulators can be developed by combining components, such as a 'dynamical core', a radiative transfer solver, a parametrization of subgrid-scale turbulence and convection, a thermal ground model and a volatile phase change code. On this basis, we can aspire to build reliable climate predictors for exoplanets. However, whatever the accuracy of the models, predicting the actual climate regime on a specific planet will remain challenging because climate systems are affected by strong positive feedbacks. They can drive planets with very similar forcing and volatile inventory to completely different states. For instance, the coupling among temperature, volatile phase changes and radiative properties results in instabilities, such as runaway glaciations and runaway greenhouse effect. PMID:24664919

Forget, F; Leconte, J

2014-04-28

358

A Photometric Diagnostic to Aid in the Identification of Transiting Extra-Solar Planets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

One of the obstacles in the search for exoplanets via transits is the large number of candidates that must be followed up, few of which ultimately prove to be exoplanets. Any method that could make this process more efficient by somehow identifying the best candidates and eliminating the worst would therefore be very useful. Seager and Mallen-Ornelas (2003) demonstrated that it was possible to discern between blends and exoplanets using only the photometric characteristics o...

Tingley, B.; Sackett, P. D.

2005-01-01

359

Identifying new opportunities for exoplanet characterisation at high spectral resolution  

DEFF Research Database (Denmark)

Context. Recently, there have been a series of detections of molecules in the atmospheres of extrasolar planets using high spectral resolution (R ~ 100 000) observations, mostly using the CRyogenic high-resolution InfraRed Echelle Spectrograph (CRIRES) on the Very Large Telescope. These measurements are able to resolve molecular bands into individual absorption lines. Observing many lines simultaneously as their Doppler shift changes with time allows the detection of specific molecules in the atmosphere of the exoplanet. Aims: We aim to identify new ways of increasing the planet signal in these kinds of high-resolution observations. First of all, we wish to determine what wavelength settings can best be used to target certain molecules. Furthermore, we want to simulate exoplanet spectra of the day-side and night-side to see whether night-side observations are feasible at high spectral resolution. Methods: We performed simulations of high-resolution CRIRES observations of a planet's thermal emission and transit between 1 and 5 ?m and performed a cross-correlation analysis on these results to assess how well the planet signal can be extracted. These simulations take into account telluric absorption, sky emission, realistic noise levels, and planet-to-star contrasts. We also simulated day-side and night-side spectra at high spectral resolution for planets with and without a day-side temperature inversion, based on the cases of HD 189733b and HD 209458b. Results: Several small wavelength regions in the L-band promise to yield cross-correlation signals from the thermal emission of hot Jupiters of H2O, CH4, CO2, C2H2, and HCN that can exceed those of the current detections by up to a factor of 2-3 for the same integration time. For transit observations, the H-band is also attractive, with the H, K, and L-bands giving cross-correlation signals of similar strength. High-resolution night-side spectra of hot Jupiters can give cross-correlation signals as high as the day-side, or even higher. Conclusions: We show that there are many new possibilities for high-resolution observations of exoplanet atmospheres that have expected planet signals at least as high as those already detected. Hence, high-resolution observations at well-chosen wavelengths and at different phases can improve our knowledge about hot Jupiter atmospheres significantly, already with currently available instrumentation.

de Kok, R. J.; Birkby, J.

2014-01-01

360

LkCa 15: A YOUNG EXOPLANET CAUGHT AT FORMATION?  

International Nuclear Information System (INIS)

Young and directly imaged exoplanets offer critical tests of planet-formation models that are not matched by radial velocity surveys of mature stars. These targets have been extremely elusive to date, with no exoplanets younger than 10-20 Myr and only a handful of direct-imaged exoplanets at all ages. We report the direct-imaging discovery of a likely (proto)planet around the young (?2 Myr) solar analog LkCa 15, located inside a known gap in the protoplanetary disk (a 'transitional disk'). Our observations use non-redundant aperture masking interferometry at three epochs to reveal a faint and relatively blue point source (MK'=9.1±0.2, K' – L' = 0.98 ± 0.22), flanked by approximately co-orbital emission that is red and resolved into at least two sources (ML'=7.5±0.2, K' – L' = 2.7 ± 0.3; ML'=7.4±0.2, K' – L' = 1.94 ± 0.16). We propose that the most likely geometry consists of a newly formed (proto)planet that is surrounded by dusty material. The nominal estimated mass is ?6 MJup according to the 1 Myr hot-start models. However, we argue based on its luminosity, color, and the presence of circumplanetary material that the planet has likely been caught at its epoch of assembly, and hence this mass is an upper limit due to its extreme youth and flux contributed by accretion. The projected separations (71.9 ± 1.6 mas, 100.7 ± 1.9 mas, and 88.2 ± 1.8 mas) and deprojected orbital nd deprojected orbital radii (16, 21, and 19 AU) correspond to the center of the disk gap, but are too close to the primary star for a circular orbit to account for the observed inner edge of the outer disk, so an alternative explanation (i.e., additional planets or an eccentric orbit) is likely required. This discovery is the first direct evidence that at least some transitional disks do indeed host newly formed (or forming) exoplanetary systems, and the observed properties provide crucial insight into the gas giant formation process.

 
 
 
 
361

Transiting exoplanets from the CoRoT space missionXIX. CoRoT-19b: A low density planet orbiting an old inactive F9V-star  

CERN Document Server

Observations of transiting extrasolar planets are of key importance to our understanding of planets because their mass, radius, and mass density can be determined. The CoRoT space mission allows us to achieve a very high photometric accuracy. By combining CoRoT data with high-precision radial velocity measurements, we derive precise planetary radii and masses. We report the discovery of CoRoT-19b, a gas-giant planet transiting an old, inactive F9V-type star with a period of four days. After excluding alternative physical configurations mimicking a planetary transit signal, we determine the radius and mass of the planet by combining CoRoT photometry with high-resolution spectroscopy obtained with the echelle spectrographs SOPHIE, HARPS, FIES, and SANDIFORD. To improve the precision of its ephemeris and the epoch, we observed additional transits with the TRAPPIST and Euler telescopes. Using HARPS spectra obtained during the transit, we then determine the projected angle between the spin of the star and the orbi...

