HATS9-b and HATS10-b: Two Compact Hot Jupiters in Field 7 of the K2 Mission

Abstract

We report the discovery of two transiting extrasolar planets by the HATSouth survey. HATS-9b orbits an old (10.8 ± 1.5 Gyr) V = 13.3 G dwarf star with a period P » 1.9153 days. The host star has a mass of 1.03 M☉, radius of 1.503 R☉ , and effective temperature 5366 ± 70 K. The planetary companion has a mass of 0.837 MJ and radius of 1.065 RJ, yielding a mean density of 0.85 - g cm 3. HATS-10b orbits a V = 13.1 G dwarf star with a period P » 3.3128 days. The host star has a mass of 1.1 M☉, radius of 1.11 R☉ , and effective temperature 5880 ± 120 K. The planetary companion has a mass of 0.53 MJ and radius of 0.97 RJ, yielding a mean density of 0.7 - g cm 3. Both planets are compact in comparison with planets receiving similar irradiation from their host stars and lie in the nominal coordinates of Field 7 of K2, but only HATS-9b falls on working silicon. Future characterization of HATS-9b with the exquisite photometric precision of the Kepler telescope may provide measurements of its reflected light signature.