THERMAL EMISSION AND TIDAL HEATING OF THE HEAVY AND ECCENTRIC PLANET XO-3b

We determined the flux ratios of the heavy and eccentric planet XO-3b to its parent star in the four Infrared Array Camera bands of the Spitzer Space Telescope: 0.101% +- 0.004% at 3.6 {mu}m; 0.143% +- 0.006% at 4.5 {mu}m; 0.134% +- 0.049% at 5.8 {mu}m; and 0.150% +- 0.036% at 8.0 {mu}m. The flux ratios are within [-2.2, 0.3, -0.8, and -1.7]sigma of the model of XO-3b with a thermally inverted stratosphere in the 3.6 {mu}m, 4.5 {mu}m, 5.8 {mu}m, and 8.0 {mu}m channels, respectively. XO-3b has a high illumination from its parent star (F{sub p} {approx} (1.9-4.2) x 10{sup 9} erg cm{sup -2} s{sup -1}) and is thus expected to have a thermal inversion, which we indeed observe. When combined with existing data for other planets, the correlation between the presence of an atmospheric temperature inversion and the substellar flux is insufficient to explain why some high insolation planets like TrES-3 do not have stratospheric inversions and some low insolation planets like XO-1b do have inversions. Secondary factors such as sulfur chemistry, atmospheric metallicity, amounts of macroscopic mixing in the stratosphere, or even dynamical weather effects likely play a role. Using the secondary eclipse timing centroids, we determinedmore » the orbital eccentricity of XO-3b as e = 0.277 +- 0.009. The model radius-age trajectories for XO-3b imply that at least some amount of tidal heating is required to inflate the radius of XO-3b, and the tidal heating parameter of the planet is constrained to Q{sub p} {approx}< 10{sup 6}.« less

[1]  John Asher Johnson,et al.  ON THE SPIN–ORBIT MISALIGNMENT OF THE XO-3 EXOPLANETARY SYSTEM , 2009, 0902.3461.

[2]  I. Hubeny,et al.  Possible Solutions to the Radius Anomalies of Transiting Giant Planets , 2006 .

[3]  P. Gregory.  Bayesian Logical Data Analysis for the Physical Sciences: A Comparative Approach with Mathematica® Support , 2005 .

[4]  Adam Burrows,et al.  CAN TiO EXPLAIN THERMAL INVERSIONS IN THE UPPER ATMOSPHERES OF IRRADIATED GIANT PLANETS? , 2009, 0902.3995.

[5]  I. Baraffe,et al.  Structure and evolution of super-Earth to super-Jupiter exoplanets - I. Heavy element enrichment in the interior , 2008, 0802.1810.

[6]  T. Guillot,et al.  Giant Planets at Small Orbital Distances , 1995, astro-ph/9511109.

[7]  S. Ravi.  Bayesian Logical Data Analysis for the Physical Sciences: a Comparative Approach with Mathematica® Support , 2007 .

[8]  A. Burrows,et al.  DETECTION OF A TEMPERATURE INVERSION IN THE BROADBAND INFRARED EMISSION SPECTRUM OF TrES-4 , 2008, 0810.0021.

[9]  Michel Mayor,et al.  The Broadband Infrared Emission Spectrum of the Exoplanet HD 189733b , 2008, 0802.0845.

[10]  Adam Burrows,et al.  COUPLED EVOLUTION WITH TIDES OF THE RADIUS AND ORBIT OF TRANSITING GIANT PLANETS: GENERAL RESULTS , 2009, 0902.3998.

[11]  G. Fazio,et al.  The Infrared Array Camera (IRAC) for the Spitzer Space Telescope , 2004, astro-ph/0405616.

[12]  W. C. Bowman,et al.  SPITZER IRAC SECONDARY ECLIPSE PHOTOMETRY OF THE TRANSITING EXTRASOLAR PLANET HAT-P-1b , 2009, 0911.2218.

[13]  Richard S. Freedman,et al.  A Unified Theory for the Atmospheres of the Hot and Very Hot Jupiters: Two Classes of Irradiated Atmospheres , 2007, 0710.2558.

[14]  Drake Deming,et al.  Rapid heating of the atmosphere of an extrasolar planet , 2009, Nature.

[15]  David Charbonneau,et al.  THE 8 μm PHASE VARIATION OF THE HOT SATURN HD 149026b , 2009, 0908.1977.

[16]  Drake Deming,et al.  Infrared radiation from an extrasolar planet , 2005, Nature.

[17]  David Charbonneau,et al.  Theoretical Spectral Models of the Planet HD 209458b with a Thermal Inversion and Water Emission Bands , 2007, 0709.3980.

[18]  R. Kuschnig,et al.  WATER, METHANE, AND CARBON DIOXIDE PRESENT IN THE DAYSIDE SPECTRUM OF THE EXOPLANET HD 209458b , 2009, 0908.4010.

[19]  G. Laughlin,et al.  On the Radii of Extrasolar Giant Planets , 2003 .

[20]  I. Hubeny,et al.  A Possible Bifurcation in Atmospheres of Strongly Irradiated Stars and Planets , 2003 .

