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Sample records for jupiter-mass exoplanet transiting

  1. 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.

  2. A short-period censor of sub-Jupiter mass exoplanets with low density

    CERN Document Server

    Szabó, Gy M

    2010-01-01

    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 R_J); 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 different distributions in the period-radius parameter plane. The branch of sub-Jupiter mass exoplanets is censored by the orbital period at large-radii: no planets with mass between 0.02--0.8 M_J or with radius between 0.25--1.0 R_J are known with P_orb<2.5 days. This clustering is not predicted by current theories of planet formation and evolution that we also review briefly.

  3. A short-period censor of sub-Jupiter mass exoplanets with low density

    OpenAIRE

    Szabó, Gy. M.; Kiss, L. L.

    2010-01-01

    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 R_J); and another one with ...

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

    OpenAIRE

    Smalley, B; Anderson, D.R.; Collier-Cameron, A.; Doyle, A P; Gillon, Michaël; Hellier, C.; Jehin, Emmanuel; Lendl, M.; Maxted, P F L; PEPE, F.; Pollacco, D.; Queloz, D.; Segransan, D.; Smith, A. M. S.; Southworth, J.

    2012-01-01

    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. Planetary parameters have been determined using a simultaneous fit to WASP and TRAPPIST transit photometry and CORALIE radial-velocity measurements. For WASP-78b a planetary mass of 0.89 +/- 0.08 M_Jup and a radius of 1.70 +/- 0.11 R...

  5. Transiting Exoplanets with JWST

    OpenAIRE

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

    2008-01-01

    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 sign...

  6. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  8. Discovery and characterization of WASP-6b, an inflated sub-Jupiter mass planet transiting a solar-type star

    CERN Document Server

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

    2009-01-01

    We report the discovery of WASP-6b, an inflated sub-Jupiter mass planet transiting every 3.3610060 +0.0000022-0.0000035 days a mildly metal-poor solar-type star of magnitude V=11.9. A combined analysis of the WASP photometry, high-precision followup transit photometry and radial velocities yield a planetary mass M_p = 0.503 +0.019-0.038 M_jup and radius R_p = 1.224 +0.051-0.052 R_jup, resulting in a density rho_p = 0.27 +-0.05 rho_jup. The mass and radius for the host star are M_s = 0.88 +0.05-0.08 M_sun and R_s = 0.870 +0.025-0.036 R_sun. The non-zero orbital eccentricity e = 0.054 +0.018-0.015 that we measure suggests that the planet underwent a massive tidal heating ~1 Gyr ago that could have contributed to its inflated radius. High-precision radial velocities obtained during a transit allow us to measure a sky-projected angle between the stellar spin and orbital axis Beta = 11 +14-18 deg. In addition to similar published measurements, this result favors a dominant migration mechanism based on tidal intera...

  9. KOI-183b: a half-Jupiter mass planet transiting a very old solar-like star

    CERN Document Server

    Gandolfi, D; Deeg, H J; Lanza, A F; Fridlund, M; Moroni, P G Prada; Alonso, R; Augusteijn, T; Cabrera, J; Evans, T; Geier, S; Hatzes, A P; Holczer, T; Hoyer, S; Kangas, T; Mazeh, T; Pagano, I; Tal-Or, L; Tingley, B

    2014-01-01

    We report the spectroscopic confirmation of the Kepler object of interest KOI-183b (also known as KOI-183.01), a half-Jupiter mass planet transiting an old solar-like star every 2.7 days. Our analysis is the first to combine the full Kepler photometry (quarters 1-17) with high-precision radial velocity measurements taken with the FIES spectrograph at the Nordic Optical Telescope. We simultaneously modelled the photometric and spectroscopic data-sets using Bayesian approach coupled with Markov chain Monte Carlo sampling. We found that the Kepler pre-search data conditioned (PDC) light curve of KOI-183 exhibits quarter-to-quarter systematic variations of the transit depth, with a peak-to-peak amplitude of about 4.3 % and seasonal trends reoccurring every four quarters. We attributed these systematics to an incorrect assessment of the quarterly variation of the crowding metric. The host star KOI-183 is a G4 dwarf with $M_\\star=0.85\\pm0.04$ M$_\\rm{Sun}$, $R_\\star=0.95\\pm0.04$ R$_\\rm{Sun}$, $T_\\mathrm{eff}=5560\\pm...

  10. Saturn as a Transiting Exoplanet

    Science.gov (United States)

    Dalba, Paul A.; Muirhead, Philip S.; Fortney, Jonathan J.; Hedman, Matthew M.; Nicholson, Philip D.; Veyette, Mark J.

    2015-11-01

    Previous investigations of exoplanet atmospheres have not targeted those resembling the gas giant planets in our solar system. These types of exoplanets are too cold to be directly imaged or observed in emission, and their low transit probabilities and frequencies make characterization via transmission spectroscopy a challenging endeavor. However, studies of cold giant exoplanets would be highly valuable to our understanding of planet formation and migration and could place the gas giant members of our own solar system in a greater context. Here, we use solar occultations observed by the Visual and Infrared Mapping Spectrometer aboard the Cassini Spacecraft to extract the 1 to 5 ?m transmission spectrum of Saturn, as if it were a transiting exoplanet. We detect absorption features from several molecules despite the presence of ammonia clouds. Self-consistent exoplanet atmosphere models show good agreement with Saturn's transmission spectrum but fail to reproduce the largest feature in the spectrum. We also find that atmospheric refraction determines the minimum altitude that could be probed during mid-transit of a Saturn-twin exoplanet around a Sun-like star. These results suggest that transmission spectroscopy of cold, long-period gaseous exoplanets should be possible with current and future observatories.

  11. Discovery and characterization of WASP-6b, an inflated sub-Jupiter mass planet transiting a solar-type star

    Science.gov (United States)

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

    2009-07-01

    We report the discovery of WASP-6b, an inflated sub-Jupiter mass planet transiting every 3.3610060+ 0.0000022 - 0.0000035 days a mildly metal-poor solar-type star of magnitude V = 11.9. A combined analysis of the WASP photometry, high-precision followup transit photometry and radial velocities yield a planetary mass Mp = 0.503+0.019-0.038 MJ and radius Rp = 1.224+0.051-0.052 R_J, resulting in a density ?p = 0.27 ± 0.05 ?_J. The mass and radius for the host star are M_ast = 0.88+0.05-0.08 M_? and R_ast = 0.870+0.025-0.036 R_?. The non-zero orbital eccentricity e = 0.054^+0.018-0.015 that we measure suggests that the planet underwent a massive tidal heating 1 Gyr ago that could have contributed to its inflated radius. High-precision radial velocities obtained during a transit allow us to measure a sky-projected angle between the stellar spin and orbital axis ? = 11+14-18 deg. In addition to similar published measurements, this result favors a dominant migration mechanism based on tidal interactions with a protoplanetary disk. Based on data collected with the HARPS spectrograph at ESO La Silla Observatory in the programs 082.C-0040(E) and 082.C-0608. The photometric time-series and radial velocities (Tables 4, 5) used in this work are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/501/785

  12. Transiting Exoplanet Survey Satellite (TESS)

    DEFF Research Database (Denmark)

    Ricker, George R.; Winn, Joshua N.; Vanderspek, Roland; Latham, David W.; Bakos, Gáspár. Á.; Bean, Jacob L.; Berta-Thompson, Zachory K.; Brown, Timothy M.; Buchhave, Lars; Butler, Nathaniel R.; Butler, R. Paul; Chaplin, William J.; Charbonneau, David; Christensen-Dalsgaard, Jørgen; Clampin, Mark; Deming, Drake; Doty, John; De Lee, Nathan; Dressing, Courtney; Dunham, E. W.; Endl, Michael; Fressin, Francois; Ge, Jian; Henning, Thomas; Holman, Matthew J.; Howard, Andrew W.; Ida, Shigeru; Jenkins, Jon; Jernigan, Garrett; Johnson, John A.; Kaltenegger, Lisa; Kawai, Nobuyuki; Kjeldsen, Hans; Laughlin, Gregory; Levine, Alan M.; Lin, Douglas; Lissauer, Jack J.; MacQueen, Phillip; Marcy, Geoffrey; McCullough, P. R.; Morton, Timothy D.; Narita, Norio; Paegert, Martin; Palle, Enric; Pepe, Francesco; Pepper, Joshua; Quirrenbach, Andreas; Rinehart, S. A.; Sasselov, Dimitar; Sato, Bun'ei; Seager, Sara; Sozzetti, Alessandro; Stassun, Keivan G.; Sullivan, Peter; Szentgyorgyi, Andrew; Torres, Guillermo; Udry, Stephane; Villasenor, Joel

    2014-01-01

    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...

  13. Transiting Exoplanet Survey Satellite (TESS)

    DEFF Research Database (Denmark)

    Ricker, George R.; Winn, Joshua N.; Vanderspek, Roland; Latham, David W.; Bakos, Gáspár. Á.; Bean, Jacob L.; Berta-Thompson, Zachory K.; Brown, Timothy M.; Buchhave, Lars; Butler, Nathaniel R.; Butler, R. Paul; Chaplin, William J.; Charbonneau, David; Christensen-Dalsgaard, Jørgen; Clampin, Mark; Deming, Drake; Doty, John; De Lee, Nathan; Dressing, Courtney; Dunham, E. W.; Endl, Michael; Fressin, Francois; Ge, Jian; Henning, Thomas; Holman, Matthew J.; Howard, Andrew W.; Ida, Shigeru; Jenkins, Jon; Jernigan, Garrett; Johnson, John A.; Kaltenegger, Lisa; Kawai, Nobuyuki; Kjeldsen, Hans; Laughlin, Gregory; Levine, Alan M.; Lin, Douglas; Lissauer, Jack J.; MacQueen, Phillip; Marcy, Geoffrey; McCullough, P. R.; Morton, Timothy D.; Narita, Norio; Paegert, Martin; Palle, Enric; Pepe, Francesco; Pepper, Joshua; Quirrenbach, Andreas; Rinehart, S. A.; Sasselov, Dimitar; Sato, Bun'ei; Seager, Sara; Sozzetti, Alessandro; Stassun, Keivan G.; Sullivan, Peter; Szentgyorgyi, Andrew; Torres, Guillermo; Udry, Stephane; Villasenor, Joel

    2014-01-01

    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 t...

  14. 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

    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

    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...

  15. Comparative Habitability of Transiting Exoplanets

    Science.gov (United States)

    Barnes, Rory; Meadows, Victoria S.; Evans, Nicole

    2015-12-01

    Exoplanet habitability is traditionally assessed by comparing a planet’s semimajor axis to the location of its host star’s “habitable zone,” the shell around a star for which Earth-like planets can possess liquid surface water. The Kepler space telescope has discovered numerous planet candidates near the habitable zone, and many more are expected from missions such as K2, TESS, and PLATO. These candidates often require significant follow-up observations for validation, so prioritizing planets for habitability from transit data has become an important aspect of the search for life in the universe. We propose a method to compare transiting planets for their potential to support life based on transit data, stellar properties and previously reported limits on planetary emitted flux. For a planet in radiative equilibrium, the emitted flux increases with eccentricity, but decreases with albedo. As these parameters are often unconstrained, there is an “eccentricity-albedo degeneracy” for the habitability of transiting exoplanets. Our method mitigates this degeneracy, includes a penalty for large-radius planets, uses terrestrial mass-radius relationships, and, when available, constraints on eccentricity to compute a number we call the “habitability index for transiting exoplanets” that represents the relative probability that an exoplanet could support liquid surface water. We calculate it for Kepler objects of interest and find that planets that receive between 60% and 90% of the Earth’s incident radiation, assuming circular orbits, are most likely to be habitable. Finally, we make predictions for the upcoming TESS and James Webb Space Telescope missions.

  16. Transiting Exoplanet Survey Satellite (TESS)

    Science.gov (United States)

    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. N.; Winn, J. N.; Worden, S. P.

    2010-01-01

    TESS is a low-cost SMEX-class satellite mission. In a two-year all-sky survey, TESS will observe more than 2,000,000 nearby stars, searching for temporary drops in brightness caused by planetary transits. TESS is expected to identify more than 1000 transiting exoplanet candidates, including a sample of about 100 Super Earths---small rock-and-ice planets in the range 1 to 10 Earth masses---orbiting F, G, K, and M dwarfs. TESS's "wide-shallow” survey complements the "narrow-deep” CoRoT and Kepler surveys. TESS-discovered transiting systems will be nearby (France). TESS was funded by NASA for a Phase A study from May 2008 - June 2009, but was not selected for flight. Additional funding leading to a flight opportunity is being sought. Support has also been provided by the Kavli Foundation, Google, and the Smithsonian Institution. TESS could launch as early as 2013-2014.

  17. Comparative Habitability of Transiting Exoplanets

    CERN Document Server

    Barnes, Rory; Evans, Nicole

    2015-01-01

    Exoplanet habitability is traditionally assessed by comparing a planet's semi-major axis to the location of its host star's "habitable zone," the shell around a star for which Earth-like planets can possess liquid surface water. The Kepler space telescope has discovered numerous planet candidates near the habitable zone, and many more are expected from missions such as K2, TESS and PLATO. These candidates often require significant follow-up observations for validation, so prioritizing planets for habitability from transit data has become an important aspect of the search for life in the universe. We propose a method to compare transiting planets for their potential to support life based on transit data, stellar properties and previously reported limits on planetary emitted flux. For a planet in radiative equilibrium, the emitted flux increases with eccentricity, but decreases with albedo. As these parameters are often unconstrained, there is an "eccentricity-albedo degeneracy" for the habitability of transiti...

  18. Young Exoplanet Transit Initiative (YETI)

    CERN Document Server

    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

    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...

  19. The Transiting Exoplanet Survey Satellite

    CERN Document Server

    Ricker, George R; Vanderspek, Roland; Latham, David W; Bakos, Gaspar A; Bean, Jacob L; Berta-Thompson, Zachory K; Brown, Timothy M; Buchhave, Lars; Butler, Nathaniel R; Butler, R Paul; Chaplin, William J; Charbonneau, David; Christensen-Dalsgaard, Jorgen; Clampin, Mark; Deming, Drake; Doty, John; De Lee, Nathan; Dressing, Courtney; Dunham, E W; Endl, Michael; Fressin, Francois; Ge, Jian; Henning, Thomas; Holman, Matthew J; Howard, Andrew W; Ida, Shigeru; Jenkins, Jon; Jernigan, Garrett; Johnson, John Asher; Kaltenegger, Lisa; Kawai, Nobuyuki; Kjeldsen, Hans; Laughlin, Gregory; Levine, Alan M; Lin, Douglas; Lissauer, Jack J; MacQueen, Phillip; Marcy, Geoffrey; McCullough, P R; Morton, Timothy D; Narita, Norio; Paegert, Martin; Palle, Enric; Pepe, Francesco; Pepper, Joshua; Quirrenbach, Andreas; Rinehart, S A; Sasselov, Dimitar; Sato, Bun'ei; Seager, Sara; Sozzetti, Alessandro; Stassun, Keivan G; Sullivan, Peter; Szentgyorgyi, Andrew; Torres, Guillermo; Udry, Stephane; Villasenor, Joel

    2014-01-01

    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 I<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 the pioneering Kepler missio...

  20. Transiting Exoplanet Survey Satellite (TESS)

    DEFF Research Database (Denmark)

    Ricker, George R.; Winn, Joshua N.

    2014-01-01

    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.

  1. Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy

    Science.gov (United States)

    Wyttenbach, Aurélien; Ehrenreich, David

    2015-12-01

    The field of exoplanet atmospheres is booming thanks to (low-resolution) space-borne spectrographs and high-resolution (narrow-ranged) NIR spectrographs on ground-based 8m-class telescopes. Atmospheres are important because they are our observing window on the physical, chemical, and evolutionary processes occurring on exoplanets. Transiting exoplanets are the best suitable targets for atmospheric studies. Observing a transit in different filters or with a spectrograph reveals the transmission spectrum of the planet atmosphere. More than one decade of such observations allowed the exploration of these remote words by detecting some constituents of their atmospheres, but revealing also the presence of scattering hazes and clouds in several exoplanets preventing the detection of major chemical constituents at low to medium resolution even from space.Transit observations from the ground with stabilised high-resolution spectrograph, such HARPS, have key roles to play in this context. Observation of the hot-jupiter HD 189733b with HARPS allow the detection of sodium in the planet atmosphere. The high-resolution transmission spectra allowed to probe a new region high in the atmosphere and revealed rapid winds and a heating thermosphere. This new use of the famous planet hunter turned HARPS into a powerful exoplanet characterisation machine. It has the precision level of the Hubble Space Telescope, albeit at 20 higher resolution.A survey of a large set of known hot transiting exoplanets with HARPS and later with ESPRESSO will allow the detection of key tracers of atmospheric physics, chemistry, and evolution, above the scattering haze layers known to dominate low-resolution visible spectra of exoplanets.Such observation, in total sinergy with other technics, will rmly establish stabilised, high-resolution spectrographs on 4m telescopes as corner-stones for the characterisation of exoplanets. This is instrumental considering the upcoming surveys (NGTS,K2, CHEOPS, TESS, PLATO) that will deliver hundreds of exoplanets amenable to atmospheric characterisation.

  2. CoRoT pictures transiting exoplanets

    CERN Document Server

    Moutou, Claire

    2015-01-01

    The detection and characterization of exoplanets have made huge progresses since the first discoveries in the late nineties. In particular, the independent measurement of the mass and radius of planets, by combining the transit and radial-velociy techniques, allowed exploring their density and hence, their internal structure. With CoRoT (2007-2012), the pioneering CNES space-based mission in this investigation, about thirty new planets were characterized. CoRoT has enhanced the diversity of giant exoplanets and discovered the first telluric exoplanet. Following CoRoT, the NASA Kepler mission has extended our knowledge to small-size planets, multiple systems and planets orbiting binaries. Exploring these new worlds will continue with the NASA/TESS (2017) and ESA/PLATO (2024) missions.

  3. Observations and investigations of transiting exoplanets

    Science.gov (United States)

    Sokov, E. N.; Vereshchagina, I. A.; Devyatkin, A. V.; Gnedin, Yu. N.; Gorshanov, D. L.

    2012-05-01

    Since mid of 2010yr. in the Pulkovo Observatory observations of several transiting exoplanets have been made. The observations are made with the use ZA-320M and MTM-500M telescopes of the Pulkovo Observatory. Also we collaborate with a lot of observatories of Russia and with some observatories of Greece and USA. Collected observations data allowed us to estimate such parameters of exoplanet systems, as: duration of the transits the MID-transit point, planet radius and inclination of its orbit. For a number of exoplanets Teq of their atmosphere and albedo are estimated. For the planet candidate KOI 256b, a number of parameters was estimated: Rpl ? 1.83 ± 0.16 Rjup; Inclination ? 74.79°. The deviation from the predicted time of the MID-transit of the KOI 256b reaches the value of {-30} minutes. The orbit motion of the KOI 256b around parent star varies, because the depth in the transit moment of the KOI 256b changes in the range [0.028; 0.042] mag. This fact may indicate that the orbit of KOI 256b is perturbed by other objects that may be other planets in this system.

  4. Mass-loss rates for transiting exoplanets

    OpenAIRE

    Ehrenreich, David; Désert, Jean-Michel

    2011-01-01

    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...

  5. The Transiting Exoplanet Survey Satellite: Mission Status

    Science.gov (United States)

    Ricker, George R.; TESS Team

    2015-01-01

    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.

  6. The WASP-South search for transiting exoplanets

    Directory of Open Access Journals (Sweden)

    Queloz D.

    2011-02-01

    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.

  7. The WASP-South search for transiting exoplanets

    OpenAIRE

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

    2010-01-01

    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.

  8. Characterization of Transiting Exoplanets by Way of Differential Photometry

    Science.gov (United States)

    Cowley, Michael; Hughes, Stephen

    2014-01-01

    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…

  9. Transiting exoplanets: From planet statistics to their physical nature

    OpenAIRE

    Rauer H.

    2011-01-01

    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 ...

  10. Five kepler target stars that show multiple transiting exoplanet candidates

    DEFF Research Database (Denmark)

    Steffen..[], Jason H.; Batalha, N. M.; Broucki, W J.; Buchhave, Lars C. Astrup

    2010-01-01

    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 fals...

  11. Transiting Exoplanet Simulations with the James Webb Space Telescope

    OpenAIRE

    Batalha, Natasha; Kalirai, Jason; Lunine, Jonathan; Clampin, Mark; Lindler, Don

    2015-01-01

    In this white paper, we assess the potential for JWST to characterize the atmospheres of super-Earth exoplanets, by simulating a range of transiting spectra with different masses and temperatures. Our results are based on a JWST simulator tuned to the expected performance of the workhorse spectroscopic instrument NIRSpec, and is based on the latest exoplanet transit models by Howe & Burrows (2012). This study is especially timely since the observing modes for the science instruments on JWST a...

  12. The observation of exoplanet transit events in China

    Directory of Open Access Journals (Sweden)

    Fang X.-S.

    2011-07-01

    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.

  13. KELT-10b: The First Transiting Exoplanet from the KELT-South Survey -- A Hot Sub-Jupiter Transiting a V = 10.7 Early G-Star

    CERN Document Server

    Kuhn, Rudolf B; Collins, Karen A; Lund, Michael B; Siverd, Robert J; Colón, Knicole D; Pepper, Joshua; Stassun, Keivan G; Cargile, Phillip A; James, David J; Penev, Kaloyan; Zhou, George; Bayliss, Daniel; Tan, T G; Curtis, Ivan A; Udry, Stephane; Segransan, Damien; Mawet, Dimitri; Soutter, Jack; Hart, Rhodes; Carter, Brad; Gaudi, B Scott; Myers, Gordon; Beatty, Thomas G; Eastman, Jason D; Reichart, Daniel E; Haislip, Joshua B; Kielkopf, John; Bieryla, Allyson; Latham, David W; Jensen, Eric L N; Oberst, Thomas E; Stevens, Daniel J

    2015-01-01

    We report the discovery of KELT-10b, the first transiting exoplanet discovered using the KELT-South telescope. KELT-10b is a highly inflated sub-Jupiter mass planet transiting a relatively bright $V = 10.7$ star (TYC 8378-64-1), with T$_{eff}$ = $5948\\pm74$ K, $\\log{g}$ = $4.319_{-0.030}^{+0.020}$ and [Fe/H] = $0.09_{-0.10}^{+0.11}$, an inferred mass M$_{*}$ = $1.112_{-0.061}^{+0.055}$ M$_{\\odot}$ and radius R$_{*}$ = $1.209_{-0.035}^{+0.047}$ R$_{\\odot}$. The planet has a radius R$_{P}$ = $1.399_{-0.049}^{+0.069}$ R$_{J}$ and mass M$_{P}$ = $0.679_{-0.038}^{+0.039}$ M$_{J}$. The planet has an eccentricity consistent with zero and a semi-major axis $a$ = $0.05250_{-0.00097}^{+0.00086}$ AU. The best fitting linear ephemeris is $T_{0}$ = 2457066.72045$\\pm$0.00027 BJD$_{TDB}$ and P = 4.1662739$\\pm$0.0000063 days. This planet joins a group of highly inflated transiting exoplanets with a radius much larger and a mass much less than those of Jupiter. The planet, which boasts deep transits of 1.4%, has a relatively ...

  14. Characterizing transiting exoplanet atmospheres with JWST

    CERN Document Server

    Greene, Thomas P; Montero, Cezar; Fortney, Jonathan J; Lustig-Yeager, Jacob; Luther, Kyle

    2015-01-01

    We explore how well James Webb Space Telescope (JWST) spectra will likely constrain bulk atmospheric properties of transiting exoplanets. We start by modeling the atmospheres of archetypal hot Jupiter, warm Neptune, warm sub-Neptune, and cool super-Earth planets with clear, cloudy, or high mean molecular weight atmospheres. Next we simulate the $\\lambda = 1 - 11$ $\\mu$m transmission and emission spectra of these systems for several JWST instrument modes for single transit and eclipse events. We then perform retrievals to determine how well temperatures and molecular mixing ratios (CH$_4$, CO, CO$_2$, H$_2$O, NH$_3$) can be constrained. We find that $\\lambda = 1 - 2.5$ $\\mu$m transmission spectra will often constrain the major molecular constituents of clear solar composition atmospheres well. Cloudy or high mean molecular weight atmospheres will often require full $1 - 11$ $\\mu$m spectra for good constraints, and emission data may be more useful in cases of sufficiently high $F_p$ and high $F_p/F_*$. Strong t...

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

    CERN Document Server

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

    2014-01-01

    (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, ...

  16. Target of Opportunity: New Transiting Exoplanets

    Science.gov (United States)

    Harrington, Joseph; Bakos, Gaspar; Deming, Drake; Fischer, Debra; Seager, Sara; Wheatley, Peter

    2007-05-01

    We propose a Target of Opportunity (ToO) program to observe eclipses of new extrasolar planets. The measured band fluxes constrain models of composition, chemistry, and atmospheric dynamics. They also provide the basic information needed for follow-on work. Since the spacecraft is nearing the end of its limited lifetime, rapid characterization is crucial. Well below Spitzer's nominal sensitivity, these measurements are challenging, and optimized observing and analysis techniques that are not obvious are required to bring in the best signal. Many Discretionary Time proposals have been approved on this topic. Our goals, achieved with our Cycle-3 ToO program and continued here, are to ensure that each bandpass is observed for every planet with good predicted S/N, to obtain the best possible observations, to make these high-impact data public for everyone to use in planning followups, and to make the process of observing exoplanets smooth for observers and Spitzer by allocating a predictable number of events for the community through the TAC process. Based on actual discovery statistics and the known quantities of survey data in hand, we confidently predict about 22 new transiting-planet announcements in the coming year. Of these, one may be bright enough to measure in six bandpasses, and several may be marginal for Spitzer. We thus request 120 hours to cover about 18 6:40-hour eclipse events in low-impact ToOs. We provide quantitative criteria for activating ToOs. Our archival product will be calibrated lightcurves, to be submitted as electronic attachments with journal articles. Transiting extrasolar planets are among the least anticipated and most productive targets for Spitzer. They are also among the most publicly stimulating. These direct measurements provide the only emission fluxes possible with current telescopes for extrasolar planets, and stand as a Spitzer legacy for posterity. The next opportunity to observe them is with JWST.

  17. Characterizing Transiting Exoplanet Atmospheres with JWST

    Science.gov (United States)

    Greene, Thomas P.; Line, Michael R.; Montero, Cezar; Fortney, Jonathan J.; Lustig-Yaeger, Jacob; Luther, Kyle

    2016-01-01

    We explore how well spectra from the James Webb Space Telescope (JWST) will likely constrain bulk atmospheric properties of transiting exoplanets. We start by modeling the atmospheres of archetypal hot Jupiter, warm Neptune, warm sub-Neptune, and cool super-Earth planets with atmospheres that are clear, cloudy, or of high mean molecular weight (HMMW). Next we simulate the ? = 1-11 ?m transmission and emission spectra of these systems for several JWST instrument modes for single-transit or single-eclipse events. We then perform retrievals to determine how well temperatures and molecular mixing ratios (CH4, CO, CO2, H2O, NH3) can be constrained. We find that ? = 1-2.5 ?m transmission spectra will often constrain the major molecular constituents of clear solar-composition atmospheres well. Cloudy or HMMW atmospheres will often require full 1-11 ?m spectra for good constraints, and emission data may be more useful in cases of sufficiently high Fp and high Fp/F*. Strong temperature inversions in the solar-composition hot-Jupiter atmosphere should be detectable with 1-2.5+ ?m emission spectra, and 1-5+ ?m emission spectra will constrain the temperature-pressure profiles of warm planets. Transmission spectra over 1-5+ ?m will constrain [Fe/H] values to better than 0.5 dex for the clear atmospheres of the hot and warm planets studied. Carbon-to-oxygen ratios can be constrained to better than a factor of 2 in some systems. We expect that these results will provide useful predictions of the scientific value of single-event JWST spectra until its on-orbit performance is known.

  18. Transiting exoplanets: From planet statistics to their physical nature

    Directory of Open Access Journals (Sweden)

    Rauer H.

    2011-02-01

    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 effect 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.

  19. Parametrized post-Newtonian secular transit timing variations for exoplanets

    International Nuclear Information System (INIS)

    Ground-based and space-borne observatories used for studying exoplanet transits now and in the future will considerably increase the number of exoplanets known from transit data 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 to test the general theory of relativity in these systems. To build a framework for these possible tests, we extend previous studies on the observability of the general relativistic precessions of periastron in transiting exoplanets to variations in secular transit timing under parametrized post-Newtonian formalism. We find that if one can measure the difference between observed and predicted variations of general relativistic secular transit timing to 1 s yr?1 in a transiting exoplanet system with a Sun-like mass, a period of ? 1 day and a relatively small eccentricity of ? 0.1, general relativity will be tested to the level of ? 6%

  20. Transiting Exoplanet Simulations with the James Webb Space Telescope

    CERN Document Server

    Batalha, Natasha; Lunine, Jonathan; Clampin, Mark; Lindler, Don

    2015-01-01

    In this white paper, we assess the potential for JWST to characterize the atmospheres of super-Earth exoplanets, by simulating a range of transiting spectra with different masses and temperatures. Our results are based on a JWST simulator tuned to the expected performance of the workhorse spectroscopic instrument NIRSpec, and is based on the latest exoplanet transit models by Howe & Burrows (2012). This study is especially timely since the observing modes for the science instruments on JWST are finalized (Clampin 2010) and because NASA has selected the TESS mission as an upcoming Explorer. TESS is expected to identify more than 1000 transiting exoplanet candidates, including a sample of about 100 nearby (<50 pc) super- Earths (Ricker et al. 2010).

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

    OpenAIRE

    Anderson, DR; Cameron, AC; Delrez, L.; Doyle, AP; Faedi, F.; Fumel, A.; Gillon, M.; Chew, YGM; Hellier, C.; Jehin, E.; Lendl, M.; Maxted, PFL; PEPE, F.; Pollacco, D.; Queloz, D.

    2014-01-01

    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 MJup, 1.06 RJup) in a 3.868-d period around an active, ?1-Gyr, mid-K dwarf. ROSAT detected X-rays 60±27 arcsec from WASP-69. If the star is the source then the planet could be undergoing mass-loss at a rate of ?1012 g s?1. This is one to two orders of magnitude higher than the evaporation rate estimated for HD 209458...

  2. Search for transit timing variations in some Exoplanet systems.

    Science.gov (United States)

    Sutaria, Firoza

    2012-07-01

    The presence of multiple, hitherto undetected exoplanets orbiting their host star can cause variations in the transit time of a known exoplanet in that system. This transit time variation (TTV) can be particularly sharp over an interval of several transits, if the perturbing planet is in mean motion resonance with the transiting planet. TTV studies are the one method to determine orbital and physical (mass, radius) characteristics of perturbing planets whose orbits are so inclined as to prevent any line-of-sight transits of the host star. I present in this paper results from our transit observations of 3 hot Jupiters (HAT-P-13b, HAT-P-16b and WASP-12b), taken during 2010-2012. While these observations suggest little evidence for the presence of HAT-P-13d, we cannot rule out the possiblity of a non-transiting perturber in the other two systems.

  3. Characterizing Transiting Exoplanet Atmospheres with Gemini/GMOS: First Results

    Science.gov (United States)

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

    2015-01-01

    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.

  4. Characterization of transiting exoplanets by way of differential photometry

    CERN Document Server

    Cowley, Michael

    2015-01-01

    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 its size, orbital radius and habitability. The activity has been designed for a high school or undergraduate university level and introduces fundamental concepts in astrophysics and an understanding of the basis for exoplanetary science, the transit method and digital photometry.

  5. KELT-1b: A STRONGLY IRRADIATED, HIGHLY INFLATED, SHORT PERIOD, 27 JUPITER-MASS COMPANION TRANSITING A MID-F STAR

    Energy Technology Data Exchange (ETDEWEB)

    Siverd, Robert J.; Pepper, Joshua; Stassun, Keivan G. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Beatty, Thomas G.; Scott Gaudi, B. [Department of Astronomy, Ohio State University, 140 W. 18th Avenue, Columbus, OH 43210 (United States); Eastman, Jason D.; Street, Rachel; Fulton, Benjamin J. [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Santa Barbara, CA 93117 (United States); Collins, Karen [Department of Physics and Astronomy, University of Louisville, Louisville, KY 40292 (United States); Bieryla, Allyson; Latham, David W.; Berlind, Perry; Calkins, Michael L.; Esquerdo, Gilbert A.; Furesz, Gabor; Geary, John C. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Buchhave, Lars A. [Niels Bohr Institute, University of Copenhagen, Juliane Maries vej 30, DK-21S00 Copenhagen (Denmark); Jensen, Eric L. N. [Department of Physics and Astronomy, Swarthmore College, Swarthmore, PA 19081 (United States); Crepp, Justin R. [Department of Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); DePoy, D. L. [Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); and others

    2012-12-20

    We present the discovery of KELT-1b, the first transiting low-mass companion from the wide-field Kilodegree Extremely Little Telescope-North (KELT-North) transit survey. A joint analysis of the spectroscopic, radial velocity, and photometric data indicates that the V = 10.7 primary is a mildly evolved mid-F star with T{sub eff} = 6516 {+-} 49 K, log g 4.228{sup +0.014}{sub -0.021}, and [Fe/H] = 0.052 {+-} 0.079, with an inferred mass M{sub *} = 1.335 {+-} 0.063 M{sub Sun} and radius R{sub *} 1.471{sup +0.045}{sub -0.035} R{sub Sun }. The companion is a low-mass brown dwarf or a super-massive planet with mass M{sub P} = 27.38 {+-} 0.93 M{sub Jup} and radius R{sub P} = 1.116{sup +0.038}{sub -0.029} R{sub Jup}. The companion is on a very short ({approx}29 hr) period circular orbit, with an ephemeris T{sub c} (BJD{sub TDB}) = 2455909.29280 {+-} 0.00023 and P = 1.217501 {+-} 0.000018 days. KELT-1b receives a large amount of stellar insolation, resulting in an estimated equilibrium temperature assuming zero albedo and perfect redistribution of T{sub eq} = 2423{sup +34}{sub -27} K. Comparison with standard evolutionary models suggests that the radius of KELT-1b is likely to be significantly inflated. Adaptive optics imaging reveals a candidate stellar companion to KELT-1 with a separation of 588 {+-} 1 mas, which is consistent with an M dwarf if it is at the same distance as the primary. Rossiter-McLaughlin measurements during transit imply a projected spin-orbit alignment angle {lambda} = 2 {+-} 16 deg, consistent with a zero obliquity for KELT-1. Finally, the vsin I{sub *} = 56 {+-} 2 km s{sup -1} of the primary is consistent at {approx}2{sigma} with tidal synchronization. Given the extreme parameters of the KELT-1 system, we expect it to provide an important testbed for theories of the emplacement and evolution of short-period companions, as well as theories of tidal dissipation and irradiated brown dwarf atmospheres.

  6. Five Kepler target stars that show multiple transiting exoplanet candidates

    CERN Document Server

    Steffen, Jason H; Borucki, William J; Buchhave, Lars A; Caldwell, Douglas A; Cochran, William D; Endl, Michael; Fabrycky, Daniel C; Fressin, François; Ford, Eric B; Fortney, Jonathan J; Haas, Michael J; Holman, Matthew J; Isaacson, Howard; Jenkins, Jon M; Koch, David; Latham, David W; Lissauer, Jack J; Moorhead, Althea V; Morehead, Robert C; Marcy, Geoffrey; MacQueen, Phillip J; Quinn, Samuel N; Ragozzine, Darin; Rowe, Jason F; Sasselov, Dimitar D; Seager, Sara; Torres, Guillermo; Welsh, William F

    2010-01-01

    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 multitransiting systems have on the distribution of orbital inclinations in planetary systems, and hence their dynamical histories; as well as their likely masses and chemical compos...

  7. Using color photometry to separate transiting exoplanets from false positives

    CERN Document Server

    Tingley, B

    2004-01-01

    The radial velocity technique is currently used to classify transiting objects. While capable of identifying grazing binary eclipses, this technique cannot reliably identify blends, a chance overlap of a faint background eclipsing binary with an ordinary foreground star. Blends generally have no observable radial velocity shifts, as the foreground star is brighter by several magnitudes and therefore dominates the spectrum, but their combined light can produce events that closely resemble those produced by transiting exoplanets. The radial velocity technique takes advantage of the mass difference between planets and stars to classify exoplanet candidates. However, the existence of blends renders this difference an unreliable discriminator. Another difference must therefore be utilized for this classification -- the physical size of the transiting body. Due to the dependence of limb darkening on color, planets and stars produce subtly different transit shapes. These differences can be relatively weak, little mo...

  8. PYTRANSIT: fast and easy exoplanet transit modelling in PYTHON

    Science.gov (United States)

    Parviainen, Hannu

    2015-07-01

    We present a fast and user friendly exoplanet transit light-curve modelling package PYTRANSIT, implementing optimized versions of the Giménez and Mandel & Agol transit models. The package offers an object-oriented PYTHON interface to access the two models implemented natively in FORTRAN with OpenMP parallelization. A partial OpenCL version of the quadratic Mandel-Agol model is also included for GPU-accelerated computations. The aim of PYTRANSIT is to facilitate the analysis of photometric time series of exoplanet transits consisting of hundreds of thousands of data points, and of multipassband transit light curves from spectrophotometric observations, as a part of a researcher's programming toolkit for building complex, problem-specific analyses.

  9. Detection of transiting Jovian exoplanets by Gaia photometry - expected yield

    OpenAIRE

    Dzigan, Yifat; Zucker, Shay

    2012-01-01

    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 a few hundreds to a few thousands transiting exoplanets.

  10. Stellar activity effects on high energy exoplanet transits

    Science.gov (United States)

    Llama, Joe; Shkolnik, Evgenya

    2016-01-01

    High energy (X-ray / UV) observations of transiting exoplanets have revealed the presence of extended atmospheres around a number of systems. At such high energies, stellar radiation is absorbed high up in the planetary atmosphere, making X-ray and UV observations a potential tool for investigating the upper atmospheres of exoplanets. At these high energies, stellar activity can dramatically impact the observations. At short wavelengths the stellar disk appears limb-brightened, and active regions appear as extended bright features that evolve on a much shorter timescale than in the optical making it difficult . These features impact both the transit depth and shape, affecting our ability to measure the true planet-to-star radius ratio.I will show results of simulated exoplanet transit light curves using Solar data obtained in the soft X-ray and UV by NASA's Solar Dynamics Observatory to investigate the impact of stellar activity at these wavelengths. By using a limb-brightened transit model coupled with disk resolved Solar images in the X-ray, extreme- and far-UV I will show how both occulted and unocculted active regions can mimic an inflated planetary atmosphere by changing the depth and shape of the transit profile. I will also show how the disk integrated Lyman-alpha Solar irradiance varies on both short and long timescales and how this variability can impact our ability to recover the true radius ratio of a transiting exoplanet.Finally, I will present techniques on how to overcome these effects to determine the true planet-to-star radius in X-ray and UV observations.

  11. The GATE Initiative (GAia Transiting Exoplanets): The Way to fully Exploit Gaia's Potential to Detect Transiting Exoplanets

    Science.gov (United States)

    Zucker, Shay; Eyer, Laurent; Hodgkin, Simon; Clementini, Gisella

    2015-08-01

    The traditional assumption about low cadence photometric surveys, such as those of Gaia and its predecessor Hipparcos, was that they are not suitable for the detection of transiting exoplanets. The posterior detection of the transits of the planets HD209458b and HD189733b in the Hipparcos photometric data has challenged this view. Inspired by those detections, we have shown in a series of papers that under specific circumstances, the low-cadence photometric data of Gaia will enable the detection of such planets. The chances of detection will improve significantly with the help of carefully scheduled ground-based photometric observations, using Bayesian considerations. The GATE initiative will use this philosophy, combined with the Gaia Science Alerts resources, to maximize the number of transiting exoplanet detections of Gaia. The same approach can be used by other low-cadence surveys.

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

    OpenAIRE

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

    2013-01-01

    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...

  13. Transiting planets with LSST. I. Potential for LSST exoplanet detection

    Energy Technology Data Exchange (ETDEWEB)

    Lund, Michael B.; Pepper, Joshua; Stassun, Keivan G., E-mail: michael.b.lund@vanderbilt.edu [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States)

    2015-01-01

    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.

  14. High Precision Photometry of Bright Transiting Exoplanet Hosts

    Science.gov (United States)

    Wilson, Maurice; Eastman, Jason; Johnson, John A.

    2016-01-01

    Within the past two decades, the successful search for exoplanets and the characterization of their physical properties have shown the immense progress that has been made towards finding planets with characteristics similar to Earth. For most exoplanets with a radius about the size of Earth, evaluating their physical properties, such as the mass, radius and equilibrium temperature, cannot be determined with satisfactory precision. The MINiature Exoplanet Radial Velocity Array (MINERVA) was recently built to obtain spectroscopic and photometric measurements to find, confirm, and characterize Earth-like exoplanets. MINERVA's spectroscopic survey targets the brightest, nearby stars which are well-suited to the array's capabilities, while its primary photometric goal is to search for transits around these bright targets. Typically, it is difficult to find satisfactory comparison stars within a telescope's field of view when the primary target is very bright. This issue is resolved by using one of MINERVA's telescopes to observe the primary bright star while the other telescopes observe a distinct field of view that contains satisfactory bright comparison stars. We describe the code used to identify nearby comparison stars, schedule the four telescopes, produce differential photometry from multiple telescopes, and show the first results from this effort.This work has been funded by the Ronald E. McNair Post-Baccalaureate Achievement Program, the ERAU Honors Program, the ERAU Undergraduate Research Spark Fund, and the Banneker Institute at the Harvard-Smithsonian Center for Astrophysics.

  15. New tools and improvements in the Exoplanet Transit Database

    Directory of Open Access Journals (Sweden)

    Pejcha O.

    2011-02-01

    Full Text Available Comprehensive collection of the available light curves, prediction possibilities and the online model ?tting procedure, that are available via Exoplanet Transit Database became very popular in the community. In this paper we summarized the changes, that we made in the ETD during last year (including the Kepler candidates into the prediction section, modeling of an unknown planet in the model-?t section and some other small improvements. All this new tools cannot be found in the main ETD paper.

  16. Transmission spectrum of Venus as a transiting exoplanet

    OpenAIRE

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

    2011-01-01

    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 observ...

  17. FIVE KEPLER TARGET STARS THAT SHOW MULTIPLE TRANSITING EXOPLANET CANDIDATES

    International Nuclear Information System (INIS)

    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.

  18. 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.

  19. Five Kepler target stars that show multiple transiting exoplanet candidates

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, Jason H.; /Fermilab; Batalha, Natalie M.; /San Jose State U.; Borucki, William J.; /NASA, Ames; Buchhave, Lars A.; /Harvard-Smithsonian Ctr. Astrophys. /Bohr Inst.; Caldwell, Douglas A.; /NASA, Ames /SETI Inst., Mtn. View; Cochran, William D.; /Texas U.; Endl, Michael; /Texas U.; Fabrycky, Daniel C.; /Harvard-Smithsonian Ctr. Astrophys.; Fressin, Francois; /Harvard-Smithsonian Ctr. Astrophys.; Ford, Eric B.; /Florida U.; Fortney, Jonathan J.; /UC, Santa Cruz, Phys. Dept. /NASA, Ames

    2010-06-01

    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 multitransiting 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 (TTV) 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.

  20. Inferring asymmetric limb cloudiness on exoplanets from transit light curves

    CERN Document Server

    von Paris, P; Bordé, P; Leconte, J; Selsis, F

    2016-01-01

    Clouds have been shown to be present in many exoplanetary atmospheres. Cloud formation modeling predicts considerable inhomogeneities of cloud cover, consistent with optical phase curve observations. However, optical phase curves cannot resolve some existing degeneracies between cloud location and cloud optical properties. We present a conceptually simple technique to detect inhomogeneous cloud cover on exoplanets. Such an inhomogeneous cloud cover produces an asymmetric primary transit of the planet in front of the host star. Asymmetric transits produce characteristic residuals compared to a standard symmetric model. Furthermore, bisector spans can be used to determine asymmetries in the transit light curve. We apply a model of asymmetric transits to the light curves of HAT-P-7b, Kepler-7b and HD209458b and search for possible cloud signatures. The nearly uninterrupted Kepler photometry is particularly well-suited for this method since it allows for a very high time resolution. We do not find any statistical...

  1. Dynamics and Transit Variations of Resonant Exoplanets

    CERN Document Server

    Nesvorny, D

    2016-01-01

    The Transit Timing Variations (TTVs) are deviations of the measured mid-transit times from the exact periodicity. One of the most interesting causes of TTVs is the gravitational interaction between planets. Here we consider a case of two planets in a mean motion resonance (orbital periods in a ratio of small integers). This case is important because the resonant interaction can amplify the TTV effect and allow planets to be detected more easily. We develop an analytic model of the resonant dynamics valid for small orbital eccentricities and use it to derive the principal TTV terms. We find that a resonant system should show TTV terms with two basic periods (and their harmonics). The resonant TTV period is proportional (m/M_*)^(-2/3), where m and M_* are the planetary and stellar masses. For m=10^(-4) M_*, for example, the TTV period exceeds the orbital period by ~2 orders of magnitude. The amplitude of the resonant TTV terms scales linearly with the libration amplitude. The ratio of the TTV amplitudes of two ...

  2. Direct Detection of Exoplanets

    OpenAIRE

    Beuzit, Jean-Luc; Mouillet, David; Oppenheimer, Ben R.; Monnier, John D.

    2006-01-01

    Direct detection of exoplanets from the ground is now within reach of existing astronomical instruments. Indeed, a few planet candidates have already been imaged and analyzed and the capability to detect (through imaging or interferometry) young, hot, Jupiter-mass planets exists. We present here an overview of what such detection methods can be expected to do in the near and far term. These methods will provide qualitatively new information about exoplanets, including spectroscopic data that ...

  3. WASP-29b: A Saturn-sized Transiting Exoplanet

    OpenAIRE

    Hellier, Coel; Anderson, D. R.; Collier Cameron, A; Gillon, Michaël; 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

    2010-01-01

    We report the discovery of a Saturn-sized planet transiting a V = 11.3, K4 dwarf star every 3.9 days. WASP-29b has a mass of 0.24 ± 0.02 M [SUB]Jup[/SUB] and a radius of 0.79 ± 0.05 R [SUB]Jup[/SUB], 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 h...

  4. WASP-29b: A SATURN-SIZED TRANSITING EXOPLANET

    International Nuclear Information System (INIS)

    We report the discovery of a Saturn-sized planet transiting a V = 11.3, K4 dwarf star every 3.9 days. 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.

  5. PyTransit: Fast and Easy Exoplanet Transit Modelling in Python

    CERN Document Server

    Parviainen, Hannu

    2015-01-01

    We present a fast and user friendly exoplanet transit light curve modelling package PyTransit, implementing optimised versions of the Gimen\\'ez and the Mandel & Agol transit models. The package offers an object-oriented Python interface to access the two models implemented natively in Fortran with OpenMP parallelisation. A partial OpenCL version of the quadratic Mandel-Agol model is also included for GPU-accelerated computations. The aim of PyTransit is to facilitate the analysis of photometric time series of exoplanet transits consisting of hundreds of thousands of datapoints, and of multi-passband transit light curves from spectrophotometric observations, as a part of a researcher's programming toolkit for building complex, problem-specific, analyses.

