Theory for the Secondary Eclipse Fluxes, Spectra, Atmospheres, and Light Curves of Transiting Extrasolar Giant Planets

We have created a general methodology for calculating thewavelength-dependent light curves of close-in extrasolar giant planets (EGPs)as they traverse their orbits. Focussing on the transiting EGPs HD189733b,TrES-1, and HD209458b, we calculate planet/star flux ratios during secondaryeclipse and compare them with the Spitzer data points obtained so far in themid-infrared. We introduce a simple parametrization for the redistribution ofheat to the planet's nightside, derive constraints on this parameter (P_n), andprovide a general set of predictions for planet/star contrast ratios as afunction of wavelength, model, and phase. Moreover, we calculate averagedayside and nightside atmospheric temperature/pressure profiles for eachtransiting planet/P_n pair with which existing and anticipated Spitzer data canbe used to probe the atmospheric thermal structure of severely irradiated EGPs.We find that the baseline models do a good job of fitting the current secondaryeclipse dataset, but that the Spitzer error bars are not yet small enough todiscriminate cleanly between all the various possibilities.Comment: 14 figures, 7 text pages (in two-column emulateapj format); Accepted to the Ap.J. June 26, 2006; one cosmetic change made to astro-ph version