Guenther, E W; Gazzano, J -C; Mazeh, T; Rouan, D; Gibson, N; Csizmadia, Sz; Aigrain, S; Alonso, R; Almenara, J M; Auvergne, M; Baglin, A; Barge, P; Bonomo, A S; Borde, P; Bouchy, F; Bruntt, H; Cabrera, J; Carone, L; Carpano, S; Cavarroc, C; Deeg, H J; Deleuil, M; Dreizler, S; Dvorak, R; Erikson, A; Ferraz-Mello, S; Fridlund, M; Gandolfi, D; Gillon, M; Guillot, T; Hatzes, A; Havel, M; Hebrard, G; Jehin, E; Jorda, L; Lammer, H; Leger, A; Moutou, C; Nortmann, L; Ollivier, M; Ofir, A; Pasternacki, Th; Paetzold, M; Parviainen, H; Queloz, D; Rauer, H; Samuel, B; Santerne, A; Schneider, J; Tal-Or, L; Tingley, B; Weingrill, J; Wuchterl, G

2011-01-01

362

System parameters, transit times and secondary eclipse constraints of the exoplanet systems HAT-P-4, TrES-2, TrES-3 and WASP-3 from the NASA EPOXI Mission of Opportunity  

CERN Document Server

As part of the NASA EPOXI Mission of Opportunity, we observed seven known transiting extrasolar planet systems in order to construct time series photometry of extremely high phase coverage and precision. Here we present the results for four "hot-Jupiter systems" with near-solar stars - HAT-P-4, TrES-3, TrES-2 and WASP-3. We observe ten transits of HAT-P-4, estimating the planet radius Rp = 1.332 \\pm 0.052 RJup, the stellar radius R \\star = 1.602 \\pm 0.061 R \\odot, the inclination i = 89.67 \\pm 0.30 degrees and the transit duration from first to fourth contact T = 255.6 \\pm 1.9 minutes. For TrES-3, we observe seven transits, and find Rp = 1.320 \\pm 0.057 RJup, R\\star = 0.817 \\pm 0.022 R\\odot, i = 81.99 \\pm 0.30 degrees and T = 81.9 \\pm 1.1 minutes. We also note a long term variability in the TrES-3 light curve, which may be due to star spots. We observe nine transits of TrES-2, and find Rp = 1.169 \\pm 0.034 RJup, R\\star = 0.940 \\pm 0.026 R\\odot, i = 84.15 \\pm 0.16 degrees and T = 107.3 \\pm 1.1 minutes. Finally...

Christiansen, Jessie L; Charbonneau, David; Deming, Drake; Holman, Matthew J; Madhusudhan, Nikku; Seager, Sara; Wellnitz, Dennis D; Barry, Richard K; Livengood, Timothy A; Hewagama, Tilak; Hampton, Don L; Lisse, Carey M; A'Hearn, Michael F

2010-01-01

363

A search for transit timing variation  

CERN Document Server

Photometric follow-ups of transiting exoplanets (TEPs) may lead to discoveries of additional, less massive bodies in extrasolar systems. This is possible by detecting and then analysing variations in transit timing of transiting exoplanets. In 2009 we launched an international observing campaign, the aim of which is to detect and characterise signals of transit timing variation (TTV) in selected TEPs. The programme is realised by collecting data from 0.6--2.2-m telescopes spread worldwide at different longitudes. We present our observing strategy and summarise first results for WASP-3b with evidence for a 15 Earth-mass perturber in an outer 2:1 orbital resonance.

Maciejewski, G; Raetz, St; Errmann, R; Kramm, U; Schmidt, T O B

2010-01-01

364

SYSTEM PARAMETERS, TRANSIT TIMES, AND SECONDARY ECLIPSE CONSTRAINTS OF THE EXOPLANET SYSTEMS HAT-P-4, TrES-2, TrES-3, and WASP-3 FROM THE NASA EPOXI MISSION OF OPPORTUNITY  

International Nuclear Information System (INIS)

As part of the NASA EPOXI Mission of Opportunity, we observed seven known transiting extrasolar planet systems in order to construct time series photometry of extremely high phase coverage and precision. Here we present the results for four 'hot-Jupiter systems' with near-solar stars-HAT-P-4, TrES-3, TrES-2, and WASP-3. We observe 10 transits of HAT-P-4, estimating the planet radius Rp = 1.332 ± 0.052 RJup, the stellar radius R* = 1.602 ± 0.061 Rsun, the inclination i = 89.67 ± 0.30 deg, and the transit duration from first to fourth contact ? = 255.6 ± 1.9 minutes. For TrES-3, we observe seven transits and find Rp = 1.320 ± 0.057 RJup, R* = 0.817 ± 0.022 Rsun, i = 81.99 ± 0.30 deg, and ? = 81.9 ± 1.1 minutes. We also note a long-term variability in the TrES-3 light curve, which may be due to star spots. We observe nine transits of TrES-2 and find Rp = 1.169 ± 0.034 RJup, R* = 0.940 ± 0.026 Rsun, i = 84.15 ± 0.16 deg, and ? = 107.3 ± 1.1 minutes. Finally, we observe eight transits of WASP-3, finding Rp = 1.385 ± 0.060 RJup, R* = 1.354 ± 0.056 Rsun, i = 84.22 ± 0.81 deg, and ? = 167.3 ± 1.3 minutes. We present refined orbital periods and times of transit for each target. We state 95% confidence upper limits on the secondary eclipse depths in our broadband visible bandpass centevisible bandpass centered on 650 nm. These limits are 0.073% for HAT-P-4, 0.062% for TrES-3, 0.16% for TrES-2, and 0.11% for WASP-3. We combine the TrES-3 secondary eclipse information with the existing published data and confirm that the atmosphere likely does not have a temperature inversion.

365

MAPPING DIRECTLY IMAGED GIANT EXOPLANETS  

International Nuclear Information System (INIS)

With the increasing number of directly imaged giant exoplanets, the current atmosphere models are often not capable of fully explaining the spectra and luminosity of the sources. A particularly challenging component of the atmosphere models is the formation and properties of condensate cloud layers, which fundamentally impact the energetics, opacity, and evolution of the planets. Here we present a suite of techniques that can be used to estimate the level of rotational modulations these planets may show. We propose that the time-resolved observations of such periodic photometric and spectroscopic variations of extrasolar planets due to their rotation can be used as a powerful tool to probe the heterogeneity of their optical surfaces. In this paper, we develop simulations to explore the capabilities of current and next-generation ground- and space-based instruments for this technique. We address and discuss the following questions: (1) what planet properties can be deduced from the light curve and/or spectra, and in particular can we determine rotation periods, spot coverage, spot colors, and spot spectra?; (2) what is the optimal configuration of instrument/wavelength/temporal sampling required for these measurements?; and (3) can principal component analysis be used to invert the light curve and deduce the surface map of the planet? Our simulations describe the expected spectral differences between homogeneous (clear or cloudy) and patchy atmospheres, outline the sigy) and patchy atmospheres, outline the significance of the dominant absorption features of H2O, CH4, and CO, and provide a method to distinguish these two types of atmospheres. Assuming surfaces with and without clouds for most currently imaged planets the current models predict the largest variations in the J band. Simulated photometry from current and future instruments is used to estimate the level of detectable photometric variations. We conclude that future instruments will be able to recover not only the rotation periods, cloud cover, cloud colors, and spectra but even cloud evolution. We also show that a longitudinal map of the planet's atmosphere can be deduced from its disk-integrated light curves.