  6. Optical Observations of the Transiting Exoplanet GJ 1214b

    CERN Document Server

    Teske, Johanna K; Mueller, Matthias; Griffith, Caitlin A

    2013-01-01

    We observed nine primary transits of the super-Earth exoplanet GJ 1214b in several optical photometric bands from March to August 2012, with the goal of constraining the short-wavelength slope of the spectrum of GJ 1214b. Our observations were conducted on the Kuiper 1.55 m telescope in Arizona and the STELLA-I robotic 1.2 m telescope in Tenerife, Spain. From the derived light curves we extracted transit depths in R (0.65 {\\mu}m), V (0.55 {\\mu}m), and g' (0.475 {\\mu}m) bands. Most previous observations of this exoplanet suggest a flat spectrum varying little with wavelength from the near-infrared to the optical, corresponding to a low-scale-height, high-molecular-weight atmosphere. However, a handful of observations around Ks band (~2.15 {\\mu}m) and g-band (~0.46 {\\mu}m) are inconsistent with this scenario and suggest a variation on a hydrogen- or water-dominated atmosphere that also contains a haze layer of small particles. In particular, the g-band observations of de Mooij et al. (2012), consistent with Ray...

  7. Emulating JWST Exoplanet Transit Observations in a Testbed laboratory experiment

    Science.gov (United States)

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

    2014-12-01

    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 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.

  8. Exploring LSST's Transiting Exoplanet Yield for the Large Magellanic Cloud

    Science.gov (United States)

    Lund, Michael B.; Jacklin, Savannah Renee; Pepper, Joshua; Stassun, Keivan

    2015-12-01

    The Large Synoptic Survey Telescope (LSST) will observe over half the sky during its ten-year mission, and will provide light curves for around one billion stars between 16th and 24th magnitude in the ugrizy bands. The combination of sky coverage and magnitude range will mean that a significant portion of the stars that LSST will observe will be in stellar populations that have rarely been observed by existing transiting planet searches. These new regimes that LSST will explore include Sun-like stars in the Galactic bulge, distant stellar clusters, the Magellanic Clouds, and nearby red dwarfs. We explore the potential yield of transiting exoplanets that LSST will be able to detect in the Large Magellanic Cloud. This presents a first opportunity to detect extragalactic planets.

  9. Practical suggestions on detecting exomoons in exoplanet transit light curves

    CERN Document Server

    Szabo, Gy M; Kiss, L L; Regaly, Zs

    2010-01-01

    The number of known transiting exoplanets is rapidly increasing, which has recently inspired significant interest as to whether they can host a detectable moon. Although there has been no such example where the presence of a satellite was proven, several methods have already been investigated for such a detection in the future. All these methods utilize post-processing of the measured light curves, and the presence of the moon is decided by the distribution of a timing parameter. Here we propose a method for the detection of the moon directly in the raw transit light curves. When the moon is in transit, it puts its own fingerprint on the intensity variation. In realistic cases, this distortion is too little to be detected in the individual light curves, and must be amplified. Averaging the folded light curve of several transits helps decrease the scatter, but it is not the best approach because it also reduces the signal. The relative position of the moon varies from transit to transit, the moon's wing will a...

  10. ExTrA: Exoplanets in Transit and their Atmospheres

    CERN Document Server

    Bonfils, X; Jocou, L; Wunsche, A; Kern, P; Delboulbé, A; Delfosse, X; Feautrier, P; Forveille, T; Gluck, L; Lafrasse, S; Magnard, Y; Maurel, D; Moulin, T; Murgas, F; Rabou, P; Rochat, S; Roux, A; Stadler, E

    2015-01-01

    The ExTrA facility, located at La Silla observatory, will consist of a near-infrared multi-object spectrograph fed by three 60-cm telescopes. ExTrA will add the spectroscopic resolution to the traditional differential photometry method. This shall enable the fine correction of color-dependent systematics that would otherwise hinder ground-based observations. With both this novel method and an infrared-enabled efficiency, ExTrA aims to find transiting telluric planets orbiting in the habitable zone of bright nearby M dwarfs. It shall have the versatility to do so by running its own independent survey and also by concurrently following-up on the space candidates unveiled by K2 and TESS. The exoplanets detected by ExTrA will be amenable to atmospheric characterisation with VLTs, JWST, and ELTs and could give our first peek into an exo-life laboratory.

  11. Characterising the atmospheres of transiting exoplanets using narrowband spectrophotometry

    Science.gov (United States)

    Wilson, Paul Anthony; Sing, David; Nikolov, Nikolay; Lecavelier des Etangs, Alain; Pont, Frédéric; Fortney, Jonathan; Ballester, Gilda; Lopez-Morales, Mercedes; Desert, Jean-Michel; Vidal-Madjar, Alfred

    2015-08-01

    Transiting hot-Jupiters provide an excellent opportunity to detect and characterise exoplanetary atmospheres. However, to be able to perform a wide scale comparative exoplanetology we have to observe targets which are too faint for the Hubble Space Telescope (HST). To do this, we use the the 10.4 m Gran Telescopio Canarias (GTC) telescope together with unique tunable filters capable of precision narrowband photometry at specific wavelengths. This technique coupled with the use of the world’s largest optical telescope allows us to obtain photon-limited sub-mmag narrowband transit spectrophotometry, capable of detecting Na, K, TiO and other important atmospheric species. The detection (and non-detection) of such key species can provide information on the temperature profile of the atmosphere determine the presence and extent of condensate clouds and give us insight into the chemical processes at play. This information is vital to be able to discern different exoplanet atmospheres and will in the future allow us to categorise exoplanets into different sub-classes.In this talk I will present the ground based detection of potassium in HAT-P-1b and describe the techniques used to deal with the systematics present in the data. I will discuss, in context of HST observations, the effects resolution has on the measurements and how atmospheric signatures could be missed if the resolution is not sufficiently high. Tunable filters allow the atmosphere to be probed higher up, where the pressures are lower and where the temperatures may be higher. Such conditions could cause the dissociation of molecular hydrogen into atomic hydrogen by the EUV flux from the host star. This will have important effects on the amplitude of the detection of alkali metals. With studies such as this one, we are well on our way to performing comparative exoplanetology using statistical methods.

  12. Toward the detection of exoplanet transits with polarimetry

    Energy Technology Data Exchange (ETDEWEB)

    Wiktorowicz, Sloane J. [NASA Sagan Fellow. (United States); Laughlin, Gregory P., E-mail: sloanew@ucolick.org [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)

    2014-11-01

    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° scattering angle and low optical depth experienced by photons at the limb. In addition to the ratio R {sub p}/R {sub *}, 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 the POLISH2 polarimeter at the Lick Observatory Shane 3 m telescope. We conclude that unmodeled telescope systematic effects prevented polarimetric detection of this event. We outline a roadmap for further refinements of exoplanet polarimetry, whose eventual success will require a further factor of ten reduction in systematic noise.

  13. On the Possibility of Detecting Class A Stellar Engines Using Exoplanet Transit Curves

    CERN Document Server

    Forgan, Duncan H

    2013-01-01

    The Class A stellar engine (also known as a Shkadov thruster) is a spherical arc mirror, designed to use the impulse from a star's radiation pressure to generate a thrust force, perturbing the star's motion. If this mirror obstructs part of the stellar disc during the transit of an exoplanet, then this may be detected by studying the shape of the transit light curve, presenting another potential means by which the action of extraterrestrial intelligence (ETI) can be discerned. We model the light curves produced by exoplanets transiting a star which possesses a Shkadov thruster, and show how the parameters of the planet and the properties of the thruster can be disentangled. provided that radial velocity follow-up measurements are possible, and that other obscuring phenomena typical to exoplanet transit curves (such as the presence of starspots or intrinsic stellar noise) do not dominate. These difficulties aside, we estimate the a priori probability of detecting a Shkadov thruster during an exoplanet transit,...

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

    Science.gov (United States)

    Hatzes, Artie P

    2014-09-18

    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

  15. Transmission spectrum of Venus as a transiting exoplanet

    CERN Document Server

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

    2011-01-01

    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...

  16. How do starspots influence the transit timing variations of exoplanets? Simulations of individual and consecutive transits

    CERN Document Server

    Ioannidis, P; Schmitt, J H M M

    2015-01-01

    Transit timing variations (TTVs) of exoplanets are normally interpreted as the consequence of gravitational interaction with additional bodies in the system. However, TTVs can also be caused by deformations of the system transits by starspots, which might thus pose a serious complication in their interpretation. We therefore simulate transit light curves deformed by spot-crossing events for different properties of the stellar surface and the planet, such as starspot position, limb darkening, planetary period, and impact parameter. Mid-transit times determined from these simulations can be significantly shifted with respect to the input values; these shifts cannot be larger than ~1% of the transit duration and depend most strongly on the longitudinal position of the spot during the transit and the transit duration. Consequently, TTVs with amplitudes larger than the above limit are very unlikely to be caused by starspots. We also investigate whether TTVs from sequences of consecutive transits with spot-crossing...

  17. Transiting Exoplanet Studies and Community Targets for JWST's Early Release Science Program

    OpenAIRE

    Stevenson, Kevin B.; Lewis, Nikole K.; Bean, Jacob L.; Beichman, Charles; Fraine, Jonathan; Kilpatrick, Brian M.; Krick, J. E.; Lothringer, Joshua D.; Mandell, Avi M.; Valenti, Jeff A.; Agol, Eric; Angerhausen, Daniel; Barstow, Joanna K.; Birkmann, Stephan M.; Burrows, Adam

    2016-01-01

    The James Webb Space Telescope will revolutionize transiting exoplanet atmospheric science due to its capability for continuous, long-duration observations and its larger collecting area, spectral coverage, and spectral resolution compared to existing space-based facilities. However, it is unclear precisely how well JWST will perform and which of its myriad instruments and observing modes will be best suited for transiting exoplanet studies. In this article, we describe a prefatory JWST Early...

  18. The GTC exoplanet transit spectroscopy survey. IV.: No asymmetries in the transit of Corot-29b

    CERN Document Server

    Palle, E; Alonso, R; Nowak, G; Deeg, H; Cabrera, J; Murgas, F; Parviainen, H; Nortmann, L; Hoyer, S; Prieto-Arranz, J; Nespral, D; Lavers, A Cabrera; Iro, N

    2016-01-01

    Context. The launch of the exoplanet space missions obtaining exquisite photometry from space has resulted in the discovery of thousands of planetary systems with very different physical properties and architectures. Among them, the exoplanet CoRoT-29b was identified in the light curves the mission obtained in summer 2011, and presented an asymmetric transit light curve, which was tentatively explained via the effects of gravity darkening. Aims. Transits of CoRoT-29b are measured with precision photometry, to characterize the reported asymmetry in their transit shape. Methods. Using the OSIRIS spectrograph at the 10-m GTC telescope, we perform spectro-photometric di?erential observations, which allow us to both calculate a high-accuracy photometric light curve, and a study of the color-dependence of the transit. Results. After careful data analysis, we find that the previously reported asymmetry is not present in either of two transits, observed in July 2014 and July 2015 with high photometric precisions of 3...

  19. Transiting Exoplanet Studies and Community Targets for JWST's Early Release Science Program

    CERN Document Server

    Stevenson, Kevin B; Bean, Jacob L; Beichman, Charles; Fraine, Jonathan; Kilpatrick, Brian M; Krick, J E; Lothringer, Joshua D; Mandell, Avi M; Valenti, Jeff A; Agol, Eric; Angerhausen, Daniel; Barstow, Joanna K; Birkmann, Stephan M; Burrows, Adam; Cowan, Nicolas B; Crouzet, Nicolas; Cubillos, Patricio E; Curry, S M; Dalba, Paul A; de Wit, Julien; Deming, Drake; Desert, Jean-Michel; Doyon, Rene; Dragomir, Diana; Ehrenreich, David; Fortney, Jonathan J; Munoz, Antonio Garcia; Gibson, Neale P; Gizis, John E; Greene, Thomas P; Harrington, Joseph; Heng, Kevin; Kataria, Tiffany; Kempton, Eliza M -R; Knutson, Heather; Kreidberg, Laura; Lafreniere, David; Lagage, Pierre-Olivier; Line, Michael R; Lopez-Morales, Mercedes; Madhusudhan, Nikku; Morley, Caroline V; Rocchetto, Marco; Schlawin, Everett; Shkolnik, Evgenya L; Shporer, Avi; Sing, David K; Todorov, Kamen O; Tucker, Gregory S; Wakeford, Hannah R

    2016-01-01

    The James Webb Space Telescope will revolutionize transiting exoplanet atmospheric science due to its capability for continuous, long-duration observations and its larger collecting area, spectral coverage, and spectral resolution compared to existing space-based facilities. However, it is unclear precisely how well JWST will perform and which of its myriad instruments and observing modes will be best suited for transiting exoplanet studies. In this article, we describe a prefatory JWST Early Release Science (ERS) program that focuses on testing specific observing modes to quickly give the community the data and experience it needs to plan more efficient and successful future transiting exoplanet characterization programs. We propose a multi-pronged approach wherein one aspect of the program focuses on observing transits of a single target with all of the recommended observing modes to identify and understand potential systematics, compare transmission spectra at overlapping and neighboring wavelength regions...

  20. C/O Ratios of Stars with Transiting Hot Jupiter Exoplanets

    CERN Document Server

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

    2014-01-01

    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...

  1. On the characterization of transiting exoplanets and magnetic spots with optical interferometry

    CERN Document Server

    Ligi, R; Lagrange, A -M; Perraut, K; Chiavassa, A

    2014-01-01

    Stellar activity causes difficulties in the characterization of transiting exoplanets. Studies have been performed to quantify its impact on infrared interferometry, but not in the visible domain, which however allows reaching better angular resolution and is also the one mostly used for spectroscopic and photometric measurements. We use a textbook case to make a complete analysis of the impact of an exoplanet and a spot on interferometric observables and relate it to current instruments capabilities, taking into account realistic achievable precisions. We have built a numerical code called COMETS using analytical formulae to perform a simple comparison of exoplanets and spots' signals. We explore instrumental specificities needed to detect them, like the baseline length required, the accuracy and SNR. We also discuss the impact of exoplanets and spot's parameters on squared visibility and phase. We find that the main improvement to bring is the sensitivity of instruments. The accuracy on squared visibilities...

  2. Search for transiting exoplanets and variable stars in the open cluster NGC 7243

    CERN Document Server

    Garai, Z; Hambálek, L; Errmann, R; Adam, Ch; Buder, S; Butterley, T; Dhillon, V S; Dincel, B; Gilbert, H; Ginski, Ch; Hardy, L K; Kellerer, A; Kitze, M; Kundra, E; Littlefair, S P; Mugrauer, M; Nedoroš?ík, J; Neuhäuser, R; Pannicke, A; Raetz, S; Schmidt, J G; Schmidt, T O B; Seeliger, M; Va?ko, M; Wilson, R W

    2016-01-01

    We report results of the first five observing campaigns for the open stellar cluster NGC 7243 in the frame of project Young Exoplanet Transit Initiative (YETI). The project focuses on the monitoring of young and nearby stellar clusters, with the aim to detect young transiting exoplanets, and to study other variability phenomena on time-scales from minutes to years. After five observing campaigns and additional observations during 2013 and 2014, a clear and repeating transit-like signal was detected in the light curve of J221550.6+495611. Furthermore, we detected and analysed 37 new eclipsing binary stars in the studied region. The best fit parameters and light curves of all systems are given. Finally, we detected and analysed 26 new, presumably pulsating variable stars in the studied region. The follow-up investigation of these objects, including spectroscopic measurements of the exoplanet candidate, is currently planned.

  3. The Transit Light Curve Project. XII. Six Transits of the Exoplanet XO-2b

    CERN Document Server

    Fernandez, Jose M; Winn, Joshua N; Torres, Guillermo; Shporer, Avi; Mazeh, Tsevi; Esquerdo, Gilbert A; Everett, Mark E

    2009-01-01

    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 rjup and the planetary mass to be 0.565 +/- 0.054 mjup. These results are consistent with those reported previously, and are also consistent with theoretical models for gas giant planets. The mid-transit times are accurate to within 1 min and are consistent with a constant period. However, the period we derive differs by 2.5 sigma 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.

  4. Observations of Transiting Exoplanets with the James Webb Space Telescope (JWST)

    Science.gov (United States)

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

    2014-12-01

    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 ratio (S/N). 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.

  5. C/O ratios of stars with transiting hot Jupiter exoplanets ,

    International Nuclear Information System (INIS)

    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.

  6. C/O ratios of stars with transiting hot Jupiter exoplanets ,

    Energy Technology Data Exchange (ETDEWEB)

    Teske, Johanna K.; Cunha, Katia [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Smith, Verne V. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Schuler, Simon C. [University of Tampa, 401 West Kennedy Boulevard, Tampa, FL 33606 (United States); Griffith, Caitlin A., E-mail: jteske@as.arizona.edu [Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States)

    2014-06-10

    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] λ6300 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{sub ☉} = 0.54), versus previously measured C/O{sub host} {sub 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.

  7. How do starspots influence the transit timing variations of exoplanets? Simulations of individual and consecutive transits

    Science.gov (United States)

    Ioannidis, P.; Huber, K. F.; Schmitt, J. H. M. M.

    2016-01-01

    Transit timing variations (TTVs) of exoplanets are normally interpreted as the consequence of gravitational interaction with additional bodies in the system. However, TTVs can also be caused by deformations of the system transits by starspots, which might thus pose a serious complication in their interpretation. We therefore simulate transit light curves deformed by spot-crossing events for different properties of the stellar surface and the planet, such as starspot position, limb darkening, planetary period, and impact parameter. Mid-transit times determined from these simulations can be significantly shifted with respect to the input values; these shifts cannot be larger than 1% of the transit duration and depend very strongly on the longitudinal position of the spot during the transit and the transit duration. Consequently, TTVs with amplitudes larger than the above limit are very unlikely to be caused by starspots. We also investigate whether TTVs from sequences of consecutive transits with spot-crossing anomalies can be misinterpreted as the result of an additional body in the system. We use the Generalized Lomb-Scargle periodogram to search for periods in TTVs and conclude that low-amplitude TTVs with statistically significant periods around active stars are the most problematic cases. In those cases where the photometric precision is high enough to inspect the transit shapes for deformations it should be possible to identify TTVs caused by starspots; however, especially for cases with low signal-to-noise in transit (TSNR ? 15) light curves it becomes quite difficult to reliably decide whether these periods come from starspots, physical companions in the system, or if they are random noise artifacts.

  8. The "missing link": a 4-day period transiting exoplanet around OGLE-TR-111

    CERN Document Server

    Pont, F; Queloz, D; Santos, N; Melo, C; Mayor, M; Udry, S; Pont, Frederic; Bouchy, Francois; Queloz, Didier; Santos, Nuno; Melo, Claudio; Mayor, Michel; Udry, Stephane

    2004-01-01

    We report the discovery of a transiting hot Jupiter around OGLE-TR-111, from our radial velocity follow-up of OGLE transiting candidates in Carina. The planet has a mass of 0.53 +- 0.11 M_J and a radius of 1.0 +0.13-0.06 R_J. Three transiting exoplanets have already been found among OGLE candidates, all with periods near 1.5 days. The planet presented here, with P=4.0 days, is the first exoplanet detected by transits with the characteristics of a "normal" hot Jupiter, as found in abundance by radial velocity surveys The radius of OGLE-TR-111b and the scarcity of hot Jupiters detected among OGLE transit candidates tend to indicate that the case of HD209458b, with a radius of 1.4 R_J, is exceptional, with most hot Jupiters being smaller.

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

    Science.gov (United States)

    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

    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.

  10. Transit, Secondary Eclipse, and Phase Curve Modeling to Characterize Kepler Exoplanet Candidates

    Science.gov (United States)

    Tarnas, Jesse; Redfield, Seth

    2016-01-01

    The high sensitivity and continuous coverage of Kepler allows for analysis of optical phase curves, which provide detailed exoplanet characterization by fitting photometric features caused by thermal emission, reflected light, Doppler boosting, and ellipsoidal variations. Combined with transit and secondary eclipse analysis to reduce model degeneracy, phase curves can resolve atmospheric characteristics, dayside-nightside temperatures, and even mass using single-band photometry. We will present an integrated phase curve, transit, and secondary eclipse analysis of Kepler exoplanet candidates, building on the phase curve model constructed by Serindag & Redfield (2015). Phase curves can also be present in non-transiting systems. We will explore the feasibility of detecting and characterizing these non-transiting exoplanets. We will also investigate the possibility of analyzing exoplanet phase curves in K2 data. We gratefully acknowledge support through a grant (14-K2GO1_2-0071) associated with the K2 Guest Observer — Cycle 1 program of Research Opportunities in Space and Earth Sciences (ROSES-2014; NNH14ZDA001N).

  11. Exoplanet Transit Spectroscopy of Hot Jupiters Using HST/WFC3

    Science.gov (United States)

    Haynes, Korey; Mandell, Avi M.; Sinukoff, Evan; Madhusudhan, Nikku; Burrows, Adam; Deming, Drake

    2014-01-01

    We present analysis of transit spectroscopy of three extrasolar planets, WASP-12 b, WASP-17 b, and WASP-19 b, using the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). Measurement of molecular absorption in the atmospheres of these planets offers the chance to explore several outstanding questions regarding the atmospheric structure and composition of these highly irradiated, Jupiter-mass objects. We analyze the data for a single transit for each planet, using a strategy similar in certain aspects to the techniques used by Berta (2012), and achieve almost photon-limited results for individual spectral bins. Our final transit spectra are consistent with the presence of a broad absorption feature at 1.4 ?m most likely due to water, but the amplitude of the absorption is less than expected based on previous observations with Spitzer, possibly due to hazes absorbing in the NIR. However, the degeneracy of models with different compositions and temperature structures combined with the low amplitude of any features in the data preclude our ability to place unambiguous constraints on the atmospheric composition without a comprehensive multi-wavelength analysis.

  12. A new powerful method for probing the atmospheres of transiting exoplanets

    CERN Document Server

    Snellen, I

    2004-01-01

    Although atmospheric transmission spectroscopy of HD209458b with the Hubble Space Telescope has been very successful, attempts to detect its atmospheric absorption features using ground-based telescopes have so far been fruitless. Here we present a new method for probing the atmospheres of transiting exoplanets which may be more suitable for ground-based observations, making use of the Rossiter effect. During a transit, an exoplanet sequentially blocks off light from the approaching and receding parts of the rotating star, causing an artificial radial velocity wobble. The amplitude of this signal is directly proportional to the effective size of the transiting object, and the wavelength dependence of this effect can reveal atmospheric absorption features, in a similar way as with transmission spectroscopy. The advantage of this method over conventional atmospheric transmission spectroscopy is that it does not rely on accurate photometric comparisons of observations on and off transit, but instead depends on t...

  13. ASTEP South: An Antarctic Search for Transiting ExoPlanets around the celestial South pole

    OpenAIRE

    Crouzet, N; Guillot, T.; Agabi, A; Rivet, J-P; Bondoux, E; Challita, Z.; Fantei-Caujolle, Y; Fressin, F; Mekarnia, D.; Schmider, F-X; Valbousquet, F; Blazit, A.; Bonhomme, S.; Abe, L.; Daban, J-B

    2009-01-01

    Context: 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, favorable weather conditions, and low scintillation. Aims: The ASTEP project (Antarctic Search for Transiting ExoPlanets) is a pilot project to discover transiting planets and understand the limits of visible photometry from the Concordia site. Methods: ASTEP South is the first phase of the ASTEP project. The instrument is a fix...

  14. DETECTION OF TRANSITING JOVIAN EXOPLANETS BY GAIA PHOTOMETRY-EXPECTED YIELD

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  15. 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.

  16. Microlensing Constraints on the Frequency of Jupiter Mass Planets

    OpenAIRE

    Gaudi, B. Scott; Albrow, M. D.; An, Jin H.; Beaulieu, J.-P.; Caldwell, J. A. R.; DePoy, D. L.; Dominik, M.; Gould, A; Greenhill, J.; Hill, K; Kane, S.; Martin, R.; Menzies, J.; Pogge, R. W; Pollard, K.

    2000-01-01

    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...

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

    Science.gov (United States)

    Griffith, Caitlin A

    2014-04-28

    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 four atmospheric scale heights at each wavelength band. Derived mixing ratios from these data are highly sensitive to errors in the radius of the planet at a reference pressure. For example, an uncertainty of 1% in the radius of a 1000?K and H2-based exoplanet with Jupiter's radius and mass causes an uncertainty of a factor of approximately 100-10,000 in the derived gas mixing ratios. The degree of sensitivity depends on how the line strength increases with the optical depth (i.e. the curve of growth) and the atmospheric scale height. Temperature degeneracies in the solutions of the primary transit data, which manifest their effects through the scale height and absorption coefficients, are smaller. We argue that these challenges can be partially surmounted by a combination of selected wavelength sampling of optical and infrared measurements and, when possible, the joint analysis of transit and secondary eclipse data of exoplanets. However, additional work is needed to constrain other effects, such as those owing to planetary clouds and star spots. Given the current range of open questions in the field, both observations and theory, there is a need for detailed measurements with space-based large mirror platforms (e.g. James web space telescope) and smaller broad survey telescopes as well as ground-based efforts. PMID:24664920

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

    Science.gov (United States)

    Holman, Matthew J.; Winn, Joshua N.; Latham, David W.; O'Donovan, Francis T.; Charbonneau, David; Bakos, Gáspár A.; Esquerdo, Gilbert A.; Hergenrother, Carl; Everett, Mark E.; Pál, András

    2006-12-01

    We present RIz photometry of four consecutive transits of the newly discovered exoplanet XO-1b. We improve on the estimates of the transit parameters, finding the planetary radius to be RP=1.184+0.028-0.018RJ, and the stellar radius to be R*=0.928+0.018-0.013 Rsolar, assuming a stellar mass of M*=(1.00+/-0.03) Msolar. 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 Msolar is assumed for the stellar mass. Our estimate of the planetary radius is smaller than that reported by McCullough and coworkers, and the resulting estimate for the mean density of XO-1b is intermediate between that of the low-density planet HD 209458b and the higher density planets 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.

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

    CERN Document Server

    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

    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.

  20. Maps and Masses of Transiting Exoplanets: Towards New Insights into Atmospheric and Interior Properties of Planets

    CERN Document Server

    de Wit, Julien

    2015-01-01

    With over 1800 planets discovered outside of the Solar System in the past two decades, the field of exoplanetology has broadened our perspective on planetary systems. Research priorities are now moving from planet detection to planet characterization. In this context, transiting exoplanets are of special interest due to the wealth of data made available by their orbital configuration. Here, I introduce two methods to gain new insights into the atmospheric and interior properties of exoplanets. The first method aims to map an exoplanet's atmosphere based on the scanning obtained while it is occulted by its host star. I introduce the basics of eclipse mapping, its caveats, and a framework to mitigate their effects via global analyses including transits, phase curves, and radial velocity measurements. I use this method to create the first 2D map and the first cloud map of an exoplanet for the hot-Jupiters HD189733b and Kepler-7b, respectively. Ultimately temperature, composition, and circulation patterns could b...

  1. Using near infra-red spectroscopy for characterization of transiting exoplanets

    CERN Document Server

    Aronson, Erik; Piskunov, Nikolai

    2015-01-01

    We propose a method for observing transiting exoplanets with near-infrared high-resolution spectrometers. We aim to create a robust data analysis method for recovering atmospheric transmission spectra from transiting exoplanets over a wide wavelength range in the near infrared. By using an inverse method approach, combined with stellar models and telluric transmission spectra, the method recovers the transiting exoplanet's atmospheric transmittance at high precision over a wide wavelength range. We describe our method and have tested it by simulating observations. This method is capable of recovering transmission spectra of high enough accuracy to identify absorption features from molecules such as O2, CH4, CO2, and H2O. This accuracy is achievable for Jupiter-size exoplanetsat S/N that can be reached for 8m class telescopes using high-resolution spectrometers (R>20 000) during a single transit, and for Earth-size planets and super-Earths transiting late K or M dwarf stars at S/N reachable during observations...

  2. Thermal phase curves of non-transiting terrestrial exoplanets 1. Characterizing atmospheres

    CERN Document Server

    Selsis, Franck; Forget, François

    2011-01-01

    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 non-transiting configurations, and could be observed for hot terrestrial exoplanets. We study the wavelength and phase changes of the thermal emission of a tidally-locked terrestrial planet as atmospheric pressure increases, and address the observability of these multiband phase-curves and the ability to use them to detect atmospheric constituents. We used a 3D climate model (GCM) to simulate the CO2 atmosphere of a terrestrial planet on an 8-day orbit around a M3 dwarf and its apparent infrared emission as a function of its orbital phase. We estimated the signal to photon-noise ratio in narrow bands betw...

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

    Science.gov (United States)

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

    2015-01-01

    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.

  4. Improving Transit Predictions of Known Exoplanets with TERMS

    OpenAIRE

    Mahadevan S.; Laughlin G.; Jensen E.; Howard A; Fischer D.; Henry G.; Ciardi D.; Kane S. R.; von Braun K.; Wright J.

    2010-01-01

    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 refinement 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.

  5. Improving Transit Predictions of Known Exoplanets with TERMS

    Directory of Open Access Journals (Sweden)

    Mahadevan S.

    2011-02-01

    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.

  6. C/O Ratios of Stars with Transiting Hot Jupiter Exoplanets

    Science.gov (United States)

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

    2014-06-01

    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.

  7. Scientific, Back-Illuminated CCD Development for the Transiting Exoplanet Survey Satellite

    Science.gov (United States)

    Suntharalingam, V.; Ciampi, J.; Cooper, M. J.; Lambert, R. D.; O'Mara, D. M.; Prigozhin, I.; Young, D. J.; Warner, K.; Burke, B. E.

    2015-01-01

    We describe the development of the fully depleted, back illuminated charge coupled devices for the Transiting Exoplanet Survey Satellite, which includes a set of four wide angle telescopes, each having a 2x2 array of CCDs. The devices are fabricated on the newly upgraded 200-mm wafer line at Lincoln Laboratory. We discuss methods used to produce the devices and present early performance results from the 100- micron thick, 15x15-microns, 2k x 4k pixel frame transfer CCDs.

  8. ASTERIA: A CubeSat for Exoplanet Transit and Stellar Photometry

    Science.gov (United States)

    Knapp, Mary; Seager, Sara

    2015-12-01

    We present ASTERIA, a 6U CubeSat demonstrator for exoplanet transit photometry. ASTERIA, currently in development at JPL and due to be launched in mid to late 2016, is a testbed for a two-stage pointing system capable of data will be used to study flares and stellar activity on a variety of stellar types. This presentation will focus on ASTERIA's science mission.

  9. The Guest Investigator Program for the Transiting Exoplanet Survey Satellite (TESS)

    Science.gov (United States)

    Rinehart, Stephen; Ricker, George R.; Seager, Sara; Latham, David W.; Kraft Vanderspek, Roland; Winn, Joshua N.

    2016-01-01

    Over the summer of 2015, NASA HQ approved the establishment of a Guest Investigator (GI) Program for the Transiting Exoplanet Survey Satellite (TESS). This office, being established at NASA's Goddard Space Flight Center, will provide support to the Astronomical Community for working with data from the TESS mission. In this presentation, we discuss the overall structure and plan for the GI program, and show the schedule for Community involvement.

  10. Towards the Albedo of an Exoplanet: MOST Satellite Observations of Bright Transiting Exoplanetary Systems

    OpenAIRE

    Rowe, Jason F.; Matthews, Jaymie M.; Seager, Sara; Sasselov, Dimitar; Kuschnig, Rainer; Guenther, David B.; Moffat, Anthony F. J.; Rucinski, Slavek M.; Walker, Gordon A. H; Weiss, Werner W.

    2008-01-01

    The Canadian MOST satellite is a unique platform for observations of bright transiting exoplanetary systems. Providing nearly continuous photometric observations for up to 8 weeks, MOST can produce important observational data to help us learn about the properties of exosolar planets. We review our current observations of HD 209458, HD 189733 with implications towards the albedo and our progress towards detecting reflected light from an exoplanet.

  11. 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 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.

  12. Investigating Close-in Exoplanets through Transit Observations

    CERN Document Server

    Jiang, Ing-Guey; Thakur, Parijat; Chien, Ping; Lin, Yi-Ling; Wu, Yu-Ting; Chen, Hong-Yu; Sun, Zhao; Ji, Jianghui

    2013-01-01

    Through the international collaborators, we recently established a network of existing and working meter-class telescopes to look for planetary transit events. As a first step, we focus on the TrES3 system, and conclude that there could be some level of transit timing variations.

  13. 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 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.

  14. Five kepler target stars that show multiple transiting exoplanet candidates

    DEFF Research Database (Denmark)

    Steffen..[], Jason H.; Batalha, N. M.; Broucki, W J.; Buchhave, Lars C. Astrup

    2010-01-01

    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...... 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....

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

    Directory of Open Access Journals (Sweden)

    Désert J.-M.

    2011-07-01

    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.

  16. A Method to Identify the Boundary Between Rocky and Gaseous Exoplanets from Tidal Theory and Transit Durations

    CERN Document Server

    Barnes, Rory

    2013-01-01

    The determination of an exoplanet as rocky is critical for the assessment of planetary habitability. Observationally, the number of small-radius, transiting planets with accompanying mass measurements is insufficient for a robust determination of the transitional mass or radius. Theoretically, models predict that rocky planets can grow large enough to become gas giants when they reach ~10 Earth-masses, but the transitional mass remains unknown. Here I show how transit data, interpreted in the context of tidal theory, can reveal the critical radius that separates rocky and gaseous exoplanets. Standard tidal models predict that rocky exoplanets' orbits are tidally circularized much more rapidly than gaseous bodies', suggesting the former will tend to be found on circular orbits at larger semi-major axes than the latter. Well-sampled transits can provide a minimum eccentricity of the orbit, allowing a measurement of this differential circularization. I show that this effect should be present in the data from the...

  17. The mass of the Mars-sized exoplanet Kepler-138 b from transit timing

    CERN Document Server

    Jontof-Hutter, Daniel; Lissauer, Jack J; Fabrycky, Daniel C; Ford, Eric B

    2015-01-01

    Extrasolar planets that pass in front of their host star (transit) cause a temporary decrease in the apparent brightness of the star once per orbit, providing a direct measure of the planet's size and orbital period. In some systems with multiple transiting planets, the times of the transits are measurably affected by the gravitational interactions between neighbouring planets. In favorable cases, the departures from Keplerian orbits implied by the observed transit times permit planetary masses to be measured, which is key to determining bulk densities. Characterizing rocky planets is particularly difficult, since they are generally smaller and less massive than gaseous planets. Thus, few exoplanets near Earth's size have had their masses measured. Here we report the sizes and masses of three planets orbiting Kepler-138, a star much fainter and cooler than the Sun. We measure the mass of the Mars-sized inner planet based on on the transit times of its neighbour and thereby provide the first density measuremen...

  18. Transit Timing Variations as a Tool for the Bayesian Characterization of Exoplanets

    Science.gov (United States)

    Ford, Eric B.; Jontof-Hutter, Daniel; Dawson, Rebekah; Fabrycky, Daniel; Mills, Sean; Ragozzine, Darin; Rogers, Leslie Anne; Shabram, Megan

    2015-08-01

    NASA's Kepler mission has revolutionized time-domain photometry with its photometric precision, high duty cycle, and long observing baseline. In addition to discovering thousands of planet candidates that pass in front of their host star, Kepler's has enabled the precise measurement of transit timing variations (TTV), deviations of transit times from a Keplerian ephemeris due to gravitational interactions among planets (or more massive bodies in the same planetary system). For dozens of planets, TTVs enable the precise characterization of planet masses and orbits, including many planets for which characterization via Doppler observations is impractical.For example, TTVs have: 1) characterized of masses of planets in systems with 2-6 transiting exoplanets, 2) measured densities for low-mass, low-density mass planets that orbit stars with periods of ~50-200 days, and provided precise measurements of orbital eccentricities even in the challenging regime of etimes for populations of transiting planets (including those for which no deviations from Keplerian orbits are detected) enable the characterization of the exoplanet distribution function.In both cases, attention to details of the statistical model and computational methods are essential for drawing robust conclusions. I will present selected TTV success stories, describing how these studies dealt with various statistical and computational challenges. Finally, I will describe opportunities for further improvements in the statistical analyses of transit timing variations and the potential science return.

  19. Venus transit 2004: Illustrating the capability of exoplanet transmission spectroscopy

    OpenAIRE

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

    2011-01-01

    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...

  20. Hubble Space Telescope search for the transit of the Earth-mass exoplanet Alpha Centauri Bb

    CERN Document Server

    Demory, Brice-Olivier; Queloz, Didier; Seager, Sara; Gilliland, Ronald; Chaplin, William J; Proffitt, Charles; Gillon, Michael; Guenther, Maximilian N; Benneke, Bjoern; Dumusque, Xavier; Lovis, Christophe; Pepe, Francesco; Segransan, Damien; Triaud, Amaury; Udry, Stephane

    2015-01-01

    Results from exoplanet surveys indicate that small planets (super-Earth size and below) are abundant in our Galaxy. However, little is known about their interiors and atmospheres. There is therefore a need to find small planets transiting bright stars, which would enable a detailed characterisation of this population of objects. We present the results of a search for the transit of the Earth-mass exoplanet Alpha Centauri Bb with the Hubble Space Telescope (HST). We observed Alpha Centauri B twice in 2013 and 2014 for a total of 40 hours. We achieve a precision of 115 ppm per 6-s exposure time in a highly-saturated regime, which is found to be consistent across HST orbits. We rule out the transiting nature of Alpha Centauri Bb with the orbital parameters published in the literature at 96.6% confidence. We find in our data a single transit-like event that could be associated to another Earth-size planet in the system, on a longer period orbit. Our program demonstrates the ability of HST to obtain consistent, hi...

  1. Observing transiting exoplanets: Removing systematic errors to constrain atmospheric chemistry and dynamics

    Science.gov (United States)

    Zellem, Robert Thomas

    2015-03-01

    The > 1500 confirmed exoplanets span a wide range of planetary masses ( 1 MEarth -20 MJupiter), radii ( 0.3 R Earth -2 RJupiter), semi-major axes ( 0.005-100 AU), orbital periods ( 0.3-1 x 105 days), and host star spectral types. The effects of a widely-varying parameter space on a planetary atmosphere's chemistry and dynamics can be determined through transiting exoplanet observations. An exoplanet's atmospheric signal, either in absorption or emission, is on the order of 0.1% which is dwarfed by telescope-specific systematic error sources up to 60%. This thesis explores some of the major sources of error and their removal from space- and ground-based observations, specifically Spitzer /IRAC single-object photometry, IRTF/SpeX and Palomar/TripleSpec low-resolution single-slit near-infrared spectroscopy, and Kuiper/Mont4k multi-object photometry. The errors include pointing-induced uncertainties, airmass variations, seeing-induced signal loss, telescope jitter, and system variability. They are treated with detector efficiency pixel-mapping, normalization routines, a principal component analysis, binning with the geometric mean in Fourier-space, characterization by a comparison star, repeatability, and stellar monitoring to get within a few times of the photon noise limit. As a result, these observations provide strong measurements of an exoplanet's dynamical day-to-night heat transport, constrain its CH4 abundance, investigate emission mechanisms, and develop an observing strategy with smaller telescopes. The reduction methods presented here can also be applied to other existing and future platforms to identify and remove systematic errors. Until such sources of uncertainty are characterized with bright systems with large planetary signals for platforms such as the James Webb Space Telescope, for example, one cannot resolve smaller objects with more subtle spectral features, as expected of exo-Earths.

  2. Transiting exoplanets from the CoRoT space mission

    DEFF Research Database (Denmark)

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

    2012-01-01

    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 combin...

  3. Estimating transiting exoplanet masses from precise optical photometry

    CERN Document Server

    Mislis, D; Schmitt, J H M M; Hodgkin, S

    2011-01-01

    We present a theoretical analysis of the optical light curves (LCs) for short-period high-mass transiting extrasolar planet systems. Our method considers the primary transit, the secondary eclipse, and the overall phase shape of the LC between the occultations. Phase variations arise from (i) reflected and thermally emitted light by the planet, (ii) the ellipsoidal shape of the star due to the gravitational pull of the planet, and (iii) the Doppler shift of the stellar light as the star orbits the center of mass of the system. Our full model of the out-of-eclipse variations contains information about the planetary mass, orbital eccentricity, the orientation of periastron and the planet's albedo. For a range of hypothetical systems we demonstrate that the ellipsoidal variations (ii.) can be large enough to be distinguished from the remaining components and that this effect can be used to constrain the planet's mass. To detect the ellipsoidal variations, the LC requires a minimum precision of 10-4, which coinci...

  4. Venus transit 2004: Illustrating the capability of exoplanet transmission spectroscopy

    CERN Document Server

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

    2011-01-01

    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.

  5. Venus transit 2004: Illustrating the capability of exoplanet transmission spectroscopy

    Science.gov (United States)

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

    2011-09-01

    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.

  6. Investigation of the environment around close-in transiting exoplanets using CLOUDY

    OpenAIRE

    Turner, Jake D.; Christie, Duncan; Arras, Phil; Johnson, Robert E.; Schmidt, Carl

    2016-01-01

    It has been suggested that hot stellar wind gas in a bow shock around an exoplanet is sufficiently opaque to absorb stellar photons and give rise to an observable transit depth at optical and UV wavelengths. In the first part of this paper, we use the CLOUDY plasma simulation code to model the absorption from X-ray to radio wavelengths by 1-D slabs of gas in coronal equilibrium with varying densities ($10^{4}-10^{8} \\, {\\rm cm^{-3}}$) and temperatures ($2000-10^{6} \\ {\\rm K}$) illuminated by ...

  7. Asteroseismology of the Transiting Exoplanet Host HD 17156 with Hubble Space Telescope Fine Guidance Sensor

    DEFF Research Database (Denmark)

    Gilliland, Ronald L.; McCullough, Peter R.; Nelan, Edmund P.; Brown, Timothy M.; Charbonneau, David; Nutzman, Philip; Christensen-Dalsgaard, Jørgen; Kjeldsen, Hans

    2011-01-01

    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 × 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 ...

  8. Defocused Observations of Selected Exoplanet Transits with T100 in TUBITAK National Observatory of Turkey (TUG)

    CERN Document Server

    Basturk, Ozgur; Ozavci, Ibrahim; Yorukoglu, Onur; Selam, Selim O

    2015-01-01

    It is crucial to determine masses and radii of extrasolar planets with high precision to have constraints on their chemical composition, internal structure and thereby their formation and evolution. In order to achieve this goal, we apply the defocus technique in the observations of selected planetary systems with the 1 m Turkish telescope T100 in TUBITAK National Observatory (TUG). With this contribution, we aim to present preliminary analyses of transit light curves of the selected exoplanets KELT-3b, HAT-P-10b/WASP-11b, HAT-P-20b, and HAT-P-22b, observed with this technique using T100.

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

    CERN Document Server

    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

    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...

  10. WASP-19b: THE SHORTEST PERIOD TRANSITING EXOPLANET YET DISCOVERED

    International Nuclear Information System (INIS)

    We report on the discovery of a new extremely short period transiting extrasolar planet, WASP-19b. The planet has mass Mpl = 1.15 ± 0.08 MJ , radius Rpl = 1.31 ± 0.06 RJ , and orbital period P = 0.7888399 ± 0.0000008 days. Through spectroscopic analysis, we determine the host star to be a slightly super-solar metallicity ([M/H] = 0.1 ± 0.1 dex) G-dwarf with Teff = 5500 ± 100 K. In addition, we detect periodic, sinusoidal flux variations in the light curve which are used to derive a rotation period for the star of Prot = 10.5 ± 0.2 days. The relatively short stellar rotation period suggests that either WASP-19 is somewhat young (? 600 Myr old) or tidal interactions between the two bodies have caused the planet to spiral inward over its lifetime resulting in the spin-up of the star. Due to the detection of the rotation period, this system has the potential to place strong constraints on the stellar tidal quality factor, Q's, if a more precise age is determined.

  11. Bayesian mass and age estimates for transiting exoplanet host stars

    CERN Document Server

    Maxted, P F L; Southworth, J

    2014-01-01

    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...

  12. The search for single exoplanet transits in the Kepler light curves

    Science.gov (United States)

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

    2015-08-01

    The planet discoveries made using data from the Kepler mission have revolutionized the field of exoplanet statistics. Thousands of planets have been discovered with orbital periods ranging from hours to two years. Some of the most dynamically interesting planets (Jupiter analogs, for example) only show a single transit in the four-year baseline of the Kepler mission and, as a result, they have not yet been found. Upcoming transit surveys like K2, TESS, and PLATO all have shorter contiguous observation baselines. It is therefore crucial to develop robust techniques for the discovery of single transit events. We present a search procedure designed to find single transits using a supervised classification model. To search for a transit signal in a given month-long light curve from Kepler, we train a random forest classifier on tens of thousands of simulated transit signals injected into the light curve of the same star at other times. Using a different set of simulations, we tune the model to maximize the precision of the recovered signals---minimizing the false alarm rate. With this model, we classify each section of the test light curve into two categories: transit and no transit. We demonstrate that this model is robust to systematic false positives and present an automated catalog of convincing single transit candidates.

  13. Accurate radius and mass of the transiting exoplanet OGLE-TR-132b

    CERN Document Server

    Moutou, C; Bouchy, F; Mayor, M

    2004-01-01

    The exoplanet OGLE-TR-132b belongs to the new class of very hot giant planets, together with OGLE-TR-56b and OGLE-TR-113b, detected by their transits. Recently, radial velocity measurements provided a planetary mass estimate for OGLE-TR-132b. The planet parameters, however, were poorly cons trained, because of the very shallow transit in the OGLE light curve. In this letter, based on new VLT/FORS2 photometric follow-up of OGLE-TR-132 of unprecedented quality (1.2 millimagnitude relative photometry), we confirm the planetary nature of the orbiting object, and we derive an accurate measurement of its radius and mass: 1.13 +- 0.08 R_J and 1.19 +- 0.13 M_J. The refined ephemeris of OGLE-TR-132 transits is T_0 = 2453142.5888 and P = 1.689857 days.

  14. Astrophysical false positives in exoplanet transit surveys: why do we need bright stars ?

    CERN Document Server

    Santerne, A; Almenara, J -M; Lethuillier, A; Deleuil, M; Moutou, C

    2013-01-01

    Astrophysical false positives that mimic planetary transit are one of the main limitation to exoplanet transit surveys. In this proceeding, we review the issue of the false positive in transit survey and the possible complementary observations to constrain their presence. We also review the false-positive rate of both Kepler and CoRoT missions and present the basics of the planet-validation technique. Finally, we discuss the interest of observing bright stars, as PLATO 2.0 and TESS will do, in the context of the false positives. According to simulations with the Besan\\c{c}on galactic model, we find that PLATO 2.0 is expected to have less background false positives than Kepler, and thus an even lower false-positive rate.

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

    Science.gov (United States)

    Misra, Amit; Meadows, Victoria; Crisp, Dave

    2014-09-01

    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 Pallé et al. We perform detectability studies to show the potential effects of refraction on hypothetical observations of Earth analogs with the James Webb Space Telescope 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 (S/N) of absorption features by 60%, while for an Earth-analog planet orbiting in the habitable zone of an M5V star it is possible to probe almost the entire atmosphere with minimal decreases in S/N. We also show that refraction can result in temporal variations in the transit transmission spectrum which may provide a way to obtain altitude-dependent spectra of exoplanet atmospheres. Additionally, the variations prior to ingress and subsequent to egress provide a way to probe pressures greater than the maximum tangent pressure that can be probed during transit. Therefore, probing the maximum range of atmospheric altitudes, and in particular the near-surface environment of an Earth-analog exoplanet, will require looking at out-of-transit refracted light in addition to the in-transit spectrum.

