We report the discovery of a planet transiting a moderately bright (V = 12.00) G star, with an orbital period of 2.788491 +/-0.000025 days. From the transit light curve we determine that the radius of the planet is Rp = 1.257 +/- 0.053 RJup. HAT-P-5b has a mass of Mp = 1.06 +/- 0.11 MJup, similar to the average mass of previously-known transiting exoplanets, and a density of rho = 0.66 +/- 0.11 g cm^-3 . We find that the center of transit is Tc = 2,454,241.77663 +/- 0.00022 (HJD), and the total transit duration is 0.1217 +/- 0.0012 days.
@article{arxiv.0710.1841,
title = {HAT-P-5b: A Jupiter-like hot Jupiter Transiting a Bright Star},
author = {G. A. Bakos and A. Shporer and A. Pal and G. Torres and Geza Kovacs and D. W. Latham and T. Mazeh and A. Ofir and R. W. Noyes and D. D. Sasselov and F. Bouchy and F. Pont and D. Queloz and S. Udry and G. Esquerdo and B. Sipocz and Gabor Kovacs and J. Lazar and I. Papp and P. Sari},
journal= {arXiv preprint arXiv:0710.1841},
year = {2009}
}