366

MAPPING DIRECTLY IMAGED GIANT EXOPLANETS  

Energy Technology Data Exchange (ETDEWEB)

With the increasing number of directly imaged giant exoplanets, the current atmosphere models are often not capable of fully explaining the spectra and luminosity of the sources. A particularly challenging component of the atmosphere models is the formation and properties of condensate cloud layers, which fundamentally impact the energetics, opacity, and evolution of the planets. Here we present a suite of techniques that can be used to estimate the level of rotational modulations these planets may show. We propose that the time-resolved observations of such periodic photometric and spectroscopic variations of extrasolar planets due to their rotation can be used as a powerful tool to probe the heterogeneity of their optical surfaces. In this paper, we develop simulations to explore the capabilities of current and next-generation ground- and space-based instruments for this technique. We address and discuss the following questions: (1) what planet properties can be deduced from the light curve and/or spectra, and in particular can we determine rotation periods, spot coverage, spot colors, and spot spectra?; (2) what is the optimal configuration of instrument/wavelength/temporal sampling required for these measurements?; and (3) can principal component analysis be used to invert the light curve and deduce the surface map of the planet? Our simulations describe the expected spectral differences between homogeneous (clear or cloudy) and patchy atmospheres, outline the significance of the dominant absorption features of H{sub 2}O, CH{sub 4}, and CO, and provide a method to distinguish these two types of atmospheres. Assuming surfaces with and without clouds for most currently imaged planets the current models predict the largest variations in the J band. Simulated photometry from current and future instruments is used to estimate the level of detectable photometric variations. We conclude that future instruments will be able to recover not only the rotation periods, cloud cover, cloud colors, and spectra but even cloud evolution. We also show that a longitudinal map of the planet's atmosphere can be deduced from its disk-integrated light curves.

Kostov, Veselin [Department of Physics and Astronomy, Johns Hopkins University, 366 Bloomberg Center, 3400 North Charles Street, Baltimore, MD 21218 (United States); Apai, Daniel, E-mail: vkostov@pha.jhu.edu [Department of Astronomy, The University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85718 (United States)

2013-01-01

367

The Transit Monitoring in the South (TraMoS project  

Directory of Open Access Journals (Sweden)

Full Text Available We present the Transit Monitoring in the South (TraMoS project. TraMoS has monitored transits of 30 exoplanets with telescopes located in Chile since 2008, whit the following goals: (1 to refine the physical and/or orbital parameters of those exoplanet system, and (2 to search for variations in the mid-times of the transits and in other parameters such as orbital inclination or transit's depth, that could indicate the presence of additional bodies in the system. We highlight here the first results of TraMoS in three selected exoplanets.

López-Morales Mercedes

2013-04-01

368

Optical transmission photometry of the highly inflated exoplanet WASP-17b  

CERN Document Server

We present ground-based high-precision observations of the transit of WASP-17b using the multi-band photometer ULTRACAM on ESO's NTT in the context of performing transmission spectrophotometry of this highly inflated exoplanet. Our choice of filters (SDSS u', g' and r' bands) is designed to probe for the presence of opacity sources in the upper atmosphere. We find evidence for a wavelength dependence in the planet radius in the form of enhanced absorption in the SDSS r' band, consistent with a previously detected broad sodium feature. We present a new independent measurement of the planetary radius at Rpl = 1.97 +/- 0.06 Rjup, which confirms this planet as the most inflated exoplanet known to date. Our measurements are most consistent with an atmospheric profile devoid of enhanced TiO opacity, previously predicted to be present for this planet.

Bento, J; Copperwheat, C M; Fortney, J J; Dhillon, V S; Hickman, R; Littlefair, S P; Marsh, T R; Parsons, S G; Southworth, J

2013-01-01

369

Validation of the Exoplanet Kepler-21b using PAVO/CHARA Long-Baseline Interferometry  

CERN Document Server

We present long-baseline interferometry of the Kepler exoplanet host star HD179070 (Kepler-21) using the PAVO beam combiner at the CHARA Array. The visibility data are consistent with a single star and exclude stellar companions at separations ~1-1000 mas (~ 0.1-113 AU) and contrasts < 3.5 magnitudes. This result supports the validation of the 1.6 R_{earth} exoplanet Kepler-21b by Howell et al. (2012) and complements the constraints set by adaptive optics imaging, speckle interferometry, and radial velocity observations to rule out false-positives due to stellar companions. We conclude that long-baseline interferometry has strong potential to validate transiting extrasolar planets, particularly for future projects aimed at brighter stars and for host stars where radial velocity follow-up is not available.

Huber, Daniel; Bedding, Timothy R; Howell, Steve B; Maestro, Vicente; Mérand, Antoine; Tuthill, Peter G; White, Timothy R; Farrington, Christopher D; Goldfinger, P J; McAlister, Harold A; Schaefer, Gail H; Sturmann, Judit; Sturmann, Laszlo; Brummelaar, Theo A ten; Turner, Nils H

2012-01-01

370

Miniature Exoplanet Radial Velocity Array (MINERVA) I. Design, Commissioning, and First Science Results  

CERN Document Server

The MINiature Exoplanet Radial Velocity Array (MINERVA) is a US-based observational facility dedicated to the discovery and characterization of exoplanets around a nearby sample of bright stars. MINERVA employs a robotic array of four 0.7 m telescopes outfitted for both high-resolution spectroscopy and photometry, and is designed for completely autonomous operation. The primary science program is a dedicated radial velocity survey and the secondary science objective is to obtain high precision transit light curves. The modular design of the facility and the flexibility of our hardware allows for both science programs to be pursued simultaneously, while the robotic control software provides a robust and efficient means to carry out nightly observations. In this article, we describe the design of MINERVA including major hardware components, software, and science goals. The telescopes and photometry cameras are characterized at our test facility on the Caltech campus in Pasadena, CA, and their on-sky performance...

Swift, Jonathan J; Johnson, John A; Wright, Jason T; McCrady, Nate; Wittenmyer, Robert A; Plavchan, Peter; Riddle, Reed; Muirhead, Philip S; Herzig, Erich; Myles, Justin; Blake, Cullen H; Eastman, Jason; Beatty, Thomas G; Lin, Brian; Zhao, Ming; Gardner, Paul; Falco, Emilio; Criswell, Stephen; Nava, Chantanelle; Robinson, Connor; Sliski, David H; Hedrick, Richard; Ivarsen, Kevin; Hjelstrom, Annie; de Vera, Jon; Szentgyorgyi, Andrew

2014-01-01

371

High resolution transmission spectrum of the Earth's atmosphere -- Seeing Earth as an exoplanet using a lunar eclipse  

CERN Document Server

With the rapid developments in the exoplanet field, more and more terrestrial exoplanets are being detected. Characterising their atmospheres using transit observations will become a key datum in the quest for detecting an Earth-like exoplanet. The atmospheric transmission spectrum of our Earth will be an ideal template for comparison with future exo-Earth candidates. By observing a lunar eclipse, which offers a similar configuration to that of an exoplanet transit, we have obtained a high resolution and high signal-to-noise ratio transmission spectrum of the Earth's atmosphere. This observation was performed with the High Resolution Spectrograph at Xinglong Station, China during the total lunar eclipse in December 2011. We compare the observed transmission spectrum with our atmospheric model, and determine the characteristics of the various atmospheric species in detail. In the transmission spectrum, O2, O3, O2-O2, NO2 and H2O are detected, and their column densities are measured and compared with the satell...