  16. The effects of refraction on transit transmission spectroscopy: application to Earth-like exoplanets

    Energy Technology Data Exchange (ETDEWEB)

    Misra, Amit; Meadows, Victoria [Astronomy Department, University of Washington, Box 351580, Seattle, WA 98195 (United States); Crisp, Dave, E-mail: amit0@astro.washington.edu [NAI Virtual Planetary Laboratory, Seattle, WA (United States)

    2014-09-01

    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 Pallé et al. We perform detectability studies to show the potential effects of refraction on hypothetical observations of Earth analogs with the James Webb Space Telescope 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 (S/N) of absorption features by 60%, while for an Earth-analog planet orbiting in the habitable zone of an M5V star it is possible to probe almost the entire atmosphere with minimal decreases in S/N. We also show that refraction can result in temporal variations in the transit transmission spectrum which may provide a way to obtain altitude-dependent spectra of exoplanet atmospheres. Additionally, the variations prior to ingress and subsequent to egress provide a way to probe pressures greater than the maximum tangent pressure that can be probed during transit. Therefore, probing the maximum range of atmospheric altitudes, and in particular the near-surface environment of an Earth-analog exoplanet, will require looking at out-of-transit refracted light in addition to the in-transit spectrum.

  17. The effects of refraction on transit transmission spectroscopy: application to Earth-like exoplanets

    International Nuclear Information System (INIS)

    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 Pallé et al. We perform detectability studies to show the potential effects of refraction on hypothetical observations of Earth analogs with the James Webb Space Telescope 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 (S/N) of absorption features by 60%, while for an Earth-analog planet orbiting in the habitable zone of an M5V star it is possible to probe almost the entire atmosphere with minimal decreases in S/N. We also show that refraction can result in temporal variations in the transit transmission spectrum which may provide a way to obtain altitude-dependent spectra of exoplanet atmospheres. Additionally, the variations prior to ingress and subsequent to egress provide a way to probe pressures greater than the maximum tangent pressure that can be probed during transit. Therefore, probing the maximum range of atmospheric altitudes, and in particular the near-surface environment of an Earth-analog exoplanet, will require looking at out-of-transit refracted light in addition to the in-transit spectrum.

  18. Towards Automatic Classification of Exoplanet-Transit-Like Signals: A Case Study on Kepler Mission Data

    Science.gov (United States)

    Valizadegan, Hamed; Martin, Rodney; McCauliff, Sean D.; Jenkins, Jon Michael; Catanzarite, Joseph; Oza, Nikunj C.

    2015-08-01

    Building new catalogues of planetary candidates, astrophysical false alarms, and non-transiting phenomena is a challenging task that currently requires a reviewing team of astrophysicists and astronomers. These scientists need to examine more than 100 diagnostic metrics and associated graphics for each candidate exoplanet-transit-like signal to classify it into one of the three classes. Considering that the NASA Explorer Program's TESS mission and ESA's PLATO mission survey even a larger area of space, the classification of their transit-like signals is more time-consuming for human agents and a bottleneck to successfully construct the new catalogues in a timely manner. This encourages building automatic classification tools that can quickly and reliably classify the new signal data from these missions. The standard tool for building automatic classification systems is the supervised machine learning that requires a large set of highly accurate labeled examples in order to build an effective classifier. This requirement cannot be easily met for classifying transit-like signals because not only are existing labeled signals very limited, but also the current labels may not be reliable (because the labeling process is a subjective task). Our experiments with using different supervised classifiers to categorize transit-like signals verifies that the labeled signals are not rich enough to provide the classifier with enough power to generalize well beyond the observed cases (e.g. to unseen or test signals). That motivated us to utilize a new category of learning techniques, so-called semi-supervised learning, that combines the label information from the costly labeled signals, and distribution information from the cheaply available unlabeled signals in order to construct more effective classifiers. Our study on the Kepler Mission data shows that semi-supervised learning can significantly improve the result of multiple base classifiers (e.g. Support Vector Machines, AdaBoost, and Decision Tree) and is a good technique for automatic classification of exoplanet-transit-like signal.

  19. Classical and relativistic long-term time variations of some observables for transiting exoplanets

    CERN Document Server

    Iorio, Lorenzo

    2010-01-01

    We analytically work out the long-term, i.e. averaged over one orbital revolution, time variations of some direct observable quantities Y induced by classical and general relativistic dynamical perturbations of the two-body pointlike Newtonian acceleration in the case of transiting exoplanets moving along elliptic orbits. More specifically, the observables $Y$ with which we deal are the transit duration, the radial velocity and the time interval between primary and secondary eclipses. The dynamical effects considered are the centrifugal oblateness of both the star and the planet, their tidal bulges mutually raised on each other, a distant third body X, and general relativity (both Schwarzschild and Lense-Thirring). We take into account the effects due to the perturbations of all the Keplerian orbital elements involved in a consistent and uniform way. First, we explicitly compute their instantaneous time variations due to the dynamical effects considered and plug them in the general expression for the instanta...

  20. Catalog of Nearby Exoplanets

    OpenAIRE

    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

    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...

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

    DEFF Research Database (Denmark)

    Pätzold, M.; Endl, M.; Csizmadia, Sz.; Gandolfi, D.; Jorda, L.; Grziwa, S.; Carone, L.; Pasternacki, T.; Aigrain, S.; Almenara, J. M.; Alonso, R.; Auvergne, M.; Baglin, A.; Barge, P.; Bonomo, A. S.; Bordé, P.; Bouchy, F.; Cabrera, J.; Cavarroc, C.; Cochran, W. B.; Deleuil, M.; Deeg, H. J.; Díaz, R.; Dvorak, R.; Erikson, A.; Ferraz-Mello, S.; Fridlund, M.; Gillon, M.; Guillot, T.; Hatzes, A.; Hébrard, G.; Léger, A.; Llebaria, A.; Lammer, H.; MacQueen, P. J.; Mazeh, T.; Moutou, C.; Ofir, A.; Ollivier, M.; Parviainen, H.; Queloz, D.; Rauer, H.; Rouan, D.; Santerne, A.; Schneider, J.; Tingley, B.; Weingrill, J.; Wuchterl, G.

    2012-01-01

    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 circu...

  2. Comparison of gyrochronological and isochronal age estimates for transiting exoplanet host stars

    Science.gov (United States)

    Maxted, P. F. L.; Serenelli, A. M.; Southworth, J.

    2015-05-01

    Context. Tidal interactions between planets and their host stars are not well understood, but may be an important factor in their formation, structure, and evolution. Previous studies suggest that these tidal interactions may be responsible for discrepancies between the ages of exoplanet host stars estimated using stellar models (isochronal age estimates) and age estimates based on the stars' rotation periods (gyrochronological age estimates). Recent improvements in our understanding of the rotational evolution of single stars and a substantial increase in the number of exoplanet host stars with accurate rotation period measurements make it worthwhile to revisit this question. Aims: Our aim is to determine whether the gyrochronological age estimates for transiting exoplanet host stars with accurate rotation period measurements are consistent with their isochronal age estimates, and whether this is indicative of tidal interaction between the planets and their host stars. Methods: We have compiled a sample of 28 transiting exoplanet host stars with measured rotation periods, including two stars (HAT-P-21 and WASP-5) for which the rotation period based on the light curve modulation is reported here for the first time. We use our recently developed Bayesian Markov chain Monte Carlo method to determine the joint posterior distribution for the mass and age of each star in the sample. We extend our Bayesian method to include a calculation of the posterior distribution of the gyrochronological age estimate that accounts for the uncertainties in the mass and age, the strong correlation between these values, and the uncertainties in the mass-rotation-age calibration. Results: The gyrochronological age estimate (?gyro) is significantly lower than the isochronal age estimate for about half of the stars in our sample. Tidal interactions between the star and planet are a reasonable explanation for this discrepancy in some cases, but not all. The distribution of ?gyro values is evenly spread from very young ages up to a maximum value of a few Gyr, i.e. there is no obvious pile-up of stars at very low or very high values of ?gyro as might be expected if some evolutionary or selection effect were biasing the age distribution of the stars in this sample. There is no clear correlation between ?gyro and the strength of the tidal force on the star due to the innermost planet. There is clear evidence that the isochronal age estimates for some K-type stars are too high, and this may also be the case for some G-type stars. This may be the result of magnetic inhibition of convection. The densities of HAT-P-11 and WASP-84 are too high to be reproduced by any stellar models within the observed constraints on effective temperature and metallicity. These stars may have strongly enhanced helium abundances. There is currently no satisfactory explanation for the discrepancy between the young age for CoRoT-2 estimated from either gyrochronology or its high lithium abundance, and the extremely old age for its K-type stellar companion inferred from its very low X-ray flux. Conclusions: There is now strong evidence that the gyrochronological age estimates for some transiting exoplanet host stars are significantly lower than the isochronal age estimates, but it is not always clear that this is good evidence for tidal interactions between the star and the planet.

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

    CERN Document Server

    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

    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 ...

  4. Multi-band transit observations of the TrES-2b exoplanet

    CERN Document Server

    Mislis, D; Schmitt, J H M M; Cordes, O; Reif, K

    2009-01-01

    We present a new data set of transit observations of the TrES-2b exoplanet taken in spring 2009, using the 1.2m Oskar-Luhning telescope (OLT) of Hamburg Observatory and the 2.2m telescope at Calar Alto Observatory using BUSCA (Bonn University Simultaneous CAmera). Both the new OLT data, taken with the same instrumental setup as our data taken in 2008, as well as the simultaneously recorded multicolor BUSCA data confirm the low inclination values reported previously, and in fact suggest that the TrES-2b exoplanet has already passed the first inclination threshold (i_min,1 = 83.417) and is not eclipsing the full stellar surface any longer. Using the multi-band BUSCA data we demonstrate that the multicolor light curves can be consistently fitted with a given set of limb darkening coefficients without the need to adjust these coefficients, and further, we can demonstrate that wavelength dependent stellar radius changes must be small as expected from theory. Our new observations provide further evidence for a chan...

  5. Directly imaged L-T transition exoplanets in the mid-infrared {sup ,}

    Energy Technology Data Exchange (ETDEWEB)

    Skemer, Andrew J.; Hinz, Philip M.; Morzinski, Katie M.; Leisenring, Jarron M.; Close, Laird M.; Bailey, Vanessa P.; Defrere, Denis; Follette, Katherine B.; Males, Jared R.; Rodigas, Timothy J. [Steward Observatory, Department of Astronomy, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Marley, Mark S. [NASA Ames Research Center, MS-245-3, Moffett Field, CA 94035 (United States); Skrutskie, Michael F. [Department of Astronomy, University of Virginia, 530 McCormick Road, Charlottesville, VA 22904 (United States); Saumon, Didier [Los Alamos National Laboratory, Mail Stop F663, Los Alamos, NM 87545 (United States); Briguglio, Runa; Esposito, Simone; Puglisi, Alfio; Xompero, Marco [Istituto Nazionale di Astrofisica, Osservatorio Astrofisico di Arcetri Largo E. Fermi 5 50125 Firenze (Italy); Hill, John M. [Large Binocular Telescope Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)

    2014-09-01

    Gas-giant planets emit a large fraction of their light in the mid-infrared (?3 ?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 ?m), which are the longest wavelengths currently accessible to ground-based, high-contrast imagers. We present binocular LBT adaptive optics (AO) images of the HR 8799 planetary system in six narrow-band filters from 3 to 4 ?m, and a Magellan AO image of the 2M1207 planetary system in a broader 3.3 ?m band. These systems encompass the five known exoplanets with luminosities consistent with L ? 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 (spanned by the narrow-band filters and encompassed by the broader 3.3 ?m filter). For 2M1207 b, we find that thick clouds and non-equilibrium chemistry caused by vertical mixing can explain the object's appearance. For the HR 8799 planets, we present new models that suggest the atmospheres must have patchy clouds, along with non-equilibrium chemistry. Together, the presence of a heterogeneous surface and vertical mixing presents a picture of dynamic planetary atmospheres in which both horizontal and vertical motions influence the chemical and condensate profiles.

  6. A comparison of gyrochronological and isochronal age estimates for transiting exoplanet host stars

    CERN Document Server

    Maxted, P F L; Southworth, J

    2015-01-01

    Previous studies suggest that tidal interactions may be responsible for discrepancies between the ages of exoplanet host stars estimated using stellar models (isochronal ages) and age estimates based on the stars' rotation periods (gyrochronological ages). We have compiled a sample of 28 transiting exoplanet host stars with measured rotation periods. We use a Bayesian Markov chain Monte Carlo method to determine the joint posterior distribution for the mass and age of each star in the sample, and extend this method to include a calculation of the posterior distribution of the gyrochronological age. The gyrochronological age ($\\tau_{\\rm gyro}$) is significantly less than the isochronal age for about half of the stars in our sample. Tidal interactions between the star and planet are a reasonable explanation for this discrepancy in some cases, but not all. The distribution of $\\tau_{\\rm gyro}$ values is evenly spread from very young ages up to a maximum value of a few Gyr. There is no clear correlation between $...

  7. Directly imaged L-T transition exoplanets in the mid-infrared ,

    International Nuclear Information System (INIS)

    Gas-giant planets emit a large fraction of their light in the mid-infrared (?3 ?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 ?m), which are the longest wavelengths currently accessible to ground-based, high-contrast imagers. We present binocular LBT adaptive optics (AO) images of the HR 8799 planetary system in six narrow-band filters from 3 to 4 ?m, and a Magellan AO image of the 2M1207 planetary system in a broader 3.3 ?m band. These systems encompass the five known exoplanets with luminosities consistent with L ? 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 (spanned by the narrow-band filters and encompassed by the broader 3.3 ?m filter). For 2M1207 b, we find that thick clouds and non-equilibrium chemistry caused by vertical mixing can explain the object's appearance. For the HR 8799 planets, we present new models that suggest the atmospheres must have patchy clouds, along with non-equilibrium chemistry. Together, the presence of a heterogeneous surface and vertical mixing presents a picture of dynamic planetary atmospheres in which both horizontal and vertical motions influence the chemical and condensate profiles.

  8. Departure from the constant-period ephemeris for the transiting exoplanet WASP-12 b

    CERN Document Server

    Maciejewski, G; Fernández, M; Sota, A; Nowak, G; Ohlert, J; Nikolov, G; Bukowiecki, Ł; Hinse, T C; Pallé, E; Tingley, B; Kjurkchieva, D; Lee, J W; Lee, C -U

    2016-01-01

    Most hot Jupiters are expected to spiral in towards their host stars due to transfering of the angular momentum of the orbital motion to the stellar spin. Their orbits can also precess due to planet-star interactions. Calculations show that both effects could be detected for the very-hot exoplanet WASP-12 b using the method of precise transit timing over a timespan of the order of 10 yr. We acquired new precise light curves for 29 transits of WASP-12 b, spannning 4 observing seasons from November 2012 to February 2016. New mid-transit times, together with literature ones, were used to refine the transit ephemeris and analyse the timing residuals. We find that the transit times of WASP-12 b do not follow a linear ephemeris with a 5 sigma confidence level. They may be approximated with a quadratic ephemeris that gives a rate of change in the orbital period of -2.56 +/- 0.40 x 10^{-2} s/yr. The tidal quality parameter of the host star was found to be equal to 2.5 x 10^5 that is comparable to theoretical predicti...

  9. Analysis of Repeatability and Reliability of Warm IRAC Observations of Transiting Exoplanets

    Science.gov (United States)

    Carey, Sean J.; Krick, Jessica; Ingalls, James

    2015-12-01

    Extracting information about thermal profiles and composition of the atmospheres of transiting exoplanets is extremely challenging due to the small differential signal of the atmosphere in observations of transits, secondary eclipses, and full phase curves for exoplanets. The relevant signals are often at the level of 100 ppm or smaller and require the removal of significant instrumental systematics in the two infrared instruments currently capable of providing information at this precision, WFC3 on HST and IRAC aboard the Spitzer Space Telescope. For IRAC, the systematics are due to the interplay of residual telescope pointing variation with intra-pixel gain variations in the moderately undersampled camera. There is currently a debate in the community on the reliability of repeated IRAC observations of exoplanets particularly those in eclipse from which inferences about atmospheric temperature and pressure profiles can made. To assess the repeatability and reliability of post-cryogenic observations with IRAC, the Spitzer Science Center in conjunction with volunteers from the astronomical community has performed a systematic analysis of the removal of systematics and repeatability of warm IRAC observations. Recently, a data challenge consisting of the measurement of ten secondary eclipses of XO-3b (see Wong et al. 2014) and a complementary analysis of a synthetic version of the XO-3b data was undertaken. We report on the results of this data challenge. Five different techniques were applied to the data (BLISS mapping [Stevenson et al. (2012)], kernel regression using the science data [Wong et al. (2015)] and calibration data [Krick et al. (2015)], pixel-level decorrelation [Deming et al. (2015)], ICA [Morello et al. (2015)] and Gaussian Processes [Evans et al. (2015)]) and found consistent results in terms of eclipse depth and reliability in both the actual and synthetic data. In addition, each technique obtained the input eclipse depth in the simulated data within the stated measurement uncertainty. The reported uncertainties for each measurement approach the photon noise limit. These findings generally refute the results of Hansen et al. (2014) and suggest that inferences about atmospheric properties can be reasonably made using warm IRAC data. Application of our test methods to future observations using JWST (in particular the MIRI instrument) will be discussed.

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

    OpenAIRE

    Sing, David K.; Désert, Jean-Michel; Fortney, Jonathan J.; Lecavalier des Etangs, Alain; Ballester, Gilda E.; Cepa, Jordi; Ehrenreich, David; López-Morales, Mercedes; Pont, Frédéric; Shabram, Megan; Vidal-Madjar, Alfred

    2010-01-01

    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, ...

  11. Limb-darkening and exoplanets II: Choosing the Best Law for Optimal Retrieval of Transit Parameters

    Science.gov (United States)

    Espinoza, Néstor; Jordán, Andrés

    2016-01-01

    Very precise measurements of exoplanet transit lightcurves both from ground and space based observatories make it now possible to fit the limb-darkening coefficients in the transit-fitting procedure rather than fix them to theoretical values. This strategy has been shown to give better results, as fixing the coefficients to theoretical values can give rise to important systematic errors which directly impact the physical properties of the system derived from such lightcurves such as the planetary radius. However, studies of the effect of limb darkening assumptions on the retrieved parameters have mostly focused on the widely used quadratic limb-darkening law, leaving out other proposed laws that are either simpler or better descriptions of model intensity profiles. In this work, we show that laws such as the logarithmic, square-root and three-parameter law do a better job that the quadratic and linear laws when deriving parameters from transit lightcurves, both in terms of bias and precision, for a wide range of situations. We therefore recommend to study which law to use on a case-by-case basis. We provide code to guide the decision of when to use each of these laws and select the optimal one in a mean-square error sense, which we note has a dependence on both stellar and transit parameters. Finally, we demonstrate that the so-called exponential law is non-physical as it typically produces negative intensities close to the limb and should therefore not be used.

  12. The Transiting Exoplanet Survey Satellite: Simulations of planet detections and astrophysical false positives

    CERN Document Server

    Sullivan, Peter W; Berta-Thompson, Zachory K; Charbonneau, David; Deming, Drake; Dressing, Courtney D; Latham, David W; Levine, Alan M; McCullough, Peter R; Morton, Timothy; Ricker, George R; Vanderspek, Roland; Woods, Deborah

    2015-01-01

    The Transiting Exoplanet Survey Satellite (TESS) is a NASA-sponsored Explorer mission that will perform a wide-field survey for planets that transit bright host stars. Here, we predict the properties of the transiting planets that TESS will detect along with the eclipsing binary stars that produce false-positive photometric signals. The predictions are based on Monte Carlo simulations of the nearby population of stars, occurrence rates of planets derived from Kepler, and models for the photometric performance and sky coverage of the TESS cameras. We expect that TESS will find approximately 1700 transiting planets from 200,000 pre-selected target stars. This includes 556 planets smaller than twice the size of Earth, of which 419 are hosted by M dwarf stars and 137 are hosted by FGK dwarfs. Approximately 130 of the R < 2 R_Earth planets will have host stars brighter than K = 9. Approximately 48 of the planets with R < 2 R_Earth lie within or near the habitable zone (0.2 < S/S_Earth < 2), and between...

  13. The mass of the Mars-sized exoplanet Kepler-138 b from transit timing.

    Science.gov (United States)

    Jontof-Hutter, Daniel; Rowe, Jason F; Lissauer, Jack J; Fabrycky, Daniel C; Ford, Eric B

    2015-06-18

    Extrasolar planets that pass in front of their host star (transit) cause a temporary decrease in the apparent brightness of the star, providing a direct measure of the planet's size and orbital period. In some systems with multiple transiting planets, the times of the transits are measurably affected by the gravitational interactions between neighbouring planets. In favourable cases, the departures from Keplerian orbits (that is, unaffected by gravitational effects) implied by the observed transit times permit the planetary masses to be measured, which is key to determining their bulk densities. Characterizing rocky planets is particularly difficult, because they are generally smaller and less massive than gaseous planets. Therefore, few exoplanets near the size of Earth have had their masses measured. Here we report the sizes and masses of three planets orbiting Kepler-138, a star much fainter and cooler than the Sun. We determine that the mass of the Mars-sized inner planet, Kepler-138 b, is 0.066(+0.059)(-0.037) Earth masses. Its density is 2.6(+2.4)(-1.5) grams per cubic centimetre. The middle and outer planets are both slightly larger than Earth. The middle planet's density (6.2(+5.8)(-3.4) grams per cubic centimetre) is similar to that of Earth, and the outer planet is less than half as dense at 2.1(+2.2)(-1.2) grams per cubic centimetre, implying that it contains a greater portion of low-density components such as water and hydrogen. PMID:26085271

  14. An unconsidered configuration of astrophysical false positives in exoplanet-transit surveys

    CERN Document Server

    Santerne, A; Díaz, R F; Figueira, P; Almenara, J -M; Santos, N C

    2013-01-01

    We investigate in this paper the astrophysical false-positive configuration in exoplanet-transit surveys that involves eclipsing binaries and giant planets which present only a secondary eclipse, as seen from the Earth. To test how an eclipsing binary configuration can mimic a planetary transit, we generate synthetic light curve of three examples of secondary-only eclipsing binary systems that we fit with a circular planetary model. Then, to evaluate its occurrence we model a population of binaries in double and triple system based on binary statistics and occurrence. We find that 0.061% +/- 0.017% of main-sequence binary stars are secondary-only eclipsing binaries mimicking a planetary transit candidate down to the size of the Earth. We then evaluate the occurrence that an occulting-only giant planet can mimic an Earth-like planet or even smaller planet. We find that 0.009% +/- 0.002% of stars harbor a giant planet that present only the secondary transit. Occulting-only giant planets mimic planets smaller th...

  15. The Exoplanet Orbit Database

    CERN Document Server

    Wright, Jason T; Marcy, Geoffrey W; Han, Eunkyu; Feng, Ying; Johnson, John Asher; Howard, Andrew W; Valenti, Jeff A; Anderson, Jay; Piskunov, Nikolai

    2010-01-01

    We present a database of well determined orbital parameters of exoplanets. This database comprises spectroscopic orbital elements measured for 421 planets orbiting 357 stars from radial velocity and transit measurements as reported in the literature. We have also compiled fundamental transit parameters, stellar parameters, and the method used for the planets discovery. This Exoplanet Orbit Database includes all planets with robust, well measured orbital parameters reported in peer-reviewed articles. The database is available in a searchable, filterable, and sortable form on the Web at http://exoplanets.org through the Exoplanets Data Explorer Table, and the data can be plotted and explored through the Exoplanets Data Explorer Plotter. We use the Data Explorer to generate publication-ready plots giving three examples of the signatures of exoplanet migration and dynamical evolution: We illustrate the character of the apparent correlation between mass and period in exoplanet orbits, the selection different biase...

  16. A method to identify the boundary between rocky and gaseous exoplanets from tidal theory and transit durations

    Science.gov (United States)

    Barnes, Rory

    2015-04-01

    The determination of an exoplanet as rocky is critical for the assessment of planetary habitability. Observationally, the number of small-radius, transiting planets with accompanying mass measurements is insufficient for a robust determination of the transitional mass or radius. Theoretically, models predict that rocky planets can grow large enough to become gas giants when they reach ~10 MEarth, but the transitional mass remains unknown. Here I show how transit data, interpreted in the context of tidal theory, can reveal the critical radius that separates rocky and gaseous exoplanets. Standard tidal models predict that rocky exoplanets' orbits are tidally circularized much more rapidly than gaseous bodies', suggesting the former will tend to be found on circular orbits at larger semi-major axes than the latter. Well-sampled transits can provide a minimum eccentricity of the orbit, allowing a measurement of this differential circularization. I show that this effect should be present in the data from the Kepler spacecraft, but is not apparent. Instead, it appears that there is no evidence of tidal circularization at any planetary radius, probably because the publicly-available data, particularly the impact parameters, are not accurate enough. I also review the bias in the transit duration towards values that are smaller than that of planets on circular orbits, stressing that the azimuthal velocity of the planet determines the transit duration. The ensemble of Kepler planet candidates may be able to determine the critical radius between rocky and gaseous exoplanets, tidal dissipation as a function of planetary radius, and discriminate between tidal models.

  17. Astrometric exoplanet surveys in practice: challenges, opportunities, and results

    Science.gov (United States)

    Sahlmann, Johannes

    2015-08-01

    Conversely to the transit photometry and radial velocity methods, the astrometric discovery of exoplanets is still limited by the sensitivity of available instruments. Furthermore, the signature of a planet (described by 7 free parameters) is orders of magnitude smaller than the standard motion of a star (5 free parameters), which has to be solved for first. This has important implications in the design and implementation of astrometric planet search surveys and the large parameter space to be explored calls for efficient fitting algorithms. I will present results of the so-far most precise astrometric planet search from the ground, targeting 20 very low-mass stars and brown dwarfs with an accuracy of 100 micro-arcseconds, which include the discovery of binaries with components in the planetary mass regime and several planet candidates with Neptune-to-Jupiter masses. The employed genetic and MCMC algorithms were shown to be efficient in constraining all astrometric parameters, which makes them important tools for the exploitation of the data currently collected by the Gaia satellite. Gaia is expected to astrometrically discover thousands of giant exoplanets and I will report on several ongoing projects in preparation of this unique harvest, including the expected yield of circumbinary planets.

  18. Investigation of the environment around close-in transiting exoplanets using CLOUDY

    CERN Document Server

    Turner, Jake D; Arras, Phil; Johnson, Robert E; Schmidt, Carl

    2016-01-01

    It has been suggested that hot stellar wind gas in a bow shock around an exoplanet is sufficiently opaque to absorb stellar photons and give rise to an observable transit depth at optical and UV wavelengths. In the first part of this paper, we use the CLOUDY plasma simulation code to model the absorption from X-ray to radio wavelengths by 1-D slabs of gas in coronal equilibrium with varying densities ($10^{4}-10^{8} \\, {\\rm cm^{-3}}$) and temperatures ($2000-10^{6} \\ {\\rm K}$) illuminated by a solar spectrum. For slabs at coronal temperatures ($10^{6} \\ {\\rm K}$) and densities even orders of magnitude larger than expected for the compressed stellar wind ($10^{4}-10^{5} \\, {\\rm cm^{-3}}$), we find optical depths orders of magnitude too small ($> 3\\times10^{-7}$) to explain the $\\sim3\\%$ UV transit depths seen with Hubble. Using this result and our modeling of slabs with lower temperatures ($2000-10^4 {\\rm K}$), the conclusion is that the UV transits of WASP-12b and HD 189733b are likely due to atoms originatin...

  19. PlanetPack3: a software tool for exoplanets characterization from radial velocity and transit data

    Science.gov (United States)

    Baluev, Roman V.

    2015-08-01

    We describe the forthcoming third major release of the PlanetPack software tool for exoplanets detection and characterization from Doppler and/or transit data. Among other things, this major update will bring routines for the joint fitting of radial velocities and transits, optionally taking into account various subtle effects: the Rossiter-McLaughlin effect, the light arrival time delay between the radial velocity and transit curves, new experimental models of the Doppler or photometry noise, including non-stationary models with variable noise magnitude (due to e.g. the stellar activity variations).This work was supported by the Russian Foundation for Basic Research (project No. 14-02-92615 KO_a), the UK Royal Society International Exchange grant IE140055, by the President of Russia grant for young scientists (No. MK-733.2014.2), by the programme of the Presidium of Russian Academy of Sciences P21, and by the Saint Petersburg State University research grant 6.37.341.2015.

  20. Limb-darkening and exoplanets II: Choosing the Best Law for Optimal Retrieval of Transit Parameters

    CERN Document Server

    Espinoza, Néstor

    2016-01-01

    Very precise measurements of exoplanet transit lightcurves both from ground and space based observatories make it now possible to fit the limb-darkening coefficients in the transit-fitting procedure rather than fix them to theoretical values. This strategy has been shown to give better results, as fixing the coefficients to theoretical values can give rise to important systematic errors which directly impact the physical properties of the system derived from such lightcurves such as the planetary radius. However, studies of the effect of limb darkening assumptions on the retrieved parameters have mostly focused on the widely used quadratic limb-darkening law, leaving out other proposed laws that are either simpler or better descriptions of model intensity profiles. In this work, we show that laws such as the logarithmic, square-root and three-parameter law do a better job that the quadratic and linear laws when deriving parameters from transit lightcurves, both in terms of bias and precision, for a wide range...

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

    CERN Document Server

    Winn, Joshua N; 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; Adams, Elisabeth R; Lockhart, Matthew; Crossfield, Ian J; Valenti, Jeff A; Dantowitz, Ronald; Carter, Joshua A

    2009-01-01

    We present the results of a pan-American 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 32-87 deg with 68.3% confidence and between 14-142 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 noteworthy that all 3 exoplanetary systems with known spin-orbit misalignments have massive planets on eccentric orbits, suggesting ...

  2. 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.

  3. Expected Planet and False Positive Detection Rates for the Transiting Exoplanet Survey Satellite

    CERN Document Server

    Brown, Timothy M

    2008-01-01

    The proposed Transiting Exoplanet Survey Satellite (TESS) will survey the entire sky to locate the nearest and brightest transiting extrasolar planets with orbital periods up to about 36 days. Here we estimate the number and kind of astrophysical false positives that TESS will report, along with the number of extrasolar planets. These estimates are then used to size the ground-based follow-up observing efforts needed to confirm and characterize the planets. We estimate that the needed observing resources will be about 1400 telescope-nights of imaging with 0.5m to 1m-class telescopes, 300 telescope-nights with 1m to 2m-class telescopes for the classification of the host stars and for radial velocity measurements with roughly 1 km/s precision, and 380 telescope-nights with 2m to 4m-class telescopes for radial velocity studies with precision of a few m/s. Follow-up spectroscopy of the smallest planets discovered by TESS at the best possible velocity precision will be limited by the number of telescope nights ava...

  4. ASTEP 400: a telescope designed for exoplanet transit detection from Dome C, Antarctica

    Science.gov (United States)

    Daban, Jean-Baptiste; Gouvret, Carole; Guillot, Tristan; Agabi, Abdelkrim; Crouzet, Nicolas; Rivet, Jean-Pierre; Mekarnia, Djamel; Abe, Lyu; Bondoux, Erick; Fanteï-Caujolle, Yan; Fressin, François; Schmider, François-Xavier; Valbousquet, Franck; Blanc, Pierre-Eric; Le van Suu, Auguste; Rauer, Heike; Erikson, Anders; Pont, Frederic; Aigrain, Suzanne

    2010-07-01

    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, favorable weather conditions, and low scintillation. The ASTEP project (Antarctic Search for Transiting ExoPlanets) is a pilot project which seeks to identify transiting planets and understand the limits of visible photometry from this site. ASTEP 400 is an optical 40cm telescope with a field of view of 1° x 1°. The expected photometric sensitivity is 1E-3, per hour for at least 1,000 stars. The optical design guarantees high homogeneity of the PSF sizes in the field of view. The use of carbon fibers in the telescope structure guarantees high stability. The focal optics and the detectors are enclosed in a thermally regulated box which withstands extremely low temperatures. The telescope designed to run at -80°C (-110°F) was set up at Dome C during the southern summer 2009- 2010. It began its nightly observations in March 2010.

  5. A new look at Spitzer primary transit observations of the exoplanet HD 189733b

    International Nuclear Information System (INIS)

    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.

  6. The Transiting Exoplanet Survey Satellite: Simulations of Planet Detections and Astrophysical False Positives

    Science.gov (United States)

    Sullivan, Peter W.; Winn, Joshua N.; Berta-Thompson, Zachory K.; Charbonneau, David; Deming, Drake; Dressing, Courtney D.; Latham, David W.; Levine, Alan M.; McCullough, Peter R.; Morton, Timothy; Ricker, George R.; Vanderspek, Roland; Woods, Deborah

    2015-08-01

    The Transiting Exoplanet Survey Satellite (TESS) is a NASA-sponsored Explorer mission that will perform a wide-field survey for planets that transit bright host stars. Here, we predict the properties of the transiting planets that TESS will detect along with the EB stars that produce false-positive photometric signals. The predictions are based on Monte Carlo simulations of the nearby population of stars, occurrence rates of planets derived from Kepler, and models for the photometric performance and sky coverage of the TESS cameras. We expect that TESS will find approximately 1700 transiting planets from 2× {10}5 pre-selected target stars. This includes 556 planets smaller than twice the size of Earth, of which 419 are hosted by M dwarf stars and 137 are hosted by FGK dwarfs. Approximately 130 of the R\\lt 2 {R}\\oplus planets will have host stars brighter than {K}s=9. Approximately 48 of the planets with R\\lt 2 {R}\\oplus lie within or near the habitable zone (0.2\\lt S/{S}\\oplus \\lt 2); between 2 and 7 such planets have host stars brighter than {K}s=9. We also expect approximately 1100 detections of planets with radii 2-4 {R}\\oplus , and 67 planets larger than 4 {R}\\oplus . Additional planets larger than 2 {R}\\oplus can be detected around stars that are not among the pre-selected target stars, because TESS will also deliver full-frame images at a 30-minute cadence. The planet detections are accompanied by over 1000 astrophysical false positives. We discuss how TESS data and ground-based observations can be used to distinguish the false positives from genuine planets. We also discuss the prospects for follow-up observations to measure the masses and atmospheres of the TESS planets.

  7. Investigation of the environment around close-in transiting exoplanets using CLOUDY

    Science.gov (United States)

    Turner, Jake D.; Christie, Duncan; Arras, Phil; Johnson, Robert E.; Schmidt, Carl

    2016-03-01

    It has been suggested that hot stellar wind gas in a bow shock around an exoplanet is sufficiently opaque to absorb stellar photons and give rise to an observable transit depth at optical and UV wavelengths. In the first part of this paper, we use the CLOUDY plasma simulation code to model the absorption from X-ray to radio wavelengths by 1-D slabs of gas in coronal equilibrium with varying densities (104 - 108 cm-3) and temperatures (2000 - 106 K) illuminated by a solar spectrum. For slabs at coronal temperatures (106 K) and densities even orders of magnitude larger than expected for the compressed stellar wind (104 - 105 cm-3), we find optical depths orders of magnitude too small (>3 × 10-7) to explain the ˜3% UV transit depths seen with Hubble. Using this result and our modeling of slabs with lower temperatures (2000 - 104K), the conclusion is that the UV transits of WASP-12b and HD 189733b are likely due to atoms originating in the planet, as the stellar wind is too highly ionized. A corollary of this result is that transport of neutral atoms from the denser planetary atmosphere outward must be a primary consideration when constructing physical models. In the second part of this paper, additional calculations using CLOUDY are carried out to model a slab of planetary gas in radiative and thermal equilibrium with the stellar radiation field. Promising sources of opacity from the X-ray to radio wavelengths are discussed, some of which are not yet observed.

  8. Molecular opacities for exoplanets.

    Science.gov (United States)

    Bernath, Peter F

    2014-04-28

    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

  9. The Exoplanet Orbit Database II: Updates to exoplanets.org

    OpenAIRE

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

    2014-01-01

    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 fi...

  10. ASTEP South: An Antarctic Search for Transiting ExoPlanets around the celestial South pole

    CERN Document Server

    Crouzet, Nicolas; Agabi, Karim; Rivet, Jean-Pierre; Bondoux, Erick; Challita, Zalpha; Fanteï-Caujolle, Yan; Fressin, François; Mékarnia, Djamel; Schmider, François-Xavier; Valbousquet, Franck; Blazit, Alain; Bonhomme, Serge; Abe, Lyu; Daban, Jean-Baptiste; Gouvret, Carole; Fruth, Thomas; Rauer, Heike; Erikson, Anders; Barbieri, Mauro; Aigrain, Suzanne; Pont, Frédéric

    2009-01-01

    ASTEP South is the first phase of the ASTEP project (Antarctic Search for Transiting ExoPlanets). The instrument is a fixed 10 cm refractor with a 4kx4k CCD camera in a thermalized box, pointing continuously a 3.88 degree x 3.88 degree field of view centered on the celestial South pole. ASTEP South became fully functional in June 2008 and obtained 1592 hours of data during the 2008 Antarctic winter. The data are of good quality but the analysis has to account for changes in the point spread function due to rapid ground seeing variations and instrumental effects. The pointing direction is stable within 10 arcseconds on a daily timescale and drifts by only 34 arcseconds in 50 days. A truly continuous photometry of bright stars is possible in June (the noon sky background peaks at a magnitude R=15 arcsec-2 on June 22), but becomes challenging in July (the noon sky background magnitude is R=12.5 arcsec?2 on July 20). The weather conditions are estimated from the number of stars detected in the field. For the 2008...

  11. WASP-1b and WASP-2b: Two new transiting exoplanets detected with SuperWASP and SOPHIE

    OpenAIRE

    Collier Cameron, A.; Bouchy, F.; Hebrard, G.; Maxted, P.; Pollacco, D.; Pont, F.; Skillen, I.; Smalley, B; Street, R. A.; West, R. G; Wilson, D. M.; Aigrain, S; Christian, D. J.; W. I. Clarkson; Enoch, B.

    2006-01-01

    We have detected low-amplitude radial-velocity variations in two stars, USNO-B1.0 1219-0005465 (GSC 02265-00107 = WASP-1) and USNO-B1.0 0964-0543604 (GSC 00522-01199 = WASP-2). Both stars were identified as being likely host stars of transiting exoplanets in the 2004 SuperWASP wide-field transit survey. Using the newly-commissioned radial-velocity spectrograph SOPHIE at the Observatoire de Haute-Provence, we found that both objects exhibit reflex orbital radial-velocity variations with amplit...

  12. Lessons learnt and results from the first survey of transiting exoplanet atmospheres using a multi-object spectrograph

    Science.gov (United States)

    Desert, Jean-Michel

    2015-12-01

    We present results from the first comprehensive survey program dedicated to probing transiting exoplanet atmospheres using transmission spectroscopy with a multi-object spectrograph (MOS). Our three-year survey focused on nine close-in giant planets for which the wavelength dependent transit depths in the visible were measured with Gemini/GMOS. In total, about 40 transits (200 hours) have been secured, with each exoplanet observed on average during four transits. This approach allows for a high spectrophotometric precision (200-500 ppm / 10 nm) and for a unique and reliable estimate of systematic uncertainties. We present the main results from this survey, the challenges faced by such an experiment, and the lessons learnt for future MOS observations and instrument designs. We show that the precision achieved by this survey permits us to distinguish hazy atmospheres from cloud-free scenarios. We lay out the challenges that are in front of us whilst preparing future atmospheric reconnaissance of habitable worlds with multi-object spectrographs.

  13. SOPHIE velocimetry of Kepler transit candidates. X. KOI-142 c: first radial velocity confirmation of a non-transiting exoplanet discovered by transit timing

    Science.gov (United States)

    Barros, S. C. C.; Díaz, R. F.; Santerne, A.; Bruno, G.; Deleuil, M.; Almenara, J.-M.; Bonomo, A. S.; Bouchy, F.; Damiani, C.; Hébrard, G.; Montagnier, G.; Moutou, C.

    2014-01-01

    The exoplanet KOI-142b (Kepler-88b) shows transit timing variations (TTVs) with a semi-amplitude of ~12 h, which earned it the nickname "king of transit variations". Only the transit of planet b was detected in the Kepler data with an orbital period of ~10.92 days and a radius of ~0.36 RJup. The TTVs together with the transit duration variations of KOI-142b were analysed recently, finding a unique solution for a companion-perturbing planet. An outer non-transiting companion was predicted, KOI-142c, with a mass of 0.626 ± 0.03 MJup and a period of 22.3397-0.0018+0.0021 days, which is close to the 2:1 mean-motion resonance with the inner transiting planet. We report an independent confirmation of KOI-142c using radial velocity observations with the SOPHIE spectrograph at the Observatoire de Haute-Provence. We derive an orbital period of 22.10 ± 0.25 days and a minimum planetary mass of 0.760.16+0.32 MJup, both in good agreement with the predictions by previous transit timing analysis. Therefore, this is the first radial velocity confirmation of a non-transiting planet discovered with TTVs, providing an independent validation of the TTVs technique. Based on observations collected with the NASA Kepler satellite and with the SOPHIE spectrograph on the 1.93-m telescope at Observatoire de Haute-Provence (CNRS), France.Tables 2 and 3 are available in electronic form at http://www.aanda.org

  14. Defocused Observations of Selected Exoplanet Transits with T100 at the TÜB?TAK National Observatory of Turkey (TUG)

    Science.gov (United States)

    Ba?türk, Ö.; Hinse, T. C.; Özavc&ainodot; , ?.; Yörüko?lu, O.; Selam, S. O.

    2015-07-01

    Determining masses and radii of extrasolar planets with high precision is key to our understanding of their chemical composition, internal structure, and thereby their formation and evolution. Toward this goal we are applying the defocusing technique for the photometric observation of selected planetary systems with the 1 m Turkish telescope T100 at the TÜB?TAK National Observatory (TUG). In this contribution we present preliminary analyses of transit light curves obtained using this technique for the exoplanets KELT-3b, HAT-P-10b/WASP-11b, HAT-P-20b, and HAT-P-22b.

  15. The Transiting Exoplanet Survey Satellite (TESS): Discovering New Earths and Super-Earths in the Solar Neighborhood

    Science.gov (United States)

    Ricker, George R.

    2015-12-01

    The Transiting Exoplanet Survey Satellite (TESS) will discover thousands of exoplanets in orbit around the brightest stars in the sky. In its two-year prime survey mission, TESS will monitor more than 200,000 bright stars in the solar neighborhood 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.An additional data product from the TESS mission will be full frame images (FFI) with a cadence of 30 minutes or less. These FFI will provide precise photometric information for every object within the 2300 square degree instantaneous field of view of the TESS cameras. These objects will include more than 1 million stars and bright galaxies observed during sessions of several weeks. In total, more than 30 million objects brighter than I=16 will be precisely photometered during the two-year prime mission. In principle, the lunar-resonant TESS orbit could provide opportunities for an extended mission lasting more than a decade, with data rates in excess of 100 Mbits/s.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, as well as commensal survey candidates from the FFI. A NASA Guest Investigator program is planned for TESS. The TESS legacy will be a catalog of the nearest and brightest main-sequence stars hosting transiting exoplanets, which should endure as the most favorable targets for detailed future investigations.TESS is targeted for launch in 2017 as a NASA Astrophysics Explorer mission.

  16. Solution of newly observed transit of the exoplanet HAT-P-24b: no TTV and TDV signals

    CERN Document Server

    Kjurkchieva, Diana; Ibryamov, Sunay

    2015-01-01

    We present photometric observations of transit of the exoplanet HAT-P-24b using the Rozhen 2 m telescope. Its solution gives relative stellar radius r_{s}=0.1304 (a/R_{s}=7.669), relative planet radius r_{p}=0.01304 and orbital inclination of 90 degree. The calculated planet radius is R_{p}=1.316 R_{J} and corresponds to planet density of rho_{p}=0.37 g cm^{-3}. Our parameter values are between those of the previous two solutions. We did not find evidences of TTV and TDV signals of HAT-P-24b.

  17. A Study of the Effects of Underlying Assumptions in the Reduction of Multi-Object Photometry of Transiting Exoplanets

    Science.gov (United States)

    Ryleigh Fitzpatrick, M.; Pearson, Kyle; Griffith, Caitlin Ann; Dunn, Marina; Montiel, Nicholas John; Zellem, Robert T.; Calahan, Jenny; Chance, Quadry; Henrici, Andrew; Sanchez, Dominic; AzGOE

    2016-01-01

    The analysis of ground-based photometric observations of planetary transits must treat the effects of the Earth's atmosphere, which exceed the signal of the extrasolar planet. Generally, this is achieved by dividing the signal of the host star and planet from that of nearby field stars. For bright hot Jupiter exoplanets this procedure reveals the lightcurve. The lightcurve is then fit to a model of the planet's orbit and the physical characteristics, also taking into account the characteristics of the star. The fit to the in-transit data coupled with the fit of the out-of-transit data establish the depth of the lightcurve.The question then arises, what is the best way to select and treat the reference stars such that we can best characterize and remove the shared atmospheric systematics that plague our transit signal. To explore these questions we examine the effects of several assumptions that underline the calculation of the light curve depth. Our study involves photometric observations of hot Jupiter primary transits in the U and B filters taken with the University of Arizona's Kuiper 1.55m telescope and Mont4K CCD. The data consists of repeated transit observations of a variety of exoplanets, each of which offers a unique field with stars of various brightness, spectral types, and angular distance from the host star. While these observations are part of a larger study of the Rayleigh scattering signature of hot Jupiter exoplanets, here we study the effects of various choices during the reduction phase, specifically the treatment of the reference stars and atmospheric systematics. Our study calculates the lightcurve for all permutations of the reference stars, considering several different out-of-transit assumptions (e.g. linear, quadratic or exponential). We assess the sensitivity of the transit depths based on the spread of the values and look for characteristics that minimize the scatter in the reduced lightcurve as well as analyze the effects of the treatment of individual variables on the resultant model. This research group, referred to as AzGOE, is made of primarily undergraduate students from the University of Arizona, in cooperation with the University of Arizona Astronomy Club.

  18. The Exoplanet Orbit Database

    OpenAIRE

    Wright, Jason T; Fakhouri, Onsi; Marcy, Geoffrey W.; Han, Eunkyu; Ying FENG; Johnson, John Asher; Howard, Andrew W.; Fischer, Debra A.; Valenti, Jeff A.; Anderson, Jay; Piskunov, Nikolai

    2010-01-01

    We present a database of well determined orbital parameters of exoplanets. This database comprises spectroscopic orbital elements measured for 427 planets orbiting 363 stars from radial velocity and transit measurements as reported in the literature. We have also compiled fundamental transit parameters, stellar parameters, and the method used for the planets discovery. This Exoplanet Orbit Database includes all planets with robust, well measured orbital parameters reported i...

