Of the nearby transiting exoplanets that are amenable to detailed study, TrES-2 is both the most massive and has the largest impact parameter. We present z-band photometry of three transits of TrES-2. We improve upon the estimates of the planetary, stellar, and orbital parameters, in conjunction with the spectroscopic analysis of the host star by Sozzetti and co-workers. We find the planetary radius to be 1.222 +/- 0.038 R_Jup and the stellar radius to be 1.003 +/- 0.027 R_Sun. The quoted uncertainties include the systematic error due to the uncertainty in the stellar mass (0.980 +/- 0.062 M_Sun). The timings of the transits have an accuracy of 25s and are consistent with a uniform period, thus providing a baseline for future observations with the NASA Kepler satellite, whose field of view will include TrES-2.
@article{arxiv.0704.2907,
title = {The Transit Light Curve Project. VI. Three Transits of the Exoplanet TrES-2},
author = {Matthew J. Holman and Joshua N. Winn and David W. Latham and Francis T. O'Donovan and David Charbonneau and Guillermo Torres and Alessandro Sozzetti and Jose Fernandez and Mark E. Everett},
journal= {arXiv preprint arXiv:0704.2907},
year = {2009}
}