[21]  Drake Deming,et al.  STUDYING THE ATMOSPHERE OF THE EXOPLANET HAT-P-7b VIA SECONDARY ECLIPSE MEASUREMENTS WITH EPOXI, SPITZER, AND KEPLER , 2009, 0912.2132.

[22]  Joseph L. Hora,et al.  A ccepted forpublication in The A strophysicalJournal D etection of T herm alE m ission of X O -2b: E vidence for a W eak Tem perature Inversion , 2022 .

[23]  David Charbonneau,et al.  The 3.6-8.0 μm Broadband Emission Spectrum of HD 209458b: Evidence for an Atmospheric Temperature Inversion , 2007, 0709.3984.

[24]  David Charbonneau,et al.  A map of the day–night contrast of the extrasolar planet HD 189733b , 2007, Nature.

[25]  Pin Chen,et al.  Submitted to the Astrophysical Journal Letters Molecular Signatures in the Near Infrared Dayside Spectrum of , 2022 .

[26]  K. Lodders,et al.  ATMOSPHERIC SULFUR PHOTOCHEMISTRY ON HOT JUPITERS , 2009, 0903.1663.

[27]  M. Nagasawa,et al.  Formation of Hot Planets by a Combination of Planet Scattering, Tidal Circularization, and the Kozai Mechanism , 2008, 0801.1368.

[28]  A. P. Showman,et al.  The Influence of Atmospheric Dynamics on the Infrared Spectra and Light Curves of Hot Jupiters , 2006 .

[29]  Jonathan Tennyson,et al.  Water vapour in the atmosphere of a transiting extrasolar planet , 2007, Nature.

[30]  David Charbonneau,et al.  ATMOSPHERIC CIRCULATION OF HOT JUPITERS: COUPLED RADIATIVE-DYNAMICAL GENERAL CIRCULATION MODEL SIMULATIONS OF HD 189733b and HD 209458b , 2008, 0809.2089.

[31]  Peter Bodenheimer,et al.  On the Tidal Inflation of Short-Period Extrasolar Planets , 2001 .

[32]  Peter Bodenheimer,et al.  The Effect of Tidal Inflation Instability on the Mass and Dynamical Evolution of Extrasolar Planets with Ultrashort Periods , 2003, astro-ph/0303362.

[33]  Carl J. Grillmair,et al.  Strong water absorption in the dayside emission spectrum of the planet HD 189733b , 2008, Nature.

[34]  S. T. Megeath,et al.  A Sensitive Search for Variability in Late L Dwarfs: The Quest for Weather , 2005 .

[35]  Mark S. Marley,et al.  Planetary Radii across Five Orders of Magnitude in Mass and Stellar Insolation: Application to Transits , 2006 .

[36]  David Charbonneau,et al.  MULTIWAVELENGTH CONSTRAINTS ON THE DAY–NIGHT CIRCULATION PATTERNS OF HD 189733b , 2008, 0802.1705.

[37]  E. Agol,et al.  Analytic Light Curves for Planetary Transit Searches , 2002, astro-ph/0210099.

[38]  S. Tremaine,et al.  Dynamical Origin of Extrasolar Planet Eccentricity Distribution , 2007, astro-ph/0703160.

[39]  Drake Deming,et al.  The hottest planet , 2007, Nature.

[40]  Aisey M Andel.  ANALYTIC LIGHTCURVES FOR PLANETARY TRANSIT SEARCHES , 2002 .

[41]  Adam Burrows,et al.  Theoretical Radii of Extrasolar Giant Planets: The Cases of TrES-4, XO-3b, and HAT-P-1b , 2008, 0805.1733.

[42]  Gautam Vasisht,et al.  The presence of methane in the atmosphere of an extrasolar planet , 2008, Nature.

[43]  David Charbonneau,et al.  Detection of Thermal Emission from an Extrasolar Planet , 2005 .

[44]  F. Allard,et al.  The Evolution of Irradiated Planets: Application to Transits , 2004, astro-ph/0401487.

[45]  Steven Soter,et al.  Q in the solar system , 1966 .

[46]  C. Moutou,et al.  Misaligned spin-orbit in the XO-3 planetary system?† , 2008, Proceedings of the International Astronomical Union.

[47]  Richard Greenberg,et al.  Tidal Heating of Extrasolar Planets , 2008, 0803.0026.

[48]  Peter R. McCullough,et al.  XO-3b: A Massive Planet in an Eccentric Orbit Transiting an F5 V Star , 2007, 0712.4283.

[49]  D. Ehrenreich,et al.  SEARCH FOR CARBON MONOXIDE IN THE ATMOSPHERE OF THE TRANSITING EXOPLANET HD 189733b , 2009, 0903.3405.

[50]  Joseph L. Hora,et al.  Accepted for publication in The Astrophysical Journal Preprint typeset using L ATEX style emulateapj v. 10/09/06 THERMAL EMISSION OF EXOPLANET XO-1B , 2022 .

[51]  I. Hubeny,et al.  Theoretical Spectra and Light Curves of Close-in Extrasolar Giant Planets and Comparison with Data , 2007, 0709.4080.