Discovery of WASP-65b and WASP-75b: Two hot Jupiters without highly inflated radii

Abstract

We report the discovery of two transiting hot Jupiters, WASP-65b (Mpl = 1.55 ± 0.16 MJ; Rpl = 1.11 ± 0.06 RJ), and WASP-75b (Mpl = 1.07 ± 0.05 MJ; Rpl = 1.27 ± 0.05 RJ). They orbit their host star every ?2.311, and ?2.484 days, respectively. The planet host WASP-65 is a G6 star (Teff = 5600 K, [Fe/H] = ?0.07 ± 0.07, age 8 Gyr); WASP-75 is an F9 star (Teff = 6100 K, [Fe/H] = 0.07 ± 0.09, age ? 3 Gyr).WASP-65b is one of the densest known exoplanets in the mass range 0.1 and 2.0 MJ (?pl = 1.13 ± 0.08 ?J), a mass range where a large fraction of planets are found to be inflated with respect to theoretical planet models. WASP-65b is one of only a handful of planets with masses of ?1.5 MJ, a mass regime surprisingly underrepresented among the currently known hot Jupiters. The radius of WASP-75b is slightly inflated (10%) as compared to theoretical planet models with no core, and has a density similar to that of Saturn (?pl = 0.52 ± 0.06 ?J). © ESO 2013.