Yan, Fei; Petr-Gotzens, Monika G; Zhao, Gang; Wang, Wei; Wang, Liang; Liu, Yujuan; Pallé, Enric

2014-01-01

372

A TEMPERATURE AND ABUNDANCE RETRIEVAL METHOD FOR EXOPLANET ATMOSPHERES  

International Nuclear Information System (INIS)

We present a new method to retrieve molecular abundances and temperature profiles from exoplanet atmosphere photometry and spectroscopy. We run millions of one-dimensional (1D) atmosphere models in order to cover the large range of allowed parameter space. In order to run such a large number of models, we have developed a parametric pressure-temperature (P-T) profile coupled with line-by-line radiative transfer, hydrostatic equilibrium, and energy balance, along with prescriptions for non-equilibrium molecular composition and energy redistribution. The major difference from traditional 1D radiative transfer models is the parametric P-T profile, which essentially means adopting energy balance only at the top of the atmosphere and not in each layer. We see the parametric P-T model as a parallel approach to the traditional exoplanet atmosphere models that rely on several free parameters to encompass unknown absorbers and energy redistribution. The parametric P-T profile captures the basic physical features of temperature structures in planetary atmospheres (including temperature inversions), and fits a wide range of published P-T profiles, including those of solar system planets. We apply our temperature and abundance retrieval method to the atmospheres of two transiting exoplanets, HD 189733b and HD 209458b, which have the best Spitzer and Hubble Space Telescope data available. For HD 189733b, we find efficient day-night redistribution of energy in the atmosphere, and mibution of energy in the atmosphere, and molecular abundance constraints confirming the presence of H2O, CO, CH4, and CO2. For HD 209458b, we confirm and constrain the dayside thermal inversion in an average 1D temperature profile. We also report independent detections of H2O, CO, CH4, and CO2 on the dayside of HD 209458b, based on six-channel Spitzer photometry. We report constraints for HD 189733b due to individual data sets separately; a few key observations are variable in different data sets at similar wavelengths. Moreover, a noticeably strong CO2 absorption in one data set is significantly weaker in another. We must, therefore, acknowledge the strong possibility that the atmosphere is variable, both in its energy redistribution state and in the chemical abundances.

373

Instrumentation for the detection and characterization of exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In no other field of astrophysics has the impact of new instrumentation been as substantial as in the domain of exoplanets. Before 1995 our knowledge about exoplanets was mainly based on philosophical and theoretical considerations. The following years have been marked, instead, by surprising discoveries made possible by high-precision instruments. More recently the availability of new techniques moved the focus from detection to the characterization of exoplanets. Next-gene...

Pepe, Francesco; Ehrenreich, David; Meyer, Michael R.

2014-01-01

374

Characterizing the Coolest Atmospheres: Exoplanets to Brown Dwarfs  

Science.gov (United States)

We present the results of two complementary programs characterizing planetary temperature sub-stellar targets. The first project is a near-infrared surveys monitoring 74 L, T and Y brown dwarfs for variability. With the discovery of Y dwarfs by the WISE mission, the population of field brown dwarfs now extends to objects with temperatures comparable to those of Solar System planets. To investigate the atmospheres of these ultracool brown dwarfs with temperatures covering the range of transiting and directly imaged planets, we conducted a large near-infrared photometric monitoring campaign in the J-band using both the SOFI camera on the 3.5 NTT and the SWIRC camera on the 6.5-m MMT. Breakup of the iron and silicate clouds into a patchy cloud layer has been suggested as an explanation of several large variables identified at the L/T transition, and a similar process with sulfide and salt clouds may be manifest in T/Y transition objects. We detected a total of 16 variable targets in the sample with 11 of these being new previously unknown variables. The second project is designed to characterize the planetary system HR8799 in the near infrared water bands obscured by the Earths atmosphere with the Hubble Space Telescope. These dataset will provide invaluable in the generation of new atmospheric models of brown dwarfs and directly detected exoplanets.

Rajan, A.; Patience, J.; Barman, T.; Soummer, R.; Wilson, P. A.; Pueyo, L.; Pont, F.; Rosa, R. J. D.; Morley, C. V.; Fortney, J. J.; Marois, C.; Macintosh, B.

2014-03-01

375

A lower mass for the exoplanet WASP-21b  

CERN Document Server

We present high precision transit observations of the exoplanet WASP-21b, obtained with the RISE instrument mounted on 2.0m Liverpool Telescope. A transit model is fitted, coupled with an MCMC routine to derive accurate system parameters. The two new high precision transits allow to estimate the stellar density directly from the light curve. Our analysis suggests that WASP-21 is evolving off the main sequence which led to a previous overestimation of the stellar density. Using isochrone interpolation, we find a stellar mass of 0.86 \\pm 0.04 Msun which is significantly lower than previously reported (1.01 \\pm 0.03 Msun). Consequently, we find a lower planetary mass of $0.27 \\pm 0.01 Mjup$. A lower inclination (87.4 \\pm 0.3 degrees) is also found for the system than previously reported, resulting in a slightly larger stellar (R_* =1.10 \\pm 0.03 Rsun) and planetary radius (R_p = 1.14 \\pm 0.04 Rjup). The planet radius suggests a hydrogen/helium composition with no core which strengthens the correlation between pl...

Barros, S C C; Gibson, N P; Howarth, I D; Keenan, F P; Simpson, E K; Skillen, I; Steele, I A; .,

2011-01-01

376

Instrumentation for the detection and characterization of exoplanets.  

Science.gov (United States)

In no other field of astrophysics has the impact of new instrumentation been as substantial as in the domain of exoplanets. Before 1995 our knowledge of exoplanets was mainly based on philosophical and theoretical considerations. The years that followed have been marked, instead, by surprising discoveries made possible by high-precision instruments. Over the past decade, the availability of new techniques has moved the focus of research from the detection to the characterization of exoplanets. Next-generation facilities will produce even more complementary data that will lead to a comprehensive view of exoplanet characteristics and, by comparison with theoretical models, to a better understanding of planet formation. PMID:25230658

Pepe, Francesco; Ehrenreich, David; Meyer, Michael R

2014-09-18

377

Instrumentation for the detection and characterization of exoplanets  

CERN Document Server

In no other field of astrophysics has the impact of new instrumentation been as substantial as in the domain of exoplanets. Before 1995 our knowledge about exoplanets was mainly based on philosophical and theoretical considerations. The following years have been marked, instead, by surprising discoveries made possible by high-precision instruments. More recently the availability of new techniques moved the focus from detection to the characterization of exoplanets. Next-generation facilities will produce even more complementary data that will lead to a comprehensive view of exoplanet characteristics and, by comparison with theoretical models, to a better understanding of planet formation.