  19. Ground-based near-UV observations of 15 transiting exoplanets: Constraints on their atmospheres and no evidence for asymmetrical transits

    CERN Document Server

    Turner, Jake D; Biddle, Lauren I; Smart, Brianna M; Zellem, Robert T; Teske, Johanna K; Hardegree-Ullman, Kevin K; Griffith, Caitlin C; Leiter, Robin M; Cates, Ian T; Nieberding, Megan N; Smith, Carter-Thaxton W; Thompson, Robert M; Hofmann, Ryan; Berube, Michael P; Nguyen, Chi H; Small, Lindsay C; Guvenen, Blythe C; Richardson, Logan; McGraw, Allison; Raphael, Brandon; Crawford, Benjamin E; Robertson, Amy N; Tombleson, Ryan; Carleton, Timothy M; Towner, Allison P M; Walker-LaFollette, Amanda M; Hume, Jeffrey R; Watson, Zachary T; Jones, Christen K; Lichtenberger, Matthew J; Hoglund, Shelby R; Cook, Kendall L; Crossen, Cory A; Jorgensen, Curtis R; Thompson, James M Romine Alejandro R; Villegas, Christian F; Wilson, Ashley A; Sanford, Brent; Taylor, Joanna M

    2016-01-01

    Transits of exoplanets observed in the near-UV have been used to study the scattering properties of their atmospheres and possible star-planet interactions. We observed the primary transits of 15 exoplanets (CoRoT-1b, GJ436b, HAT-P-1b, HAT-P-13b, HAT-P-16b, HAT-P-22b, TrES-2b, TrES-4b, WASP-1b, WASP-12b, WASP-33b, WASP-36b, WASP-44b, WASP-48b, and WASP-77Ab) in the near-UV and several optical photometric bands to update their planetary parameters, ephemerides, search for a wavelength dependence in their transit depths to constrain their atmospheres, and determine if asymmetries are visible in their light curves. Here we present the first ground-based near-UV light curves for 12 of the targets (CoRoT-1b, GJ436b, HAT-P-1b, HAT-P-13b, HAT-P-22b, TrES-2b, TrES-4b, WASP-1b, WASP-33b, WASP-36b, WASP-48b, and WASP-77Ab). We find that none of the near-UV transits exhibit any non-spherical asymmetries, this result is consistent with recent theoretical predictions by Ben-Jaffel et al. and Turner et al. The multi-wavele...

  20. Hiding in the Shadows II: Collisional Dust as Exoplanet Markers

    CERN Document Server

    Dobinson, Jack; Lines, Stefan; Carter, Philip J; Dodson-Robinson, Sarah E; Teanby, Nick A

    2016-01-01

    Observations of the youngest planets ($\\sim$1-10 Myr for a transitional disk) will increase the accuracy of our planet formation models. Unfortunately, observations of such planets are challenging and time-consuming to undertake even in ideal circumstances. Therefore, we propose the determination of a set of markers that can pre-select promising exoplanet-hosting candidate disks. To this end, N-body simulations were conducted to investigate the effect of an embedded Jupiter mass planet on the dynamics of the surrounding planetesimal disk and the resulting creation of second generation collisional dust. We use a new collision model that allows fragmentation and erosion of planetesimals, and dust-sized fragments are simulated in a post process step including non-gravitational forces due to stellar radiation and a gaseous protoplanetary disk. Synthetic images from our numerical simulations show a bright double ring at 850 $\\mu$m for a low eccentricity planet, whereas a high eccentricity planet would produce a ch...

  1. Constraining the atmosphere of exoplanet WASP-34b

    Science.gov (United States)

    Challener, Ryan; Harrington, Joseph; Cubillos, Patricio; Garland, Justin; Foster, Andrew S. D.; Blecic, Jasmina; Foster, Austin James; Smalley, Barry

    2016-01-01

    WASP-34b is a short-period exoplanet with a mass of 0.59 +/- 0.01 Jupiter masses orbiting a G5 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 Infrared Array Camera aboard the Spitzer Space Telescope in 2010 (Program 60003). We applied our Photometry for Orbits, Eclipses, and Transits (POET) code to present eclipse-depth measurements, estimates of infrared brightness temperatures, and a refined orbit. With our Bayesian Atmospheric Radiative Transfer (BART) code, we characterized the atmosphere's temperature and pressure profile, and molecular abundances. Spitzer is operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. This work was supported by NASA Planetary Atmospheres grant NNX12AI69G and NASA Astrophysics Data Analysis Program grant NNX13AF38G. J. Blecic holds a NASA Earth and Space Science Fellowship.

  2. 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

    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

    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.

  3. The NASA Exoplanet Archive

    Science.gov (United States)

    Akeson, Rachel L.

    2015-11-01

    The NASA Exoplanet Archive is an online astronomical exoplanet and stellar catalog and data service that collates and cross-correlates astronomical data on exoplanets and their host stars and provides tools to work with these data. The Exoplanet Archive is dedicated to collecting and serving important public data sets involved in the search for and characterization of extrasolar planets and their host stars. The data include stellar parameters, exoplanet parameters and discovery/characterization data from the astronomical literature. The Archive also hosts mission and survey data, including Kepler pipeline data such as candidate lists and data validation products and ground-based surveys from SuperWASP and KELT. Tools provided for users to work with these data include a transit ephemeris predictor, light curve viewing utilities and a periodogram service.

  4. 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

    OpenAIRE

    Cabrera, J.; Bruntt, H.; Ollivier, M.; Diaz, RF; Csizmadia, S.; Aigrain, S.; Alonso, R.; Almenara, J-M; Auvergne, M.; Baglin, A; P. Barge; Bonomo, AS; Borde, P.; Bouchy, F; Carone, L.

    2010-01-01

    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[SUP]-3[/SUP]. It orbits a G0V star with T_eff = 5 945 K, M[SUB]*...

  5. Accretion of Jupiter-mass planets in the limit of vanishing viscosity

    International Nuclear Information System (INIS)

    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 bodies. Obtaining longer timescales for gas accretion may require using realistic equations of states, or accounting for the dynamics of the circumplanetary disk (CPD) in the low-viscosity regime, or both. Here we explore the second way by using global, three-dimensional isothermal hydrodynamical simulations with eight 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 a prescribed viscosity, Jupiter's mass-doubling time is ?104 yr, 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 identify two planet-accretion mechanisms that are independent of the viscosity in the CPD: (1) the polar inflow—defined as a part of the vertical inflow with a centrifugal radius smaller than two Jupiter radii and (2) the torque exerted by the star on the CPD. In the limit of zero effective viscosity, these two mechanisms would produce an accretion rate 40 times smaller than in the simulation.

  6. Molecular opacities for exoplanets

    OpenAIRE

    Peter F. Bernath

    2014-01-01

    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...

  7. NASA's Missions for Exoplanet Exploration

    Science.gov (United States)

    Unwin, Stephen

    2014-05-01

    Exoplanets are detected and characterized using a range of observational techniques - including direct imaging, astrometry, transits, microlensing, and radial velocities. Each technique illuminates a different aspect of exoplanet properties and statistics. This diversity of approach has contributed to the rapid growth of the field into a major research area in only two decades. In parallel with exoplanet observations, major efforts are now underway to interpret the physical and atmospheric properties of exoplanets for which spectroscopy is now possible. In addition, comparative planetology probes questions of interest to both exoplanets and solar system studies. In this talk I describe NASA's activities in exoplanet research, and discuss plans for near-future missions that have reflected-light spectroscopy as a key goal. The WFIRST-AFTA concept currently under active study includes a major microlensing survey, and now includes a visible light coronagraph for exoplanet spectroscopy and debris disk imaging. Two NASA-selected community-led teams are studying probe-scale (exoplanet science (such as transit spectroscopy and debris disk imaging with HST and Spitzer) or are under development (survey of nearby transiting exoplanets with TESS, and followup of the most important targets with transit spectroscopy on JWST), and build on the work of ground-based instruments such as LBTI and observing with HIRES on Keck. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. Copyright 2014. California Institute of Technology. Government sponsorship acknowledged.

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

    OpenAIRE

    Benneke, Bjoern; 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

    2014-01-01

    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 pro...

  9. Synthesizing Exoplanet Demographics

    Science.gov (United States)

    Clanton, Christian

    2016-01-01

    The discovery of thousands of exoplanets has revealed a large diversity of systems, the majority of which look nothing like our own. On the theoretical side, we are able to make ab initio calculations that make predictions about the properties of exoplanets. However, in order to link these predictions with observations, we must construct a statistical census of exoplanet demographics over as broad a range of parameters as possible. Current constraints on exoplanet demographics are typically constructed using the results of individual surveys using a single detection technique, and thus are incomplete. The only way to derive a statistically-complete census that samples a wide region of exoplanet parameter space is to synthesize the results from surveys employing all of the different discovery methods at our disposal. I present the first studies to demonstrate that this is actually possible, and describe a (mostly) de-biased exoplanet census that is constructed from the synthesis of results from microlensing, radial velocity, and direct imaging surveys. I will also discuss future work that will include the results of transit surveys (in particular, Kepler discoveries) to complete the census of exoplanets in our Galaxy, and describe the application of this census to develop the most comprehensive, observationally-constrained models of planet formation and evolution that have been derived to date.

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

    CERN Document Server

    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

    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...

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

    OpenAIRE

    Rameau, J.; Chauvin, G.; 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.

    2013-01-01

    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 tha...

  12. Testing the Tidal Heating Hypothesis for the Transiting Exoplanets HAT-P-1b and TrES-4b

    Science.gov (United States)

    Armstrong, Amber; Bean, J. L.; McArthur, B.; Reiners, A.; Dreizler, S.; Benedict, G. F.

    2007-12-01

    One of the most interesting results that has emerged from the detection and study of transiting exoplanets is that some Hot Jupiters have larger radii, and thus lower densities, than models predict. A few mechanisms have been suggested as the cause of this, including one hypothesis that there is an unknown source of internal heat inflating these planets. Such a source of heat could be the dissipation of energy arising from the ongoing tidal circularization of the planets' eccentric orbits. However, the tidal circularization timescale for such close in planets is predicted to be at least an order of magnitude shorter than the putative ages of the systems. Therefore, if an inflated Hot Jupiter's orbital eccentricity is truly non-zero, there must be a perturber - possibly an additional undiscovered planet - in the system to regularly excite its eccentricity. We are currently carrying out high cadence and high precision radial velocity measurements of the host stars to inflated Hot Jupiters with the Hobby-Eberly-Telescope to constrain their orbital eccentricities, search for additional planets in the systems, and ultimately test the tidal heating hypothesis. We present here preliminary results for the systems HAT-P-1 and TrES-4. At the time of this writing, TrES-4b is by far the lowest density exoplanet and the most discrepant from theoretical models. Support for this work was provided by NASA through grants GO-10103, GO-10610, and GO-10989 from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

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

    CERN Document Server

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

    2014-01-01

    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...

  14. Recovering the Signal: Comparison of data analysis methods used for exoplanet transit and eclipse spectra with HST WFC3

    Science.gov (United States)

    Varley, Ryan; Tsiaras, Angelos; Waldmann, Ingo Peter; Tinetti, Giovanna

    2015-08-01

    When observing exoplanet transit spectra we are typically looking for variations in the signal of 1 part in 10000. This is below the calibration level of many non-purpose built instruments like HST WFC3 meaning that data analysis techniques are required to recover the signal from the instrument noise and systematics. Errors and oversights in the analysis can lead to erroneous signals, or a failure to recover the signal altogether.This problem forms one of the central debates around transit and eclipse spectra, with several cases of different groups reporting different spectra when analysing the same data. The question that arises is "How do we know the retrieved signal is the real one?". Typically favoured methods in the field to tackle this problem include signal injection, analysing parts of the data independently and testing the residuals of the light curve fit for gaussianity.The main issues with these confirmation techniques is that they assess the end result and major systematics, and not the unknown factors introduced by the instrument and analysis itself, in particular the introduction of random noise at the level of the signal. Some spectral features could then be the result of unknown instrumental effects, or artificially imprinted from the analysis. Flat spectra present a more interesting question, to what do degree do current analysis techniques preserve the intrinsic modulations due to the science signal?.We present a new method to assess the recovery of data analysis techniques end-to-end, from the reduction of observations to the production of the spectrum and provide this tool to the community.We apply this technique to commonly used data reduction and analysis techniques for HST WFC3 over a range of cases to determine their effectiveness with different sources of noise, systematics and planets along with some new techniques to aid recovery.We use the results to help answer the questions regarding recent findings "Are flat spectra a recurring feature of exoplanets? Clouds? The instrument? Our analysis? Or the sum of these effects?".

  15. Exoplanet properties from Lick, Keck and AAT

    International Nuclear Information System (INIS)

    Doppler-shift measurements with a remarkable precision of ??/?=3x10-9, corresponding to velocities of 1 m s-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 ?15 MJUP to as low as ?5 MEarth and rises toward lower masses as dN/dM?M-1.1. The distribution with orbital distance, a, rises (in logarithmic intervals) as dN/d log a?a+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-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

  16. SOPHIE velocimetry of Kepler transit candidates XVII. The physical properties of giant exoplanets within 400 days of period

    CERN Document Server

    Santerne, A; Tsantaki, M; Bouchy, F; Hébrard, G; Adibekyan, V; Almenara, J -M; Amard, L; Barros, S C C; Boisse, I; Bonomo, A S; Bruno, G; Courcol, B; Deleuil, M; Demangeon, O; Díaz, R F; Guillot, T; Havel, M; Montagnier, G; Rajpurohit, A S; Rey, J; Santos, N C

    2015-01-01

    While giant extrasolar planets have been studied for more than two decades now, there are still some open questions such as their dominant formation and migration process, as well as their atmospheric evolution in different stellar environments. In this paper, we study a sample of giant transiting exoplanets detected by the Kepler telescope with orbital periods up to 400 days. We first defined a sample of 129 giant-planet candidates that we followed up with the SOPHIE spectrograph (OHP, France) in a 6-year radial velocity campaign. This allow us to unveil the nature of these candidates and to measure a false-positive rate of 54.6 +/- 6.5 % for giant-planet candidates orbiting within 400 days of period. Based on a sample of confirmed or likely planets, we then derive the occurrence rates of giant planets in different ranges of orbital periods. The overall occurrence rate of giant planets within 400 days is 4.6 +/- 0.6 %. We recover, for the first time in the Kepler data, the different populations of giant plan...

  17. Transit timing analysis of the exoplanets TrES-1 and TrES-2

    OpenAIRE

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

    2009-01-01

    The aim of this work is a detailed analysis of transit light curves from TrES-1 and TrES-2, obtained over a period of three to four years, in order to search for variabilities in observed mid-transit times and to set limits for the presence of additional third bodies. Using the IAC 80cm telescope, we observed transits of TrES-1 and TrES-2 over several years. Based on these new data and previously published work, we studied the observed light curves and searched for variations in the differenc...

  18. The Effect of Conjunctions on the Transit Timing Variations of Exoplanets

    CERN Document Server

    Nesvorny, David

    2014-01-01

    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.

  19. WASP-37b: A 1.8 MJ EXOPLANET TRANSITING A METAL-POOR STAR

    International Nuclear Information System (INIS)

    We report on the discovery of WASP-37b, a transiting hot Jupiter orbiting an mv = 12.7 G2-type dwarf, with a period of 3.577469 ± 0.000011 d, transit epoch T0 = 2455338.6188 ± 0.0006 (HJD; dates throughout the paper are given in Coordinated Universal Time (UTC)), and a transit duration 0.1304+0.0018-0.0017 d. The planetary companion has a mass Mp = 1.80 ± 0.17 MJ and radius Rp = 1.16+0.07-0.06 RJ, yielding a mean density of 1.15+0.12-0.15 ?J. From a spectral analysis, we find that the host star has M* = 0.925 ± 0.120 Msun, R* = 1.003 ± 0.053 Rsun, Teff = 5800 ± 150 K, and [Fe/H] = -0.40 ± 0.12. WASP-37 is therefore one of the lowest metallicity stars to host a transiting planet.

  20. The effect of conjunctions on the transit timing variations of exoplanets

    Energy Technology Data Exchange (ETDEWEB)

    Nesvorný, David [Department of Space Studies, Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States); Vokrouhlický, David, E-mail: davidn@boulder.swri.edu, E-mail: vokrouhl@cesnet.cz [Institute of Astronomy, Charles University, V Holešovi?kách 2, CZ-18000 Prague 8 (Czech Republic)

    2014-07-20

    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.

  1. WASP-37b: a 1.7 MJ exoplanet transiting a metal-poor star

    CERN Document Server

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

    2010-01-01

    We report on the discovery of WASP-37b, a transiting hot Jupiter orbiting a mv = 12.7 G2-type dwarf, with a period of 3.577471 +/- 0.00001 d, transit epoch T0 = 2455338.6189 +/- 0.0006 (HJD), and a transit duration 0.1307 +/- 0.0019 d. The planetary companion has a mass Mp = 1.696(+0.123)(-0.128) MJ and radius Rp = 1.136(+0.060){-0.051} RJ, yielding a mean density of 1.169(+0.119)(-0.152) times that of Jupiter. From a spectral analysis and comparisons with stellar models, we find the host star has M* = 0.849(+0.067)(-0.040) Msun, R* = 0.977(+0.045)(-0.042) Rsun, Teff = 5800 +/- 150 K and [Fe/H] = -0.40 +/- 0.12. WASP-37 is therefore one of the lowest metallicity stars to host a transiting planet.

  2. Investigation of transit-selected exoplanet candidates from the MACHO survey

    CERN Document Server

    Huegelmeyer, S D; Homeier, D; Reiners, A

    2007-01-01

    Context: Planets outside our solar system transiting their host star, i. e. those with an orbital inclination near 90 degree, are of special interest to derive physical properties of extrasolar planets. With the knowledge of the host star's physical parameters, the planetary radius can be determined. Combined with spectroscopic observations the mass and therefore the density can be derived from Doppler-measurements. Depending on the brightness of the host star, additional information, e. g. about the spin-orbit alignment between the host star and planetary orbit, can be obtained. Aims: The last few years have witnessed a growing success of transit surveys. Among other surveys, the MACHO project provided nine potential transiting planets, several of them with relatively bright parent stars. The photometric signature of a transit event is, however, insufficient to confirm the planetary nature of the faint companion. The aim of this paper therefore is a determination of the spectroscopic parameters of the host s...

  3. The Mass-Radius-Eccentricity Distribution of Near-Resonant Transiting Exoplanet Pairs Detected by Kepler

    Science.gov (United States)

    Shabram, Megan; Jontof-Hutter, Daniel; Ford, Eric B.

    2015-12-01

    We characterize the mass-radius-eccentricity distribution of transiting planets near first-order mean motion resonances using Transit Timing Variation (TTV) observations from NASA's Kepler mission. Kepler's precise measurements of transit times (Mazeh et al. 2014; Rowe et al. 2015) constrain the planet-star mass ratio, eccentricity and pericenter directions for hundreds of planets. Strongly-interacting planetary systems allow TTVs to provide precise measurements of masses and orbital eccentricities separately (e.g., Kepler-36, Carter et al. 2012). In addition to these precisely characterized planetary systems, there are several systems harboring at least two planets near a mean motion resonance (MMR) for which TTVs provide a joint constraint on planet masses, eccentricities and pericenter directions (Hadden et al. 2015). Unfortunately, a near degeneracy between these parameters leads to a posterior probability density with highly correlated uncertainties. Nevertheless, the population encodes valuable information about the distribution of planet masses, orbital eccentricities and the planet mass-radius relationship. We characterize the distribution of masses and eccentricities for near-resonant transiting planets by combining a hierarchical Bayesian model with an analytic model for the TTV signatures of near-resonant planet pairs (Lithwick & Wu 2012). By developing a rigorous statistical framework for analyzing the TTV signatures of a population of planetary systems, we significantly improve upon previous analyses. For example, our analysis includes transit timing measurements of near-resonant transiting planet pairs regardless of whether there is a significant detection of TTVs, thereby avoiding biases due to only including TTV detections.

  4. Limb darkening and exoplanets: testing stellar model atmospheres and indentifying biases in transit parameters

    CERN Document Server

    Espinoza, Néstor

    2015-01-01

    Limb-darkening is fundamental in determining transit lightcurve shapes, and is typically modeled by a variety of laws that parametrize the intensity profile of the star that is being transited. Confronted with a transit lightcurve, some authors fix the parameters of these laws, the so-called limb-darkening coefficients (LDCs), while others prefer to let them float in the lightcurve fitting procedure. Which of these is the best strategy, however, is still unclear, as well as how and by how much each of these can bias the retrieved transit parameters. In this work we attempt to clarify those points by first re-calculating these LDCs, comparing them to measured values from Kepler transit lightcurves using an algorithm that takes into account uncertainties in both the geometry of the transit and the parameters of the stellar host. We show there are significant departures from predicted model values, suggesting that our understanding of limb-darkening still needs to improve. Then, we show through simulations that ...

  5. Transit timing analysis of the exoplanets TrES-1 and TrES-2

    CERN Document Server

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

    2009-01-01

    The aim of this work is a detailed analysis of transit light curves from TrES-1 and TrES-2, obtained over a period of three to four years, in order to search for variabilities in observed mid-transit times and to set limits for the presence of additional third bodies. Using the IAC 80cm telescope, we observed transits of TrES-1 and TrES-2 over several years. Based on these new data and previously published work, we studied the observed light curves and searched for variations in the difference between observed and calculated (based on a fixed ephemeris) transit times. To model possible transit timing variations, we used polynomials of different orders, simulated O-C diagrams corresponding to a perturbing third mass and sinusoidal fits. For each model we calculated the chi-squared residuals and the False Alarm Probability (FAP). For TrES-1 we can exclude planetary companions (>1 M_earth) in the 3:2 and 2:1 MMRs having high FAPs based on our transit observations from ground. Additionally, the presence of a ligh...

  6. Dust Coagulation in the Vicinity of a Gap-Opening Jupiter-Mass Planet

    CERN Document Server

    Carballido, Augusto; Hyde, Truell W

    2015-01-01

    We analyze the coagulation of dust in and around a gap opened by a Jupiter-mass planet. To this end, we carry out a high-resolution magnetohydrodynamic (MHD) simulation of the gap environment, which is turbulent due to the magnetorotational instability. From the MHD simulation, we obtain values of the gas velocities, densities and turbulent stresses a) close to the gap edge, b) in one of the two gas streams that accrete onto the planet, c) inside the low-density gap, and d) outside the gap. The MHD values are then supplied to a Monte Carlo dust coagulation algorithm, which models grain sticking and compaction. We consider two dust populations for each region: one whose initial size distribution is monodisperse, with monomer radius equal to 1 $\\mu$m, and another one whose initial size distribution follows the Mathis-Rumpl-Nordsieck distribution for interstellar dust grains, with an initial range of monomer radii between 0.5 and 10 $\\mu$m. Our Monte Carlo calculations show initial growth of dust aggregates foll...

  7. Search for Carbon Monoxide in the atmosphere of the Transiting Exoplanet HD189733b

    CERN Document Server

    Desert, Jean-Michel; Hebrard, Guillaume; Sing, David K; Ehrenreich, David; Ferlet, Roger; Vidal-Madjar, Alfred

    2009-01-01

    Water, methane and carbon-monoxide are expected to be among the most abundant molecules besides molecular hydrogen in the hot atmosphere of close-in EGPs. Transit observations in the mid-IR allow the atmospheric content of transiting planets to be determined. We present new primary transit observations of the hot-jupiter HD189733b, obtained simultaneously at 4.5 and 8 micron with IRAC instrument onboard Spitzer. Together with a new refined analysis of previous observations at 3.6 and 5.8 micron 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 (R_p/R_*)= 0.1545 +/- 0.0003, 0.1557 +/- 0.0003, 0.1547 +/- 0.0005, 0.1544 +/- 0.0004 at 3.6, 4.5, 5.8, and 8 micron respectively. The high accuracy of the measurement allows the search for atmospheric molecular absorbers...

  8. The CoRoT exoplanet programme: exploring the gas-giant/terrestrial planet transition

    CERN Document Server

    Aigrain, S; Deleuil, M; Fressin, F; Moutou, C; Queloz, D; Auvergne, M; Baglin, A

    2007-01-01

    CoRoT, which was launched successfully on the 27th of December 2006, is the first space mission to have the search for planetary transits at the heart of its science programme. It is expected to be able to detect transits of planets with radii down to approximately two Earth radii and periods up to approximately a month. Thus, CoRoT will explore the hereto uncharted area of parameter space which spans the transition between the gaseous giant planets discovered in large numbers from the ground, and terrestrial planets more akin to our own. This papers briefly sketches out the main technical characteristics of the mission before summarising estimates of its detection potential and presenting the data analysis and follow-up strategy.

  9. MOST Spacebased Photometry of the Transiting Exoplanet System HD 209458: Transit Timing to Search for Additional Planets

    CERN Document Server

    Miller-Ricci, E; Sasselov, D; Matthews, J M; Günther, D B; Kuschnig, R; Moffat, A F J; Rucinski, S M; Walker, G A H; Weiss, W W

    2008-01-01

    We report on the measurement of transit times for the HD 209458 planetary system from photometry obtained with the MOST (Microvariability & Oscillations of STars) space telescope. Deviations from a constant orbital period can indicate the presence of additional planets in the system that are yet undetected, potentially with masses approaching an Earth mass. The MOST data sets of HD 209458 from 2004 and 2005 represent unprecedented time coverage with nearly continuous observations spanning 14 and 43 days and monitoring 3 transits and 12 consecutive transits, respectively. The transit times we obtain show no variations on three scales: (a) no long-term change in P since before 2004 at the 25 ms level, (b) no trend in transit timings during the 2005 run, and (c) no individual transit timing deviations above 80 sec level. Together with previously published transit times from Agol & Steffen (2007), this allows us to place limits on the presence of additional close-in planets in the system, in some cases do...

  10. Exoplanet atmospheres physical processes

    CERN Document Server

    Seager, Sara

    2010-01-01

    Over the past twenty years, astronomers have identified hundreds of extrasolar planets--planets orbiting stars other than the sun. Recent research in this burgeoning field has made it possible to observe and measure the atmospheres of these exoplanets. This is the first textbook to describe the basic physical processes--including radiative transfer, molecular absorption, and chemical processes--common to all planetary atmospheres, as well as the transit, eclipse, and thermal phase variation observations that are unique to exoplanets. In each chapter, Sara Seager offers a conceptual introdu

  11. Secondary eclipse observations and the atmosphere of exoplanet WASP-34b

    Science.gov (United States)

    Challener, Ryan C.; Harrington, Joseph; Cubillos, Patricio; Garland, Justin; Foster, Andrew S. D.; Blecic, Jasmina; Foster, AJ; Smalley, Barry

    2015-11-01

    WASP-34b is a short-period exoplanet with a mass of 0.59 ± 0.01 Jupiter masses orbiting a G5 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 ?m channels of the Infrared Array Camera aboard the Spitzer Space Telescope in 2010 (Program 60003). We applied our Photometry for Orbits, Eclipses, and Transits (POET) code to present eclipse-depth measurements, estimates of infrared brightness temperatures, and a refined orbit. With our Bayesian Atmospheric Radiative Transfer (BART) code, we characterized the atmosphere's temperature and pressure profile, and molecular abundances. Spitzer is operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. This work was supported by NASA Planetary Atmospheres grant NNX12AI69G and NASA Astrophysics Data Analysis Program grant NNX13AF38G. J. Blecic holds a NASA Earth and Space Science Fellowship.

  12. What asteroseismology can do for exoplanets

    DEFF Research Database (Denmark)

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

    2015-01-01

    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 [1]. This is one of the brightest (V = 9.4) Kepler exoplanet host stars, containing a small (2.8 R?) transiting planet in a long orbit (1...

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

    Science.gov (United States)

    Mandell, Avram Max; Haynes, Korey N.; Sinukoff, Evan; Madhusudhan, Nikku; Burrows, Adam; Deming, Drake

    2013-01-01

    We report an analysis of transit spectroscopy of the extrasolar planets WASP-12 b, WASP-17 b, and WASP-19 b using the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (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., 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 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 nano meter most likely due to water. However, the amplitude of the absorption is less than that expected based on previous observations with Spitzer, possibly due to hazes absorbing in the NIR or non-solar compositions. The degeneracy of models with different compositions and temperature structures combined with the low amplitude of any features in the data preclude our ability to place unambiguous constraints on the atmospheric composition without additional observations with WFC3 to improve the signal-to-noise ratio and/or a comprehensive multi-wavelength analysis.

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

    CERN Document Server

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

    2013-01-01

    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...

  15. Five New Transit Epochs of the Exoplanet OGLE-TR-111b

    CERN Document Server

    Hoyer, Sergio; López-Morales, Mercedes; Díaz, Rodrigo; Chambers, John E; Minniti, Dante

    2011-01-01

    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 April and May 2008. 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 discard TTVs with amplitudes larger than 1.5 minutes over a 4-year observation time baseline, in agreement with the recent result by Adams et al.(2010a). Dynamical simulations fully exclude the presence of additional planets in the system with masses greater than 1.3, 0.4 and 0.5 M_earth at the 3:2, 1:2, 2:1 resonances, respectively. We also place an upper limit of about 30 M_earth on the mass of potential second planets in the region between the 3:2 and 1:2 mean-motion resonances.

  16. MOST Spacebased Photometry of the Transiting Exoplanet System HD 189733: Precise Timing Measurements for Transits Across an Active Star

    CERN Document Server

    Miller-Ricci, E; Sasselov, D; Matthews, J M; Kuschnig, R; Croll, B; Günther, D B; Moffat, A F J; Rucinski, S M; Walker, G A H; Weiss, W W

    2008-01-01

    We have measured transit times for HD 189733b passing in front of its bright (V = 7.67) chromospherically active and spotted parent star. Nearly continuous broadband optical photometry of this system was obtained with the MOST (Microvariability & Oscillations of STars) space telescope during 21 days in August 2006, monitoring 10 consecutive transits. We have used these data to search for deviations from a constant orbital period which can indicate the presence of additional planets in the system that are as yet undetected by Doppler searches. There are no transit timing variations above the level of ${\\pm}45$ s, ruling out super-Earths (of masses $1 - 4 M_{\\earth}$) in the 1:2 and 2:3 inner resonances and planets of 20 $M_{\\earth}$ in the 2:1 outer resonance of the known planet. We also discuss complications in measuring transit times for a planet that transits an active star with large star spots, and how the transits can help constrain and test spot models. This has implications for the large number of ...

  17. Asteroseismology and Exoplanet Hosts

    Science.gov (United States)

    Huber, Daniel

    2015-08-01

    Asteroseismology is among the most powerful observational tools to determine fundamental properties of stars. Space-based photometry has recently enabled the systematic detection of oscillations in exoplanet host stars, allowing a combination of asteroseismology with transit and radial-velocity measurements to precisely characterize planetary systems. In this talk I will review the latest asteroseismic detections in exoplanet host stars spanning from the main sequence to the red-giant branch, focusing in particular on radii and ages of stars hosting small (sub-Neptune sized) planets discovered by the Kepler mission. I will furthermore discuss applications of asteroseismology to measure spin-orbit inclinations in multiplanet systems, and their implications for formation theories of hot Jupiters. Finally I will give an outlook on asteroseismic studies of exoplanet hosts with current and future space- and ground-based facilities such as K2, SONG, TESS, and PLATO.

  18. Exoplanet Detection Techniques

    CERN Document Server

    Fischer, Debra A; Laughlin, Greg P; Macintosh, Bruce; Mahadevan, Suvrath; Sahlmann, Johannes; Yee, Jennifer C

    2015-01-01

    We are still in the early days of exoplanet discovery. Astronomers are beginning to model the atmospheres and interiors of exoplanets and have developed a deeper understanding of processes of planet formation and evolution. However, we have yet to map out the full complexity of multi-planet architectures or to detect Earth analogues around nearby stars. Reaching these ambitious goals will require further improvements in instrumentation and new analysis tools. In this chapter, we provide an overview of five observational techniques that are currently employed in the detection of exoplanets: optical and IR Doppler measurements, transit photometry, direct imaging, microlensing, and astrometry. We provide a basic description of how each of these techniques works and discuss forefront developments that will result in new discoveries. We also highlight the observational limitations and synergies of each method and their connections to future space missions.

  19. Observations of transits of K2 exoplanet discoveries EPIC 203371098b&c

    Science.gov (United States)

    Werner, Michael; Gorjian, Varoujan; Beichmani, Charles; Akeson, Rachel; Ciardi, Dave; Christiansen, Jessie; Crossfield, Ian; Petigura, Erik; Krick, Jessica

    2015-08-01

    We request DDT time to observe transits of two super-Neptune planets orbiting a bright G star, EPIC 203371098. Erik Petigura has brought to our attention a particularly interesting K2 discovery that consists of two sub-Saturn-sized planets (5.9 RE and 7.8 RE) orbiting EPIC-203371098, a bright G star (K = 9.2). The orbital periods of the planets are 20.9 d and 42.4 d, respectively. The planets have sizes between that of Neptune and Saturn; sizes not represented among the Solar System planets. Due to the brightness of the host star, this system is an ideal laboratory to study this new class of planets. Over the past two months, our team has conducted radial velocity (RV) follow up of EPIC-203371098 with Keck/HIRES. Our preliminary measurements suggest these planets have low densities, ~0.6 g/cc and ~0.4 g/cc, respectively. Low planet masses translate into larger atmospheric scale heights, which sets the amplitude of the features in planet transmission spectra. The apparent commensurability of their orbits suggest that this is a resonant system where transit timing variations may be particularly large. Our Spitzer observations, compared with the previous K2 first epoch observations, can provide initial evidence for TTVs and set the stage for future campaigns from Spitzer and other telescopes which will independently determine the planetary masses; they will also pin down the ephemerides of these interesting planets - including the hard to capture orbital eccentricity - for possible JWST study.It is important to carry out these observations in the upcoming apparition of this star in the October-December time frame because multiple observations are required for accurate studies of TTVs, and to prevent secular errors in timing from building up to a point where the system is hard to recover. The size of these planets and the brightness of the star shows us that we will achieve S/N>20 per transit on each planet.We will propose to observe one transit of each planet.We expect to spend of order 15 hours observing each of the two transits and request a total of 35 hours of DDT time to provide some headroom; a more precise estimate will be submitted with the forthcoming AORs.The observation strategy and data reduction will be drawn from our approved cycle 11 program to study transiting planets around M stars identified by K2.

  20. Radial velocity follow-up of CoRoT transiting exoplanets

    Directory of Open Access Journals (Sweden)

    Deleuil M.

    2011-02-01

    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.

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

    Science.gov (United States)

    Mandell, Avi M.; Haynes, Korey; Sinukoff, Evan; Madhusudhan, Nikku; Burrows, Adam; Deming, Drake

    2013-01-01

    We report an analysis of transit spectroscopy of the extrasolar planets WASP-12 b, WASP-17 b, and WASP-19 b using the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (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., 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 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 most likely due to water. However, the amplitude of the absorption is less than that expected based on previous observations with Spitzer, possibly due to hazes absorbing in the NIR or non-solar compositions. The degeneracy of models with different compositions and temperature structures combined with the low amplitude of any features in the data preclude our ability to place unambiguous constraints on the atmospheric composition without additional observations with WFC3 to improve the signal-to-noise ratio and/or a comprehensive multi-wavelength analysis. Key words: planetary systems - techniques: photometric - techniques: spectroscopic

  2. Exoplanet transit spectroscopy using WFC3: WASP-12 b, WASP-17 b, and WASP-19 b

    International Nuclear Information System (INIS)

    We report an analysis of transit spectroscopy of the extrasolar planets WASP-12 b, WASP-17 b, and WASP-19 b using the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (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., 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 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 ?m most likely due to water. However, the amplitude of the absorption is less than that expected based on previous observations with Spitzer, possibly due to hazes absorbing in the NIR or non-solar compositions. The degeneracy of models with different compositions and temperature structures combined with the low amplitude of any features in the data preclude our ability to place unambiguous constraints on the atmospheric composition without additional observations with WFC3 to improve the signal-to-noise ratio and/or a comprehensive multi-wavelength analysis.

  3. Improved Modeling of the Rossiter-McLaughlin Effect for Transiting Exoplanets

    OpenAIRE

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

    2011-01-01

    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 ...

  4. Three WASP-South Transiting Exoplanets: WASP-74b, WASP-83b, and WASP-89b

    Science.gov (United States)

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

    2015-07-01

    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 0.95MJup planet with a moderately bloated radius of 1.5 {R}{Jup} in a 2 day 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 day orbit around a fainter (V = 12.9) G8 star. WASP-89b is a 6 MJup planet in a 3 day 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 days, 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.

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

    CERN Document Server

    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

    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.

  6. Line-profile tomography of exoplanet transits I: The Doppler shadow of HD 189733b

    CERN Document Server

    Cameron, A Collier; Miller, G R M; Triaud, A H M J; Queloz, D

    2009-01-01

    We present a direct method for isolating the component of the starlight blocked by a planet as it transits its host star, and apply it to spectra of the bright transiting planet HD 189733b. We model the global shape of the stellar cross-correlation function as the convolution of a limb-darkened rotation profile and a gaussian representing the Doppler core of the average photospheric line profile. The light blocked by the planet during the transit is a gaussian of the same intrinsic width, whose trajectory across the line profile yields a precise measure of the misalignment angle and an independent measure of v sin I. We show that even when v sin I is less than the width of the intrinsic line profile, the travelling Doppler "shadow" cast by the planet creates an identifiable distortion in the line profiles which is amenable to direct modelling. Direct measurement of the trajectory of the missing starlight yields self-consistent measures of the projected stellar rotation rate, the intrinsic width of the mean lo...

  7. SEARCH FOR CARBON MONOXIDE IN THE ATMOSPHERE OF THE TRANSITING EXOPLANET HD 189733b

    International Nuclear Information System (INIS)

    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 μm 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 μm 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 μm 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 *)3.6μm = 0.1545 ± 0.0003, (Rp /R*)4.5μm = 0.1557 ± 0.0003, (Rp /R *)5.8μm = 0.1547 ± 0.0005, and (Rp/R*)8μm = 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 μm is not detected in this photometric data set. Furthermore, in the band centered around 4.5 μm we find a hint of excess absorption with an apparent planetary radius ΔRp /R * = 0.00128 ± 0.00056 larger (2.3σ) than the one measured simultaneously at 8 μm. This value is 4σ 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 μm 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.

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

    Science.gov (United States)

    Loyd, R. O. Parke; France, Kevin

    2014-03-01

    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, C II ??1334, 1335 and Si III ?1206 one enclosing Si IV ??1393, 1402; and 36.5 Å of interspersed continuum. For each star/band combination, we generated 60 s cadence lightcurves from archival Hubble Space Telescope Cosmic Origins Spectrograph and Space Telescope Imaging Spectrograph 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 hr, over 50% last 4 minutes or less, and most produce the strongest response in Si IV. If the flare occurred during a transit measurement integrated for 60 minutes, 90/116 would destroy the signal of an Earth, 27/116 Neptune, and 7/116 Jupiter, with the upward bias in flux ranging from 1% to 109% of quiescent levels. Fluctuations: photon noise and underlying stellar fluctuations produce scatter in the quiescent data. We model the stellar fluctuations as Gaussian white noise with standard deviation ? x . Maximum likelihood values of ? x range from 1% to 41% for 60 s measurements. These values suggest that many cool stars will only permit a transit detection to high confidence in ultraviolet resonance lines if the radius of the occulting disk is gsim1 RJ . However, for some M dwarfs this limit can be as low as several R ?.

  9. FLUCTUATIONS AND FLARES IN THE ULTRAVIOLET LINE EMISSION OF COOL STARS: IMPLICATIONS FOR EXOPLANET TRANSIT OBSERVATIONS

    International Nuclear Information System (INIS)

    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, C II ??1334, 1335 and Si III ?1206; one enclosing Si IV ??1393, 1402; and 36.5 Å of interspersed continuum. For each star/band combination, we generated 60 s cadence lightcurves from archival Hubble Space Telescope Cosmic Origins Spectrograph and Space Telescope Imaging Spectrograph 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 hr, over 50% last 4 minutes or less, and most produce the strongest response in Si IV. If the flare occurred during a transit measurement integrated for 60 minutes, 90/116 would destroy the signal of an Earth, 27/116 Neptune, and 7/116 Jupiter, with the upward bias in flux ranging from 1% to 109% of quiescent levels. Fluctuations: photon noise and underlying stellar fluctuations produce scatter in the quiescent data. We model the stellar fluctuations as Gaussian white noise with standard deviation ? x. Maximum likelihood values of ? x range from 1% to 41% for 60 s measurements. These values suggest that many cool stars will only permit a transit detection to high confidence in ultraviolet resonance lines if the radius of the occulting disk is ?1 RJ . However, for some M dwarfs this limit can be as low as several R ?

  10. FLUCTUATIONS AND FLARES IN THE ULTRAVIOLET LINE EMISSION OF COOL STARS: IMPLICATIONS FOR EXOPLANET TRANSIT OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Loyd, R. O. Parke [Center for Astrophysics and Space Astronomy, Boulder, CO 80303 (United States); France, Kevin, E-mail: robert.loyd@colorado.edu [NASA Nancy Grace Roman Fellow. (United States)

    2014-03-01

    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, C II ??1334, 1335 and Si III ?1206; one enclosing Si IV ??1393, 1402; and 36.5 Å of interspersed continuum. For each star/band combination, we generated 60 s cadence lightcurves from archival Hubble Space Telescope Cosmic Origins Spectrograph and Space Telescope Imaging Spectrograph 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 hr, over 50% last 4 minutes or less, and most produce the strongest response in Si IV. If the flare occurred during a transit measurement integrated for 60 minutes, 90/116 would destroy the signal of an Earth, 27/116 Neptune, and 7/116 Jupiter, with the upward bias in flux ranging from 1% to 109% of quiescent levels. Fluctuations: photon noise and underlying stellar fluctuations produce scatter in the quiescent data. We model the stellar fluctuations as Gaussian white noise with standard deviation ? {sub x}. Maximum likelihood values of ? {sub x} range from 1% to 41% for 60 s measurements. These values suggest that many cool stars will only permit a transit detection to high confidence in ultraviolet resonance lines if the radius of the occulting disk is ?1 R{sub J} . However, for some M dwarfs this limit can be as low as several R {sub ?}.

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

    CERN Document Server

    Misra, Amit; Crisp, Dave

    2014-01-01

    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...

  12. Three WASP-South Transiting Exoplanets: WASP-74b, WASP-83b, and WASP-89b

    OpenAIRE

    Hellier, Coel; Anderson, D.R.; Collier Cameron, A.; Delrez, Laetitia; Gillon, Michaël; Jehin, Emmanuel; Lendl, Monika; Maxted, P F L; PEPE, F.; Pollacco, D.; Queloz, D.; Ségransan, D.; Smalley, B; Smith, A. M. S.; Southworth, J.

    2015-01-01

    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 0.95M[SUB]Jup[/SUB] planet with a moderately bloated radius of 1.5 {R}[SUB]{Jup[/SUB]} in a 2 day orbit around a slightly evolved F9 star. WASP-83b is a Saturn-mass planet at 0.3 {M}[SUB]{Jup[/SUB]} with a radius of 1.0 {R}[SUB]{Jup...

  13. Improved Modeling of the Rossiter-McLaughlin Effect for Transiting Exoplanets

    CERN Document Server

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

    2011-01-01

    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...

  14. MuSCAT: a multicolor simultaneous camera for studying atmospheres of transiting exoplanets

    CERN Document Server

    Narita, Norio; Kusakabe, Nobuhiko; Onitsuka, Masahiro; Ryu, Tsuguru; Yanagisawa, Kenshi; Izumiura, Hideyuki; Tamura, Motohide; Yamamuro, Tomoyasu

    2015-01-01

    We report a development of a multi-color simultaneous camera for the 188cm telescope at Okayama Astrophysical Observatory in Japan. The instrument, named MuSCAT, has a capability of 3-color simultaneous imaging in optical wavelength where CCDs are sensitive. MuSCAT is equipped with three 1024x1024 pixel CCDs, which can be controlled independently. The three CCDs detect lights in $g'_2$ (400--550 nm), $r'_2$ (550--700 nm), and $z_{s,2}$ (820--920 nm) bands using Astrodon Photometrics Generation 2 Sloan filters. The field of view of MuSCAT is 6.1x6.1 arcmin$^2$ with the pixel scale of 0.358 arcsec per pixel. The principal purpose of MuSCAT is to perform high precision multi-color transit photometry. For the purpose, MuSCAT has a capability of self autoguiding which enables to fix positions of stellar images within ~1 pix. We demonstrate relative photometric precisions of 0.101%, 0.074%, and 0.076% in $g'_2$, $r'_2$, and $z_{s,2}$ bands, respectively, for GJ436 (magnitudes in $g'$=11.81, $r'$=10.08, and $z'$=8.6...

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

    Directory of Open Access Journals (Sweden)

    Damiani C.

    2011-02-01

    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 configuration offers 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.

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

    CERN Document Server

    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

    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...

  17. Independent discovery and refined parameters of the transiting exoplanet HAT-P-14b

    CERN Document Server

    Simpson, E K; Brown, D J A; Cameron, A Collier; Pollacco, D; Skillen, I; Stempels, H C; Boisse, I; Faedi, F; Hebrard, G; McCormac, J; Sorensen, P; Street, R A; Bento, J; Bouchy, F; Butters, O W; Enoch, B; Haswell, C A; Hebb, L; Holmes, S; Horne, K; Keenan, F P; Lister, T A; Miller, G R M; Moulds, V; Moutou, C; Norton, A J; Parley, N; Santerne, A; Todd, I; Watson, C A; West, R G; Wheatley, P J

    2010-01-01

    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 refine the parameters by combining our datasets. We also provide additional evidence against astronomical false positives. Due to the brightness of the host star, V = 10, HAT-P-14 is an attractive candidate for further characterisation observations. The planet has a high impact parameter, b = 0.907 +/- 0.004, 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, e = 0.095 +/- 0.011. The system geometry suggests that the planet narrowly fails to undergo a secondary ecl...

  18. IMPROVED MODELING OF THE ROSSITER-McLAUGHLIN EFFECT FOR TRANSITING EXOPLANETS

    International Nuclear Information System (INIS)

    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 simulations. Finally, as one application of the new formula, we reassess the impact of the differential rotation on the RM velocity anomaly. We show that differential rotation of a rapidly rotating star may have a significant impact on future RM observations.

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

    CERN Document Server

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

    2015-01-01

    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...

  20. SOPHIE velocimetry of Kepler transit candidates. XII. KOI-1257 b: a highly eccentric three-month period transiting exoplanet

    Science.gov (United States)

    Santerne, A.; Hébrard, G.; 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.

    2014-11-01

    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 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 ± 3 s and a high eccentricity of 0.772 ± 0.045. The planet transits the main star of a metal-rich, relatively old binary system with stars of mass of 0.99 ± 0.05 M? and 0.70 ± 0.07 M? for the primary and secondary, respectively. This binary system is constrained thanks to a self-consistent modelling of the Kepler transit light curve, the SOPHIE radial velocities, line bisector and full-width half maximum (FWHM) variations, and 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 accounting for the dilution from the binary both in photometry and in radial velocity, we find that the planet has a mass of 1.45 ± 0.35 M? , and a radius of 0.94 ± 0.12 R? , and thus a bulk density of 2.1 ± 1.2 g cm-3. The planet has an equilibrium temperature of 511 ± 50 K, making it one of the few known members of the warm-Jupiter population. The HARPS-N spectrograph was also used to observe a transit of KOI-1257 b, simultaneously with a joint amateur and professional photometric follow-up, with the aim of constraining the orbital obliquity of the planet. However, the Rossiter-McLaughlin effect was not clearly detected, resulting in poor constraints on the orbital obliquity of the planet. Based on observations made with SOPHIE on the 1.93 m telescope at Observatoire de Haute-Provence (CNRS), France, and with the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma by the Fundación Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. Part of the observations were made with the IAC80 operated on the Spanish Observatorio del Teide of the Instituto de Astrofísica de Canarias.Appendices are available in electronic form at http://www.aanda.orgFull Tables C.5-C.7 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/571/A37

  1. 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 convergence of Markov chains that employ the Metropolis random walk sampler. The electronic supplement contains light-curve files.

