HAT-P-5b: A Jupiter-like Hot Jupiter Transiting a Bright Star

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 R p = 1.257 ± 0.053 R J . HAT-P-5b has a mass of M p = 1.06 ± 0.11 M J , similar to the average mass of previously known transiting exoplanets, and a density of ρ p = 0.66 ± 0.11 g cm −3 . We find that the center of transit is T c = 2,454,241.77663 ± 0.00022 days (HJD), and the total transit duration is 0.1217 ± 0.0012 days.