WASP-24b: A New Transiting Close-in Hot Jupiter orbiting a late F-star

We report the discovery of a new transiting close-in giant planet, WASP-24 b, in a 2.341 d orbit, 0.036 AU from its F8-9 type host star. By matching the star’s spectrum with theoretical models, we infer an effective temperature T_eff =6075±100 K and a surface gravity of log g=4.15±0.10. A comparison of these parameters with theoretical isochrones and evolutionary mass tracks places only weak constraints on the age of the host star, which we estimate to be 1.6+2.1−1.6 Gyr. The planetary nature of the companion was confirmed by radial velocity measurements and additional photometric observations. These data were fit simultaneously in order to determine the most probable parameter set for the system, from
which we infer a planetary mass of 1.032+0.038−0.037 M_Jup and radius 1.104+0.052−0.057 R_Jup .