  2. Evolution of Exoplanets and their Parent Stars

    OpenAIRE

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

    2013-01-01

    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...

  3. 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

    CERN Document Server

    Boyajian, Tabetha; 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; Brummelaar, Theo A ten; Ciardi, David R; McAlister, Harold A; Ridgway, Stephen; Goldfinger, P J; Turner, Nils H; Sturmann, Laszlo

    2014-01-01

    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 theta_LD = 0.3848 +/- 0.0055 and 0.2254 +/- 0.0072 milliarcsec 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 (T_eff = 4875 +/- 43, 6093 +/- 103 K), stellar linear radii (R_* = 0.805 +/- 0.016, 1.203 +/- 0.061 R_sun), mean stellar densities (rho_* = 1.62 +/- 0.11, 0.58 +/- 0.14 rho_sun), planetary radii (R_p = 1.216 +/- 0.024, 1.451 +/- 0.074 R_Jup), and mean ...

  4. Exoplanet habitability.

    Science.gov (United States)

    Seager, Sara

    2013-05-01

    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

  5. Asteroseismology of Exoplanet Host Stars

    CERN Document Server

    Huber, Daniel

    2015-01-01

    Asteroseismology is among the most powerful observational tools to determine fundamental properties of stars. Space-based photometry has recently enabled the systematic detection of oscillations in exoplanet host stars, allowing a combination of asteroseismology with transit and radial-velocity measurements to characterize planetary systems. In this contribution I will review the key synergies between asteroseismology and exoplanet science such as the precise determination of radii and ages of exoplanet host stars, as well as applications of asteroseismology to measure spin-orbit inclinations in multiplanet systems and orbital eccentricities of small planets. Finally I will give a brief outlook on asteroseismic studies of exoplanet hosts with current and future space-based missions such as K2 and TESS.

  6. THE TRANSIT LIGHT-CURVE PROJECT. XIV. CONFIRMATION OF ANOMALOUS RADII FOR THE EXOPLANETS TrES-4b, HAT-P-3b, AND WASP-12b

    International Nuclear Information System (INIS)

    We present transit photometry of three exoplanets, TrES-4b, HAT-P-3b, and WASP-12b, allowing for refined estimates of the systems' parameters. TrES-4b and WASP-12b were confirmed to be 'bloated' planets, with radii of 1.706 ± 0.056RJup and 1.736 ± 0.092RJup, respectively. These planets are too large to be explained with standard models of gas giant planets. In contrast, HAT-P-3b has a radius of 0.827 ± 0.055RJup, smaller than a pure hydrogen-helium planet and indicative of a highly metal-enriched composition. Analyses of the transit timings revealed no significant departures from strict periodicity. For TrES-4, our relatively recent observations allow for improvement in the orbital ephemerides, which is useful for planning future observations.

  7. Infrared spectroscopy of exoplanets: observational constraints

    OpenAIRE

    Encrenaz, Thérèse

    2014-01-01

    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...

  8. The Exoplanet Orbit Database II: Updates to exoplanets.org

    CERN Document Server

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

    2014-01-01

    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...

  9. Precisely measuring the density of small transiting exoplanets with particular emphasis on longer period planet using the HARPS-N spectrograph

    Science.gov (United States)

    Buchhave, Lars A.

    2015-08-01

    The majority of exoplanets discovered by the Kepler Mission have sizes that range between 1-4 Earth radii, populating a regime of planets with no Solar System analogues. This regime is critical for understanding the frequency of potentially habitable worlds and to help inform planet formation theories, because it contains the transition from lower-density planets with extended H/He envelopes to higher-density rocky planets with compact atmospheres. HARPS-N is an ultra-stable high-resolution spectrograph optimized for the measurement of precise radial velocities, yielding precise planetary masses and thus densities of small transiting exoplanets. In this talk, I will review the progress to populate the mass-radius parameter space with precisely measured densities of small planets. I will in particular focus on the latest HARPS-N results and their implication for our understanding of these super-Earth and small Neptune type planets.Additionally, I will discuss our progress to measure the masses of longer period sub-Neptune sized planets. In Buchhave el al. 2014, we found suggestive observational evidence that the transition from rocky to gaseous planets might depend on the orbital period, such that larger planets further away from their host star could be massive planets without a large gaseous envelope. To test this hypothesis, we have used HARPS-N to observe longer period planet candidates to determine whether they are in fact massive rocky planets or if they have extended H/He envelopes and thus lower bulk densities.HARPS-N at the Telescopio Nazionale Galileo, La Palma is an international collaboration and was funded by the Swiss Space Office, the Harvard Origin of Life Initiative, the Scottish Universities Physics Alliance, the University of Geneva, the Smithsonian Astrophysical Observatory, and the Italian National Astrophysical Institute, University of St. Andrews, Queens University Belfast, and University of Edinburgh.

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

    CERN Document Server

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

    2009-01-01

    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.

  11. Exoplanet Chemistry

    OpenAIRE

    Lodders, Katharina

    2009-01-01

    The terrestrial and gas-giant planets in our solar system may represent some prototypes for planets around other stars; the exoplanets because most stars have similar overall elemental abundances as our sun. The solar system planets represent at least four chemical planet types, depending on the phases that make them: Terrestrial-like planets made of rock (metal plus silicates), Plutonian planets made of rock and ice, Neptunian giant planets of rocky, icy with low H and He c...

  12. Water in exoplanets.

    Science.gov (United States)

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

    2012-06-13

    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

  13. Eccentricity of small exoplanets

    Science.gov (United States)

    Van Eylen, Vincent; Albrecht, Simon

    2015-12-01

    Solar system planets move on almost circular orbits. In strong contrast, many massive gas giant exoplanets travel on highly elliptical orbits, whereas the shape of the orbits of smaller, more terrestrial, exoplanets remained largely elusive. This is because the stellar radial velocity caused by these small planets is extremely challenging to measure. Knowing the eccentricity distribution in systems of small planets would be important as it holds information about the planet's formation and evolution. Furthermore the location of the habitable zone depends on eccentricity, and eccentricity also influences occurrence rates inferred for these planets because planets on circular orbits are less likely to transit. We make these eccentricity measurements of small planets using photometry from the Kepler satellite and utilizing a method relying on Kepler's second law, which relates the duration of a planetary transit to its orbital eccentricity, if the stellar density is known.I present a sample of 28 multi-planet systems with precise asteroseismic density measurements, which host 74 planets with an average radius of 2.6 R_earth. We find that the eccentricity of planets in these systems is low and can be described by a Rayleigh distribution with sigma = 0.049 +- 0.013. This is in full agreement with solar system eccentricities, but in contrast to the eccentricity distributions previously derived for exoplanets from radial velocity studies. I further report the first results on the eccentricities of over 50 Kepler single-planet systems, and compare them with the multi-planet systems. I close the talk by showing how transit durations help distinguish between false positives and true planets, and present six new planets.

  14. ExoplanetSat: The Search for Earth-Sized Planets

    Science.gov (United States)

    Jensen-Clem, Rebecca; Seager, S.; Smith, M. W.; Pong, C.; Knapp, M.; Miller, D.

    2011-05-01

    ExoplanetSat combines the low cost CubeSat platform with an innovative two-stage attitude control system to detect exoplanets. ExoplanetSat will be capable of detecting transiting Earth-sized planets in the habitable zone of the brightest sun-like stars with a detection threshold of 7 sigma. The choice of targeting the brightest sun-like stars is motivated by the desire to conduct spectral follow-up observations to determine the habitability of exoplanet candidates. We present the design of the first three-unit ExoplanetSat, which will launch in the next two years under NASA's CubeSat Launch Initiative.

  15. 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

    Science.gov (United States)

    Cabrera, J.; Bruntt, H.; Ollivier, M.; Díaz, R. F.; Csizmadia, Sz.; Aigrain, S.; Alonso, R.; Almenara, J.-M.; Auvergne, M.; Baglin, A.; Barge, P.; Bonomo, A. S.; Bordé, 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.; Hébrard, G.; Jorda, L.; Léger, A.; Llebaria, A.; Lammer, H.; Lovis, C.; Mazeh, T.; Moutou, C.; Ofir, A.; von Paris, P.; Pätzold, M.; Queloz, D.; Rauer, H.; Rouan, D.; Santerne, A.; Schneider, J.; Tingley, B.; Titz-Weider, R.; Wuchterl, G.

    2010-11-01

    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 T_eff = 5 945 K, M* = 1.09 M?, R_* = 1.01 R?, solar metallicity, a lithium content of + 1.45 dex, and an estimated age of 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, implies that heavy elements are present with a mass of between about 140 and 300 {M}?. 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. Part of the observations were obtained at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii. Based on observations made with HARPS spectrograph on the 3.6-m European Organisation for Astronomical Research in the Southern Hemisphere telescope at La Silla Observatory, Chile (ESO program 184.C-0639). Based on observations made with the IAC80 telescope operated on the island of Tenerife by the Instituto de Astrofísica de Canarias in the Spanish Observatorio del Teide. Part 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.

  16. Transiting exoplanets from the CoRoT space mission. V. CoRoT-Exo-4b: stellar and planetary parameters

    Science.gov (United States)

    Moutou, C.; Bruntt, H.; Guillot, T.; Shporer, A.; Guenther, E.; Aigrain, S.; Almenara, J. M.; Alonso, R.; Auvergne, M.; Baglin, A.; Barbieri, M.; Barge, P.; Benz, W.; Bordé, P.; Bouchy, F.; Deeg, H. J.; de La Reza, R.; Deleuil, M.; Dvorak, R.; Erikson, A.; Fridlund, M.; Gillon, M.; Gondoin, P.; Hatzes, A.; Hébrard, G.; Jorda, L.; Kabath, P.; Lammer, H.; Léger, A.; Llebaria, A.; Loeillet, B.; Magain, P.; Mayor, M.; Mazeh, T.; Ollivier, M.; Pätzold, M.; Pepe, F.; Pont, F.; Queloz, D.; Rabus, M.; Rauer, H.; Rouan, D.; Schneider, J.; Udry, S.; Wuchterl, G.

    2008-09-01

    Aims: The CoRoT satellite has announced its fourth transiting planet (Aigrain et al. 2008, A&A, 488, L43) with space photometry. We describe and analyse complementary observations of this system performed to establish the planetary nature of the transiting body and to estimate the fundamental parameters of the planet and its parent star. Methods: We have analysed high precision radial-velocity data, ground-based photometry, and high signal-to-noise ratio spectroscopy. Results: The parent star CoRoT-Exo-4 (2MASS 06484671-0040219) is a late F-type star of mass of 1.16 M? and radius of 1.17 R?. The planet has a circular orbit with a period of 9.20205 d. The planet radius is 1.19 R_Jup and the mass is 0.72 M_Jup. It is a gas-giant planet with a “normal” internal structure of mainly H and He. CoRoT-Exo-4b has the second longest period of the known transiting planets. It is an important discovery since it occupies an empty area in the mass-period diagram of transiting exoplanets. Based on observations obtained with CoRoT, a space project operated by the French Space Agency, CNES, with participation of the Science Programme of ESA, ESTEC/RSSD, Austria, Belgium, Brazil, Germany and Spain; and on observations made with the SOPHIE spectrograph at Observatoire de Haute Provence, France (PNP.07B.MOUT), and the HARPS spectrograph at ESO La Silla Observatory (079.C-0127/F). Table 2 and Fig. 5 are only available in electronic form at http://www.aanda.org

  17. Formation of Jupiter-mass planets from hydrodynamic simulations -- the role of the circumplanetary disk in the accretion process

    Science.gov (United States)

    Szulagyi, Judit; Morbidelli, Alessandro; Masset, Frederic; Lega, Elena; Crida, Aurelien; Guillot, Tristan

    2015-12-01

    In the era of observing young planetary systems with growing planets, it is necessary to study planet formation with numerical simulations to provide predictions for observations and also to update planet formation models. In this talk we are going to summarize a PhD thesis on the topic of accretion of giant planets with hydrodynamic simulations.One of the main problems with the core accretion formation model is that it predicts a runaway growth phase for the giant planets at the last stages of the formation process, which would indicate a presence of an unseen population of super-giants. We performed isothermal and radiative hydrodynamic simulations in 3D on a Jupiter-mass planet in an MMSN disk to simulate the fastest part of the runaway growth for our Jupiter. This massive planet can form a circumplanetary disk around it, which can limit the accretion in this late stage of planet formation, and is the focus point of our study. We have found that the 90% of the accreted gas by the planet is coming from the vertical direction, from the top layers of the circumstellar disk falling through the planetary gap, in an inflow hitting the circumplanetary disk and directly the planet as well. We will show that this vertical influx is part of a feedback loop -- a meridional circulation -- between the circumstellar and circumplanetary disks.We have also revisited the question of circumplanetary disk formation. Planets which are massive enough to open gaps (above ~Saturn's mass) were believed to form circumplanetary disk, while planets below this mass threshold were only capable to form an envelope. We will prove that the planetary surface temperature is also playing a large role in this question. We carried out a series of simulations with various planetary surface temperatures, and found that in the hottest case even a Jupiter-mass planet, which was capable to open a planetary gap, cannot form a circumplanetary disk, only an envelope, similarly to small mass planets. We will show the quantitative differences between the envelope and disk cases which have implications on the satellite formation and for the future observations of circumplanetary disks/envelopes around giant planets as well.

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

    DEFF Research Database (Denmark)

    Guenther, E. W.; Díaz, R. F.; 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.; Bordé, 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.; Hébrard, G.; Jehin, E.; Jorda, L.; Lammer, H.; Léger, A.; Moutou, C.; Nortmann, L.; Ollivier, M.; Ofir, A.; Pasternacki, Th.; Pätzold, M.; Parviainen, H.; Queloz, D.; Rauer, H.; Samuel, B.; Santerne, A.; Schneider, J.; Tal-Or, L.; Tingley, B.; Weingrill, J.; Wuchterl, G.

    2012-01-01

    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 gener...... 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....

  19. What asteroseismology can do for exoplanets

    Directory of Open Access Journals (Sweden)

    Van Eylen Vincent

    2015-01-01

    Full Text Available 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 [1]. This is one of the brightest (V = 9.4 Kepler exoplanet host stars, containing a small (2.8 R? 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.

  20. What asteroseismology can do for exoplanets

    CERN Document Server

    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

    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.

  1. Eclipsing Binary Science Via the Merging of Transit and Doppler Exoplanet Survey Data - A Case Study With the MARVELS Pilot Project and SuperWASP

    CERN Document Server

    Fleming, Scott W; Hebb, Leslie; Stassun, Keivan G; Ge, Jian; Cargile, Phillip A; Ghezzi, Luan; De Lee, Nathan M; Wisniewski, John; Gary, Bruce; de Mello, Gustavo F Porto; Ferreira, Leticia; Zhao, Bo; Anderson, David R; Wan, Xiaoke; Hellier, Coel; Guo, Pengcheng; West, Richard G; Mahadevan, Suvrath; Pollacco, Don; Lee, Brian; Cameron, Andrew Collier; van Eyken, Julian C; Skillen, Ian; Crepp, Justin R; Nguyen, Duy Cuong; Kane, Stephen R; Paegert, Martin; da Costa, Luiz Nicolaci; Maia, Marcio A G; Santiago, Basilio X

    2011-01-01

    Exoplanet transit and Doppler surveys discover many binary stars during their operation that can be used to conduct a variety of ancillary science. Specifically, eclipsing binary stars can be used to study the stellar mass-radius relationship and to test predictions of theoretical stellar evolution models. By cross-referencing 24 binary stars found in the MARVELS Pilot Project with SuperWASP photometry, we find two new eclipsing binaries, TYC 0272-00458-1 and TYC 1422-01328-1, which we use as case studies to develop a general approach to eclipsing binaries in survey data. TYC 0272-00458-1 is a single-lined spectroscopic binary for which we calculate a mass of the secondary and radii for both components using reasonable constraints on the primary mass through several different techniques. For a primary mass of M_1 = 0.92 +/- 0.1 M_solar, we find M_2 = 0.610 +/- 0.036 M_solar, R_1 = 0.932 +/- 0.076 R_solar and R_2 = 0.559 +/- 0.102 R_solar, and find that both stars have masses and radii consistent with model pr...

  2. 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 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.

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

    DEFF Research Database (Denmark)

    Pätzold, M.; Endl, M.; Csizmadia, Sz.; Gandolfi, D.; Jorda, L.; Grziwa, S.; Carone, L.; Pasternacki, T.; Aigrain, S.; Almenara, J. M.; Alonso, R.; Auvergne, M.; Baglin, A.; Barge, P.; Bonomo, A. S.; Bordé, P.; Bouchy, F.; Cabrera, J.; Cavarroc, C.; Cochran, W. B.; Deleuil, M.; Deeg, H. J.; Díaz, R.; Dvorak, R.; Erikson, A.; Ferraz-Mello, S.; Fridlund, M.; Gillon, M.; Guillot, T.; Hatzes, A.; Hébrard, G.; Léger, A.; Llebaria, A.; Lammer, H.; MacQueen, P. J.; Mazeh, T.; Moutou, C.; Ofir, A.; Ollivier, M.; Parviainen, H.; Queloz, D.; Rauer, H.; Rouan, D.; Santerne, A.; Schneider, J.; Tingley, B.; Weingrill, J.; Wuchterl, G.

    2012-01-01

    -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...

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

    CERN Document Server

    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

    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...

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

    CERN Document Server

    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

    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...

  6. Analysis of Exoplanet Light Curves

    Science.gov (United States)

    Erdem, A.; Budding, E.; Rhodes, M. D.; Püsküllü, Ç.; Soydugan, F.; Soydugan, E.; Tüysüz, M.; Demircan, O.

    2015-07-01

    We have applied the close binary system analysis package WINFITTER to a variety of exoplanet transiting light curves taken both from the NASA Exoplanet Archive and our own ground-based observations. WINFitter has parameter options for a realistic physical model, including gravity brightening and structural parameters derived from Kopal's applications of the relevant Radau equation, and it includes appropriate tests for determinacy and adequacy of its best fitting parameter sets. We discuss a number of issues related to empirical checking of models for stellar limb darkening, surface maculation, Doppler beaming, microvariability, and transit time variation (TTV) effects. The Radau coefficients used in the light curve modeling, in principle, allow structural models of the component stars to be tested.

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

    Directory of Open Access Journals (Sweden)

    Lattanzi M.G.

    2013-04-01

    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.

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

    Science.gov (United States)

    Christille, Jean-Marc; Bernagozzi, A.; Bertolini, E.; Calcidese, P.; Carbognani, A.; Cenadelli, D.; Damasso, M.; Giacobbe, P.; Lanteri, L.; Lattanzi, M. G.; Sozzetti, A.; Smart, R.

    2013-04-01

    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.

  9. 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

    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

    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.

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

    CERN Document Server

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

    2010-01-01

    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-...

  11. Evolution of Exoplanets and their Parent Stars

    CERN Document Server

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

    2014-01-01

    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...

  12. Observations of Exoplanet Atmospheres

    CERN Document Server

    Crossfield, Ian J M

    2015-01-01

    Detailed characterization of an extrasolar planet's atmosphere provides the best hope for distinguishing the makeup of its outer layers, and the only hope for understanding the interplay between initial composition, chemistry, dynamics & circulation, and disequilibrium processes. In recent years, some areas have seen rapid progress while developments in others have come more slowly and/or have been hotly contested. This article gives an observer's perspective on the current understanding of extrasolar planet atmospheres prior to the considerable advances expected from the next generation of observing facilities. Atmospheric processes of both transiting and directly-imaged planets are discussed, including molecular and atomic abundances, cloud properties, thermal structure, and planetary energy budgets. In the future we can expect a continuing and accelerating stream of new discoveries, which will fuel the ongoing exoplanet revolution for many years to come.

  13. Observations of Exoplanet Atmospheres

    Science.gov (United States)

    Crossfield, Ian J. M.

    2015-11-01

    Detailed characterization of an extrasolar planet's atmosphere provides the best hope for distinguishing the makeup of its outer layers, and the only hope for understanding the interplay between initial composition, chemistry, dynamics and circulation, and disequilibrium processes. In recent years, some areas have seen rapid progress, while developments in others have come more slowly and/or have been hotly contested. This article gives an observer's perspective on the current understanding of extrasolar planet atmospheres prior to the considerable advances expected from the next generation of observing facilities. Atmospheric processes of both transiting and directly imaged planets are discussed, including molecular and atomic abundances, cloud properties, thermal structure, and planetary energy budgets. In the future we can expect a continuing and accelerating stream of new discoveries, which will fuel the ongoing exoplanet revolution for many years to come.

  14. Transit spectrophotometry of the exoplanet HD189733b. I. Searching for water but finding haze with HST NICMOS

    CERN Document Server

    Sing, David K; Etangs, A Lecavelier des; Ballester, G E; Vidal-Madjar, A; Parmentier, V; Hébrard, G; Henry, G W

    2009-01-01

    We present Hubble Space Telescope near-infrared transit photometry of the nearby hot-Jupiter HD189733b. The observations were taken with the NICMOS instrument during five transits, with three transits executed with a narrowband filter at 1.87 microns and two performed with a narrowband filter at 1.66 microns. Our observing strategy using narrowband filters is insensitive to the usual HST intra-orbit and orbit-to-orbit measurement of systematic errors, allowing us to accurately and robustly measure the near-IR wavelength dependance of the planetary radius. Our measurements fail to reproduce the Swain et al. absorption signature of atmospheric water below 2 microns at a 5-sigma confidence level. We measure a planet-to-star radius contrast of 0.15498+/-0.00035 at 1.66 microns and a contrast of 0.15517+/-0.00019 at 1.87 microns. Both of our near-IR planetary radii values are in excellent agreement with the levels expected from Rayleigh scattering by sub-micron haze particles, observed at optical wavelengths, indi...

  15. ECLIPSING BINARY SCIENCE VIA THE MERGING OF TRANSIT AND DOPPLER EXOPLANET SURVEY DATA-A CASE STUDY WITH THE MARVELS PILOT PROJECT AND SuperWASP

    International Nuclear Information System (INIS)

    Exoplanet transit and Doppler surveys discover many binary stars during their operation that can be used to conduct a variety of ancillary science. Specifically, eclipsing binary stars can be used to study the stellar mass-radius relationship and to test predictions of theoretical stellar evolution models. By cross-referencing 24 binary stars found in the MARVELS Pilot Project with SuperWASP photometry, we find two new eclipsing binaries, TYC 0272-00458-1 and TYC 1422-01328-1, which we use as case studies to develop a general approach to eclipsing binaries in survey data. TYC 0272-00458-1 is a single-lined spectroscopic binary for which we calculate a mass of the secondary and radii for both components using reasonable constraints on the primary mass through several different techniques. For a primary mass of M1 = 0.92 ± 0.1 Msun, we find M2 = 0.610 ± 0.036 Msun, R1 = 0.932 ± 0.076 Rsun, and R2 = 0.559 ± 0.102 Rsun, and find that both stars have masses and radii consistent with model predictions. TYC 1422-01328-1 is a triple-component system for which we can directly measure the masses and radii of the eclipsing pair. We find that the eclipsing pair consists of an evolved primary star (M1 = 1.163 ± 0.034 Msun, R1 = 2.063 ± 0.058 Rsun) and a G-type dwarf secondary (M2 = 0.905 ± 0.067 Msun, R2 = 0.887 ± 0.037 Rsun). We provide the framework necessary to apply this analysis to much larger data sets.

  16. Eclipsing Binary Science via the Merging of Transit and Doppler Exoplanet Survey Data—A Case Study with the MARVELS Pilot Project and SuperWASP

    Science.gov (United States)

    Fleming, Scott W.; Maxted, Pierre F. L.; Hebb, Leslie; Stassun, Keivan G.; Ge, Jian; Cargile, Phillip A.; Ghezzi, Luan; De Lee, Nathan M.; Wisniewski, John; Gary, Bruce; Porto de Mello, G. F.; Ferreira, Leticia; Zhao, Bo; Anderson, David R.; Wan, Xiaoke; Hellier, Coel; Guo, Pengcheng; West, Richard G.; Mahadevan, Suvrath; Pollacco, Don; Lee, Brian; Collier Cameron, Andrew; van Eyken, Julian C.; Skillen, Ian; Crepp, Justin R.; Nguyen, Duy Cuong; Kane, Stephen R.; Paegert, Martin; Nicolaci da Costa, Luiz; Maia, Marcio A. G.; Santiago, Basilio X.

    2011-08-01

    Exoplanet transit and Doppler surveys discover many binary stars during their operation that can be used to conduct a variety of ancillary science. Specifically, eclipsing binary stars can be used to study the stellar mass-radius relationship and to test predictions of theoretical stellar evolution models. By cross-referencing 24 binary stars found in the MARVELS Pilot Project with SuperWASP photometry, we find two new eclipsing binaries, TYC 0272-00458-1 and TYC 1422-01328-1, which we use as case studies to develop a general approach to eclipsing binaries in survey data. TYC 0272-00458-1 is a single-lined spectroscopic binary for which we calculate a mass of the secondary and radii for both components using reasonable constraints on the primary mass through several different techniques. For a primary mass of M 1 = 0.92 ± 0.1 M sun, we find M 2 = 0.610 ± 0.036 M sun, R 1 = 0.932 ± 0.076 R sun, and R 2 = 0.559 ± 0.102 R sun, and find that both stars have masses and radii consistent with model predictions. TYC 1422-01328-1 is a triple-component system for which we can directly measure the masses and radii of the eclipsing pair. We find that the eclipsing pair consists of an evolved primary star (M 1 = 1.163 ± 0.034 M sun, R 1 = 2.063 ± 0.058 R sun) and a G-type dwarf secondary (M 2 = 0.905 ± 0.067 M sun, R 2 = 0.887 ± 0.037 R sun). We provide the framework necessary to apply this analysis to much larger data sets.

  17. EXOPLANET CHARACTERIZATION BY PROXY: A TRANSITING 2.15 R? PLANET NEAR THE HABITABLE ZONE OF THE LATE K DWARF KEPLER-61

    International Nuclear Information System (INIS)

    We present the validation and characterization of Kepler-61b: a 2.15 R? planet orbiting near the inner edge of the habitable zone of a low-mass star. Our characterization of the host star Kepler-61 is based upon a comparison with a set of spectroscopically similar stars with directly measured radii and temperatures. We apply a stellar prior drawn from the weighted mean of these properties, in tandem with the Kepler photometry, to infer a planetary radius for Kepler-61b of 2.15 ± 0.13 R? and an equilibrium temperature of 273 ± 13 K (given its period of 59.87756 ± 0.00020 days and assuming a planetary albedo of 0.3). The technique of leveraging the physical properties of nearby ''proxy'' stars allows for an independent check on stellar characterization via the traditional measurements with stellar spectra and evolutionary models. In this case, such a check had implications for the putative habitability of Kepler-61b: the planet is 10% warmer and larger than inferred from K-band spectral characterization. From the Kepler photometry, we estimate a stellar rotation period of 36 days, which implies a stellar age of >1 Gyr. We summarize the evidence for the planetary nature of the Kepler-61 transit signal, which we conclude is 30,000 times more likely to be due to a planet than a blend scenario. Finally, we discuss possible compositions for Kepler-61b with a comparison to theoretical models as well as to known exoplanets with similar radii and dynamically measured masses

  18. EXOPLANET CHARACTERIZATION BY PROXY: A TRANSITING 2.15 R{sub Circled-Plus} PLANET NEAR THE HABITABLE ZONE OF THE LATE K DWARF KEPLER-61

    Energy Technology Data Exchange (ETDEWEB)

    Ballard, Sarah; Charbonneau, David; Fressin, Francois; Torres, Guillermo; Irwin, Jonathan; Newton, Elisabeth [University of Washington, Seattle, WA 98195 (United States); Desert, Jean-Michel; Crepp, Justin R.; Shporer, Avi [California Institute of Technology, Pasadena, CA 91125 (United States); Mann, Andrew W. [Institute for Astronomy, University of Hawai' i, Honolulu, HI 96822 (United States); Ciardi, David R. [NASA Exoplanet Science Institute/Caltech, Pasadena, CA 91125 (United States); Henze, Christopher E.; Bryson, Stephen T.; Howell, Steven B. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Horch, Elliott P. [Southern Connecticut State University, New Haven, CT 06515 (United States); Everett, Mark E., E-mail: sarahba@uw.edu [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States)

    2013-08-20

    We present the validation and characterization of Kepler-61b: a 2.15 R{sub Circled-Plus} planet orbiting near the inner edge of the habitable zone of a low-mass star. Our characterization of the host star Kepler-61 is based upon a comparison with a set of spectroscopically similar stars with directly measured radii and temperatures. We apply a stellar prior drawn from the weighted mean of these properties, in tandem with the Kepler photometry, to infer a planetary radius for Kepler-61b of 2.15 {+-} 0.13 R{sub Circled-Plus} and an equilibrium temperature of 273 {+-} 13 K (given its period of 59.87756 {+-} 0.00020 days and assuming a planetary albedo of 0.3). The technique of leveraging the physical properties of nearby ''proxy'' stars allows for an independent check on stellar characterization via the traditional measurements with stellar spectra and evolutionary models. In this case, such a check had implications for the putative habitability of Kepler-61b: the planet is 10% warmer and larger than inferred from K-band spectral characterization. From the Kepler photometry, we estimate a stellar rotation period of 36 days, which implies a stellar age of >1 Gyr. We summarize the evidence for the planetary nature of the Kepler-61 transit signal, which we conclude is 30,000 times more likely to be due to a planet than a blend scenario. Finally, we discuss possible compositions for Kepler-61b with a comparison to theoretical models as well as to known exoplanets with similar radii and dynamically measured masses.

  19. Stellar-coronagraph observations of the phase curves of exoplanets

    Science.gov (United States)

    Frolov, P. N.; Anan'eva, V. I.; Ksanfomality, L. V.; Tavrov, A. V.

    2015-12-01

    Over the two decades that have passed since the discovery of the first extrasolar planet 51 Peg b, almost all of the newly discovered exoplanets have been found either by radial velocity observations or by the transit method. Here we discuss the possibilities for observation of exoplanets and their phase curves by stellar coronagraphy, which has proven effective in experiments.

  20. Project PANOPTES: Crowdsourcing the Search for Exoplanets

    Science.gov (United States)

    Stump, Chad

    2014-01-01

    Since the first exoplanets were discovered twenty years ago, nearly 1,000 have been confirmed. Over a third of these were found with the transit method, which holds the promise of more wide-scale searches. If Earth is in their orbital plane, exoplanets will partially eclipse their parent star. The transit method looks for this dimming to measure the size and orbit of the planet. Project PANOPTES is a crowdsourced search for new exoplanets using hobbyist digital cameras, keeping the cost low to make the search broadly accessible. We present information from our attempts to use a Canon EOS Rebel T4i DSLR camera with a Rokinon 85mm aspherical lens to detect transits, and we evaluate the feasibility of building a PANOPTES observatory in Southern Ohio.

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

    CERN Document Server

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

    2015-01-01

    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 ...

  2. GTC OSIRIS transiting exoplanet atmospheric survey: detection of potassium in HAT-P-1b from narrowband spectrophotometry

    CERN Document Server

    Wilson, P A; Nikolov, N; Etangs, A Lecavelier des; Pont, F; Fortney, J J; Ballester, G E; López-Morales, M; Désert, J -M; Vidal-Madjar, A

    2015-01-01

    We present the detection of potassium in the atmosphere of HAT-P-1b using optical transit narrowband photometry. The results are obtained using the 10.4 m Gran Telescopio Canarias (GTC) together with the OSIRIS instrument in tunable filter imaging mode. We observed four transits, two at continuum wavelengths outside the potassium feature, at 6792 {\\AA} and 8844 {\\AA}, and two probing the potassium feature in the line wing at 7582.0 {\\AA} and the line core at 7664.9 {\\AA} using a 12 {\\AA} filter width (R~650). The planet-to-star radius ratios in the continuum are found to be $R_{\\rm{pl}}/R_{\\star}$ = 0.1176 $\\pm$ 0.0013 at 6792 {\\AA} and $R_{\\rm{pl}}/R_{\\star}$ = 0.1168 $\\pm$ 0.0022 at 8844 {\\AA}, significantly lower than the two observations in the potassium line: $R_{\\rm{pl}}/R_{\\star}$ = 0.1248 $\\pm$ 0.0014 in the line wing at 7582.0 {\\AA} and $R_{\\rm{pl}}/R_{\\star}$ = 0.1268 $\\pm$ 0.0012 in the line core at 7664.9 {\\AA}. With a weighted mean of the observations outside the potassium feature $R_{\\rm{pl}}/R_...

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

    CERN Document Server

    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

    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....

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

    OpenAIRE

    Deming, Drake; Knutson, Heather; 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

    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...

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

    Science.gov (United States)

    Kuzuhara, M.; Tamura, 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.; Grady, C. A.; Serabyn, E.

    2013-01-01

    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 of approx.. 30 AU predicted for the core accretion mechanism. GJ 504 b 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 providing novel insights into the origins of giant planets, as well as their atmospheric properties.

  6. 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 providing novel insights into the origins of giant planets as well as their atmospheric properties

  7. KOI-200b and KOI-889b: two transiting exoplanets detected and characterized with Kepler, SOPHIE and HARPS-N

    CERN Document Server

    Hebrard, G; Santerne, A; Deleuil, M; Damiani, C; Bonomo, A S; Bouchy, F; Bruno, G; Diaz, R F; Montagnier, G; Moutou, C

    2013-01-01

    We present the detection and characterization of the two new transiting, close-in, giant extrasolar planets KOI-200b and KOI-889b. They were first identified by the Kepler team as promising candidates from photometry of the Kepler satellite, then we established their planetary nature thanks to the radial velocity follow-up jointly secured with the spectrographs SOPHIE and HARPS-N. Combined analyses of the whole datasets allow the two planetary systems to be characterized. The planet KOI-200b has mass and radius of 0.68 +/- 0.09 M_Jup and 1.32 +/- 0.14 R_Jup; it orbits in 7.34 days a F8V host star with mass and radius of 1.40 (+0.14/-0.11) M_Sun and 1.51 +/- 0.14 R_Sun. KOI-889b is a massive planet with mass and radius of 9.9 +/- 0.5 M_Jup and 1.03 +/- 0.06 R_Jup; it orbits in 8.88 days an active G8V star with a rotation period of 19.2 +/- 0.3 days, and mass and radius of 0.88 +/- 0.06 M_Sun and 0.88 +/- 0.04 R_Sun. Both planets lie on eccentric orbits and are located just at the frontier between regimes where...

  8. Atmospheric Circulation of Exoplanets

    OpenAIRE

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

    2009-01-01

    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-wate...

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

    OpenAIRE

    Faedi, F.; Pollacco, D.; Barros, S. C. C.; Brown, D.; Collier Cameron, A.; Doyle, A P; Gillon, Michaël; Gomez Maqueo Chew, Y.; Hebrard, G.; Lendl, M.; Liebig, C.; Smalley, B; Triaud, A H M J; West, R. G; Wheatley, P.J.

    2013-01-01

    We present three newly discovered sub-Jupiter mass planets from the SuperWASP survey: WASP-54b is a heavily bloated planet of mass 0.636+0.025-0.024MJ and radius 1.653+0.090-0.083RJ. 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 ...

  10. First Temperate Exoplanet Sized Up

    Science.gov (United States)

    2010-03-01

    Combining observations from the CoRoT satellite and the ESO HARPS instrument, astronomers have discovered the first "normal" exoplanet that can be studied in great detail. Designated Corot-9b, the planet regularly passes in front of a star similar to the Sun located 1500 light-years away from Earth towards the constellation of Serpens (the Snake). "This is a normal, temperate exoplanet just like dozens we already know, but this is the first whose properties we can study in depth," says Claire Moutou, who is part of the international team of 60 astronomers that made the discovery. "It is bound to become a Rosetta stone in exoplanet research." "Corot-9b is the first exoplanet that really does resemble planets in our solar system," adds lead author Hans Deeg. "It has the size of Jupiter and an orbit similar to that of Mercury." "Like our own giant planets, Jupiter and Saturn, the planet is mostly made of hydrogen and helium," says team member Tristan Guillot, "and it may contain up to 20 Earth masses of other elements, including water and rock at high temperatures and pressures." Corot-9b passes in front of its host star every 95 days, as seen from Earth [1]. This "transit" lasts for about 8 hours, and provides astronomers with much additional information on the planet. This is fortunate as the gas giant shares many features with the majority of exoplanets discovered so far [2]. "Our analysis has provided more information on Corot-9b than for other exoplanets of the same type," says co-author Didier Queloz. "It may open up a new field of research to understand the atmospheres of moderate- and low-temperature planets, and in particular a completely new window in our understanding of low-temperature chemistry." More than 400 exoplanets have been discovered so far, 70 of them through the transit method. Corot-9b is special in that its distance from its host star is about ten times larger than that of any planet previously discovered by this method. And unlike all such exoplanets, the planet has a temperate climate. The temperature of its gaseous surface is expected to be between 160 degrees and minus twenty degrees Celsius, with minimal variations between day and night. The exact value depends on the possible presence of a layer of highly reflective clouds. The CoRoT satellite, operated by the French space agency CNES [3], identified the planet after 145 days of observations during the summer of 2008. Observations with the very successful ESO exoplanet hunter - the HARPS instrument attached to the 3.6-metre ESO telescope at La Silla in Chile - allowed the astronomers to measure its mass, confirming that Corot-9b is indeed an exoplanet, with a mass about 80% the mass of Jupiter. This finding is being published in this week's edition of the journal Nature. Notes [1] A planetary transit occurs when a celestial body passes in front of its host star and blocks some of the star's light. This type of eclipse causes changes in the apparent brightness of the star and enables the planet's diameter to be measured. Combined with radial velocity measurements made by the HARPS spectrograph, it is also possible to deduce the mass and, hence, the density of the planet. It is this combination that allows astronomers to study this object in great detail. The fact that it is transiting - but nevertheless not so close to its star to be a "hot Jupiter" - is what makes this object uniquely well suited for further studies. [2] Temperate gas giants are, so far, the largest known group of exoplanets discovered. [3] The CoRoT (Convection, Rotation and Transits) space telescope was constructed by CNES, with contributions from Austria, Germany, Spain, Belgium, Brazil and the European Space Agency (ESA). It was specifically designed to detect transiting exoplanets and carry out seismological studies of stars. Its results are supplemented by observations with several ground-based telescopes, among them the IAC-80 (Teide Observatory), the Canada Fra

  11. KOI-200 b and KOI-889 b: Two transiting exoplanets detected and characterized with Kepler, SOPHIE, and HARPS-N

    Science.gov (United States)

    Hébrard, G.; Almenara, J.-M.; Santerne, A.; Deleuil, M.; Damiani, C.; Bonomo, A. S.; Bouchy, F.; Bruno, G.; Díaz, R. F.; Montagnier, G.; Moutou, C.

    2013-06-01

    We present the detection and characterization of the two new transiting, close-in, giant extrasolar planets KOI-200 b and KOI-889 b. They were first identified by the Kepler team as promising candidates from photometry of the Kepler satellite; we then established their planetary nature thanks to the radial velocity follow-up jointly secured with the spectrographs SOPHIE and HARPS-N. Combined analyses of the whole datasets allow the two planetary systems to be characterized. The planet KOI-200 b has mass and radius of 0.68 ± 0.09 MJup and 1.32 ± 0.14 RJup; it orbits in 7.34 days a F8V host star with mass and radius of 1.40-0.11+0.14 M? and 1.51 ± 0.14 R?. The planet KOI-889 b is a massive planet with mass and radius of 9.9 ± 0.5 MJup and 1.03 ± 0.06 RJup; it orbits in 8.88 days an active G8V star with a rotation period of 19.2 ± 0.3 days, and mass and radius of 0.88 ± 0.06 M? and 0.88 ± 0.04 R?. Both planets lie on eccentric orbits and are located just at the frontier between regimes where tides can explain circularization and where tidal effects are negligible. The two planets are among the first detected and characterized thanks to observations secured with HARPS-N, the new spectrograph recently mounted at the Telescopio Nazionale Galileo. These results illustrate the benefits that could be obtained from joint studies using two spectrographs as SOPHIE and HARPS-N.

  12. Exoplanets: A New Era of Comparative Planetology

    Science.gov (United States)

    Meadows, Victoria

    2014-11-01

    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.

  13. Time Domain Challenges for Exoplanets

    Science.gov (United States)

    Dawson, Rebekah Ilene

    2016-01-01

    Over the past couple decades, thousands of extra-solar planets have been discovered orbiting other stars. Most have been detected and characterized using transit and/or radial velocity time series, and these techniques have undergone huge improvements in instrumental precision. However, the improvements in precision have brought to light new statistical challenges in detecting and characterizing exoplanets in the presence of correlated noise caused by stellar activity (transits and radial velocities) and gaps in the time sampling (radial velocities). These challenges have afflicted many of the most interesting exoplanets, from Earth-like planets to planetary systems whose orbital dynamics place important constraints on how planetary systems form and evolve. In the first part of the talk, I will focus on the problem of correlated noise for characterizing transiting exoplanets using transit timing variations. I will present a comparison of several techniques using wavelets, Gaussian processes, and polynomial splines to account for correlated noise in the likelihood function when inferring planetary parameters. I will also present results on the characteristics of correlated noise that cause planets to be missed by the Kepler and homegrown pipelines despite high nominal signal-to-noise. In the second part of the talk, I will focus on the problem of aliasing caused by gaps in the radial-velocity time series on yearly, daily, and monthly timescales. I will present results on identifying aliases in the Fourier domain by taking advantage of aliasing on multiple timescales and discuss the interplay between aliasing and stellar activity for several habitable-zone "planets" that have recently been called into question as possible spurious signals caused by activity. As we push toward detecting and characterizing lower mass planets, it is essential that astrostatistical advances keep pace with advances in instrumentation.

  14. Exoplanets characterisation with the JWST and particularly MIRI

    Science.gov (United States)

    Lagage, P.-O.

    2015-10-01

    The use of the James Webb Space Telescope (JWST) and especially its Mid-Infrared instrument, MIRI, to characterize the atmosphere of exoplanets is discussed. Both transit observations and direct imaging observations are considered.

  15. Astrometric exoplanet detection with Gaia

    Energy Technology Data Exchange (ETDEWEB)

    Perryman, Michael; Hartman, Joel; Bakos, Gáspár Á. [Department of Astrophysical Sciences, Peyton Hall, Princeton, NJ 08544 (United States); Lindegren, Lennart [Lund Observatory, Lund, Box 43, SE-22100 Sweden (Sweden)

    2014-12-10

    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 {sub 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.

  16. Synthesizing Exoplanet Demographics from Radial Velocity and Microlensing Surveys, I: Methodology

    CERN Document Server

    Clanton, Christian

    2014-01-01

    Motivated by the order-of-magnitude difference in the frequency of giant planets orbiting M dwarfs inferred by microlensing and radial velocity (RV) surveys, we present a method for comparing the statistical constraints on exoplanet demographics inferred from these methods. We first derive the mapping from the observable parameters of a microlensing-detected planet to those of an analogous planet orbiting an RV-monitored star. Using this mapping, we predict the distribution of RV observables for the planet population inferred from microlensing surveys, taking care to adopt reasonable priors for, and properly marginalize over, the unknown physical parameters of microlensing-detected systems. Finally, we use simple estimates of the detection limits for a fiducial RV survey to predict the number and properties of analogs of the microlensing planet population such an RV survey should detect. We find that RV and microlensing surveys have some overlap, specifically for super-Jupiter mass planets ($m_p \\gtrsim 1~M_{...

  17. Infrared spectroscopy of exoplanets: observational constraints.

    Science.gov (United States)

    Encrenaz, Thérèse

    2014-04-28

    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

  18. Structure of exoplanets

    OpenAIRE

    Spiegel, David S.; Fortney, Jonathan J; Sotin, Christophe

    2013-01-01

    Planets around other stars, or exoplanets, are now known to be common in our galaxy. Exoplanets span a much wider range of physical conditions than the planets in our solar system, and include extremely puffy gas giants to compact rocky planets that can have densities as high as that of iron. The diversity of exoplanets allows us to place the planets of our solar system in a broader perspective, and invites further research in the nascent field of comparative exoplanetology. Here we review th...

  19. Exoplanet: Trans-dimentional MCMC method for exoplanet discovery

    Science.gov (United States)

    Brewer, Brendon J.

    2015-01-01

    Exoplanet determines the posterior distribution of exoplanets by use of a trans-dimensional Markov Chain Monte Carlo method within Nested Sampling. This method finds the posterior distribution in a single run rather than requiring multiple runs with trial values.

  20. Exoplanets search and characterization with the SOPHIE spectrograph at OHP

    OpenAIRE

    Hébrard G.

    2011-01-01

    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-u...

  1. Detectability of Exoplanet Periastron Passage in the Infra-Red

    OpenAIRE

    Kane, Stephen R.; Gelino, Dawn M.

    2011-01-01

    Characterization of exoplanets has matured in recent years, particularly through studies of exoplanetary atmospheres of transiting planets at infra-red wavelenegths. 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 (JWST). A relatively unexplored region of exoplanet parameter space is the thermal detection of long-period eccentric planets during periastron passage. Here we describe t...

  2. Discriminating Between Cloudy, Hazy and Clearsky Exoplanets Using Refraction

    OpenAIRE

    Misra, Amit; Meadows, Victoria

    2014-01-01

    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 prov...

  3. Exoplanets Detection, Formation, Properties, Habitability

    CERN Document Server

    Mason, John W

    2008-01-01

    This edited, multi-author volume will be an invaluable introduction and reference to all key aspects in the field of exoplanet research. The reviews cover: Detection methods and properties of known exoplanets, Detection of extrasolar planets by gravitational microlensing. The formation and evolution of terrestrial planets in protoplanetary and debris disks. The brown dwarf-exoplanet connection. Formation, migration mechanisms and properties of hot Jupiters. Dynamics of multiple exoplanet systems. Doppler exoplanet surveys. Searching for exoplanets in the stellar graveyard. Formation and habitability of extra solar planets in multiple star systems. Exoplanet habitats and the possibilities for life. Moons of exoplanets: habitats for life. Contributing authors: •Rory Barnes •David P. Bennett •Jian Ge •Nader Haghighipour •Patrick Irwin •Hugh Jones •Victoria Meadows •Stanimir Metchev •I. Neill Reid •George Rieke •Caleb Scharf •Steinn Sigurdsson

  4. Enabling Participation In Exoplanet Science

    Science.gov (United States)

    Taylor, Stuart F.

