HATS-9b and HATS-10b: Two Compact Hot Jupiters in Field 7 of the K2 Mission

TL;DR

This paper reports the discovery and characterization of two new hot Jupiters, HATS-9b and HATS-10b, found by the HATSouth survey, highlighting their physical properties and potential for future detailed study.

Contribution

First discovery of two compact hot Jupiters in the K2 Field 7, with detailed stellar and planetary parameters provided.

Findings

HATS-9b has a mass of 0.837 M_J and a radius of 1.065 R_J.

HATS-10b has a mass of 0.53 M_J and a radius of 0.97 R_J.

Both planets are denser than typical hot Jupiters, with densities around 0.7-0.85 g/cm^3.

Abstract

We report the discovery of two transiting extrasolar planets by the HATSouth survey. HATS-9b orbits an old (10.8 $\pm$ 1.5 Gyr) V=13.3 G dwarf star, with a period P = 1.9153 d. The host star has a mass of 1.03 M$_{\odot}$, radius of 1.503 R$_\odot$ and effective temperature 5366 $\pm$ 70 K. The planetary companion has a mass of 0.837 M$_J$, and radius of 1.065 R$_J$ 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 d. The host star has a mass of 1.1 M$_\odot$, radius of 1.11 R$_\odot$ and effective temperature 5880 $\pm$ 120 K. The planetary companion has a mass of 0.53 M$_J$, and radius of 0.97 R$_J$ 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 characterisation of HATS-9b with the exquisite photometric precision of the Kepler telescope may provide measurements of its reflected light signature.