HAT-P-56b: An Inflated Hot Jupiter Around an F Dwarf

An inflated massive Hot Jupiter transiting a bright F star followed up with K2.0 observations

Authors:

Huang et al

Abstract:

We report the discovery of HAT-P-56b by the HATNet survey, an inflated hot Jupiter transiting a bright F type star in Field 0 of NASA's K2 mission. We combine ground-based discovery and follow-up light curves with high precision photometry from K2, as well as ground-based radial velocities from TRES on the FLWO~1.5m telescope to determine the physical properties of this system. HAT-P-56b has a mass of Mp≈2.18MJ, radius of Rp≈1.47RJ, and transits its host star on a near-grazing orbit with a period of P≈ 2.7908 d. The radius of HAT-P-56b is among the largest known for a planet with Mp>2MJ. The host star has a V-band magnitude of 10.9, mass of 1.30 M⊙, and radius of 1.43 R⊙. The periodogram of the K2 light curve suggests the star is a γ Dor variable. HAT-P-56b is an example of a ground-based discovery of a transiting planet, where space-based observations greatly improve the confidence in the confirmation of its planetary nature, and also improve the accuracy of the planetary parameters.