    2015-08-01

    Determining the distribution of exoplanets has required the contributions of a community of astronomers, who all require the support of colleagues to finish their projects in a manner to enable them to enter new collaborations to continue to contribute to understanding exoplanet science.The contributions of each member of the astronomy community are to be encouraged and must never be intentionally obstructed.We present a member’s long pursuit to be a contributing part of the exoplanet community through doing transit photometry as a means of commissioning the telescopes for a new observatory, followed by pursuit of interpreting the distributions in exoplanet parameter data.We present how the photometry projects have been presented as successful by the others who have claimed to have completed them, but how by requiring its employees to present results while omitting one member has been obstructive against members working together and has prevented the results from being published in what can genuinely be called a peer-reviewed fashion.We present how by tolerating one group to obstruct one member from finishing participation and then falsely denying credit is counterproductive to doing science.We show how expecting one member to attempt to go around an ostracizing group by starting something different is destructive to the entire profession. We repeat previously published appeals to help ostracized members to “go around the observatory” by calling for discussion on how the community must act to reverse cases of shunning, bullying, and other abuses. Without better recourse and support from the community, actions that do not meet standard good collegial behavior end up forcing good members from the community. The most important actions are to enable an ostracized member to have recourse to participating in group papers by either working through other authors or through the journal. All journals and authors must expect that no co-author is keeping out a major contributor by keeping someone from finishing. No paper should be considered peer reviewed if it was kept from an author-level contributing peer with the intent of keeping out an active author.

  5. The distribution of exoplanet masses

    CERN Document Server

    Jorissen, A; Udry, S

    2001-01-01

    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...

  6. New Measurements of Polarised Light from Exoplanets

    Science.gov (United States)

    Bott, Kimberly Marie; Cotton, Daniel; Kedziora-Chudczer, Lucyna; Bailey, Jeremy

    2015-08-01

    Detections of polarised light from exoplanets are an important expansion of exoplanet studies, as they provide a complimentary and advantageous diagnostic to the other characterisation methods. However some of the earliest claimed detections of polarised light from exoplanets are disputed.The High Precision Polarimetric Instrument (HIPPI) is currently the highest sensitivity astronomical polarimeter (Bailey 2015) in the world at 4.3 ppm or better precision, and has been used to observe exoplanet systems including the disputed first detection source (Berdyugina 2008, Wiktorowicz 2009, Berdyugina 2011), HD189733b. HIPPI is designed for best sensitivity in blue light where Rayleigh scattering would produce a strong signal for hot Jupiter planets (Burrows 2008). These observations, taken at the Anglo-Australian Telescope in 2014 and 2015, are compared to models from a polarised light adaptation of the Versatile Software for the Transfer of Atmospheric Radiation (VSTAR).Our new, independent Hot Jupiter polarised light detections are discussed, including the physical sources of the detected polarised light, as well as additional contributing factors (e.g. debris, ISM anomalies). For HD 189733b we use available visible and near infrared transit and polarimetric data to create and interpret a planetary portrait using VSTAR.

  7. Evolution of exoplanets and their parent stars

    Science.gov (United States)

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

    2014-11-01

    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.

  8. Atmospheric Circulation of Exoplanets

    CERN Document Server

    Showman, Adam P; Menou, Kristen

    2009-01-01

    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...

  9. Spectroscopy of Exoplanet Atmospheres with the FINESSE Explorer

    Science.gov (United States)

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

    2012-01-01

    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.

  10. Exoplanet detection capability of the COROT space mission

    CERN Document Server

    Bordé, P J; Léger, A

    2003-01-01

    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.

  11. Astrometric Confirmation and Preliminary Orbital Parameters of the Young Exoplanet 51 Eridani b with the Gemini Planet Imager

    Science.gov (United States)

    Nielsen, Eric Ludwig; Blunt, Sarah; De Rosa, Robert; Konopacky, Quinn; Graham, James R.; Macintosh, Bruce; Marchis, Franck; Wang, Jason; Pueyo, Laurent; Rameau, Julien; Marois, Christian

    2015-12-01

    The Gemini Planet Imager Exoplanet Survey discovered the young, 2 Jupiter mass planet 51 Eri b based on observations conducted in December 2014 and January 2015. It is the lowest mass extrasolar planet ever detected by direct imaging and shows strong methane absorption, and is at a projected separation of just 13 AU from its host star. We present new astrometry from late 2015 that confirms 51 Eri b is a bound planet and not an interloping brown dwarf. Orbital motion is detected despite monitoring the system for less than a year. We have implemented a computationally efficient Monte Carlo technique for fitting a range of possible orbital motion based on astrometry covering a small fraction of the period and producing distributions of orbital parameters consistent with the measurements. We apply this technique to the astrometry of 51 Eri b and present preliminary orbital parameter distributions of this intriguing planet.

  12. 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)

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

    2011-01-01

    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......-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...

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

    CERN Document Server

    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

    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.

  14. The implications of evaporation on close-in, low-mass exoplanets

    Science.gov (United States)

    Owen, James

    2015-12-01

    Exoplanet surveys have shown that one of the dominant planet modes of planet formation produces close-in exoplanets. At very close-in separations the atmospheres of these exoplanets can be heated to temperatures high enough to drive a hydrodynamic wind. I will discuss recent theoretical work characterizing the various regimes of evaporation: e.g. energy-limited vs recombination limited and discuss how evaporating exoplanets evolve through these different regimes. I will show recent 3D-MHD simulations of exoplanet evaporation including realistic ionizing radiative transfer that indicate that the flow is anisotropic and exhibits time-dependent flow features close to the day/night-side transition, which could have interesting observational implications. Finally, I will discuss how planet evaporation will dominant the evolution of close-in exoplanets, and use the evaporation models to statistically infer the plausible evolution histories of the Kepler-36 system, an ideal test of the planet evaporation hypothesis.

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

    CERN Document Server

    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

    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...

  16. Atmospheric Circulation of Exoplanets

    Science.gov (United States)

    Showman, A. P.; Cho, J. Y.-K.; Menou, K.

    2010-12-01

    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 simple 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 dynamics are given particular attention, as these close-in planets have been the subject of most of the concrete developments in the study of exoplanetary atmospheres. We then turn to the basic elements of circulation on terrestrial planets as inferred from solar system studies, including Hadley cells, jet streams, processes that govern the large-scale horizontal temperature contrasts, and climate, and we discuss how these insights may apply to terrestrial exoplanets. Although exoplanets surely possess a greater diversity of circulation regimes than seen on the planets in our solar system, our guiding philosophy is that the multidecade study of solar system planets reviewed here provides a foundation upon which our understanding of more exotic exoplanetary meteorology must build.

  17. Light from Exoplanets: Present and Future

    Science.gov (United States)

    Deming, Leo

    2010-01-01

    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.

  18. A Systematic Search for Exoplanet Candidates in K2 Data

    Science.gov (United States)

    Kahre, Tarryn; Karnes, Katherine L.; Caldwell, Douglas A.; Smith, Jeffrey C.

    2016-01-01

    We present a catalog of 41 promising exoplanet candidates in 33 stellar systems from the K2 Campaign 3 data. The K2 Mission was developed upon the mechanical failure of the second of four reaction wheels, as the Kepler Spacecraft could not continue the original Kepler Mission. The Kepler Mission was a 4-year mission designed to determine the prevalence of exoplanets in our galaxy, and the configuration and diversity of those planetary systems discovered. The K2 Mission has a similar goal, though the spacecraft now points at fields along the ecliptic in ~75 day campaigns (Howell et al. 2014). Although the light curves in K2 data are noisier and have significant motion-induced systematics, it has been shown that there is success in finding exoplanets and exoplanet candidates (Foreman-Mackey et al. 2015; Montet et al. 2015). Utilizing the Transiting Planet Search and Data Validation from the Kepler Processing Pipeline, we systematically search K2 Campaign 3 for potential exoplanet candidates. Setting a 7.1s maximum folded statistic threshold minimum for a minimum of three transit events, we define our initial candidate list. Our list is further narrowed by the results from Data Validation, as it allows us to statistically identify false positives, such as eclipsing binaries or uncorrected roll-drift, in our sample. We further draw parallels between our results and other transit-searching pipeline results published for Campaign 3.

  19. Exoplanet Transits Registered at the Universidad de Monterrey Observatory. I. HAT-P-12b, HAT-P-13b, HAT-P-16b, HAT-P-23b, and WASP-10b

    Science.gov (United States)

    Sada, Pedro V.; Ramón-Fox, Felipe G.

    2016-02-01

    Forty transits of the exoplanets HAT-P-12b, HAT-P-13b, HAT-P-16b, HAT-P-23b, and WASP-10b were recorded with the 0.36 m telescope at the Universidad de Monterrey Observatory. The images were captured with a standard Johnson-Cousins Rc and Ic and Sloan z’ filters and processed to obtain individual light curves of the events. These light curves were successfully combined for each system to obtain a resulting one of higher quality, but with a slightly larger time sampling rate. A reduction by a factor of about four in per-point scatter was typically achieved, resulting in combined light curves with a scatter of ?1 mmag. The noise characteristics of the combined light curves were verified by comparing Allan variance plots of the residuals. The combined light curves for each system, along with radial velocity measurements from the literature when available, were modeled using a Monte Carlo method to obtain the essential parameters that characterize the systems. Our results for all these systems confirm the derived transit parameters (the planet-to-star radius ratio, {R}{{p}}/{R}*; the scaled semimajor axis, a/{R}*; the orbital inclination, i; in some cases the eccentricity, e; and argument of periastron of the orbit, ?), validating the methodology. This technique can be used by small college observatories equipped with modest-sized telescopes to help characterize known extrasolar planet systems. In some instances, the uncertainties of the essential transit parameters are also reduced. For HAT-P-23b, in particular, we derive a planet size 4.5 ± 1.0% smaller. We also derive improved linear periods for each system, useful for scheduling observations.

  20. Exploring the diversity of exoplanet atmospheres from the ground with the ACCESS Survey

    Science.gov (United States)

    Espinoza, Nestor; Jordan, Andres; Apai, Daniel; Lopez-Morales, Mercedes; Rackham, Benjamin; Lewis, Nikole K.; Fraine, Jonathan; Diaz-Pérez, Ryan; Rodler, Florian; Wells, Robert; Osip, David

    2015-12-01

    One of the most exciting possibilities enabled by transiting exoplanets is to measure their atmospheric properties through the technique of transmission spectroscopy: the variation of the transit depth as a function of wavelength due to starlight interacting with the atmosphere of the exoplanet. Motivated by the need of optical transmission spectra of exoplanets, we recently launched the Arizona-CfA-Católica Exoplanet Spectroscopy Survey (ACCESS), which aims at studying the atmospheres of ~20 exoplanets ranging from super-Earths to hot-Jupiters in the entire optical atmospheric window using ground-based facilities from both northern and southern hemispheres. In this talk, I will present the survey and its first results using Magellan/IMACS data, focusing on the lessons learned and future prospects of the survey.

  1. Exoplanet Transits Registered at the Universidad de Monterrey Observatory. Part I: HAT-P-12b, HAT-P-13b, HAT-P-16b, HAT-P-23b and WASP-10b

    CERN Document Server

    Sada, Pedro V

    2016-01-01

    Forty transits of the exoplanets HAT-P-12b, HAT-P-13b, HAT-P-16b, HAT-P-23b and WASP-10b were recorded with the 0.36m telescope at the Universidad de Monterrey Observatory. The images were captured with a standard Johnson-Cousins Rc and Ic and Sloan z' filters and processed to obtain individual light curves of the events. These light curves were successfully combined for each system to obtain a resulting one of higher quality, but with a slightly larger time sampling rate. A reduction by a factor of about four in per-point scatter was typically achieved, resulting in combined light curves with a scatter of ~1 mmag. The noise characteristics of the combined light curves were verified by comparing Allan variance plots of the residuals. The combined light curves for each system, along with radial velocity measurements from the literature when available, were modeled using a Monte Carlo method to obtain the essential parameters that characterize the systems. Our results for all these systems confirm the derived t...

  2. Discriminating Between Cloudy, Hazy and Clearsky Exoplanets Using Refraction

    CERN Document Server

    Misra, Amit

    2014-01-01

    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...

  3. Characterization of exoplanet hosts

    OpenAIRE

    Valenti Jeff A.

    2013-01-01

    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 aff...

  4. The Exoplanet Eccentricity Distribution from Kepler Planet Candidates

    OpenAIRE

    Kane, Stephen R.; Ciardi, David R.; Dawn M. Gelino; Von Braun, Kaspar

    2012-01-01

    The eccentricity distribution of exoplanets is known from radial velocity surveys to be divergent from circular orbits beyond 0.1 AU. This is particularly the case for large planets where the radial velocity technique is most sensitive. The eccentricity of planetary orbits can have a large effect on the transit probability and subsequently the planet yield of transit surveys. The Kepler mission is the first transit survey that probes deep enough into period-space to allow th...

  5. Synthesizing exoplanet demographics from radial velocity and microlensing surveys. I. Methodology

    International Nuclear Information System (INIS)

    Motivated by the order of magnitude difference in the frequency of giant planets orbiting M dwarfs inferred by microlensing and radial velocity (RV) surveys, we present a method for comparing the statistical constraints on exoplanet demographics inferred from these methods. We first derive the mapping from the observable parameters of a microlensing-detected planet to those of an analogous planet orbiting an RV-monitored star. Using this mapping, we predict the distribution of RV observables for the planet population inferred from microlensing surveys, taking care to adopt reasonable priors for, and properly marginalize over, the unknown physical parameters of microlensing-detected systems. Finally, we use simple estimates of the detection limits for a fiducial RV survey to predict the number and properties of analogs of the microlensing planet population such an RV survey should detect. We find that RV and microlensing surveys have some overlap, specifically for super-Jupiter mass planets (mp ≳ 1 M Jup) with periods between ∼3-10 yr. However, the steeply falling planetary mass function inferred from microlensing implies that, in this region of overlap, RV surveys should infer a much smaller frequency than the overall giant planet frequency (mp ≳ 0.1 M Jup) inferred by microlensing. Our analysis demonstrates that it is possible to statistically compare and synthesize data sets from multiple exoplanet detection techniques in order to infer exoplanet demographics over wider regions of parameter space than are accessible to individual methods. In a companion paper, we apply our methodology to several representative microlensing and RV surveys to derive the frequency of planets around M dwarfs with orbits of ≲ 30 yr.

  6. Synthesizing exoplanet demographics from radial velocity and microlensing surveys. I. Methodology

    Energy Technology Data Exchange (ETDEWEB)

    Clanton, Christian; Gaudi, B. Scott, E-mail: clanton@astronomy.ohio-state.edu [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)

    2014-08-20

    Motivated by the order of magnitude difference in the frequency of giant planets orbiting M dwarfs inferred by microlensing and radial velocity (RV) surveys, we present a method for comparing the statistical constraints on exoplanet demographics inferred from these methods. We first derive the mapping from the observable parameters of a microlensing-detected planet to those of an analogous planet orbiting an RV-monitored star. Using this mapping, we predict the distribution of RV observables for the planet population inferred from microlensing surveys, taking care to adopt reasonable priors for, and properly marginalize over, the unknown physical parameters of microlensing-detected systems. Finally, we use simple estimates of the detection limits for a fiducial RV survey to predict the number and properties of analogs of the microlensing planet population such an RV survey should detect. We find that RV and microlensing surveys have some overlap, specifically for super-Jupiter mass planets (m{sub p} ? 1 M {sub Jup}) with periods between ?3-10 yr. However, the steeply falling planetary mass function inferred from microlensing implies that, in this region of overlap, RV surveys should infer a much smaller frequency than the overall giant planet frequency (m{sub p} ? 0.1 M {sub Jup}) inferred by microlensing. Our analysis demonstrates that it is possible to statistically compare and synthesize data sets from multiple exoplanet detection techniques in order to infer exoplanet demographics over wider regions of parameter space than are accessible to individual methods. In a companion paper, we apply our methodology to several representative microlensing and RV surveys to derive the frequency of planets around M dwarfs with orbits of ? 30 yr.

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

    DEFF Research Database (Denmark)

    Guenther, E. W.; Díaz, R. F.

    2012-01-01

    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.

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

    Science.gov (United States)

    Csizmadia, Sz.; Moutou, C.; Deleuil, M.; Cabrera, J.; Fridlund, M.; Gandolfi, D.; Aigrain, S.; Alonso, R.; Almenara, J.-M.; Auvergne, M.; Baglin, A.; Barge, P.; Bonomo, A. S.; Bordé, P.; Bouchy, F.; Bruntt, H.; Carone, L.; Carpano, S.; Cavarroc, C.; Cochran, W.; Deeg, H. J.; Díaz, 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.; Hébrard, G.; Jehin, E.; Jorda, L.; Léger, A.; Llebaria, A.; Lammer, H.; Lovis, C.; MacQueen, P. J.; Mazeh, T.; Ollivier, M.; Pätzold, M.; Queloz, D.; Rauer, H.; Rouan, D.; Santerne, A.; Schneider, J.; Tingley, B.; Titz-Weider, R.; Wuchterl, G.

    2011-07-01

    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 ± 0.30 MJup and a radius of 1.02 ± 0.07 RJup, while its mean density is 2.82 ± 0.38 g/cm3. CoRoT-17b is in a circular orbit with a period of 3.7681 ± 0.0003 days. The host star is an old (10.7 ± 1.0 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 ~380 earth masses of heavier elements. 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. Part of the observations were obtained at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii. Based on observations made with HARPS spectrograph on the 3.6-m European Organisation for Astronomical Research in the Southern Hemisphere telescope at La Silla Observatory, Chile (ESO program 184.C-0639). Based on observations made with the IAC80 telescope operated on the island of Tenerife by the Instituto de Astrofísica de Canarias in the Spanish Observatorio del Teide. Part 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.

  9. Polarisation of Planets and Exoplanets

    Science.gov (United States)

    Bailey, Jeremy; Kedziora-Chudczer, Lucyna; Bott, Kimberly; Cotton, Daniel V.

    2015-11-01

    We present observations of the linear polarisation of several hot Jupiter systems with our new high-precision polarimeter HIPPI (HIgh Precision Polarimetric Instrument). By looking at the combined light of the star and planet we aim to detect the polarised light reflected from the planet's atmosphere. This can provide information on the presence of, and nature of clouds in the atmosphere, and constrain the geometric albedo of the planet. The method is applicable to both transitting and non-transitting planets, and can also be used to determine the inclination of the system, and thus the true mass for radial velocity detected planets.To predict and interpret the polarisation from such observations, we have also developed an advanced polarimetric modelling capability, by incoroporating full polarised radiative transfer into our atmospheric modelling code VSTAR. This is done using the VLIDORT vector radiative transfer solver (Spurr, 2006). The resulting code allows us to predict disc-resolved, phase-resolved, and spectrally-resolved intensity and linear polarisation for any planet, exoplanet, brown dwarf or cool star atmosphere that can be modelled with VSTAR. We have tested the code by reproducing benchmark calculations in polarised radiative transfer, and by Solar System test cases, including reproducing the classic Hansen and Hovenier (1974) calculation of the polarisation phase curves of Venus.Hansen, J.E., & Hovenier, J.W., 1974, J. Atmos. Sci., 31, 1137Spurr, R., 2006, JQSRT, 102, 316.

  10. Exoplanet Transmission Spectroscopy using KMOS

    CERN Document Server

    Parviainen, Hannu; Thatte, Niranjan; Barstow, Joanna K; Evans, Thomas M; Gibson, Neale

    2015-01-01

    KMOS (K-Band Multi Object Spectrograph) is a novel integral field spectrograph installed in the VLT's ANTU unit. The instrument offers an ability to observe 24 2.8"$\\times$2.8" sub-fields positionable within a 7.2' patrol field, each sub-field producing a spectrum with a 14$\\times$14-pixel spatial resolution. The main science drivers for KMOS are the study of galaxies, star formation, and molecular clouds, but its ability to simultaneously measure spectra of multiple stars makes KMOS an interesting instrument for exoplanet atmosphere characterization via transmission spectroscopy. We set to test whether transmission spectroscopy is practical with KMOS, and what are the conditions required to achieve the photometric precision needed, based on observations of a partial transit of WASP-19b, and full transits of GJ 1214b and HD 209458b. Our analysis uses the simultaneously observed comparison stars to reduce the effects from instrumental and atmospheric sources, and Gaussian processes to model the residual system...

  11. Radial Velocity Eclipse Mapping of Exoplanets

    Science.gov (United States)

    Nikolov, Nikolay; Sainsbury-Martinez, Felix

    2015-07-01

    Planetary rotation rates and obliquities provide information regarding the history of planet formation, but have not yet been measured for evolved extrasolar planets. Here we investigate the theoretical and observational perspective of the Rossiter-McLaughlin effect during secondary eclipse (RMse) ingress and egress for transiting exoplanets. Near secondary eclipse, when the planet passes behind the parent star, the star sequentially obscures light from the approaching and receding parts of the rotating planetary surface. The temporal block of light emerging from the approaching (blueshifted) or receding (redshifted) parts of the planet causes a temporal distortion in the planet’s spectral line profiles resulting in an anomaly in the planet’s radial velocity curve. We demonstrate that the shape and the ratio of the ingress-to-egress radial velocity amplitudes depends on the planetary rotational rate, axial tilt, and impact factor (i.e., sky-projected planet spin-orbital alignment). In addition, line asymmetries originating from different layers in the atmosphere of the planet could provide information regarding zonal atmospheric winds and constraints on the hot spot shape for giant irradiated exoplanets. The effect is expected to be most-pronounced at near-infrared wavelengths, where the planet-to-star contrasts are large. We create synthetic near-infrared, high-dispersion spectroscopic data and demonstrate how the sky-projected spin axis orientation and equatorial velocity of the planet can be estimated. We conclude that the RMse effect could be a powerful method to measure exoplanet spins.

  12. CHEOPS: CHaracterising ExOPlanet Satellite

    Science.gov (United States)

    Isaak, K. G.

    2015-10-01

    CHEOPS (CHaracterising ExOPlanet Satellite) is the first exoplanet mission dedicated to the search for transits of exoplanets by means of ultrahigh precision photometry of bright stars already known to host planets. CHEOPS will provide the unique capability of determining radii to ~10% accuracy for a subset of those planets in the super-Earth to Neptune mass range. The high photometric precision of CHEOPS will be achieved using a photometer covering the 0.4 - 1.1um waveband and designed around a single frame-transfer CCD which is mounted in the focal plane of a 30 cm equivalent aperture diameter, f/5 on-axis Ritchey-Chretien telescope. Key to reaching the required performance is rejection of straylight from the Earth that is achieved using a specially designed optical baffle. CHEOPS is the first S-class mission in ESA's Cosmic Vision 2015-2025, and is currently planned to be launch-ready by the end of 2017. The mission is a partnership between Switzerland and ESA's science programme, with important contributions from Austria, Belgium, France, Germany, Hungary, Italy, Portugal, Spain, Sweden and the United Kingdom. In this presentation I will give a scientific and technical overview of the mission, as well as an update on the status of the project.

  13. HST hot-Jupiter transmission spectral survey: from clear to cloudy exoplanets

    Science.gov (United States)

    Sing, David K.; Fortney, Jonathan J.; Nikolov, Nikolay; Wakeford, Hannah; Kataria, Tiffany; Evans, Tom M.; Aigrain, Suzanne; Ballester, Gilda E.; Burrows, Adam Seth; Deming, Drake; Desert, Jean-Michel; Gibson, Neale; Henry, Gregory W.; Huitson, Catherine; Knutson, Heather; Lecavelier des Etangs, Alain; Pont, Frederic; Showman, Adam P.; Vidal-Madjar, Alfred; Williamson, Michael W.; Wilson, Paul A.

    2016-01-01

    The large number of transiting exoplanets has prompted a new era of atmospheric studies, with comparative exoplanetology now possible. Here we present the comprehensive results from a Large program with the Hubble Space Telecope, which has recently obtained optical and near-IR transmission spectra for eight hot-Jupiter exoplanets in conjunction with warm Spitzer transit photometry. The spectra show a wide range of spectral behavior, which indicates diverse cloud and haze properties in their atmospheres. We will discuss the overall findings from the survey, comment on common trends observed in the exoplanet spectra, and remark on their theoretical implications.

  14. Exoplanet transmission spectroscopy using KMOS

    Science.gov (United States)

    Parviainen, Hannu; Aigrain, Suzanne; Thatte, Niranjan; Barstow, Joanna K.; Evans, Thomas M.; Gibson, Neale

    2015-11-01

    KMOS (K-Band Multi Object Spectrograph) is a novel integral field spectrograph installed in the Very Large Telescope's (VLT's) ANTU unit. The instrument offers an ability to observe 24 2.8 arcsec × 2.8 arcsec subfields positionable within a 7.2 arcmin patrol field, each subfield producing a spectrum with a 14 × 14-pixel spatial resolution. The main science drivers for KMOS are the study of galaxies, star formation, and molecular clouds, but its ability to simultaneously measure spectra of multiple stars makes KMOS an interesting instrument for exoplanet atmosphere characterization via transmission spectroscopy. We set to test whether transmission spectroscopy is practical with KMOS, and what are the conditions required to achieve the photometric precision needed, based on observations of a partial transit of WASP-19b, and full transits of GJ 1214b and HD 209458b. Our analysis uses the simultaneously observed comparison stars to reduce the effects from instrumental and atmospheric sources, and Gaussian processes to model the residual systematics. We show that KMOS can, in theory, deliver the photometric precision required for transmission spectroscopy. However, this is shown to require (a) pre-imaging to ensure accurate centring and (b) a very stable night with optimal observing conditions (seeing ˜0.8 arcsec). Combining these two factors with the need to observe several transits, each with a sufficient out-of-transit baseline (and with the fact that similar or better precision can be reached with telescopes and instruments with smaller pressure), we conclude that transmission spectroscopy is not the optimal science case to take advantage of the abilities offered by KMOS and VLT.

  15. 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)

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

    2011-01-01

    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–...

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

    DEFF Research Database (Denmark)

    Rouan, D.; Parviainen, H.; Moutou, C.; Deleuil, M.; Fridlund, M.; Ofir, A.; Havel, M.; Aigrain, S.; Alonso, R.; Auvergne, M.; Baglin, A.; Barge, P.; Bonomo, A. S.; Bordé, P.; Bouchy, F.; Cabrera, J.; Cavarroc, C.; Csizmadia, Sz.; Deeg, H. J.; 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.

    2012-01-01

    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 t...

  17. Super-Earth and Sub-Neptune Exoplanets: a First Look from the MEarth Project

    OpenAIRE

    Berta, Zachory Kaczmarczyk

    2013-01-01

    Exoplanets that transit nearby M dwarfs allow us to measure the sizes, masses, and atmospheric properties of distant worlds. Between 2008 and 2013, we searched for such planets with the MEarth Project, a photometric survey of the closest and smallest main-sequence stars. This thesis uses the first planet discovered with MEarth, the warm 2.7 Earth radius exoplanet GJ1214b, to explore the possibilities that planets transiting M dwarfs provide.

  18. New exoplanets from the SuperWASP-North survey

    Directory of Open Access Journals (Sweden)

    Keenan F.

    2011-02-01

    Full Text Available We present the current status of the WASP search for transiting exoplanets, focusing on recent planet discoveries from SuperWASP-North and the joint equatorial region (-20?Dec?+20 observed by both WASP telescopes. We report the results of monitoring of WASP planets, and discuss how these contribute to our understanding of planet properties and their diversity.

  19. New exoplanets from the SuperWASP-North survey

    OpenAIRE

    Keenan F.; Todd I.; Watson C.; Moulds V.; McCormac J.; Simpson E. K.; Pollacco D.; Barros S. C. C.; Faedi F.; Fitzsimmons A.

    2011-01-01

    We present the current status of the WASP search for transiting exoplanets, focusing on recent planet discoveries from SuperWASP-North and the joint equatorial region (-20?Dec?+20) observed by both WASP telescopes. We report the results of monitoring of WASP planets, and discuss how these contribute to our understanding of planet properties and their diversity.

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

    Science.gov (United States)

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

    2015-05-01

    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 analyzeits 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 (Mp = 1.37+0.48-0.46 MJup), with an estimated radius of Rp = 1.65+0.59-0.56 RJup (uncertainties provided in this work are 3? unless specified). This translates into a sub-Jupiter density. The planet revolves every ~7.8 days in a slightly eccentric orbit (e = 0.123+0.037-0.036) 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), which is 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 the projected planet disk occults the stellar disk. The relatively large uncertainties in the planet radius are due to the large impact parameter and short duration of the transit. Planetary transits with large impact parameters (and in particular grazing transits) can be used to detect and analyze interesting configurations, such as additional perturbing bodies, stellar pulsations, rotation of a non-spherical planet, or polar spot-crossing events. All these scenarios will periodically modify the transit properties (depth, duration, and time of mid-transit), which could be detectable with sufficiently accurate photometry. Short-cadence photometric data (at the 1-min level) would help in the search for these exotic configurations in grazing planetary transits like that of Kepler-447b. This system could then be an excellent target for the forthcoming missions TESS and CHEOPS, which will provide the required photometric precision and cadence to study this type of transit. Based on observations collected at the German-Spanish Astronomical Center, Calar Alto, jointly operated by the Max- Planck-Institut für Astronomie (Heidelberg) and the Instituto de Astrofísica de Andalucía (IAA-CSIC, Granada).

  1. Exoplanets search and characterization with the SOPHIE spectrograph at OHP

    Directory of Open Access Journals (Sweden)

    Hébrard G.

    2011-02-01

    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.

  2. 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)

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

    CERN Document Server

    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

    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...

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

    CERN Document Server

    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

    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...

  5. The search for exomoons and the characterization of exoplanet atmospheres

    CERN Document Server

    Campanella, Giammarco

    2009-01-01

    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 ...

  6. 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.

  7. EChO's view on gas giant exoplanets atmospheres

    CERN Document Server

    Parmentier, Vivien; de Wit, Julien

    2014-01-01

    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...

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

    OpenAIRE

    ZENG, LI; Seager, Sara

    2008-01-01

    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.

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

    CERN Document Server

    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

    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...

  10. 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.

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

    CERN Document Server

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

    2014-01-01

    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.

  12. Exoplanet Clouds in the Laboratory

    Science.gov (United States)

    Johnson, Alexandria; Cziczo, Daniel J.; Seager, Sara; Charbonneau, David; Bauer, Amy J. R.

    2015-12-01

    The lack of strong spectral features of some exoplanet atmospheres may suggest the presence of a cloud layer and poses great challenges for atmospheric characterization. We aim to address these observations and the challenges by leveraging lab-based terrestrial cloud particle instrumentation as a means of investigating how particles representative of those in exoplanet atmospheres interact with incoming radiation. In the end we hope to achieve two goals - First, to better understand the observable properties of cloud particles in exoplanet atmospheres. Second, to determine how these clouds might directly limit our ability to observe and characterize the atmosphere below.In this presentation I will discuss the cloud chamber used for this work, how we leverage terrestrial based cloud knowledge, our initial investigation of the light scattered by ammonium nitrate (NH4NO3) across temperature and relative humidity dependent phase changes, and future work with suspected exoplanet atmospheric condensates under various atmospheric compositions, pressures, and temperatures.

  13. A Cloudy View of Exoplanets

    Science.gov (United States)

    Deming, Drake

    2010-01-01

    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.

  14. Exploring Exoplanet Populations with NASA's Kepler Mission

    CERN Document Server

    Batalha, Natalie M

    2014-01-01

    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 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 wit...

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

    CERN Document Server

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

    2014-01-01

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

  16. Structure of exoplanets.

    Science.gov (United States)

    Spiegel, David S; Fortney, Jonathan J; Sotin, Christophe

    2014-09-01

    The hundreds of exoplanets that have been discovered in the past two decades offer a new perspective on planetary structure. Instead of being the archetypal examples of planets, those of our solar system are merely possible outcomes of planetary system formation and evolution, and conceivably not even especially common outcomes (although this remains an open question). Here, we review the diverse range of interior structures that are both known and speculated to exist in exoplanetary systems--from mostly degenerate objects that are more than 10× as massive as Jupiter, to intermediate-mass Neptune-like objects with large cores and moderate hydrogen/helium envelopes, to rocky objects with roughly the mass of Earth. PMID:24379369

  17. Characterization of exoplanet hosts

    Directory of Open Access Journals (Sweden)

    Valenti Jeff A.

    2013-04-01

    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.

  18. Geoengineering on exoplanets

    Science.gov (United States)

    Lockley, Andrew

    2015-04-01

    Solar radiation management (SRM) geoengineering can be used to deliberately alter the Earth's radiation budget, by reflecting sunlight to space. SRM has been suggested as a response to Anthropogenic Global Warming (AGW), to partly or fully balance radiative forcing from AGW [1]. Approximately 22% of sun-like stars have Earth-like exoplanets[2]. Advanced civilisations may exist on these, and may use geoengineering for positive or negative radiative forcing. Additionally, terraforming projects [e.g. 3], may be used to expand alien habitable territory, or for resource management or military operations on non-home planets. Potential observations of alien geoengineering and terraforming may enable detection of technologically advanced alien civilisations, and may help identify widely-used and stable geoengineering technologies. This knowledge may assist the development of safe and stable geoengineering methods for Earth. The potential risks and benefits of possible alien detection of Earth-bound geoengineering schemes must be considered before deployment of terrestrial geoengineering schemes.

  19. WFIRST Exoplanet Imaging: Can Broadband Colors Efficiently Descriminate Planets from the Background?

    Science.gov (United States)

    Turnbull, Margaret C.; Kotulla, Ralf C.; Gallagher, John S.; Merrelli, Aronne; L'Ecuyer, Tristan; Fu, Guangwei; Hu, Renyu

    2016-01-01

    As part of the WFIRST Preparatory Science program, we have begun exploring the broadband color combinations for WFIRST that will most efficiently (1) descriminate planets from background sources in a single image and (2) shed some light on the nature of those planets. This is a first look at the color-color space, and color-magnitude space, occupied by planets orbiting nearby K-F main sequence stars. We explore (1) Solar System analog planets, (2) a variety of Earths/Super-Earths having optically thin or partially cloudy Earth-like atmospheres over desert/forest/ocean/icey surfaces, and (3) mini-Neptunes through Jupiter-mass planets at a range of temperatures where they would potentially be detectable to WFIRST. These colors are compared to the expected Galactic and extragalactic background sources for the Galactic coordinates of high priority targets. We offer some preliminary conclusions about the expected background contamination in these fields and how well color information can be used to mitigate that threat to WFIRST's exoplanet science.

  20. From spectra to atmospheres: Solving the underconstrained retrieval problem for exoplanets

    OpenAIRE

    Barstow, JK; Aigrain, S.; Irwin, PGJ; Bowles, N; Fletcher, LN; Lee, J-M

    2013-01-01

    Spectroscopic observations of transiting exoplanets have provided the first indications of their atmospheric structure and composition. Optimal estimation retrievals have been successfully applied to solar system planets to determine the temperature, composition and aerosol properties of their atmospheres, and have recently been applied to exoplanets. We show the effectiveness of the technique when combined with simulated observations from the proposed space telescope EChO, and also discuss t...

  1. The NASA Exoplanet Exploration Program

    Science.gov (United States)

    Hudgins, Douglas M.; Blackwood, Gary H.; Gagosian, John S.

    2015-12-01

    The NASA Exoplanet Exploration Program (ExEP) is chartered to implement the NASA space science goals of detecting and characterizing exoplanets and to search for signs of life. The ExEP manages space missions, future studies, technology investments, and ground-based science that either enables future missions or completes mission science. The exoplanet science community is engaged by the Program through Science Definition Teams and through the Exoplanet Program Analysis Group (ExoPAG). The ExEP includes the space science missions of Kepler, K2 , and the proposed WFIRST-AFTA that includes dark energy science, a widefield infrared survey, a microlensing survey for outer-exoplanet demographics, and a coronagraph for direct imaging of cool outer gas- and ice-giants around nearby stars. Studies of probe-scale (medium class) missions for a coronagraph (internal occulter) and starshade (external occulter) explore the trades of cost and science and provide motivation for a technology investment program to enable consideration of missions at the next decadal survey for NASA Astrophysics. Program elements include follow-up observations using the Keck Observatory, which contribute to the science yield of Kepler and K2, and include mid-infrared observations of exo-zodiacal dust by the Large Binocular Telescope Interferometer which provide parameters critical to the design and predicted science yield of the next generation of direct imaging missions. ExEP includes the NASA Exoplanet Science Institute which provides archives, tools, and professional education for the exoplanet community. Each of these program elements contribute to the goal of detecting and characterizing earth-like planets orbiting other stars, and seeks to respond to rapid evolution in this discovery-driven field and to ongoing programmatic challenges through engagement of the scientific and technical communities.

  2. The NASA Exoplanet Exploration Program

    Science.gov (United States)

    Hudgins, Douglas M.; Blackwood, Gary; Gagosian, John

    2014-11-01

    The NASA Exoplanet Exploration Program (ExEP) is chartered to implement the NASA space science goals of detecting and characterizing exoplanets and to search for signs of life. The ExEP manages space missions, future studies, technology investments, and ground-based science that either enables future missions or completes mission science. The exoplanet science community is engaged by the Program through Science Definition Teams and through the Exoplanet Program Analysis Group. The ExEP includes the space science missions of Kepler, K2, and the proposed WFIRST-AFTA that includes dark energy science, a widefield infrared survey, a microlensing survey for outer-exoplanet demographics, and a coronagraph for direct imaging of cool outer gas- and ice-giants around nearby stars. Studies of probe-scale (medium class) missions for a coronagraph (internal occulter) and starshade (external occulter) explore the trades of cost and science and provide motivation for a technology investment program to enable consideration of missions at the next decadal survey for NASA Astrophysics. Program elements include follow-up observations using the Keck Observatory which contribute to the science yield of Kepler and K2, and include mid-infrared observations of exo-zodiacal dust by the Large Binocular Telescope Interferometer which provide parameters critical to the design and predicted science yield of the next generation of direct imaging missions. ExEP includes the NASA Exoplanet Science Institute which provides archives, tools, and professional education for the exoplanet community. Each of these program elements contribute to the goal of detecting and characterizing earth-like planets orbiting other stars, and seeks to respond to rapid evolution in this discovery-driven field and to ongoing programmatic challenges through engagement of the scientific and technical communities.

  3. Exoplanet Science in the National Science Olympiad

    Science.gov (United States)

    Komacek, Thaddeus D.; Young, Donna

    2015-11-01

    The National Science Olympiad is one of the United States' largest science competitions, reaching over 6,000 schools in 48 states. The Olympiad includes a wide variety of events, stretching a full range of potential future STEM careers, from biological sciences to engineering to earth and space sciences. The Astronomy event has been a mainstay at the high school level for well over a decade, and nominally focuses on aspects of stellar evolution. For the 2014-2015 competition season, the event focus was aligned to include exoplanet discovery and characterization along with star formation. Teams studied both the qualitative features of exoplanets and exoplanetary systems and the quantitative aspects behind their discovery and characterization, including basic calculations with the transit and radial velocity methods. Students were also expected to have a qualitative understanding of stellar evolution and understand the differences between classes of young stars including T Tauri and FU Orionis variables, and Herbig Ae/Be stars. Based on the successes of this event topic, we are continuing this event into the 2015-2016 academic year. The key modification is the selection of new exoplanetary systems for students to research. We welcome feedback from the community on how to improve the event and the related educational resources that are created for Science Olympiad students and coaches. We also encourage any interested community members to contact your regional or state Science Olympiad tournament directors and volunteer to organize competitions and supervise events locally.

  4. Direct imaging of exoplanets.

    Science.gov (United States)

    Lagrange, Anne-Marie

    2014-04-28

    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

  5. The Applicability of Emerging Quantum Computing Capabilities to Exo-Planet Research

    Science.gov (United States)

    Correll, Randall; Worden, S.

    2014-01-01

    In conjunction with the Universities Space Research Association and Google, Inc. NASA Ames has acquired a quantum computing device built by DWAVE Systems with approximately 512 “qubits.” Quantum computers have the feature that their capabilities to find solutions to problems with large numbers of variables scale linearly with the number of variables rather than exponentially with that number. These devices may have significant applicability to detection of exoplanet signals in noisy data. We have therefore explored the application of quantum computing to analyse stellar transiting exoplanet data from NASA’s Kepler Mission. The analysis of the case studies was done using the DWAVE Systems’s BlackBox compiler software emulator, although one dataset was run successfully on the DWAVE Systems’s 512 qubit Vesuvius machine. The approach first extracts a list of candidate transits from the photometric lightcurve of a given Kepler target, and then applies a quantum annealing algorithm to find periodicity matches between subsets of the candidate transit list. We examined twelve case studies and were successful in reproducing the results of the Kepler science pipeline in finding validated exoplanets, and matched the results for a pair of candidate exoplanets. We conclude that the current implementation of the algorithm is not sufficiently challenging to require a quantum computer as opposed to a conventional computer. We are developing more robust algorithms better tailored to the quantum computer and do believe that our approach has the potential to extract exoplanet transits in some cases where a conventional approach would not in Kepler data. Additionally, we believe the new quantum capabilities may have even greater relevance for new exoplanet data sets such as that contemplated for NASA’s Transiting Exoplanet Survey Satellite (TESS) and other astrophysics data sets.

  6. Characterizing Exoplanet Atmospheres with Visible-Wavelength Phase Curves

    Science.gov (United States)

    Hu, Renyu; Shporer, Avi

    2016-01-01

    Kepler has detected numerous exoplanet transits by measuring 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 atmospheres 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. With a newly established semi-analytical model framework, we show that a hot exoplanet's visible-wavelength phase curve having a significant phase offset can usually be explained by two classes of solutions: one class requires a thermal hot spot shifted to one side of the substellar point, and the other class requires reflective clouds concentrated on the same side of the substellar point. We analyze the phase curves of the gaseous planets Kepler 7 b, Kepler 12 b, and Kepler 41 b, by coupling the model with a Markov Chain Monte Carlo method to yield robust constraints on the planets' atmospheric parameters. The phase curves of these planets feature post-occultation phase offsets, best explained by reflective clouds located on the west side of the substellar point. In particular, the reflectivity of the clear part of the atmospheres should be less than 20% and that of the cloudy part should be greater than 50%. We suggest single-band photometry surveys could yield valuable information on exoplanet atmospheres and surfaces.

  7. ExELS: an exoplanet legacy science proposal for the ESA Euclid mission. II. Hot exoplanets and sub-stellar systems

    CERN Document Server

    McDonald, I; Penny, M; Beaulieu, J -P; Batista, V; Novati, S Calchi; Cassan, A; Fouque, P; Mao, S; Marquette, J B; Rattenbury, N; Robin, A C; Tisserand, P; Osorio, M R Zapatero

    2014-01-01

    The Exoplanet Euclid Legacy Survey (ExELS) proposes to determine the frequency of cold exoplanets down to Earth mass from host separations of ~1 AU out to the free-floating regime by detecting microlensing events in Galactic Bulge. We show that ExELS can also detect large numbers of hot, transiting exoplanets in the same population. The combined microlensing+transit survey would allow the first self-consistent estimate of the relative frequencies of hot and cold sub-stellar companions, reducing biases in comparing "near-field" radial velocity and transiting exoplanets with "far-field" microlensing exoplanets. The age of the Bulge and its spread in metallicity further allows ExELS to better constrain both the variation of companion frequency with metallicity and statistically explore the strength of star-planet tides. We conservatively estimate that ExELS will detect ~4100 sub-stellar objects, with sensitivity typically reaching down to Neptune-mass planets. Of these, ~600 will be detectable in both Euclid's V...

  8. Discovery, Characterization, and Dynamics of Transiting Exoplanets

    DEFF Research Database (Denmark)

    Van Eylen, Vincent

    2015-01-01

    . The measurement joins a handful of obliquity measurements, so far suggesting multi-planet systems are mostly aligned. This favors theories suggesting that hot Jupiter migration is responsible for creating misaligned planets. Moreover, unlike the planets in the solar system, which have nearly circular...

  9. Evidence for a lost population of close-in exoplanets

    OpenAIRE

    Davis, Timothy A.; Wheatley, Peter J.

    2009-01-01

    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...

  10. Follow-up Observations of PTFO 8-8695: A 3 Myr Old T-Tauri Star Hosting a Jupiter-mass Planetary Candidate

    Science.gov (United States)

    Ciardi, David R.; van Eyken, Julian C.; Barnes, Jason W.; Beichman, Charles A.; Carey, Sean J.; Crockett, Christopher J.; Eastman, Jason; Johns-Krull, Christopher M.; Howell, Steve B.; Kane, Stephen R.; . Mclane, Jacob N.; Plavchan, Peter; Prato, L.; Stauffer, John; van Belle, Gerard T.; von Braun, Kaspar

    2015-08-01

    We present Spitzer 4.5 ?m light curve observations, Keck NIRSPEC radial velocity observations, and LCOGT optical light curve observations of PTFO 8-8695, which may host a Jupiter-sized planet in a very short orbital period (0.45 days). Previous work by van Eyken et al. and Barnes et al. predicts that the stellar rotation axis and the planetary orbital plane should precess with a period of 300-600 days. As a consequence, the observed transits should change shape and depth, disappear, and reappear with the precession. Our observations indicate the long-term presence of the transit events (\\gt 3 years), and that the transits indeed do change depth, disappear and reappear. The Spitzer observations and the NIRSPEC radial velocity observations (with contemporaneous LCOGT optical light curve data) are consistent with the predicted transit times and depths for the {M}\\star =0.34 {M}? precession model and demonstrate the disappearance of the transits. An LCOGT optical light curve shows that the transits do reappear approximately 1 year later. The observed transits occur at the times predicted by a straight-forward propagation of the transit ephemeris. The precession model correctly predicts the depth and time of the Spitzer transit and the lack of a transit at the time of the NIRSPEC radial velocity observations. However, the precession model predicts the return of the transits approximately 1 month later than observed by LCOGT. Overall, the data are suggestive that the planetary interpretation of the observed transit events may indeed be correct, but the precession model and data are currently insufficient to confirm firmly the planetary status of PTFO 8-8695b.

  11. Variability of Kepler Solar-like Stars Harboring Small Exoplanets

    Science.gov (United States)

    Howell, Steve B.; Ciardi, David R.; Giampapa, Mark S.; Everett, Mark E.; Silva, David R.; Szkody, Paula

    2016-02-01

    We examine Kepler light-curve variability on habitable zone transit timescales for a large uniform sample of spectroscopically studied Kepler exoplanet host stars. The stars, taken from Everett et al., are solar-like in their properties and each harbors at least one exoplanet (or candidate) of radius ?2.5 {R}{{e}}. The variability timescale examined is typical for habitable zone planets orbiting solar-like stars and we note that the discovery of the smallest exoplanets (?1.2 {R}{{e}}) with corresponding transit depths of less than ?0.18 mmag occur for the brightest and photometrically quietest stars. Thus, these detections are quite rare in Kepler observations. Some brighter and more evolved stars (subgiants), the latter of which often show large radial velocity jitter, are found to be among the photometrically quietest solar-like stars in our sample and the most likely small planet transit hunting grounds. The Sun is discussed as a solar-like star proxy to provide insight into the nature and cause of photometric variability. It is shown that Kepler’s broad, visible light observations are insensitive to variability caused by chromospheric activity that may be present in the observed stars.

  12. Variability of Kepler Solar-Like Stars Harboring Small Exoplanets

    CERN Document Server

    Howell, Steve B; Giampapa, Mark S; Everett, Mark E; Silva, David R; Szkody, Paula

    2015-01-01

    We examine Kepler light curve variability on habitable zone transit timescales for a large uniform sample of spectroscopically studied Kepler exoplanet host stars. The stars, taken from Everett et al. (2013) are solar-like in their properties and each harbors at least one exoplanet (or candidate) of radius $\\le$2.5\\re. The variability timescale examined is typical for habitable zone planets orbiting solar-like stars and we note that the discovery of the smallest exoplanets ($\\le$1.2\\re) with corresponding transit depths of less than $\\sim$0.18 mmag, occur for the brightest, photometrically quietest stars. Thus, these detections are quite rare in $Kepler$ observations. Some brighter and more evolved stars (subgiants), the latter which often show large radial velocity jitter, are found to be among the photometrically quietest solar-like stars in our sample and the most likely small planet transit hunting grounds. The Sun is discussed as a solar-like star proxy to provide insights into the nature and cause of ph...