Pepe, Francesco; Meyer, Michael R

2014-01-01

378

Transiting exoplanets from the CoRoT space mission I - CoRoT-Exo-1b: a low-density short-period planet around a G0V star  

CERN Document Server

Context. The pioneer space mission for photometric planet searches, CoRoT, steadily monitors about 12,000 stars in each of its fields of view; it is able to detect transit candidates early in the processing of the data and before the end of a run. Aims. We report the detection of the first planet discovered by CoRoT and characterizing it with the help of follow-up observations. Methods. Raw data were filtered from outliers and residuals at the orbital period of the satellite. The orbital parameters and the radius of the planet were estimated by best fitting the phase folded light curve with 34 successive transits. Doppler measurements with the SOPHIE spectrograph permitted us to secure the detection and to estimate the planet mass. Results. The accuracy of the data is very high with a dispersion in the 2.17 min binned phase-folded light curve that does not exceed 3.10-4 in flux unit. The planet orbits a mildly metal-poor G0V star of magnitude V=13.6 in 1.5 days. The estimated mass and radius of the star are 0...

Barge, P; Auvergne, M; Rauer, H; Léger, A; Schneider, J; Pont, F; Aigrain, S; Almenara, J -M; Alonso, R; Barbieri, M; Borde, P; Bouchy, F; Deeg, H -J; De la Reza, R; Deleuil, M; Dvorak, R; Erikson, A; Fridlund, M; Gillon, M; Gondoin, P; Guillot, T; Hatzes, A; Hébrard, G; Jorda, L; Kabath, P; Lammer, H; Llebaria, A; Loeillet, B; Magain, P; Mazeh, T; Moutou, C; Ollivier, M; Patzold, M; Queloz, D; Rouan, D; Shporer, A; Wuchterl, G

2008-01-01

379

Light scattering from exoplanet oceans and atmospheres  

CERN Document Server

Orbital variation in polarized and unpolarized reflected starlight from exoplanets could eventually be used to detect liquid water on planet surfaces. Exoplanets with rough surfaces, or those dominated by atmospheric Rayleigh scattering, should reach peak brightness in full phase, orbital longitude (OL) = 180 degrees, whereas ocean-covered planets with transparent atmospheres should reach peak brightness in crescent phase near OL = 30 degrees. Application of Fresnel theory to a planet with no atmosphere covered by a calm ocean predicts a peak polarization fraction of 1 at OL = 74 degrees; however, our model shows that clouds, wind-driven waves, aerosols, absorption, and Rayleigh scattering in the atmosphere and within the water column, dilute the polarization fraction and shift the peak to other OLs. Observing at longer wavelengths reduces the obfuscation of the water polarization signature by Rayleigh scattering but does not mitigate the other effects. Planets with thick Rayleigh scattering atmospheres reach...

Zugger, Michael E; Williams, Darren M; Kane, Timothy J; Philbrick, C Russell

2010-01-01

380

Characterizing the Parents: Exoplanets Around Cool Stars  

CERN Document Server

The large majority of stars in the Milky Way are late-type dwarfs, and the frequency of low-mass exoplanets in orbits around these late-type dwarfs appears to be high. In order to characterize the radiation environments and habitable zones of the cool exoplanet host stars, stellar radius and effective temperature, and thus luminosity, are required. It is in the stellar low-mass regime, however, where the predictive power of stellar models is often limited by sparse data volume with which to calibrate the methods. We show results from our CHARA survey that provides directly determined stellar parameters based on interferometric diameter measurements, trigonometric parallax, and spectral energy distribution fitting.

von Braun, Kaspar; van Belle, Gerard T; Mann, Andrew; Kane, Stephen R

2014-01-01

 
 
 
 
381

Observing Exoplanets in the Mid-Ultraviolet  

Science.gov (United States)

There are good reasons for pushing the spectral range of observation to shorter wavelengths than currently envisaged for terrestrial planet-finding missions utilizing with a 4-m, diffraction-limited, optical telescope: (1) The angular resolution is higher, so the image of an exoplanet is better separated from that of the much brighter star. (2) The exozodiacal background per resolution element is smaller, so exposure times are reduced for the same incident flux. (3) Most importantly, the sensitivity to the ozone biomarker is increased by several hundred-fold by access to the ozone absorption band at 250-300 nm. These benefits must be weighed against challenges arising from the faintness of exoplanets in the mid-UV. We will evaluate both the technical and cost challenges including image quality of large telescopes, advanced mirror coatings and innovative designs for enhanced optical throughput, and CCD detectors optimized for 250-400 nm.

Heap. Sara

2008-01-01

382

Equatorial superrotation on tidally locked exoplanets  

CERN Document Server

The increasing richness of exoplanet observations has motivated a variety of three-dimensional atmospheric circulation models of these planets. Under strongly irradiated conditions, models of tidally locked, short-period planets (both hot Jupiters and terrestrial planets) tend to exhibit a circulation dominated by a fast eastward, or "superrotating," jet stream at the equator. Under appropriate conditions, this phenomenon can cause the hottest regions to be displaced eastward from the substellar point by tens of degrees longitude. Such an offset has been observed on HD 189733b, supporting the possibility of equatorial jets on short-period exoplanets. Despite its relevance, however, the dynamical mechanisms responsible for generating the equatorial superrotation in such models have not been identified. Here, we show that the equatorial jet results from the interaction of the mean flow with standing, planetary-scale Rossby and Kelvin waves induced by the day-night thermal forcing. The Rossby waves develop phase...

Showman, Adam P

2011-01-01

383

Astrometric detection of exoplanets from the ground  

CERN Document Server

Astrometry is a powerful technique to study the populations of extrasolar planets around nearby stars. It gives access to a unique parameter space and is therefore required for obtaining a comprehensive picture of the properties, abundances, and architectures of exoplanetary systems. In this review, we discuss the scientific potential, present the available techniques and instruments, and highlight a few results of astrometric planet searches, with an emphasis on observations from the ground. In particular, we discuss astrometric observations with the Very Large Telescope (VLT) Interferometer and a programme employing optical imaging with a VLT camera, both aimed at the astrometric detection of exoplanets. Finally, we set these efforts into the context of Gaia, ESA's astrometry mission scheduled for launch in 2013, and present an outlook on the future of astrometric exoplanet detection from the ground.

