Thomas Barclay, Daniel Huber, Jason F. Rowe, Jonathan J. Fortney, Caroline V. Morley, Elisa V. Quintana, Daniel C. Fabrycky, Geert Barentsen, Steven Bloemen, Jessie L. Christiansen, Brice-Olivier Demory, Benjamin J. Fulton, Jon M. Jenkins, Fergal Mullally, Darin Ragozzine, Shaun E. Seader, Avi Shporer, Peter Tenenbaum, Susan E. Thompson
We measure the mass and radius of the star and planet in the TrES-2 system using 2.7 years of observations by the Kepler spacecraft. The light curve shows evidence for ellipsoidal variations and Doppler beaming on a period consistent with the orbital period of the planet with amplitudes of 2.79+0.44-0.62 and 3.44+0.32-0.37 parts per million (ppm) respectively, and a difference between the day and night side planetary flux of 3.41+0.55-0.82 ppm. We present an asteroseismic analysis of solar-like oscillations on TrES-2A which we use to calculate the stellar mass of 0.94+/-0.05 MSun and radius of 0.95+/-0.02 RSun. Using these stellar parameters, a transit model fit and the phase curve variations, we determine the planetary radius of 1.162+0.020-0.024 RJup and derive a mass for TrES-2b from the photometry of 1.44+/-0.21 MJup. The ratio of the ellipsoidal variation to the Doppler beaming amplitudes agrees to better than 2{\sigma} with theoretical predications, while our measured planet mass and radius agree within 2-{\sigma} of previously published values based on spectroscopic radial velocity measurements. We measure a geometric albedo of 0.0136+0.0022-0.0033 and an occultation (secondary eclipse) depth of 6.5+1.7-1.8 ppm which we combined with the day/night planetary flux ratio to model the atmosphere of TReS-2b. We find an atmosphere model that contains a temperature inversion is strongly preferred. We hypothesize that the Kepler bandpass probes a significantly greater atmospheric depth on the night side relative to the day side.
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http://arxiv.org/abs/1210.4592
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