  13. Transiting exoplanets from the CoRoT space mission XXVIII. CoRoT-28b, a planet orbiting an evolved star, and CoRoT-29b, a planet showing an asymmetric transit

    CERN Document Server

    Cabrera, J; Montagnier, G; Fridlund, M; Eiff, M Ammler-von; Chaintreuil, S; Damiani, C; Deleuil, M; Ferraz-Mello, S; Ferrigno, A; Gandolfi, D; Guillot, T; Guenther, E W; Hatzes, A; Hébrard, G; Klagyivik, P; Parviainen, H; Pasternacki, Th; Pätzold, M; Sebastian, D; Santos, M Tadeu dos; Wuchterl, G; Aigrain, S; Alonso, R; Almenara, J -M; Armstrong, J D; Auvergne, M; Baglin, A; Barge, P; Barros, S C C; Bonomo, A S; Bordé, P; Bouchy, F; Carpano, S; Chaffey, C; Deeg, H J; Díaz, R F; Dvorak, R; Erikson, A; Grziwa, S; Korth, J; Lammer, H; Lindsay, C; Mazeh, T; Moutou, C; Ofir, A; Ollivier, M; Pallé, E; Rauer, H; Rouan, D; Samuel, B; Santerne, A; Schneider, J

    2015-01-01

    Context. We present the discovery of two transiting extrasolar planets by the satellite CoRoT. Aims. We aim at a characterization of the planetary bulk parameters, which allow us to further investigate the formation and evolution of the planetary systems and the main properties of the host stars. Methods. We used the transit light curve to characterize the planetary parameters relative to the stellar parameters. The analysis of HARPS spectra established the planetary nature of the detections, providing their masses. Further photometric and spectroscopic ground-based observations provided stellar parameters (log g,Teff,v sin i) to characterize the host stars. Our model takes the geometry of the transit to constrain the stellar density into account, which when linked to stellar evolutionary models, determines the bulk parameters of the star. Because of the asymmetric shape of the light curve of one of the planets, we had to include the possibility in our model that the stellar surface was not strictly spherical...

  14. Radial velocity eclipse mapping of exoplanets

    CERN Document Server

    Nikolov, Nikolay

    2015-01-01

    Planetary rotation rates and obliquities provide information regarding the history of planet formation, but have not yet been measured for evolved extrasolar planets. Here we investigate the theoretical and observational perspective of the Rossiter-McLauglin effect during secondary eclipse (RMse) ingress and egress for transiting exoplanets. Near secondary eclipse, when the planet passes behind the parent star, the star sequentially obscures light from the approaching and receding parts of the rotating planetary surface. The temporal block of light emerging from the approaching (blue-shifted) or receding (red-shifted) parts of the planet causes a temporal distortion in the planet's spectral line profiles resulting in an anomaly in the planet's radial velocity curve. We demonstrate that the shape and the ratio of the ingress-to-egress radial velocity amplitudes depends on the planetary rotational rate, axial tilt and impact factor (i.e. sky-projected planet spin-orbital alignment). In addition, line asymmetrie...

  15. Subaru SEEDS Survey of Exoplanets and Disks

    Science.gov (United States)

    McElwain, Michael W.

    2012-01-01

    The Strategic Exploration of Exoplanets and Disks at Subaru (SEEDS) is the first strategic observing program (SSOPs) awarded by the National Astronomical Observatory of Japan (NAOJ). SEEDS targets a broad sample of stars that span a wide range of masses and ages to explore the formation and evolution of planetary systems. This survey has been awarded 120 nights over five years time to observe nearly 500 stars. Currently in the second year, SEEDS has already produced exciting new results for the protoplanetary disk AB Aur, transitional disk LkCa15, and nearby companion to GJ 758. We present the survey architecture, performance, recent results, and the projected sample. Finally, we will discuss planned upgrades to the high contrast instrumentation at the Subaru Telescope

  16. French Pro/Am collaborations in exoplanet

    Science.gov (United States)

    Santerne, A.; Moutou, C.; Vanhuysse, M.; Bouchy, F.; Buil, C.; Cochard, F.; Thizy, O.; Martinez, P.; Desnoux, V.; Pujol, M.; Colas, F.

    2011-10-01

    Amateur astronomers have access to huge telescope time and can reach photometric precision up to a few mmag as well as radial velocity precision up to ˜ 50m.s-1 on brightest stars. We will first present some results of french amateur astronomers in transit photometry and radial velocity and then, we will present an over-view of all the collaborations which can be done between professional and amateur astronomers in the competitive exoplanet domain, and especially the current collaboration between french Pro & Am astronomers which was used in publication in A&A. Finally, we will present a new internet wiki page which goal is to develop such collaboration in different countries.

  17. Exoplanet Population Estimate from Kepler Data

    Science.gov (United States)

    Traub, Wesley A.

    2015-11-01

    The intrinsic population of exoplanets around Kepler target stars is estimated by comparing the observed numbers of planets at each radius and period against a simulation that accounts for the probability of transit and the estimated instrument sensitivity. By assuming that the population can be modeled as a function of period times a function of radius, and further assuming that these functions are broken power laws, sufficient leverage is gained such that the well-measured short-period planet distribution can effectively be used as a template for the less-well sampled long-period terrestrial planets. The resulting population distribution provides a challenge to models of the origin and evolution of planetary systems.

  18. Test of multi-object exoplanet search spectral interferometer

    Science.gov (United States)

    Zhang, Kai; Wang, Liang; Jiang, Haijiao; Zhu, Yongtian; Hou, Yonghui; Dai, Songxin; Tang, Jin; Tang, Zhen; Zeng, Yizhong; Chen, Yi; Wang, Lei; Hu, Zhongwen

    2014-07-01

    Exoplanet detection, a highlight in the current astronomy, will be part of puzzle in astronomical and astrophysical future, which contains dark energy, dark matter, early universe, black hole, galactic evolution and so on. At present, most of the detected Exoplanets are confirmed through methods of radial velocity and transit. Guo shoujing Telescope well known as LAMOST is an advanced multi-object spectral survey telescope equipped with 4000 fibers and 16 low resolution fiber spectrographs. To explore its potential in different astronomical activities, a new radial velocity method named Externally Dispersed Interferometry (EDI) is applied to serve Exoplanet detection through combining a fixed-delay interferometer with the existing spectrograph in medium spectral resolution mode (R=5,000-10,000). This new technology has an impressive feature to enhance radial velocity measuring accuracy of the existing spectrograph through installing a fixed-delay interferometer in front of spectrograph. This way produces an interference spectrum with higher sensitivity to Doppler Effect by interference phase and fixed delay. This relative system named Multi-object Exoplanet Search Spectral Interferometer (MESSI) is composed of a few parts, including a pair of multi-fiber coupling sockets, a remote control iodine subsystem, a multi-object fixed delay interferometer and the existing spectrograph. It covers from 500 to 550 nm and simultaneously observes up to 21 stars. Even if it's an experimental instrument at present, it's still well demonstrated in paper that how MESSI does explore an effective way to build its own system under the existing condition of LAMOST and get its expected performance for multi-object Exoplanet detection, especially instrument stability and its special data reduction. As a result of test at lab, inside temperature of its instrumental chamber is stable in a range of +/-0.5degree Celsius within 12 hours, and the direct instrumental stability without further observation correction is equivalent to be +/-50m/s every 20mins.

  19. The LEECH Exoplanet Imaging Survey: Characterization of the Coldest Directly Imaged Exoplanet, GJ 504 b, and Evidence for Superstellar Metallicity

    Science.gov (United States)

    Skemer, Andrew J.; Morley, Caroline V.; Zimmerman, Neil T.; Skrutskie, Michael F.; Leisenring, Jarron; Buenzli, Esther; Bonnefoy, Mickael; Bailey, Vanessa; Hinz, Philip; Defrére, Denis; Esposito, Simone; Apai, Dániel; Biller, Beth; Brandner, Wolfgang; Close, Laird; Crepp, Justin R.; De Rosa, Robert J.; Desidera, Silvano; Eisner, Josh; Fortney, Jonathan; Freedman, Richard; Henning, Thomas; Hofmann, Karl-Heinz; Kopytova, Taisiya; Lupu, Roxana; Maire, Anne-Lise; Males, Jared R.; Marley, Mark; Morzinski, Katie; Oza, Apurva; Patience, Jenny; Rajan, Abhijith; Rieke, George; Schertl, Dieter; Schlieder, Joshua; Stone, Jordan; Su, Kate; Vaz, Amali; Visscher, Channon; Ward-Duong, Kimberly; Weigelt, Gerd; Woodward, Charles E.

    2016-02-01

    As gas giant planets and brown dwarfs radiate away the residual heat from their formation, they cool through a spectral type transition from L to T, which encompasses the dissipation of cloud opacity and the appearance of strong methane absorption. While there are hundreds of known T-type brown dwarfs, the first generation of directly imaged exoplanets were all L type. Recently, Kuzuhara et al. announced the discovery of GJ 504 b, the first T dwarf exoplanet. GJ 504 b provides a unique opportunity to study the atmosphere of a new type of exoplanet with a ∼500 K temperature that bridges the gap between the first directly imaged planets (∼1000 K) and our own solar system's Jupiter (∼130 K). We observed GJ 504 b in three narrow L-band filters (3.71, 3.88, and 4.00 μm), spanning the red end of the broad methane fundamental absorption feature (3.3 μm) as part of the LBTI Exozodi Exoplanet Common Hunt (LEECH) exoplanet imaging survey. By comparing our new photometry and literature photometry with a grid of custom model atmospheres, we were able to fit GJ 504 b's unusual spectral energy distribution for the first time. We find that GJ 504 b is well fit by models with the following parameters: Teff = 544 ± 10 K, g representing the Max-Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University; The Ohio State University, and the Research Corporation, on behalf of the University of Notre Dame, University of Minnesota, and University of Virginia.

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

    Directory of Open Access Journals (Sweden)

    Rauer H.

    2011-02-01

    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.

  1. Follow-Up Observations of PTFO 8-8695: A 3 MYr Old T-Tauri Star Hosting a Jupiter-mass Planetary Candidate

    CERN Document Server

    Ciardi, David R; Barnes, J W; Beichman, C A; Carey, S J; Crockett, C J; Eastman, J; Johns-Krull, C M; Howell, S B; Kane, S R; Mclane, J N; Plavchan, P; Prato, L; Stauffer, J; van Belle, G T; von Braun, K

    2015-01-01

    We present Spitzer 4.5\\micron\\ light curve observations, Keck NIRSPEC radial velocity observations, and LCOGT optical light curve observations of PTFO~8-8695, which may host a Jupiter-sized planet in a very short orbital period (0.45 days). Previous work by \\citet{vaneyken12} and \\citet{barnes13} predicts that the stellar rotation axis and the planetary orbital plane should precess with a period of $300 - 600$ days. As a consequence, the observed transits should change shape and depth, disappear, and reappear with the precession. Our observations indicate the long-term presence of the transit events ($>3$ years), and that the transits indeed do change depth, disappear and reappear. The Spitzer observations and the NIRSPEC radial velocity observations (with contemporaneous LCOGT optical light curve data) are consistent with the predicted transit times and depths for the $M_\\star = 0.34\\ M_\\odot$ precession model and demonstrate the disappearance of the transits. An LCOGT optical light curve shows that the tran...

  2. CLOUD BASE SIGNATURE IN TRANSMISSION SPECTRA OF EXOPLANET ATMOSPHERES

    International Nuclear Information System (INIS)

    We present an analytical model for the transmission spectrum of a transiting exoplanet, showing that a cloud base can produce an observable inflection point in the spectrum. The wavelength and magnitude of the inflection can be used to break the degeneracy between the atmospheric pressure and the abundance of the main cloud material, however, the abundance still depends on cloud particle size. An observed inflection also provides a specific point on the atmospheric P-T profile, giving us a ''thermometer'' to directly validate or rule out postulated cloud species. We apply the model to the transit spectrum of HD 189733b

  3. Scalable Gaussian Processes and the search for exoplanets

    CERN Document Server

    CERN. Geneva

    2015-01-01

    Gaussian Processes are a class of non-parametric models that are often used to model stochastic behavior in time series or spatial data. A major limitation for the application of these models to large datasets is the computational cost. The cost of a single evaluation of the model likelihood scales as the third power of the number of data points. In the search for transiting exoplanets, the datasets of interest have tens of thousands to millions of measurements with uneven sampling, rendering naive application of a Gaussian Process model impractical. To attack this problem, we have developed robust approximate methods for Gaussian Process regression that can be applied at this scale. I will describe the general problem of Gaussian Process regression and offer several applicable use cases. Finally, I will present our work on scaling this model to the exciting field of exoplanet discovery and introduce a well-tested open source implementation of these new methods.

  4. Adapting Low-Tech Gear to Exoplanet Discovery

    Science.gov (United States)

    Brown, Timothy M.

    2014-01-01

    The discovery of 51 Peg b by Mayor and Queloz revealed (among other things) that discovering extrasolar planets, though certainly difficult, was not as hard as professional astronomers had previously thought. At the same time, the astronomical equipment available to amateurs -- including optics, mountings, and CCD detectors -- had become quite capable. This combination of factors led to successful exoplanet programs that leaned heavily on amateur-grade hardware, seeking faster development times and lower costs than were possible for traditional no-compromises astronomical instrument programs. I will describe two of these in which I played a role: the AFOE (Advanced Fiber Optic Echelle) spectrograph, and the STellar Astrophysics and Research on Exoplanets (STARE) transit-search wide-field imager.

  5. The observational effects and signatures of tidally distorted solid exoplanets

    Science.gov (United States)

    Saxena, Prabal; Panka, Peter; Summers, Michael

    2015-02-01

    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.

  6. The Observational Effects and Signatures of Tidally Distorted Solid Exoplanets

    CERN Document Server

    Saxena, Prabal; Summers, Michael

    2014-01-01

    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.

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

    CERN Document Server

    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

    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...

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

    OpenAIRE

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

    2014-01-01

    A unique short-period Mercury-size Kepler exoplanet candidate KIC012557548b has been discovered recently by Rappaport et al. (2012). This object is a transiting disintegrating exoplanet with a circum-planetary material - comet-like tail. Close-in exoplanets, like KIC012557548b, are subjected to the greatest planet-star interactions. This interaction may have various forms. In certain cases it may cause formation of the comet-like tail. Strong interaction with the host star, and/or presence of...

  9. The Gemini Planet Imager Exoplanet Survey

    Science.gov (United States)

    Macintosh, Bruce

    The Gemini Planet Imager (GPI) is a next-generation coronagraph constructed for the Gemini Observatory. GPI will see first light this fall. It will be the most advanced planet-imaging system in operation - an order of magnitude more sensitive than any current instrument, capable of detecting and spectroscopically characterizing young Jovian planets 107 times fainter than their parent star at separations of 0.2 arcseconds. GPI was built from the beginning as a facility-class survey instrument, and the observatory will employ it that way. Our team has been selected by Gemini Observatory to carry out an 890-hour program - the GPI Exoplanet Survey (GPIES) campaign from 2014-2017. We will observe 600 stars spanning spectral types A-M. We will use published young association catalogs and a proprietary list in preparation that adds several hundred new young (reduced GPI data products (supplementing the existing Gemini archive of raw data) for use by our collaboration, and release that archive to the public on an 18-month cycle. Most importantly, we will execute the GPI observations, initially through classical telescope visits, transitioning to remote and queue modes as our techniques are refined. As the first direct-imaging planet search with statistical depth comparable to Doppler planet detection and the first to probe into the snow line, the GPI Exoplanet Survey will provide strong constraints on paradigms for planet formation, completing the picture of the giant planet distribution throughout other solar systems, and also illuminating its evolution with stellar age and mass. We will deliver a catalog of detected exoplanets— the principal legacy of this campaign—released for follow-up by the astronomical community within 18 months of observation, as well as searchable archive of fully reduced images and detection limits for all stars surveyed. For each detected planet, we will produce estimated effective temperatures, luminosities, and semi-major axes: for a subset, high-SNR fiducial spectra, orbital eccentricities, and dynamical characterization through polarimetric imaging of attendant debris disks. GPI will complete final acceptance testing this month (May 2013) and is now ready to ship to Chile for first light in September 2013. The GPI survey will provide the best-yet view of the nature of wide-orbit planetary companions, informing our knowledge of solar system formation to guide future NASA planet hunting missions, while simultaneously offering a real- world program using the techniques - from integral field spectroscopy to advanced coronagraphy - that will someday be used to directly image Earthlike planets from space.

  10. The Radiation Environment of Exoplanet Atmospheres

    Directory of Open Access Journals (Sweden)

    Jeffrey L. Linsky

    2014-10-01

    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.

  11. DISCRIMINATING BETWEEN CLOUDY, HAZY, AND CLEAR SKY EXOPLANETS USING REFRACTION

    International Nuclear Information System (INIS)

    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

  12. DISCRIMINATING BETWEEN CLOUDY, HAZY, AND CLEAR SKY EXOPLANETS USING REFRACTION

    Energy Technology Data Exchange (ETDEWEB)

    Misra, Amit K.; Meadows, Victoria S. [Astronomy Department, University of Washington, Seattle, WA 98195 (United States)

    2014-11-01

    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.

  13. PyTransit: Transit light curve modeling

    Science.gov (United States)

    Parviainen, Hannu

    2015-05-01

    PyTransit implements optimized versions of the Giménez and Mandel & Agol transit models for exoplanet transit light-curves. The two models are implemented natively in Fortran with OpenMP parallelization, and are accessed by an object-oriented python interface. PyTransit facilitates the analysis of photometric time series of exoplanet transits consisting of hundreds of thousands of data points, and of multipassband transit light curves from spectrophotometric observations. It offers efficient model evaluation for multicolour observations and transmission spectroscopy, built-in supersampling to account for extended exposure times, and routines to calculate the projected planet-to-star distance for circular and eccentric orbits, transit durations, and more.

  14. HOMES - Holographic Optical Method for Exoplanet Spectroscopy Project

    Data.gov (United States)

    National Aeronautics and Space Administration — HOMES (Holographic Optical Method for Exoplanet Spectroscopy) is a space telescope designed for exoplanet discovery. Its double dispersion architecture employs a...

  15. Multiplicity-Study of Exoplanet Host Stars

    CERN Document Server

    Mugrauer, M; Mazeh, T; Günther, E

    2005-01-01

    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.

  16. Atmospheric Circulation of Terrestrial Exoplanets

    CERN Document Server

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

    2013-01-01

    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...

  17. VUV-absorption cross section of CO2 at high temperatures and impact on exoplanet atmospheres

    CERN Document Server

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

    2015-01-01

    Ultraviolet (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. 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 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 found that the absorption cross section of CO2 is very sensitive to temperature, especially above 160 nm....

  18. Exoplanet Science with the European Extremely Large Telescope. The Case for Visible and Near-IR Spectroscopy at High Resolution

    OpenAIRE

    Udry, S.; Lovis, C.; Bouchy, F.; Cameron, A. Collier; Henning, T.; Mayor, M.; PEPE, F.; Piskunov, N.; Pollacco, D.; Queloz, D.; Quirrenbach, A.; Rauer, H.; Rebolo, R.; N.C. Santos; Snellen, I.

    2014-01-01

    Exoplanet science is booming. In 20 years our knowledge has expanded considerably, from the first discovery of a Hot Jupiter, to the detection of a large population of Neptunes and super-Earths, to the first steps toward the characterization of exoplanet atmospheres. Between today and 2025, the field will evolve at an even faster pace with the advent of several space-based transit search missions, ground-based spectrographs, high-contrast imaging facilities, and the James Webb Space Telescope...

  19. Abundances in stars with exoplanets

    OpenAIRE

    Israelian, Garik

    2003-01-01

    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.

  20. Planetesimal Compositions in Exoplanet Systems

    OpenAIRE

    Johnson, Torrence V.; Mousis, Olivier; Lunine, Jonathan I.; Madhusudhan, Nikku

    2012-01-01

    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 mo...

  1. Stable regions around Exoplanets: the search for Exomoons

    Science.gov (United States)

    Fernandes Guimaraes, Ana Helena; Moretto Tusnski, Luis Ricardo; Vieira-Neto, Ernesto; Silva Valio, Adriana

    2015-08-01

    There are hundreds of exoplanets which the data are available to a dynamical investigation. We extracted from the data base (exoplanets.org) all planets and candidates which have the necessary data available for the numerical investigation of the orbital stability of a body around a exoplanet in a total of 2749 of those.There is a wealth diversity of exoplanets types and the expectation in find our Earth-living conditions in another planet motivates the search for extra-solar planets, and a satellite around a planet would, in addiction, help to keep a favorable climate.Using the planets class according to PHL@Arecibo, those planets were sorted out in groups. Analyses of density, distance from the primary body, and mass ratios were done beside the suggested classification to fit some no-classified planets into one of the groups.The aim of this work is to derive the upper stability limit (or upper critical orbit) of fictitious direct satellites around exoplanets of any density, or size, orbiting single stars. Our search is for stable regions around the planet, the called S-type orbits. This orbit type determines if there is any chance to exist (or not) bodies around the planets. The investigation is limited to single stars, excluding binaries.We derived such limit purely through numerical simulations. Our proposal involved long-term integration of the circular restricted three bodies problem . Basically, the cut off of the stability zone determined in the previous work by Domingos et al. (2006) were confirmed for any planet type. However, the limitation due the Roche limit of the own satellite showed to be lower. We used this to determined possible size and to adjust orbital range were a third body could orbit the exoplanet.Independently of densities, distance, and sizes of the objects involved, the idea was to delimit where to find celestial bodies in any given system around single stars. Furthermore, we aim to provide tracks to the search for exomoons using planetary transits.

  2. JWST and Exoplanets

    Science.gov (United States)

    Mather, John C.

    2009-01-01

    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.

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

    Science.gov (United States)

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

    2015-01-01

    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.

  4. Design Considerations: Falcon M Dwarf Habitable Exoplanet Survey

    Science.gov (United States)

    Polsgrove, Daniel; Novotny, Steven; Della-Rose, Devin J.; Chun, Francis; Tippets, Roger; O'Shea, Patrick; Miller, Matthew

    2016-01-01

    The Falcon Telescope Network (FTN) is an assemblage of twelve automated 20-inch telescopes positioned around the globe, controlled from the Cadet Space Operations Center (CSOC) at the US Air Force Academy (USAFA) in Colorado Springs, Colorado. Five of the 12 sites are currently installed, with full operational capability expected by the end of 2016. Though optimized for studying near-earth objects to accomplish its primary mission of Space Situational Awareness (SSA), the Falcon telescopes are in many ways similar to those used by ongoing and planned exoplanet transit surveys targeting individual M dwarf stars (e.g., MEarth, APACHE, SPECULOOS). The network's worldwide geographic distribution provides additional potential advantages. We have performed analytical and empirical studies exploring the viability of employing the FTN for a future survey of nearby late-type M dwarfs tailored to detect transits of 1-2REarth exoplanets in habitable-zone orbits . We present empirical results on photometric precision derived from data collected with multiple Falcon telescopes on a set of nearby (created from images gathered during known transits of varying transit depths. An investigation of survey design parameters is also described, including an analysis of site-specific weather data, anticipated telescope time allocation and the percentage of nearby M dwarfs with sufficient check stars within the Falcons' 11' x 11' field-of-view required to perform effective differential photometry. The results of this ongoing effort will inform the likelihood of discovering one (or more) habitable-zone exoplanets given current occurrence rate estimates over a nominal five-year campaign, and will dictate specific survey design features in preparation for initiating project execution when the FTN begins full-scale automated operations.

  5. Exploring Equilibrium Chemistry for Hot Exoplanets

    Science.gov (United States)

    Blumenthal, Sarah; Harrington, Joseph; Mandell, Avi; Hébrard, Eric; Venot, Olivia; Cubillos, Patricio; Challener, Ryan

    2015-11-01

    It has been established that equilibrium chemistry is usually achieved deep in the atmosphere of hot Jovians where timescales are short (Line and Young 2013). Thus, equilibrium chemistry has been used as a starting point (setting initial conditions) for evaluating disequilibrium processes. We explore parameters of setting these initial conditions including departures from solar metallicity, the number of species allowed in a system, the types of species allowed in a system, and different thermodynamic libraries in an attempt to create a standard for evaluating equilibrium chemistry. NASA's open source code Chemical Equilibrium and Applications (CEA) is used to calculate model planet abundances by varying the metallicity, in the pressure regime of 0.1 to 1 bar. These results are compared to a variety of exoplanets (Teq between 600 and 2100K) qualitatively by color maps of the dayside with different temperature redistributions. Additionally, CEA (with an updated thermodynamic library) is validated with the thermochemical model presented in Venot et al. (2012) for HD 209458b and HD 189733b. This same analysis has then been extended to the cooler planet HD 97658b. Spectra are generated from both models’ abundances using the open source code transit (https://github.com/exosports/transit) using the opacities of 15 molecules. We make the updated CEA thermodyanamic library and supporting Python scripts to do the CEA analyses available open source. This work was supported by NASA Planetary Atmospheres grant NNX12AI69G.

  6. Signals of exomoons in averaged light curves of exoplanets

    CERN Document Server

    Simon, A E; Kiss, L L; Szatmáry, K

    2011-01-01

    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 simulations: Kepler "short cadence", Kepler "long cadence", ground-based millimagnitude photometry with 3-min cadence, and the expected data quality of the planned ESA mission of PLATO. The method requires ~100 transit observations, therefore applicable for moons of 10-20 day period planets, assuming 3-4-5 year long observing campaigns with space observatories. The success rate for finding a 1 R_Earth moon around a 1 R_Jupiter exoplanet turned out to be quite promising even for the simulated ground-based observations, while the detection li...

  7. The Exoplanet Eccentricity Distribution from Kepler Planet Candidates

    CERN Document Server

    Kane, Stephen R; Gelino, Dawn M; von Braun, Kaspar

    2012-01-01

    The eccentricity distribution of exoplanets is known from radial velocity surveys to be divergent from circular orbits beyond 0.1 AU. This is particularly the case for large planets where the radial velocity technique is most sensitive. The eccentricity of planetary orbits can have a large effect on the transit probability and subsequently the planet yield of transit surveys. The Kepler mission is the first transit survey that probes deep enough into period-space to allow this effect to be seen via the variation in transit durations. We use the Kepler planet candidates to show that the eccentricity distribution matches that found from radial velocity surveys to a high degree of confidence. We further show that the mean eccentricity of the Kepler candidates decreases with decreasing planet size indicating that smaller planets are preferentially found in low-eccentricity orbits.

  8. Exoplanet Community Report on Direct Infrared Imaging of Exoplanets

    Science.gov (United States)

    Danchi, William C.; Lawson, Peter R.

    2009-01-01

    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.

  9. ARIEL: Atmospheric Remote-Sensing Infrared Exoplanet Large-survey

    Science.gov (United States)

    Tinetti, Giovanna

    2015-11-01

    More than 1,000 extrasolar systems have been discovered, hosting nearly 2,000 exoplanets. Ongoing and planned ESA and NASA missions from space such as GAIA, Cheops, PLATO, K2 and TESS will increase the number of known systems to tens of thousands.Of all these exoplanets we know very little, i.e. their orbital data and, for some of these, their physical parameters such as their size and mass. In the past decade, pioneering results have been obtained using transit spectroscopy with Hubble, Spitzer and ground-based facilities, enabling the detection of a few of the most abundant ionic, atomic and molecular species and to constrain the planet’s thermal structure. Future general purpose facilities with large collecting areas will allow the acquisition of better exoplanet spectra, compared to the currently available, especially from fainter targets. A few tens of planets will be observed with JWST and E-ELT in great detail.A breakthrough in our understanding of planet formation and evolution mechanisms will only happen through the observation of the planetary bulk and atmospheric composition of a statistically large sample of planets. This requires conducting spectroscopic observations covering simultaneously a broad spectral region from the visible to the mid-IR. It also requires a dedicated space mission with the necessary photometric stability to perform these challenging measurements and sufficient agility to observe multiple times ~500 exoplanets over mission life-time.The ESA-M4 mission candidate ARIEL is designed to accomplish this goal and will provide a complete, statistically significant sample of gas-giants, Neptunes and super-Earths with temperatures hotter than 600K, as these types of planets will allow direct observation of their bulk properties, enabling us to constrain models of planet formation and evolution.The ARIEL consortium currently includes academic institutes and industry from eleven countries in Europe; the consortium is open and invites new contributions and collaborations.

  10. Gaia, PLATO and WEAVE: A Powerful combination for Exoplanet Characterisation

    Science.gov (United States)

    Walton, Nicholas

    2015-12-01

    This presentation will describe the powerful linkages between the Gaia and PLATO missions and the potential impact of the WHT’s WEAVE multi-object spectrograph in the study of exoplanet populations.ESA’s Gaia mission commenced its nominal operations phase in July 2014. Its first data release is expected summer 2016. Over the course of its (at least) five year mission, it will discover, via their astrometric signatures, upwards of 20,000 massive Jupiter sized long period planets at distances out to several hundred parsecs around all star types. In addition Gaia will discover a significant number of short period hot Jupiters around M stars. This presentation will discuss the form and content of the first Gaia Data Release. The ESA PLATO mission, planned to launch in 2024, will photometrically observe a million host stars, and will detect, via the transit technique, planets down to Earth masses. PLATO will observe two fields of over 2,000 square degrees for 2 to 3 years each. At least one of these will be in the northern hemisphere. where WEAVE (a new multi object high resolution spectrograph currently under construction for the 4.2m William Herschel Telescope) will have the potential to provide detailed chemical characterisation of the host stars of the Gaia and PLATO exoplanet systems. This will enable insights into, for instance, metallicity of the host star correlations against both massive exoplanets (perhaps confirming current relationships), and lower mass exoplanets.We note how the rapid exploitation of such a potential WEAVE survey could be achieved, utilising the WEAVE processing systems being developed at the IoA, Cambridge, coupled with efficient interfaces to the Cambridge Gaia and PLATO data processing centres.

  11. Giant Transiting Planets Observations - GITPO

    Science.gov (United States)

    Afonso, C.

    2006-08-01

    The search for extrasolar planets is nowadays one of the most promising science drivers in Astronomy. The radial velocity technique proved to be successful in planet hunting, harvesting more than a hundred planets to date. In these last years, the transit method has come to fruition, with the detection of seven Jupiter-mass extrasolar transiting planets in close-in orbits (motivation and strength of this technique. The MPIA is presently building the Large Area Imager (LAIWO) for the 1m telescope in the Wise Observatory, Israel. LAIWO will have a field of view of one square degree. An intensive search for extra-solar planets will be performed with the 1m Wise telecope, together with the 1.2m MONET telescope in Texas. We will monitor three fields at a given time during three years and more than 200 nights per year. We expect several dozens of extra-solar planets.

  12. Transitions.

    Science.gov (United States)

    Field, David; And Others

    1992-01-01

    Includes four articles: "Career Aspirations" (Field); "Making the Transition to a New Curriculum" (Baker, Householder); "How about a 'Work to School' Transition?" (Glasberg); and "Technological Improvisation: Bringing CNC to Woodworking" (Charles, McDuffie). (SK)

  13. High-precision ground-based photometry of exoplanets

    Directory of Open Access Journals (Sweden)

    de Mooij Ernst J.W.

    2013-04-01

    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.

  14. An integrated payload design for the Exoplanet Characterisation Observatory (EChO)

    DEFF Research Database (Denmark)

    Tinetti, Giovanna; Tennyson, Jonathan; Tessenyi, Marcell; Waldmann, Ingo; Swinyard, Bruce; Eccleston, Paul; Ferlet, Marc; Lim, Tanya; Adriani, Alberto; Piccioni, Giuseppe; Beaulieu, Jean-Philippe; Davila, Tomas Belenguer; Zapata, Gonzalo Ramos; Bowles, Neil; Bryson, Ian; Wright, Gillian; Coustenis, Athena; Du Foresto, Vincent Coude?; Reess, Jean-Michel; Hartogh, Paul; Lagage, Pierre-Olivier; Malaguti, Giuseppe; Morgante, Gianluca; Lo?pez-Morales, Mercedes; Ribas, Ignasi; Micela, Giuseppina; Nørgaard-Nielsen, Hans Ulrik; Ollivier, Marc; Pace, Emanuele; Pascale, Enzo; Sozzetti, Alessandro; Swain, Mark R.; Winter, Berend; Osorio, Maria-Rosa Zapatero

    2012-01-01

    The Exoplanet Characterisation Observatory (EChO) is a space mission dedicated to undertaking spectroscopy of transiting exoplanets over the widest wavelength range possible. It is based around a highly stable space platform with a 1.2 m class telescope. The mission is currently being studied by ESA in the context of a medium class mission within the Cosmic Vision programme for launch post 2020. The payload suite is required to provide simultaneous coverage from the visible to the mid-infrared a...

  15. An integrated payload design for the Exoplanet Characterisation Observatory (EChO)

    DEFF Research Database (Denmark)

    Tinetti, Giovanna; Tennyson, Jonathan; Tessenyi, Marcell; Waldmann, Ingo; Swinyard, Bruce; Eccleston, Paul; Ferlet, Marc; Lim, Tanya; Adriani, Alberto; Piccioni, Giuseppe; Beaulieu, Jean-Philippe; Davila, Tomas Belenguer; Zapata, Gonzalo Ramos; Bowles, Neil; Bryson, Ian; Wright, Gillian; Coustenis, Athena; Du Foresto, Vincent Coudé; Reess, Jean-Michel; Hartogh, Paul; Lagage, Pierre-Olivier; Malaguti, Giuseppe; Morgante, Gianluca; López-Morales, Mercedes; Ribas, Ignasi; Micela, Giuseppina; Nørgaard-Nielsen, Hans Ulrik; Ollivier, Marc; Pace, Emanuele; Pascale, Enzo; Sozzetti, Alessandro; Swain, Mark R.; Winter, Berend; Osorio, Maria-Rosa Zapatero

    2012-01-01

    The Exoplanet Characterisation Observatory (EChO) is a space mission dedicated to undertaking spectroscopy of transiting exoplanets over the widest wavelength range possible. It is based around a highly stable space platform with a 1.2 m class telescope. The mission is currently being studied by...... ESA in the context of a medium class mission within the Cosmic Vision programme for launch post 2020. The payload suite is required to provide simultaneous coverage from the visible to the mid-infrared and must be highly stable and effectively operate as a single instrument. In this paper we describe...

  16. Achieving high-precision pointing on ExoplanetSat: Initial feasibility analysis

    OpenAIRE

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

    2010-01-01

    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 ...

  17. Making FORS2 fit for exoplanet observations (again)

    CERN Document Server

    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

    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.

  18. BRITE-Constellation and the chances for detecting exoplanets

    International Nuclear Information System (INIS)

    Full text: BRITE-Constellation (BRight Target Explorer) will consist of 3 pairs of nano-satellites, each pair providing data in the blue and red spectral region for stars contained in a field of view of 24 degrees. They will photometrically measure low-level oscillations and temperature variations in stars brighter than visual apparent magnitude 4 with an accuracy of 1 mmag per data point and of lower accuracy for stars down to 6th mag. The data cadence is expected to be 1 min over a data range of weeks up to 2 years. We investigated the probability of detecting transiting exoplanets. (author)

  19. The Host Stars of Keplers Habitable Exoplanets: Superflares, Rotation and Activity

    CERN Document Server

    Armstrong, D J; Broomhall, A -M; Brown, D J A; Lund, M N; Osborn, H P; Pollacco, D L

    2015-01-01

    We embark on a detailed study of the lightcurves of Keplers most Earth-like exoplanet host stars using the full length of Kepler data. We derive rotation periods, photometric activity indices, flaring energies, mass loss rates, gyrochronological ages, X-ray luminosities and consider implications for the planetary magnetospheres and habitability. Furthermore, we present the detection of superflares in the lightcurve of Kepler-438, the exoplanet with the highest Earth Similarity Index to date. Kepler-438b orbits at a distance of 0.166AU to its host star, and hence may be susceptible to atmospheric stripping. Our sample is taken from the Habitable Exoplanet Catalogue, and consists of the stars Kepler-22, Kepler-61, Kepler-62, Kepler-174, Kepler-186, Kepler-283, Kepler-296, Kepler-298, Kepler-438, Kepler-440, Kepler-442, Kepler-443 and KOI-4427, between them hosting 15 of the most habitable transiting planets known to date from Kepler.

  20. The host stars of Kepler's habitable exoplanets: superflares, rotation and activity

    Science.gov (United States)

    Armstrong, D. J.; Pugh, C. E.; Broomhall, A.-M.; Brown, D. J. A.; Lund, M. N.; Osborn, H. P.; Pollacco, D. L.

    2016-01-01

    We embark on a detailed study of the light curves of Kepler's most Earth-like exoplanet host stars using the full length of Kepler data. We derive rotation periods, photometric activity indices, flaring energies, mass-loss rates, gyrochronological ages, X-ray luminosities and consider implications for the planetary magnetospheres and habitability. Furthermore, we present the detection of superflares in the light curve of Kepler-438, the exoplanet with the highest Earth Similarity Index to date. Kepler-438b orbits at a distance of 0.166 au to its host star, and hence may be susceptible to atmospheric stripping. Our sample is taken from the Habitable Exoplanet Catalogue, and consists of the stars Kepler-22, Kepler-61, Kepler-62, Kepler-174, Kepler-186, Kepler-283, Kepler-296, Kepler-298, Kepler-438, Kepler-440, Kepler-442, Kepler-443 and KOI-4427, between them hosting 15 of the most habitable transiting planets known to date from Kepler.

  1. Atmospheric Dynamics of Hot Exoplanets

    Science.gov (United States)

    Heng, Kevin; Showman, Adam P.

    2015-05-01

    The characterization of exoplanetary atmospheres has come of age in the past decade, as astronomical techniques now allow for albedos, chemical abundances, temperature profiles and maps, rotation periods, and even wind speeds to be measured. Atmospheric dynamics sets the background state of density, temperature, and velocity that determines or influences the spectral and temporal appearance of an exoplanetary atmosphere. Hot exoplanets are most amenable to these characterization techniques. In this review, we focus on highly irradiated, large exoplanets (the hot Jupiters), as astronomical data begin to confront theoretical questions. We summarize the basic atmospheric quantities inferred from the astronomical observations. We review the state of the art by addressing a series of current questions, and look toward the future by considering a separate set of exploratory questions. Attaining the next level of understanding requires a concerted effort of constructing multifaceted, multiwavelength datasets for benchmark objects. Understanding clouds presents a formidable obstacle, as they introduce degeneracies into the interpretation of spectra, yet their properties and existence are directly influenced by atmospheric dynamics. Confronting general circulation models with these multifaceted, multiwavelength datasets will help us understand these and other degeneracies.

  2. The Origin of the Exoplanets

    CERN Document Server

    Abt, Helmut A

    2010-01-01

    We explore two ways in which objects of planetary masses can form. One is in disk systems like the solar system. The other is in dense clusters where stars and brown dwarfs form. We do not yet have the instrumental accuracy to detect multiplanet systems with masses like those in solar system; with our present technology from a distant site, only the effects of Jupiter could be detected. We show that the orbital characteristics (eccentricities and semimajor axes) of stellar, brown dwarf, and exoplanet companions of solar-type stars are all the same within our measuring accuracies and are very different than the planets in the solar system. The period ratios in multiplanet systems do not distinguish between the two models. We conclude that most of the exoplanets found to date are formed like stellar companions and not in disk systems like the solar system. This conclusion explains why metal-poor stars lack planets: because metal-poor stars lack stellar companions with short periods. The distribution of exoplane...

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

    OpenAIRE

    Wang, Ji.; Fischer, Debra A.; Barclay, Thomas; Picard, Alyssa; Ma, Bo; Bowler, Brendan P.; Schmitt, Joseph R.; Boyajian, Tabetha S.; Jek, Kian J.; LaCourse, Daryll; Baranec, Christoph; Riddle, Reed; Law, Nicholas M.; Lintott, Chris; Schawinski, Kevin

    2015-01-01

    The census of exoplanets is incomplete for orbital distances larger than 1 AU. Here, we present 41 long-period planet candidates in 38 systems identified by Planet Hunters based on Kepler archival data (Q0-Q17). Among them, 17 exhibit only one transit, 14 have two visible transits and 10 have more than three visible transits. For planet candidates with only one visible transit, we estimate their orbital periods based on transit duration and host star properties. The majority of the planet can...

  4. Age consistency between exoplanet hosts and field stars

    CERN Document Server

    Bonfanti, Andrea; Nascimbeni, Valerio

    2015-01-01

    Transiting planets around stars are discovered mostly through photometric surveys. Unlike radial velocity surveys, photometric surveys do not tend to target slow rotators, inactive and metal-rich stars. Nevertheless, we suspect that observational biases could impact also transiting-planet hosts. This paper aims at evaluating how selection effects reflect on the evolutionary stage of both a limited sample of transiting-planet host stars (TPH) and a wider sample of planet-hosting stars detected through radial velocity analysis. Then, thanks to uniform derivation of stellar ages, a homogeneous comparison between exoplanet hosts and field star age distributions is developed. Stellar parameters have been computed through our custom-developed isochrone placement algorithm, according to Padova evolutionary models. The notable aspects of our algorithm include the treatment of element diffusion, activity checks in terms of $\\log{R'_{HK}}$ and $v\\sin{i}$ and the evaluation of the stellar evolutionary speed in the Hertz...

  5. Exoplanet Science with the European Extremely Large Telescope. The Case for Visible and Near-IR Spectroscopy at High Resolution

    CERN Document Server

    Udry, S; Bouchy, F; Cameron, A Collier; Henning, T; Mayor, M; Pepe, F; Piskunov, N; Pollacco, D; Queloz, D; Quirrenbach, A; Rauer, H; Rebolo, R; Santos, N C; Snellen, I; Zerbi, F

    2014-01-01

    Exoplanet science is booming. In 20 years our knowledge has expanded considerably, from the first discovery of a Hot Jupiter, to the detection of a large population of Neptunes and super-Earths, to the first steps toward the characterization of exoplanet atmospheres. Between today and 2025, the field will evolve at an even faster pace with the advent of several space-based transit search missions, ground-based spectrographs, high-contrast imaging facilities, and the James Webb Space Telescope. Especially the ESA M-class PLATO mission will be a game changer in the field. From 2024 onwards, PLATO will find transiting terrestrial planets orbiting within the habitable zones of nearby, bright stars. These objects will require the power of Extremely Large Telescopes (ELTs) to be characterized further. The technique of ground-based high-resolution spectroscopy is establishing itself as a crucial pathway to measure chemical composition, atmospheric structure and atmospheric circulation in transiting exoplanets. A hig...

  6. Asteroseismic Determination of Obliquities of the Exoplanet Systems Kepler-50 and Kepler-65

    DEFF Research Database (Denmark)

    Chaplin, W. J.; Sanchis-Ojeda, R.; Campante, T. L.; Handberg, R.; Stello, D.; Winn, J. N.; Basu, S.; Christensen-Dalsgaard, J.; Davies, G. R.; Metcalfe, T. S.; Buchhave, L. A.; Fischer, D. A.; Bedding, T. R.; Cochran, W. D.; Elsworth, Y.; Gilliland, R. L.; Hekker, S.; Huber, D.; Isaacson, H.; Karoff, C.; Kawaler, S. D.; Kjeldsen, H.; Latham, D. W.; Lund, M. N.; Lundkvist, M.; Marcy, G. W.; Miglio, A.; Barclay, T.; Lissauer, J. J.

    2013-01-01

    Results on the obliquity of exoplanet host stars—the angle between the stellar spin axis and the planetary orbital axis—provide important diagnostic information for theories describing planetary formation. Here we present the first application of asteroseismology to the problem of stellar obliquity determination in systems with transiting planets and Sun-like host stars. We consider two systems observed by the NASA Kepler mission which have multiple transiting small (super-Earth sized) planets: ...

  7. PlanetPack software tool for exoplanets detection: coming new features

    OpenAIRE

    Baluev, Roman V.

    2014-01-01

    We briefly overview the new features of PlanetPack2, the forthcoming update of PlanetPack, which is a software tool for exoplanets detection and characterization from Doppler radial velocity data. Among other things, this major update brings parallelized computing, new advanced models of the Doppler noise, handling of the so-called Keplerian periodogram, and routines for transits fitting and transit timing variation analysis.

  8. Asteroseismic determination of obliquities of the exoplanet systems kepler-50 and kepler-65

    DEFF Research Database (Denmark)

    Chaplin, W.J.; Campante, T.L.; Davies, G.R.; Elsworth, Y.; Hekker, S.; Miglio, A.; Sanchis-Ojeda, R.; Winn, J.N.; Handberg, Rasmus; Christensen-Dalsgaard, Jørgen; Karoff, Christoffer; Kjeldsen, Helle Møgelmose; Lund, M.N.; Lundkvist, Mia; Stello, D.; Bedding, T.R.; Basu, S.; Fischer, D.A.; Metcalfe, T.S.; Buchhave, L.A.; Cochran, W.D.; Gilliland, R.L.; Huber, D.; Barclay, T.; Lissauer, J.J.; Isaacson, H.; Marcy, G.W.; Kawaler, S.D.; Latham, D.W.

    2013-01-01

    Results on the obliquity of exoplanet host stars - the angle between the stellar spin axis and the planetary orbital axis - provide important diagnostic information for theories describing planetary formation. Here we present the first application of asteroseismology to the problem of stellar obliquity determination in systems with transiting planets and Sun-like host stars. We consider two systems observed by the NASA Kepler mission which have multiple transiting small (super-Earth sized) plane...

  9. Transient Sulfate Aerosols as a Signature of Exoplanet Volcanism.

    Science.gov (United States)

    Misra, Amit; Krissansen-Totton, Joshua; Koehler, Matthew C; Sholes, Steven

    2015-06-01

    Geological activity is thought to be important for the origin of life and for maintaining planetary habitability. We show that transient sulfate aerosols could be a signature of exoplanet volcanism and therefore of a geologically active world. A detection of transient aerosols, if linked to volcanism, could thus aid in habitability evaluations of the exoplanet. On Earth, subduction-induced explosive eruptions inject SO2 directly into the stratosphere, leading to the formation of sulfate aerosols with lifetimes of months to years. We demonstrate that the rapid increase and gradual decrease in sulfate aerosol loading associated with these eruptions may be detectable in transit transmission spectra with future large-aperture telescopes, such as the James Webb Space Telescope (JWST) and European Extremely Large Telescope (E-ELT), for a planetary system at a distance of 10 pc, assuming an Earth-like atmosphere, bulk composition, and size. Specifically, we find that a signal-to-noise ratio of 12.1 and 7.1 could be achieved with E-ELT (assuming photon-limited noise) for an Earth analogue orbiting a Sun-like star and M5V star, respectively, even without multiple transits binned together. We propose that the detection of this transient signal would strongly suggest an exoplanet volcanic eruption, if potential false positives such as dust storms or bolide impacts can be ruled out. Furthermore, because scenarios exist in which O2 can form abiotically in the absence of volcanic activity, a detection of transient aerosols that can be linked to volcanism, along with a detection of O2, would be a more robust biosignature than O2 alone. PMID:26053611

  10. Keplerian Orbits and Dynamics of Exoplanets

    OpenAIRE

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

    2010-01-01

    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.

