We report the discovery of a planet transiting a moderately faint (V=12.3 mag) late F star, with an orbital period of 3.92289 +/- 0.00004 days. From the transit light curve and radial velocity measurements we determine that the radius of the planet is R_p = 1.40 +/- 0.06 R_Jup and that the mass is M_p = 0.78 +/- 0.09 M_Jup. The density of the new planet, rho = 0.35 +/- 0.06 g cm^{-3}, fits to the low-density tail of the currently known transiting planets. We find that the center of transit is at T_c = 2454417.9077 +/- 0.0003 (HJD), and the total transit duration is 0.143 +/- 0.004 days. The host star has M_s = 1.28 +/- 0.13 M_Sun and R_s = 1.32 +/- 0.07 R_Sun.
@article{arxiv.0806.4008,
title = {HAT-P-9b: A Low Density Planet Transiting a Moderately Faint F star},
author = {Avi Shporer and Gaspar A. Bakos and Francois Bouchy and Frederic Pont and Geza Kovacs and Dave W. Latham and Brigitta Sipocz and Guillermo Torres and Tsevi Mazeh and Gilbert A. Esquerdo and Andras Pal and Robert W. Noyes and Dimitar D. Sasselov and Jozsef Lazar and Istvan Papp and Pal Sari and Gabor Kovacs},
journal= {arXiv preprint arXiv:0806.4008},
year = {2011}
}
Comments
Submitted to ApJ; V2: Replaced with accepted version