Sahlmann, J; Mérand, A; Queloz, D; Ségransan, D; Woillez, J

2013-01-01

384

A Photometric Diagnostic to Aid in the Identification of Transiting Extra-Solar Planets  

CERN Document Server

One of the obstacles in the search for exoplanets via transits is the large number of candidates that must be followed up, few of which ultimately prove to be exoplanets. Any method that could make this process more efficient by somehow identifying the best candidates and eliminating the worst would therefore be very useful. Seager and Mallen-Ornelas (2003) demonstrated that it was possible to discern between blends and exoplanets using only the photometric characteristics of the transits. However, these techniques are critically dependent on the shape of the transit, characterization of which requires very high precision photometry of a sort that is atypical for candidates identified from transit searches. We present a method relying only on transit duration, depth, and period, which require much less precise photometry to determine accurately. The numerical tool we derive, the exoplanet diagnostic \\eta, is intended to identify the subset of candidates from a transit search that is most likely to contain exo...

Sackett, C T

2005-01-01

385

True Masses of Radial-Velocity Exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We explore the science power of space telescopes used to estimate the true masses of known radial-velocity exoplanets by means of astrometry on direct images. We translate a desired mass accuracy (+/10% in our example) into a minimum goal for the signal-to-noise ratio, which implies a minimum exposure time. When the planet is near a node, the mass measurement becomes difficult if not impossible, because the apparent separation becomes decoupled from the inclination angle of ...

Brown, Robert A.

2015-01-01

386

EChO - Exoplanet Characterisation Observatory  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A dedicated mission to investigate exoplanetary atmospheres represents a major milestone in our quest to understand our place in the universe by placing our Solar System in context and by addressing the suitability of planets for the presence of life. EChO -the Exoplanet Characterisation Observatory- is a mission concept specifically geared for this purpose. EChO will provide simultaneous, multi-wavelength spectroscopic observations on a stable platform that will allow very ...

Tinetti, G.; Beaulieu, J. P.; Henning, T.; Meyer, M.; Micela, G.; Ribas, I.; Stam, D.; Swain, M.; Krause, O.; Ollivier, M.; Pace, E.; Swinyard, B.; Aylward, A.; Boekel, R.; Coradini, A.

2011-01-01

387

EChO: Exoplanet characterisation observatory  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A dedicated mission to investigate exoplanetary atmospheres represents a major milestone in our quest to understand our place in the universe by placing our Solar System in context and by addressing the suitability of planets for the presence of life. EChO—the Exoplanet Characterisation Observatory—is a mission concept specifically geared for this purpose. EChO will provide simultaneous, multi-wavelength spectroscopic observations on a stable platform that will a...

Tinetti, G.; Beaulieu, Jp; Henning, T.; Meyer, M.; Micela, G.; Ribas, I.; Stam, D.; Swain, M.; Krause, O.; Ollivier, M.; Pace, E.; Swinyard, B.; Aylward, A.; Boekel, R.; Coradini, A.

2012-01-01

388

Advances in exoplanet science from Kepler  

CERN Document Server

Numerous telescopes and techniques have been used to find and study extrasolar planets, but none has been more successful than NASA's Kepler Space Telescope. Kepler has discovered the majority of known exoplanets, the smallest planets to orbit normal stars, and the worlds most likely to be similar to our home planet. Most importantly, Kepler has provided our first look at typical characteristics of planets and planetary systems for planets with sizes as small as and orbits as large as those of the Earth.

Lissauer, Jack J; Tremaine, Scott

2014-01-01

389

Thermodynamic Limits on Magnetodynamos in Rocky Exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

To ascertain whether magnetic dynamos operate in rocky exoplanets more massive or hotter than the Earth, we developed a parametric model of a differentiated rocky planet and its thermal evolution. Our model reproduces the established properties of Earth's interior and magnetic field at the present time. When applied to Venus, assuming that planet lacks plate tectonics and has a dehydrated mantle with an elevated viscosity, the model shows that the dynamo shuts down or never ...

Gaidos, Eric; Conrad, Clinton P.; Manga, Michael; Hernlund, John

2010-01-01

390

Asteroseismology of exoplanets-host stars  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Studying the internal structure of exoplanets-host stars compared to that of similar stars without detected planets is particularly important for the understanding of planetary formation. The observed overmetallicity of stars around which planets have been detected may be a hint in that respect. In this framework, asteroseismic studies represent an excellent tool to determine the structural differences between stars with and without detected planets. After a general discussi...

Vauclair, Sylvie

2006-01-01

391

Completeness of Imaging Surveys for Eccentric Exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The detection of exoplanets through direct imaging has produced numerous new positive identifications in recent years. The technique is biased towards planets at wide separations due to the difficulty in removing the stellar signature at small angular separations. Planets in eccentric orbits will thus move in and out of the detectable region around a star as a function of time. Here we use the known diversity of orbital eccentricities to determine the range of orbits which m...

Kane, Stephen R.

2013-01-01

392

Pulsation Frequencies and Modes of Giant Exoplanets  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We calculate the eigenfrequencies and eigenfunctions of the acoustic oscillations of giant exoplanets and explore the dependence of the characteristic frequency and the eigenfrequencies on several parameters: the planet mass, the planet radius, the core mass, and the heavy element mass fraction in the envelope. We provide the eigenvalues for degree $l$ up to 8 and radial order n up to 12. For the selected values of l and n, we find that the pulsation eigenfrequencies depend ...

Bihan, Bastien Le; Burrows, Adam

2012-01-01

393

Investigating Nearby Exoplanets via Interstellar Radar  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Interstellar radar is a potential intermediate step between passive observation of exoplanets and interstellar exploratory missions. Compared to passive observation, it has the traditional advantages of radar astronomy. It can measure surface characteristics, determine spin rates and axes, provide extremely accurate ranges, construct maps of planets, distinguish liquid from solid surfaces, find rings and moons, and penetrate clouds. It can do this even for planets close to t...

Scheffer, Louis K.

2013-01-01

394

Sequential Covariance Calculation for Exoplanet Image Processing  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Direct imaging of exoplanets involves the extraction of very faint signals from highly noisy data sets, with noise that often exhibits significant spatial, spectral and temporal correlations. As a results, a large number of post-processing algorithms have been developed in order to optimally decorrelate the signal from the noise. In this paper, we explore four such closely related algorithms, all of which depend heavily on the calculation of covariances between large data se...