  11. Deciphering Spectral Fingerprints of Habitable Exoplanets

    OpenAIRE

    Kaltenegger, Lisa; Selsis, Frank; Fridlund, Malcolm; Lammer, Helmut; Beichman, Charles; Danchi, William; Eiroa, Carlos; Henning, Thomas; Herbst, Tom; Léger, Alain; Liseau, René; Lunine, Jonathan; Paresce, Francesco; Penny, Alan; Quirrenbach, Andreas

    2010-01-01

    We discuss how to read a planet's spectrum to assess its habitability and search for the signatures of a biosphere. After a decade rich in giant exoplanet detections, observation techniques have advanced to a level where we now have the capability to find planets of less than 10 Earth masses (MEarth) (so-called "super Earths"), which may be habitable. How can we characterize those planets and assess whether they are habitable? This new field of exoplanet search has shown an extraordinary c...

  12. Atmospheric Chemistry of Venus-like Exoplanets

    OpenAIRE

    Schaefer, Laura; Fegley Jr, Bruce

    2010-01-01

    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 ...

  13. Mapping Directly Imaged Giant Exoplanets

    CERN Document Server

    Kostov, Veselin B

    2012-01-01

    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. We address and discuss the following questions: a) 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, spot spectra; b) what is the optimal configuration of instrument/wavelen...

  14. The LEECH Exoplanet Imaging Survey: Characterization of the Coldest Directly Imaged Exoplanet, GJ 504 b, and Evidence for Super-Stellar Metallicity

    CERN Document Server

    Skemer, Andrew J; Zimmerman, Neil T; Skrutskie, Michael F; Leisenring, Jarron; Buenzli, Esther; Bonnefoy, Mickael; Bailey, Vanessa; Hinz, Philip; Defrére, Denis; Esposito, Simone; Apai, Dániel; Biller, Beth; Brandner, Wolfgang; Close, Laird; Crepp, Justin R; De Rosa, Robert J; Desidera, Silvano; Eisner, Josh; Fortney, Jonathan; Freedman, Richard; Henning, Thomas; Hofmann, Karl-Heinz; Kopytova, Taisiya; Lupu, Roxana; Maire, Anne-Lise; Males, Jared R; Marley, Mark; Morzinski, Katie; Oza, Apurva; Patience, Jenny; Rajan, Abhijith; Rieke, George; Schertl, Dieter; Schlieder, Joshua; Stone, Jordan; Su, Kate; Vaz, Amali; Visscher, Channon; Ward-Duong, Kimberly; Weigelt, Gerd; Woodward, Charles E

    2015-01-01

    As gas giant planets and brown dwarfs radiate away the residual heat from their formation, they cool through a spectral type transition from L to T, which encompasses the dissipation of cloud opacity and the appearance of strong methane absorption. While there are hundreds of known T-type brown dwarfs, the first generation of directly-imaged exoplanets were all L-type. Recently, Kuzuhara et al. (2013) announced the discovery of GJ 504 b, the first T dwarf exoplanet. GJ 504 b provides a unique opportunity to study the atmosphere of a new type of exoplanet with a ~500 K temperature that bridges the gap between the first directly imaged planets (~1000 K) and our own Solar System's Jupiter (~130 K). We observed GJ 504 b in three narrow L-band filters (3.71, 3.88, and 4.00 microns), spanning the red end of the broad methane fundamental absorption feature (3.3 microns) as part of the LEECH exoplanet imaging survey. By comparing our new photometry and literature photometry to a grid of custom model atmospheres, we w...

  15. A Posteriori Transit Probabilities

    Science.gov (United States)

    Stevens, Daniel J.; Gaudi, B. Scott

    2013-08-01

    Given the radial velocity (RV) detection of an unseen companion, it is often of interest to estimate the probability that the companion also transits the primary star. Typically, one assumes a uniform distribution for the cosine of the inclination angle i of the companion's orbit. This yields the familiar estimate for the prior transit probability of ~Rlowast/a, given the primary radius Rlowast and orbital semimajor axis a, and assuming small companions and a circular orbit. However, the posterior transit probability depends not only on the prior probability distribution of i but also on the prior probability distribution of the companion mass Mc, given a measurement of the product of the two (the minimum mass Mc sin i) from an RV signal. In general, the posterior can be larger or smaller than the prior transit probability. We derive analytic expressions for the posterior transit probability assuming a power-law form for the distribution of true masses, dΓ/dMcvpropMcα, for integer values -3 =0, and can be arbitrarily small for α > 1. We also calculate the posterior transit probability in different mass regimes for two physically-motivated mass distributions of companions around Sun-like stars. We find that for Jupiter-mass planets, the posterior transit probability is roughly equal to the prior probability, whereas the posterior is likely higher for Super-Earths and Neptunes (10 M⊕ - 30 M⊕) and Super-Jupiters (3 MJup - 10 MJup), owing to the predicted steep rise in the mass function toward smaller masses in these regimes. We therefore suggest that companions with minimum masses in these regimes might be better-than-expected targets for transit follow-up, and we identify promising targets from RV-detected planets in the literature. Finally, we consider the uncertainty in the transit probability arising from uncertainties in the input parameters, and the effect of ignoring the dependence of the transit probability on the true semimajor axis on i.

  16. How Many Exoplanets Does it Take to Constrain the Origin of Mercury?

    Science.gov (United States)

    Rogers, Leslie

    2016-01-01

    The origin of Mercury's enhanced iron content is a matter of ongoing debate. The characterization of rocky exoplanets promises to provide new independent insights on this topic by constraining the occurrence rate and physical and orbital properties of iron-enhanced planets orbiting distant stars. The ultra-short-period transiting planet candidate KOI-1843.03 (0.6 Earth-radius, 4.245 hour orbital period) represents the first exo-Mercury planet candidate ever identified. For KOI-1843.03 to have avoided tidal disruption on such a short orbit, it must have a mean density of at least 7g/cc and be at least as iron rich as Mercury (Rappaport et al. 2013). In contrast, Dressing et al. (2015) have noted that, to date, all confirmed transiting small (planet interior structure models. In addition to deriving constraints on the distribution of iron-enhanced exo-Mercuries from the exoplanet mass-radius measurements in hand, we also apply this approach to simulated data sets to predict how the constraints should improve as increasing numbers of exoplanets are characterized. The work outlines an observational pathway toward using exoplanets to place Mercury into context.

  17. A New Analysis of the Exoplanet Hosting System HD 6434

    Science.gov (United States)

    Hinkel, Natalie R.; Kane, Stephen R.; Pilyavsky, Genady; Boyajian, Tabetha S.; James, David J.; Naef, Dominique; Fischer, Debra A.; Udry, Stephane

    2015-12-01

    The current goal of exoplanetary science is not only focused on detecting but characterizing planetary systems in hopes of understanding how they formed, evolved, and relate to the solar system. The Transit Ephemeris Refinement and Monitoring Survey (TERMS) combines both radial velocity (RV) and photometric data in order to achieve unprecedented ground-based precision in the fundamental properties of nearby, bright, exoplanet-hosting systems. Here we discuss HD 6434 and its planet, HD 6434b, which has a Mp sin i = 0.44 MJ mass and orbits every 22.0170 days with an eccentricity of 0.146. We have combined previously published RV data with new measurements to derive a predicted transit duration of ?6 hr, or 0.25 days, and a transit probability of 4%. Additionally, we have photometrically observed the planetary system using both the 0.9 and 1.0 m telescopes at the Cerro Tololo Inter-American Observatory, covering 75.4% of the predicted transit window. We reduced the data using the automated TERMS Photometry Pipeline, developed to ensure consistent and accurate results. We determine a dispositive null result for the transit of HD 6434b, excluding the full transit to a depth of 0.9% and grazing transit due to impact parameter limitations to a depth of 1.6%.

  18. 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

  19. Earth as an Exoplanet: Lessons in Recognizing Planetary Habitability

    Science.gov (United States)

    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

    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.

  20. Benchmarking the power of amateur observatories for TTV exoplanets detection

    Science.gov (United States)

    Baluev, Roman V.; Sokov, Evgenii N.; Shaidulin, Vakhit Sh.; Sokova, Iraida A.; Jones, Hugh R. A.; Tuomi, Mikko; Anglada-Escudé, Guillem; Benni, Paul; Colazo, Carlos A.; Schneiter, Matias E.; D'Angelo, Carolina S. Villarreal; Burdanov, Artem Yu.; Fernández-Lajús, Eduardo; Ba?türk, Özgür; Hentunen, Veli-Pekka; Shadick, Stan

    2015-07-01

    We perform an analysis of ˜80 000 photometric measurements for the following 10 stars hosting transiting planets: WASP-2, -4, -5, -52, Kelt-1, CoRoT-2, XO-2, TrES-1, HD 189733, GJ 436. Our analysis includes mainly transit light curves from the Exoplanet Transit Database, public photometry from the literature, and some proprietary photometry privately supplied by other authors. Half of these light curves were obtained by amateurs. From this photometry we derive 306 transit timing measurements, as well as improved planetary transit parameters. Additionally, for 6 of these 10 stars we present a set of radial velocity measurements obtained from the spectra stored in the HARPS, HARPS-N and SOPHIE archives using the HARPS-TERRA pipeline. Our analysis of these transit timing and radial velocity data did not reveal significant hints of additional orbiting bodies in almost all of the cases. In the WASP-4 case, we found hints of marginally significant TTV signals having amplitude 10-20 s, although their parameters are model dependent and uncertain, while radial velocities did not reveal statistically significant Doppler signals.

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

    CERN Document Server

    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

    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...

  2. 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

    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

    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...

  3. Optical Phase Curves of Kepler Exoplanets

    Science.gov (United States)

    Esteves, Lisa J.; De Mooij, Ernst J. W.; Jayawardhana, Ray

    2013-07-01

    We conducted a comprehensive search for optical phase variations of all close-in (a/R sstarf space telescope data. After correcting for systematics, we found eight systems that show secondary eclipses as well as phase variations. Of these, five (Kepler-5, Kepler-6, Kepler-8, KOI-64, and KOI-2133) are new and three (TrES-2, HAT-P-7, and KOI-13) have published phase curves, albeit with many fewer observations. We model the full phase curve of each planet candidate, including the primary and secondary transits, and derive their albedos, dayside and nightside temperatures, ellipsoidal variations, and Doppler beaming. We find that KOI-64 and KOI-2133 have nightside temperatures well above their equilibrium values (while KOI-2133 also has an albedo, >1), so we conclude that they are likely to be self-luminous objects rather than planets. The other six candidates have characteristics consistent with their being planets with low geometric albedos (probe atmospheric layers hotter than the planet's equilibrium temperature. For KOI-13, we detect a never-before-seen third cosine harmonic with an amplitude of 6.7 ± 0.3 ppm and a phase shift of -1.1 ± 0.1 rad in the phase curve residual, possibly due to its spin-orbit misalignment. We report derived planetary parameters for all six planets, including masses from ellipsoidal variations and Doppler beaming, and compare our results to published values when available. Our results nearly double the number of Kepler exoplanets with measured phase curve variations, thus providing valuable constraints on the properties of hot Jupiters.

  4. 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

    OpenAIRE

    Christiansen, Jessie L; Ballard, Sarah; 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.; Carey M. Lisse; A'Hearn, Michael F.

    2010-01-01

    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 R[subscript p] = 1.332 ± 0.052 R [subscript Jup], the stellar radius R [subscript ?]= 1.602 ± 0.061 R [subscrip...

  5. 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.

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

    CERN Document Server

    Hu, Renyu

    2014-01-01

    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...

  7. A Temperature and Abundance Retrieval Method for Exoplanet Atmospheres

    CERN Document Server

    Madhusudhan, N

    2009-01-01

    We present a new method to retrieve molecular abundances and temperature profiles from exoplanet atmosphere photometry and spectroscopy. We run millions of 1D atmosphere models in order to cover the large range of allowed parameter space, and present error contours in the atmospheric properties, given the data. 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. We apply our temperature and abundance retrieval method to the atmospheres of two transiting exoplanets, HD 189733b and HD 209458b, which have the best available Spitzer and HST observations. For HD 189733b, we find efficient day-night redistribution 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 da...

  8. Mapping the Distributions of Exoplanet Populations with NICI and GPI

    Science.gov (United States)

    Nielsen, Eric L.; Liu, Michael C.; Wahhaj, Zahed; Biller, Beth A.; Hayward, Thomas L.; Close, Laird M.; Close; Macintosh, Bruce; Savransky, Dmitry; Wang, Jason J.; Graham, James R.; De Rosa, Robert J.; Rajan, Abhijith; Rajan

    2016-01-01

    While more and more long-period giant planets are discovered by direct imaging, the distribution of planets at these separations (>~5 AU) has remained largely uncertain, especially compared to planets in the inner regions of solar systems probed by RV and transit techniques. The low frequency, the detection challenges, and heterogeneous samples make determining the mass and orbit distributions of directly imaged planets at the end of a survey difficult. By utilizing Monte Carlo methods that incorporate the age, distance, and spectral type of each target, we can use all stars in the survey, not just those with detected planets, to learn about the underlying population. We have produced upper limits and direct measurements of the frequency of these planets with the most recent generation of direct imaging surveys. The Gemini NICI Planet-Finding Campaign observed 220 young, nearby stars at a median H-band contrast of 14.5 magnitudes at 1'', representing the largest, deepest search for exoplanets by the completion of the survey. The Gemini Planet Imager Exoplanet Survey is in the process of surveying 600 stars, pushing these contrasts to a few tenths of an arcsecond from the star. With the advent of large surveys (many hundreds of stars) using advanced planet-imagers we gain the ability to move beyond measuring the frequency of wide-separation giant planets and to simultaneously determine the distribution as a function of planet mass, semi-major axis, and stellar mass, and so directly test models of planet formation and evolution.

  9. A Search for Ringed Exoplanets using Kepler Photometry

    CERN Document Server

    Heising, Matthew Z; Schlichting, Hilke E

    2015-01-01

    Models are developed to simulate lightcurves of stars dimmed by transiting exoplanets with and without rings. These models are then applied to \\textit{Kepler} photometry to search for planetary rings in a sample of 21 exoplanets, mostly hot Jupiters, chosen to offer the best observational opportunity for discovering potential rings. We also examine what kinds of rings might be expected for these planets, in terms of both size and orientation, based on arguments involving the host planet's equilibrium temperature, its likely obliquities, and the formation and stability of possible ring systems. Finding no evidence for rings, for each of the 21 studied planets it is determined on an observational basis which potential rings can be rejected out of a representative set of fiducial rings, varying in both size and orientation. For 12 of the 21 planets, we determined that Saturn-like rings could be ruled out for at least certain orientations. Additionally, the detectability of rings is studied, and it is found that ...

  10. The Ultraviolet Radiation Environment Around M dwarf Exoplanet Host Stars

    CERN Document Server

    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

    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...

  11. Transient Sulfate Aerosols as a Signature of Exoplanet Volcanism

    CERN Document Server

    Misra, Amit; Koehler, Matthew C; Sholes, Steven

    2015-01-01

    Geological activity is thought to be important for the origin of life and for maintaining planetary habitability. We show that transient sulfate aerosols could be a signature of exoplanet volcanism, and therefore a geologically active world. A detection of transient aerosols, if linked to volcanism, could thus aid in habitability evaluations of the exoplanet. On Earth, subduction-induced explosive eruptions inject SO2 directly into the stratosphere, leading to the formation of sulfate aerosols with lifetimes of months to years. We demonstrate that the rapid increase and gradual decrease in sulfate aerosol loading associated with these eruptions may be detectable in transit transmission spectra with future large-aperture telescopes, such as the James Webb Space Telescope (JWST) and European Extremely-Large Telescope (E-ELT) for a planetary system at a distance of 10 pc, assuming an Earth-like atmosphere, bulk composition, and size. Specifically, we find that a S/N of 12.1 and 7.1 could be achieved with E-ELT (...

  12. A lucky imaging multiplicity study of exoplanet host stars II

    CERN Document Server

    Ginski, C; Seeliger, M; Buder, S; Errmann, R; Avenhaus, H; Mouillet, D; Maire, A -L; Raetz, S

    2016-01-01

    The vast majority of extrasolar planets are detected by indirect detection methods such as transit monitoring and radial velocity measurements. While these methods are very successful in detecting short-periodic planets, they are mostly blind to wide sub-stellar or even stellar companions on long orbits. In our study we present high resolution imaging observations of 63 exoplanet hosts carried out with the lucky imaging instrument AstraLux at the Calar Alto 2.2m telescope as well as with the new SPHERE high resolution adaptive optics imager at the ESO/VLT in the case of a known companion of specific interest. Our goal is to study the influence of stellar multiplicity on the planet formation process. We detected and confirmed 4 previously unknown stellar companions to the exoplanet hosts HD197037, HD217786, Kepler-21 and Kepler-68. In addition, we detected 11 new low-mass stellar companion candidates which must still be confirmed as bound companions. We also provide new astrometric and photometric data points ...

  13. Frontiers of Exoplanet Atmosphere Characterization

    Science.gov (United States)

    Kreidberg, Laura

    2016-01-01

    Exoplanet atmosphere characterization has the potential to reveal the origins, nature, and even habitability of distant worlds. In this dissertation talk, I will present work that is a step toward realizing that potential for a diverse group of four extrasolar planets. I will discuss the results of intensive observational campaigns with the Hubble and Spitzer Space Telescopes to study the atmospheres of the super-Earth GJ 1214b and the hot Jupiters WASP-43b, WASP-12b, and WASP-103b. For GJ 1214b, I measured an unprecedentedly precise near-infrared transmission spectrum that definitively reveals the presence of clouds in the planet's atmosphere. For WASP-43b and WASP-12b, I also obtained very precise spectra. These exhibit water features at high confidence (>7 sigma). The retrieved water abundance for WASP-43b extends the well-known Solar System trend of decreasing atmospheric metallicity with increasing planet mass. The detection of water for WASP-12b marks the first spectroscopic identification of a molecule in the planet's atmosphere and implies that it has solar composition, ruling out carbon-to-oxygen ratios greater than unity. For WASP-103b, I will present preliminary results from the new technique of phase-resolved spectroscopy that constrain the planet's temperature structure, dynamics, and energy budget. Taken together, these results provide a foundation for comparative planetology beyond the Solar System and the investigation of Earth-like, potentially habitable planets with future observing facilities.

  14. 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 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.

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

    Science.gov (United States)

    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

    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.

  16. Young Brown Dwarfs as Giant Exoplanets Analogs

    Science.gov (United States)

    Faherty, Jacqueline; Cruz, Kelle; Rice, Emily; Riedel, Adric

    2013-07-01

    Young brown dwarfs and directly-imaged exoplanets have enticingly similar photometric, spectroscopic, and luminosity characteristics, indicating that their cool, low gravity atmospheres should be studied in concert. We have identified, confirmed, and characterized several new young M and L type brown dwarfs (see Faherty et al. 2013) and compared them to directly-imaged planetary mass companions and exoplanets like 2MASS 1207b and HR8799b. Similarities between the peculiar shaped H band and location on near-IR color magnitude diagrams provide important clues about how to extract physical properties of planets from current brown dwarf observations. In this poster I present a sample of age-calibrated young brown dwarfs that form the basis for comparative brown-dwarf exoplanet studies

  17. Constraining Exoplanet Mass from Transmission Spectroscopy

    CERN Document Server

    de Wit, Julien

    2014-01-01

    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.

  18. A search for transit timing variation

    CERN Document Server

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

    2010-01-01

    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.

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

    DEFF Research Database (Denmark)

    Guenther, E. W.; Díaz, R. F.; 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.; Bordé, 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.; Hébrard, G.; Jehin, E.; Jorda, L.; Lammer, H.; Léger, A.; Moutou, C.; Nortmann, L.; Ollivier, M.; Ofir, A.; Pasternacki, Th.; Pätzold, M.; Parviainen, H.; Queloz, D.; Rauer, H.; Samuel, B.; Santerne, A.; Schneider, J.; Tal-Or, L.; Tingley, B.; Weingrill, J.; Wuchterl, G.

    2012-01-01

    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 prec...

  20. Using the Inclinations of Kepler Systems to Prioritize New Titius-Bode-Based Exoplanet Predictions

    OpenAIRE

    Bovaird, Timothy; Lineweaver, Charles H.; Jacobsen, Steffen K.

    2014-01-01

    We analyze a sample of multiple-exoplanet systems which contain at least 3 transiting planets detected by the Kepler mission ("Kepler multiples"). We use a generalized Titius-Bode relation to predict the periods of 228 additional planets in 151 of these Kepler multiples. These Titius-Bode-based predictions suggest that there are, on average, ~2 planets in the habitable zone of each star. We estimate the inclination of the invariable plane for each system and prioritize our p...

  1. Detecting industrial pollution in the atmospheres of earth-like exoplanets

    OpenAIRE

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

    2014-01-01

    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...

  2. 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.

  3. Key Challenges for Exoplanet Biosignature Gas Studies

    Science.gov (United States)

    Seager, S.

    2014-03-01

    Biosignature gases are gases emitted by life that can accumulate in an exoplanet atmosphere to remotely detectable levels by future space telescopes. Until now, the dominant focus has been on Earth-like planets, because Earth is the only known planet with life. Yet exoplanets are astonishingly diverse--in terms of their masses, densities, orbits, and host star types--and this diversity motivates a radical extension of what conventionally constitutes a habitable planet. By building a general framework with which to understand a wide range of plausible biosignature gases, we will increase our chances of identifying inhabited worlds.

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

    CERN Document Server

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

    2015-01-01

    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...

  5. Possible climates on terrestrial exoplanets.

    Science.gov (United States)

    Forget, F; Leconte, J

    2014-04-28

    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

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

    Science.gov (United States)

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

    2014-07-01

    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.

  7. Massive Satellites of Close-In Gas Giant Exoplanets

    CERN Document Server

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

    2009-01-01

    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 gravity induces significant periodic eccentricity in the satellite's orbit. The resulting tidal heating rates, per unit mass, are far in excess of Io's and dominate radioactive heating out to planet orbital periods of months for reasonable satellite tidal $Q$. Inside planet orbital periods of about a week, tidal heating can completely melt the satellite. Lastly, we compute an upper limit to the satellite mass loss rate due to thermal evaporation from the surface, valid if the satellite's atmosphere is thin and vapor pressure is negligible. ...

  8. Dynamical measurements of the interior structure of exoplanets

    International Nuclear Information System (INIS)

    Giant gaseous planets often reside on orbits in sufficient proximity to their host stars for the planetary quadrupole gravitational field to become non-negligible. In presence of an additional planetary companion, a precise characterization of the system's orbital state can yield meaningful constraints on the transiting planet's interior structure. However, such methods can require a very specific type of system. This paper explores the dynamic range of applicability of these methods and shows that interior structure calculations are possible for a wide array of orbital architectures. The HAT-P-13 system is used as a case study, and the implications of perturbations arising from a third distant companion on the feasibility of an interior calculation are discussed. We find that the method discussed here is likely to be useful in studying other planetary systems, allowing the possibility of an expanded survey of the interiors of exoplanets.

  9. Dynamical Measurements of the Interior Structure of Exoplanets

    CERN Document Server

    Becker, Juliette C

    2013-01-01

    Giant gaseous planets often reside on orbits in sufficient proximity to their host stars for the planetary quadrupole gravitational field to become non-negligible. In presence of an additional planetary companion, a precise characterization of the system's orbital state can yield meaningful constraints on the transiting planet's interior structure. However, such methods can require a very specific type of system. This paper explores the dynamic range of applicability of these methods and shows that interior structure calculations are possible for a wide array of orbital architectures. The HAT-P-13 system is used as a case study, and the implications of perturbations arising from a third distant companion on the feasibility of an interior calculation are discussed. We find that the method discussed here is likely to be useful in studying other planetary systems, allowing the possibility of an expanded survey of the interiors of exoplanets.

  10. Dynamical measurements of the interior structure of exoplanets

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Juliette C. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 (United States); Batygin, Konstantin, E-mail: jbecker@caltech.edu [Institute for Theory and Computation, Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA (United States)

    2013-12-01

    Giant gaseous planets often reside on orbits in sufficient proximity to their host stars for the planetary quadrupole gravitational field to become non-negligible. In presence of an additional planetary companion, a precise characterization of the system's orbital state can yield meaningful constraints on the transiting planet's interior structure. However, such methods can require a very specific type of system. This paper explores the dynamic range of applicability of these methods and shows that interior structure calculations are possible for a wide array of orbital architectures. The HAT-P-13 system is used as a case study, and the implications of perturbations arising from a third distant companion on the feasibility of an interior calculation are discussed. We find that the method discussed here is likely to be useful in studying other planetary systems, allowing the possibility of an expanded survey of the interiors of exoplanets.

  11. Multi Epoch Multi-purpose Exoplanet Simulation System (MESS2)

    Science.gov (United States)

    Lannier, Justine

    2015-08-01

    For 2 decades, surveys for giant planets have produced the acquisition data of various kind (via transits, direct imaging (DI) or radial velocity technic (RV)). Also, some stars have been observed several times using at least one detection method. The final purpose of these surveys (RV and DI) is to better understand the formation of giant planets (GPs) at short and long separations, for different stellar spectral type, and various initial conditions. Statistical studies are then primordial to bring constraints on the planetary formation scenarios. Combining all the available data (RV and/or DI) represents a more robust approach to bring these constraints since it considers the overall available data. Multi Epoch Multi-purpose Exoplanet Simulation System (MESS2, an advanced version of MESS (Bonavita et al. 2012)) is a powerful statistical tool used for multiple epochs of DI and RV observations. It is a Monte Carlo code based on Bayesian methods.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  13. Asteroseismology of Exoplanet-Host Stars in the TESS Era

    Science.gov (United States)

    Campante, Tiago L.; Schofield, Mathew; Chaplin, William J.; Huber, Daniel; Christensen-Dalsgaard, Jørgen; Kjeldsen, Hans; Latham, David W.; Ricker, George R.; Winn, Joshua

    2015-12-01

    New insights on stellar evolution and stellar interiors physics are being made possible by asteroseismology, the study of stars by the observation of their natural, resonant oscillations. Throughout the duration of the Kepler mission, asteroseismology has also played an important role in the characterization of host stars and their planetary systems. Examples include the precise estimation of the fundamental properties of stellar hosts, the obliquity determination of planetary systems, or the orbital eccentricity determination via asterodensity profiling. The Transiting Exoplanet Survey Satellite (TESS) will perform a wide-field survey for planets that transit bright host stars. Its excellent photometric precision and long intervals of uninterrupted observations will enable asteroseismology of solar-type stars and their evolved counterparts. Based on existing all-sky simulations of the stellar and planetary populations, we investigate the asteroseismic yield of the mission, placing particular emphasis on the yield of exoplanet-host stars for which we expect to detect solar-like oscillations. This is done both for the cohort of target stars (observed at a 2-min cadence), which will mainly involve low-mass main-sequence hosts, as well as for the cohort of “full-frame image” stars (observed at a 30-min cadence). The latter cohort offers the exciting prospect of conducting asteroseismology on a significant number of evolved hosts. Also, the brightest solar-type hosts with asteroseismology will become some of the best characterized planetary systems known to date. Finally, we discuss the impact of the detected oscillations on the accuracy/precision of the derived properties of the host stars and their planetary systems.

  14. A New Analysis of the Exoplanet Hosting System HD 6434

    CERN Document Server

    Hinkel, Natalie R; Pilyavsky, Genady; Boyajian, Tabetha S; James, David J; Naef, Dominique; Fischer, Debra A; Udry, Stephane

    2015-01-01

    The current goal of exoplanetary science is not only focused on detecting but characterizing planetary systems in hopes of understanding how they formed, evolved, and relate to the Solar System. The Transit Ephemeris Refinement and Monitoring Survey (TERMS) combines both radial velocity (RV) and photometric data in order to achieve unprecedented ground-based precision in the fundamental properties of nearby, bright, exoplanet-hosting systems. Here we discuss HD 6434 and its planet, HD 6434b, which has a M_p*sin(i) = 0.44 M_J mass and orbits every 22.0170 days with an eccentricity of 0.146. We have combined previously published RV data with new measurements to derive a predicted transit duration of ~6 hrs, or 0.25 days, and a transit probability of 4%. Additionally, we have photometrically observed the planetary system using both the 0.9m and 1.0m telescopes at the Cerro Tololo Inter-American Observatory, covering 75.4% of the predicted transit window. We reduced the data using the automated TERMS Photometry P...

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

    Science.gov (United States)

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

    2015-12-01

    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.

  16. Technology for radial velocity search and characterisation of exoplanets in the 2020s and beyond

    Science.gov (United States)

    Ireland, Michael; Feger, Tobias; Bento, Joao; Rains, Adam

    2015-12-01

    In the past 20 years, radial velocity exoplanet instrumentation has been focussed on a small number of moderate sized (or moderate efficiency) telescopes. I will argue that there are two very different uses for radial velocity in the near future: transit follow-up and low-mass exoplanet detection around relatively nearby stars. For the first of these science goals, targets are relatively distant, and a high eficiency spectrograph on a large telescope is needed, for example the Gemini High-resolution Optical SpecTrograph (GHOST): a stabilised spectrograph fed by an array of multi-mode fibers at the final design stage. For the second of these goals, stellar noise due to pulsations, convective cells and activity provide a lower limit to the noise floor achievable for any given temporal sampling. I will argue through simple simulations that an array of small telescopes with precise spectrographs making a very large number of measurements is a much more effective way to detect the smallest exoplanets than instrumentation on large telescopes. I will describe the first results from the Replicable High-Resoluition Exoplanet and Asteroseismology (RHEA) spectrograph designed for 0.25 to 0.5m telescopes, which has single-epoch measurement uncertainties at the 1 m/s level and a total whole cost for detecting the smallest exoplanets that is significantly lower than medium to large telescope concepts. RHEA has an eyepiece-sized fast tip/tilt and mode reformatting system that efficiently injects a small array of single-mode fibers, feeding a <0.5m sized stabilised inexpensive spectrograph. I will show preliminary performance results from both stars and laboratory tests that verify the precision, and will discuss pathways to turn this into a broader community project.

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

    CERN Document Server

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

    2015-01-01

    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...

  18. Microphysics of Exoplanet Clouds and Hazes

    Science.gov (United States)

    Gao, Peter; Benneke, Björn; Knutson, Heather; Yung, Yuk

    2016-01-01

    Clouds and hazes are ubiquitous in the atmospheres of exoplanets. However, as most of these planets have temperatures between 600 and 2000 K, their clouds and hazes are likely composed of exotic condensates such as silicates, metals, and salts. We currently lack a satisfactory understanding of the microphysical processes that govern the distribution of these clouds and hazes, thus creating a gulf between the cloud properties retrieved from observations and the cloud composition predictions from condensation equilibrium models. In this work we present a 1D microphysical cloud model that calculates, from first principles, the rates of condensation, evaporation, coagulation, and vertical transport of chemically mixed cloud and haze particles in warm and hot exoplanet atmospheres. The model outputs the equilibrium number density of cloud particles with altitude, the particle size distribution, and the chemical makeup of the cloud particles as a function of altitude and particle mass. The model aims to (1) explain the observed variability in "cloudiness" of individual exoplanets, (2) assess whether the proposed cloud materials are capable of forming the observed particle distributions, and (3) examine the role clouds have in the transport of (cloud-forming) heavy elements in exoplanet atmospheres.

  19. Microphysics of Exoplanet Clouds and Hazes

    Science.gov (United States)

    Gao, Peter; Benneke, Björn; Knutson, Heather A.; Yung, Yuk L.

    2015-11-01

    Clouds and hazes are ubiquitous in the atmospheres of exoplanets. However, as most of these planets have temperatures between 600 and 2000 K, their clouds and hazes are likely composed of exotic condensates such as silicates, metals, and salts. We currently lack a satisfactory understanding of the microphysical processes that govern the distribution of these clouds and hazes, thus creating a gulf between the cloud properties retrieved from observations and the cloud composition predictions from condensation equilibrium models. In this work we present a 1D microphysical cloud model that calculates, from first principles, the rates of condensation, evaporation, coagulation, and vertical transport of chemically mixed cloud and haze particles in warm and hot exoplanet atmospheres. The model outputs the equilibrium number density of cloud particles with altitude, the particle size distribution, and the chemical makeup of the cloud particles as a function of altitude and particle mass. The model aims to (1) explain the observed variability in “cloudiness” of individual exoplanets, (2) assess whether the proposed cloud materials are capable of forming the observed particle distributions, and (3) examine the role clouds have in the transport of (cloud-forming) heavy elements in exoplanet atmospheres.

  20. Report on the ''Chilean Exoplanet Meeting''

    Science.gov (United States)

    Sedaghati, E.; Boffin, H.

    2015-09-01

    The contribution of the Chilean scientific community to the field of exoplanetary research has been crucial in advancing our understanding of this relatively new discipline of astronomy. In order to highlight these achievements, present current areas of research and instrumentation development, and foster further collaborations, a one-day exoplanet focus meeting was organised at ESO Vitacura. A summary of the meeting is presented.

  1. LEECH: LBTI Exozodi Exoplanet Common Hunt

    Science.gov (United States)

    Skemer, A.

    2014-03-01

    In Spring 2013, the LEECH (LBTI Exozodi Exoplanet Common Hunt) survey began its 100-night campaign from the Large Binocular Telescope (LBT) atop Mt Graham, Arizona. This survey benefits from the many technological achievements of the LBT, including two 8.4- meter mirrors on a single fixed mount, dual adaptive secondary mirrors for high Strehl performance, and a cold beam combiner to dramatically reducing the telescope's overall background emissivity. LEECH neatly complements other high-contrast planet imaging efforts by observing stars at L' (3.8 microns) with LMIRcam, as opposed to the shorter wavelength near-infrared bands (1-2.4 microns) of other similar surveys. This portion of the spectrum offers deeper mass sensitivity for intermediate age (several hundred Myr-old) systems, since their Jovian-mass planets radiate predominantly in the mid-infrared. The goals of LEECH are to (1) discover new exoplanets, (2) characterize the atmospheres of newly discovered exoplanets, (3) characterize the architectures of nearby planetary systems, and (4) establish meaningful constraints on the prevalence of wideseparation exoplanets.

  2. Microphysics of Exoplanet Clouds and Hazes

    Science.gov (United States)

    Gao, Peter; Benneke, Björn; Knutson, Heather; Yung, Yuk

    2015-12-01

    Clouds and hazes are ubiquitous in the atmospheres of exoplanets. However, as most of these planets have temperatures between 600 and 2000 K, their clouds and hazes are likely composed of exotic condensates such as silicates, metals, and salts. We currently lack a satisfactory understanding of the microphysical processes that govern the distribution of these clouds and hazes, thus creating a gulf between the cloud properties retrieved from observations and the cloud composition predictions from condensation equilibrium models. In this work we present a 1D microphysical cloud model that calculates, from first principles, the rates of condensation, evaporation, coagulation, and vertical transport of chemically mixed cloud and haze particles in warm and hot exoplanet atmospheres. The model outputs the equilibrium number density of cloud particles with altitude, the particle size distribution, and the chemical makeup of the cloud particles as a function of altitude and particle mass. The model aims to (1) explain the observed variability in “cloudiness” of individual exoplanets, (2) assess whether the proposed cloud materials are capable of forming the observed particle distributions, and (3) examine the role clouds have in the transport of (cloud-forming) heavy elements in exoplanet atmospheres.

  3. The Transit Monitoring in the South (TraMoS project

    Directory of Open Access Journals (Sweden)

    López-Morales Mercedes

    2013-04-01

    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.

  4. Mapping Directly Imaged Giant Exoplanets

    Science.gov (United States)

    Kostov, Veselin; Apai, Dániel

    2013-01-01

    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 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.

  5. A giant comet-like cloud of hydrogen escaping the warm Neptune-mass exoplanet GJ 436b.

    Science.gov (United States)

    Ehrenreich, David; Bourrier, Vincent; Wheatley, Peter J; des Etangs, Alain Lecavelier; Hébrard, Guillaume; Udry, Stéphane; Bonfils, Xavier; Delfosse, Xavier; Désert, Jean-Michel; Sing, David K; Vidal-Madjar, Alfred

    2015-06-25

    Exoplanets orbiting close to their parent stars may lose some fraction of their atmospheres because of the extreme irradiation. Atmospheric mass loss primarily affects low-mass exoplanets, leading to the suggestion that hot rocky planets might have begun as Neptune-like, but subsequently lost all of their atmospheres; however, no confident measurements have hitherto been available. The signature of this loss could be observed in the ultraviolet spectrum, when the planet and its escaping atmosphere transit the star, giving rise to deeper and longer transit signatures than in the optical spectrum. Here we report that in the ultraviolet the Neptune-mass exoplanet GJ 436b (also known as Gliese 436b) has transit depths of 56.3 ± 3.5% (1?), far beyond the 0.69% optical transit depth. The ultraviolet transits repeatedly start about two hours before, and end more than three hours after the approximately one hour optical transit, which is substantially different from one previous claim (based on an inaccurate ephemeris). We infer from this that the planet is surrounded and trailed by a large exospheric cloud composed mainly of hydrogen atoms. We estimate a mass-loss rate in the range of about 10(8)-10(9) grams per second, which is far too small to deplete the atmosphere of a Neptune-like planet in the lifetime of the parent star, but would have been much greater in the past. PMID:26108854

  6. A giant comet-like cloud of hydrogen escaping the warm Neptune-mass exoplanet GJ 436b

    CERN Document Server

    Ehrenreich, David; Wheatley, Peter J; Etangs, Alain Lecavelier des; Hébrard, Guillaume; Udry, Stéphane; Bonfils, Xavier; Delfosse, Xavier; Désert, Jean-Michel; Sing, David K; Vidal-Madjar, Alfred

    2015-01-01

    Exoplanets orbiting close to their parent stars could lose some fraction of their atmospheres because of the extreme irradiation. Atmospheric mass loss primarily affects low-mass exoplanets, leading to suggest that hot rocky planets might have begun as Neptune-like, but subsequently lost all of their atmospheres; however, no confident measurements have hitherto been available. The signature of this loss could be observed in the ultraviolet spectrum, when the planet and its escaping atmosphere transit the star, giving rise to deeper and longer transit signatures than in the optical spectrum. Here we report that in the ultraviolet the Neptune-mass exoplanet GJ 436b (also known as Gliese 436b) has transit depths of 56.3 +/- 3.5% (1 sigma), far beyond the 0.69% optical transit depth. The ultraviolet transits repeatedly start ~2 h before, and end >3 h after the ~1 h optical transit, which is substantially different from one previous claim (based on an inaccurate ephemeris). We infer from this that the planet is su...

  7. 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)

    Ollivier, M.; Gillon, M.

    2012-01-01

    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.

  8. Transiting exoplanets from the CoRoT space mission XXVIII. CoRoT-33b, an object in the brown dwarf desert with 2:3 commensurability with its host star

    CERN Document Server

    Csizmadia, Sz; Gandolfi, G; Deleuil, M; Bouchy, M; Fridlund, M; Szabados, L; Parviainen, H; Cabrera, J; Aigrain, S; Alonso, R; Almenara, J M; Baglin, A; Bordé, P; Bonomo, A S; Deeg, H J; D?az, R F; Erikson, A; Ferraz-Mello, S; Santos, M Tadeu dos; Guenther, E W; Guillot, T; Grziwa, S; Hébrard, G; Klagyivik, P; Ollivier, M; Pätzold, M; Rauer, H; Rouan, D; Santerne, A; Schneider, J; Mazeh, T; Wuchterl, G; Carpano, S; Ofir, A

    2015-01-01

    We report the detection of a rare transiting brown dwarf with a mass of 59 M_Jup and radius of 1.1 R_Jup around the metal-rich, [Fe/H] = +0.44, G9V star CoRoT-33. The orbit is eccentric (e = 0.07) with a period of 5.82 d. The companion, CoRoT-33b, is thus a new member in the so-called brown dwarf desert. The orbital period is within 3% to a 3:2 resonance with the rotational period of the star. CoRoT-33b may be an important test case for tidal evolution studies. The true frequency of brown dwarfs close to their host stars (P < 10 d) is estimated to be approximately 0.2% which is about six times smaller than the frequency of hot Jupiters in the same period range. We suspect that the frequency of brown dwarfs declines faster with decreasing period than that of giant planets.

  9. Transiting exoplanets from the CoRoT space mission?. XXVIII. CoRoT-33b, an object in the brown dwarf desert with 2:3 commensurability with its host star

    Science.gov (United States)

    Csizmadia, Sz.; Hatzes, A.; Gandolfi, D.; Deleuil, M.; Bouchy, F.; Fridlund, M.; Szabados, L.; Parviainen, H.; Cabrera, J.; Aigrain, S.; Alonso, R.; Almenara, J.-M.; Baglin, A.; Bordé, P.; Bonomo, A. S.; Deeg, H. J.; Díaz, R. F.; Erikson, A.; Ferraz-Mello, S.; Tadeu dos Santos, M.; Guenther, E. W.; Guillot, T.; Grziwa, S.; Hébrard, G.; Klagyivik, P.; Ollivier, M.; Pätzold, M.; Rauer, H.; Rouan, D.; Santerne, A.; Schneider, J.; Mazeh, T.; Wuchterl, G.; Carpano, S.; Ofir, A.

    2015-12-01

    We report the detection of a rare transiting brown dwarf with a mass of 59 MJup and radius of 1.1 RJup around the metal-rich, [Fe/H] = +0.44, G9V star CoRoT-33. The orbit is eccentric (e = 0.07) with a period of 5.82 d. The companion, CoRoT-33b, is thus a new member in the so-called brown dwarf desert. The orbital period is within 3% to a 3:2 resonance with the rotational period of the star. CoRoT-33b may be an important test case for tidal evolution studies. The true frequency of brown dwarfs close to their host stars (P< 10 d) is estimated to be approximately 0.2% which is about six times smaller than the frequency of hot Jupiters in the same period range. We suspect that the frequency of brown dwarfs declines faster with decreasing period than that of giant planets. 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. Based on observations made with HARPS (High Accuracy Radial velocity Planet Searcher) spectrograph on the 3.6-m European Organisation for Astronomical Research in the Southern Hemisphere telescope at La Silla Observatory, Chile (ESO program 188.C-0779).Based on observations obtained with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias, in time allocated by the Spanish Time Allocation Committee (CAT).

  10. Asteroseismic Determination of Obliquities of the Exoplanet Systems Kepler-50 and Kepler-65

    DEFF Research Database (Denmark)

    Chaplin, W. J.; Sanchis-Ojeda, R.; Campante, T. L.; Handberg, R.; Stello, D.; Winn, J. N.; Basu, S.; Christensen-Dalsgaard, J.; Davies, G. R.; Metcalfe, T. S.; Buchhave, L. A.; Fischer, D. A.; Bedding, T. R.; Cochran, W. D.; Elsworth, Y.; Gilliland, R. L.; Hekker, S.; Huber, D.; Isaacson, H.; Karoff, C.; Kawaler, S. D.; Kjeldsen, H.; Latham, D. W.; Lund, M. N.; Lundkvist, M.; Marcy, G. W.; Miglio, A.; Barclay, T.; Lissauer, J. J.

    2013-01-01

    Results on the obliquity of exoplanet host stars—the angle between the stellar spin axis and the planetary orbital axis—provide important diagnostic information for theories describing planetary formation. Here we present the first application of asteroseismology to the problem of stellar obliquity...... determination in systems with transiting planets and Sun-like host stars. We consider two systems observed by the NASA Kepler mission which have multiple transiting small (super-Earth sized) planets: the previously reported Kepler-50 and a new system, Kepler-65, whose planets we validate in this paper. Both...

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

    CERN Document Server

    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

    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...

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

    CERN Document Server

    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

    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.

  13. Characterizing the Coolest Atmospheres: Exoplanets to Brown Dwarfs

    Science.gov (United States)

    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

    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.

  14. VUV-absorption cross section of CO2 at high temperatures and impact on exoplanet atmospheres

    Directory of Open Access Journals (Sweden)

    Venot Olivia

    2014-02-01

    Full Text Available Ultraviolet (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. 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 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 found that the absorption cross section of CO2 is very sensitive to temperature, especially above 160 nm. Within the studied range of temperature, the CO2 cross section can vary by more than two orders of magnitude. This, in particular, makes the absorption of CO2 significant up to wavelengths as high as 230 nm, while it is negligible above 200 nm at 300 K. To investigate the influence of these new data on the photochemistry of exoplanets, we implemented the measured cross section into a 1D photochemical model. The model predicts that accounting for this temperature dependency of CO2 cross section can affect the computed abundances of NH3, CO2, and CO by one order of magnitude in the atmospheres of hot Jupiter and hot Neptune.

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

    CERN Document Server

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

    2014-01-01

    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...

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

    CERN Document Server

    Sackett, C T

    2005-01-01

    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...

  17. Instrumentation for the detection and characterization of exoplanets

    OpenAIRE

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

    2014-01-01

    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...

  18. What can exoplanets tell us about our Solar System?

    OpenAIRE

    Lineweaver, Charles H.; Grether, Daniel; Hidas, Marton

    2002-01-01

    We update our analysis of recent exoplanet data that gives us a partial answer to the question: How does our Solar System compare to the other planetary systems in the Universe? Exoplanets detected between January and August 2002 strengthen the conclusion that Jupiter is a typical massive planet rather than an outlier. The trends in detected exoplanets do not rule out the hypothesis that our Solar System is typical. They support it.

  19. Exoplanet Predictions Based on the Generalised Titius-Bode Relation

    OpenAIRE

    Bovaird, Timothy; Lineweaver, Charles H.

    2013-01-01

    We evaluate the extent to which newly detected exoplanetary systems containing at least four planets adhere to a generalized Titius-Bode (TB) relation. We find that the majority of exoplanet systems in our sample adhere to the TB relation to a greater extent than the Solar System does, particularly those detected by the Kepler mission. We use a generalized TB relation to make a list of predictions for the existence of 141 additional exoplanets in 68 multiple-exoplanet system...

  20. ON THE ORBIT OF EXOPLANET WASP-12b

    International Nuclear Information System (INIS)

    We observed two secondary eclipses of the exoplanet WASP-12b using the Infrared Array Camera on the Spitzer Space Telescope. The close proximity of WASP-12b to its G-type star results in extreme tidal forces capable of inducing apsidal precession with a period as short as a few decades. This precession would be measurable if the orbit had a significant eccentricity, leading to an estimate of the tidal Love number and an assessment of the degree of central concentration in the planetary interior. An initial ground-based secondary-eclipse phase reported by Lopez-Morales et al. (0.510 ± 0.002) implied eccentricity at the 4.5σ level. The spectroscopic orbit of Hebb et al. has eccentricity 0.049 ± 0.015, a 3σ result, implying an eclipse phase of 0.509 ± 0.007. However, there is a well-documented tendency of spectroscopic data to overestimate small eccentricities. Our eclipse phases are 0.5010 ± 0.0006 (3.6 and 5.8 μm) and 0.5006 ± 0.0007 (4.5 and 8.0 μm). An unlikely orbital precession scenario invoking an alignment of the orbit during the Spitzer observations could have explained this apparent discrepancy, but the final eclipse phase of Lopez-Morales et al. (0.510 ±+0.007-0.006) is consistent with a circular orbit at better than 2σ. An orbit fit to all the available transit, eclipse, and radial-velocity data indicates precession at <1σ; a non-precessing solution fits better. We also comment on analysis and reporting for Spitzer exoplanet data in light of recent re-analyses.