Savransky, Dmitry

2015-01-01

395

HIDING IN THE SHADOWS: SEARCHING FOR PLANETS IN PRE-TRANSITIONAL AND TRANSITIONAL DISKS  

Energy Technology Data Exchange (ETDEWEB)

Transitional and pre-transitional disks can be explained by a number of mechanisms. This work aims to find a single observationally detectable marker that would imply a planetary origin for the gap and, therefore, indirectly indicate the presence of a young planet. N-body simulations were conducted to investigate the effect of an embedded planet of one Jupiter mass on the production of instantaneous collisional dust derived from a background planetesimal disk. Our new model allows us to predict the dust distribution and resulting observable markers with greater accuracy than previous works. Dynamical influences from a planet on a circular orbit are shown to enhance dust production in the disk interior and exterior to the planet orbit, while removing planetesimals from the orbit itself, creating a clearly defined gap. In the case of an eccentric planet, the gap opened by the planet is not as clear as the circular case, but there is a detectable asymmetry in the dust disk.

Dobinson, Jack; Leinhardt, Zoë M. [School of Physics, H. H. Wills Physics Laboratory, University of Bristol, Bristol, BS8 1TL (United Kingdom); Dodson-Robinson, Sarah E. [Astronomy Department, University of Texas at Austin, Austin, TX 78712 (United States); Teanby, Nick A. [School of Earth Sciences, Wills Memorial Building, University of Bristol, Bristol, BS8 1RJ (United Kingdom)

2013-11-10

396

Mass-radius relationships for exoplanets  

CERN Document Server

For planets other than Earth, and in particular for exoplanets, interpretation of the composition and structure depends largely on a comparison of the mass and radius with the composition expected given their distance from the parent star. The composition implies a mass-radius relation for different layers within the planet, which is based heavily on equations of state calculated from electronic structure theory and measured experimentally on Earth. We summarize current techniques for predicting and measuring equations of state, and calculate mass-radius relations for key materials for which the equation of state is reasonably well established, and for Fe-rock combinations. The relations are compared with the observed masses and radii of planets and exoplanets, broadly supporting recent inferences about exoplanet structures. CoRoT-7b probably has a rocky mantle over an Fe-based core. The core is likely to be proportionately smaller than the Earth's. GJ 1214b lies between the mass-radius curves for H_2Oand CH_...

Swift, Damian; Hicks, Damien; Hamel, Sebastien; Caspersen, Kyle; Schwegler, Eric; Collins, Gilbert; Ackland, Graeme

2010-01-01

397

THE FREQUENCY OF LOW-MASS EXOPLANETS  

International Nuclear Information System (INIS)

We report first results from the Anglo-Australian Telescope Rocky Planet Search-an intensive, high-precision Doppler planet search targeting low-mass exoplanets in contiguous 48 night observing blocks. On this run, we targeted 24 bright, nearby and intrinsically stable Sun-like stars selected from the Anglo-Australian Planet Search's main sample. These observations have already detected one low-mass planet reported elsewhere (HD 16417b), and here we reconfirm the detection of HD 4308b. Further, we have Monte Carlo simulated data from this run on a star-by-star basis to produce robust detection constraints. These simulations demonstrate clear differences in the exoplanet detectability functions from star to star due to differences in sampling, data quality and intrinsic stellar stability. They reinforce the importance of star-by-star simulation when interpreting the data from Doppler planet searches. These simulations indicate that for some of our target stars we are sensitive to close-orbiting planets as small as a few Earth masses. The two low-mass planets present in our 24-star sample indicate that the exoplanet minimum mass function at low masses is likely to be a flat ? ? -1 (for dN/dM ? M ?) and that between 15% ± 10% (at ? = -0.3) and 48% ± 34% (at ? = -1.3) of stars host planets with orbital periods of less than 16 days and minimum masses greater than 3 M +.

398

TWO EXOPLANETS DISCOVERED AT KECK OBSERVATORY  

International Nuclear Information System (INIS)

We present two exoplanets detected at Keck Observatory. HD 179079 is a G5 subgiant that hosts a hot Neptune planet with M sin i = 27.5 M+ in a 14.48 days, low-eccentricity orbit. The stellar reflex velocity induced by this planet has a semiamplitude of K = 6.6 m s-1. HD 73534 is a G5 subgiant with a Jupiter-like planet of M sin i = 1.1 MJup and K = 16 m s-1 in a nearly circular 4.85 yr orbit. Both stars are chromospherically inactive and metal-rich. We discuss a known, classical bias in measuring eccentricities for orbits with velocity semiamplitudes, K, comparable to the radial velocity uncertainties. For exoplanets with periods longer than 10 days, the observed exoplanet eccentricity distribution is nearly flat for large amplitude systems (K > 80 m s-1), but rises linearly toward low eccentricity for lower amplitude systems (K > 20 m s-1).

399

Detection of a transit by the planetary companion of HD 80606  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We report the detection of a transit egress by the ~ 3.9-Jupiter-mass planet HD 80606b, an object in a highly-eccentric orbit (e ~ 0.93) about its parent star of approximately solar type. The astrophysical reality of the signal of variability in HD 80606 is confirmed by observation with two independent telescope systems, and checks against several reference stars in the field. Differential photometry with respect to the nearby comparison star HD 80607 provides a precise ligh...

Fossey, Stephen J.; Waldman, Ingo P.; Kipping, David M.

2009-01-01

400

WASP-30b: a 61 Mjup brown dwarf transiting a V=12, F8 star  

CERN Document Server

We report the discovery of a 61-Jupiter-mass brown dwarf, which transits its F8V, rotationally-synchronised host star, WASP-30, every 4.16 days. From a range of age indicators, we estimate the system age to be 1-2 Gyr. We derive a radius (0.89 \\pm 0.02 RJup) for the companion that is consistent with that predicted (0.914 RJup) by a model of a 1-Gyr-old, non-irradiated brown dwarf with a dusty atmosphere.

Anderson, D R; Hellier, C; Lendl, M; Maxted, P F L; Pollacco, D; Queloz, D; Smalley, B; Smith, A M S; Todd, I; Triaud, A H M J; West, R G; Barros, S C C; Enoch, B; Gillon, M; Lister, T A; Pepe, F; Ségransan, D; Street, R A; Udry, S

2010-01-01

 
 
 
 
401

WASP-31b: a low-density planet transiting a late-F-type star  

CERN Document Server

We report the discovery of the low-density, transiting giant planet WASP-31b. The planet is 0.47 Jupiter masses and 1.56 Jupiter radii. It is in a 3.4-day orbit around a 1-Gyr-old, late-F-type, V = 11.7 star, which is a member of a common proper motion pair. In terms of its low density, WASP-31b is second only to WASP-17b, which is a more highly irradiated planet of similar mass.

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

2010-01-01

402

Transiting exoplanets from the CoRoT space mission : XXII. CoRoT-16b: a hot Jupiter with a hint of eccentricity around a faint solar-like star  

DEFF Research Database (Denmark)

Aims. We report the discovery of CoRoT-16b, a low density hot jupiter that orbits a faint G5V star (mV = 15.63) in 5.3523 ± 0.0002 days with slight eccentricity. A fit of the data with no a priori assumptions on the orbit leads to an eccentricity of 0.33 ± 0.1. We discuss this value and also derive the mass and radius of the planet. Methods. We analyse the photometric transit curve of CoRoT-16 given by the CoRoT satellite, and radial velocity data from the HARPS and HIRES spectrometers. A combined analysis using a Markov chain Monte Carlo algorithm is used to get the system parameters. Results. CoRoT-16b is a 0.535 ?0.083/+0.085 MJ, 1.17 ?0.14/+0.16 RJ hot Jupiter with a density of 0.44 ?0.14/+0.21 g?cm-3. Despite its short orbital distance (0.0618 ± 0.0015 AU) and the age of the parent star (6.73 ± 2.8 Gyr), the planet orbit exhibits significantly non-zero eccentricity. This is very uncommon for this type of objects as tidal effects tend to circularise the orbit. This value is discussed taking into account the characteristics of the star and the observation accuracy.

Ollivier, M.; Gillon, M.

2012-01-01

403

A Framework for Quantifying the Degeneracies of Exoplanet Interior Compositions  

CERN Document Server

Several transiting super-Earths are expected to be discovered in the coming few years. While tools to model the interior structure of transiting planets exist, inferences about the composition are fraught with ambiguities. We present a framework to quantify how much we can robustly infer about super-Earth and Neptune-size exoplanet interiors from radius and mass measurements. We introduce quaternary diagrams to illustrate the range of possible interior compositions for planets with four layers (iron core, silicate mantles, water layers, and H/He envelopes). We apply our model to CoRoT-7b, GJ436b, and HAT-P-11b. Interpretation of planets with H/He envelopes is limited by the model uncertainty in the interior temperature, while for CoRoT-7b observational uncertainties dominate. We further find that our planet interior model sharpens the observational constraints on CoRoT-7b's mass and radius, assuming the planet does not contain significant amounts of water or gas. We show that the strength of the limits that c...

Rogers, L A

2009-01-01

404

THE EXOPLANET CENSUS: A GENERAL METHOD APPLIED TO KEPLER  

International Nuclear Information System (INIS)

We develop a general method to fit the underlying planetary distribution function (PLDF) to exoplanet survey data. This maximum likelihood method accommodates more than one planet per star and any number of planet or target star properties. We apply the method to announced Kepler planet candidates that transit solar-type stars. The Kepler team's estimates of the detection efficiency are used and are shown to agree with theoretical predictions for an ideal transit survey. The PLDF is fit to a joint power law in planet radius, down to 0.5 R?, and orbital period, up to 50 days. The estimated number of planets per star in this sample is ?0.7-1.4, where the range covers systematic uncertainties in the detection efficiency. To analyze trends in the PLDF we consider four planet samples, divided between shorter and longer periods at 7 days and between large and small radii at 3 R?. The size distribution changes appreciably between these four samples, revealing a relative deficit of ?3 R? planets at the shortest periods. This deficit is suggestive of preferential evaporation and sublimation of Neptune- and Saturn-like planets. If the trend and explanation hold, it would be spectacular observational support of the core accretion and migration hypotheses, and would allow refinement of these theories.

405

Electron densities and alkali atoms in exoplanet atmospheres  

CERN Document Server

We describe a detailed study on the properties of alkali atoms in extrasolar giant planets, and specifically focus on their role in generating the atmospheric free electron densities, as well as their impact on the transit depth observations. We focus our study on the case of HD 209458 b, and we show that photoionization produces a large electron density in the middle atmosphere that is about two orders of magnitude larger than the density anticipated from thermal ionization. Our purely photochemical calculations though result in a much larger transit depth for K than observed for this planet. This result does not change even if the roles of molecular chemistry and excited state chemistry are considered for the alkali atoms. In contrast, the model results for the case of exoplanet XO-2 b are in good agreement with the available observations. Given these results we discuss other possible scenarios, such as changes in the elemental abundances, changes in the temperature profiles, and the possible presence of cl...

Lavvas, Panayotis; Yelle, Roger V

2014-01-01

406

Earth-Like Exoplanets: The Science of NASA's Navigator Program  

Science.gov (United States)

This book outlines the exoplanet science content of NASA's Navigator Program, and it identifies the exoplanet research priorities. The goal of Navigator Program missions is to detect and characterize Earth-like planets in the habitable zone of nearby stars and to search for signs of life on those planets.

Lawson, Peter R. (Editor); Traub, Wesley A. (Editor)

2006-01-01

407

WASP-33: The first delta Scuti exoplanet host star and evidence of star-planet interactions  

CERN Document Server

We report the discovery of photometric oscillations in the host star of the exoplanet WASP-33 b (HD 15082). The data were obtained in the R band both in transit and out-of-transit phases from the Montcabrer (0.3-m telescope) and Montsec (0.8-m telescope) observatories. Proper fitting and subsequent removal of the transit signal reveals stellar photometric variations with an amplitude of about 1 mmag and a period of 67.57+/-0.08 min, which is typical of delta Scuti-type variable stars. Furthermore, the oscillation period is commensurable with the orbital period of the planet with a factor of 26. These findings make WASP-33 the first transiting exoplanet host star with pulsation variability and possibly experiencing tidally induced planet-star interactions. Several possible explanations for the existence of the observed high-order ressonance such as perturbations due to an eccentric orbit, rotational distortion of the star or tidal locking during planet migration are proposed.

Herrero, E; Naves, R; Ribas, I

2010-01-01

408

ExoplanetSat: Detecting transiting exoplanets using a low-cost CubeSat platform  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Nanosatellites, i.e. spacecraft that weigh between 1 and 10 kg, are drawing increasing interest as platforms for conducting on-orbit science. This trend is primarily driven by the ability to piggyback nanosatellites on the launch of large spacecraft and hence achieve orbit at greatly reduced cost. The CubeSat platform is a standardized nanosatellite configuration, consisting of one, two, or three 10 cm x 10 cm x 10 cm units (1, 2, or 3 "U"s) arranged in a row. We present a CubeSat-based conce...

Smith, Matthew William; Seager, Sara; Pong, Christopher Masaru; Villasenor, Jesus Noel Samonte; Ricker, George R.; Miller, David W.; Knapp, Mary E.; Farmer, Grant Trapnell; Jensen-clem, Rebecca M.

2010-01-01

409

Molecular-Kinetic Simulations of Escape from the Ex-planet and Exoplanets: Criterion for Transonic Flow  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The equations of gas dynamics are extensively used to describe atmospheric loss from solar system bodies and exoplanets even though the boundary conditions at infinity are not uniquely defined. Using molecular-kinetic simulations that correctly treat the transition from the continuum to the rarefied region, we confirm that the energy-limited escape approximation is valid when adiabatic expansion is the dominant cooling process. However, this does not imply that the outflow g...

Johnson, Robert E.; Volkov, Alexey N.; Erwin, Justin T.

2013-01-01

410