HATS-59b,c: A Transiting Hot Jupiter and a Cold Massive Giant Planet around a Sun-like Star

Abstract

We report the first discovery of a multi-planetary system by the HATSouth network, HATS-59b,c, a planetary system with an inner transiting hot Jupiter and an outer cold massive giant planet, which was detected via radial velocity. The inner transiting planet, HATS-59b, is on an eccentric orbit with e =  0.129 0.049, orbiting a V =  13.951 0.030 mag solar-like star (M = 1.038 0.039  M☉ and R =  1.036 0.067 R☉) with a period of 5.416081 0.000016  days. The outer companion, HATS-59c is on a circular orbit with m i sin 12.70 =  0.87 MJ and a period of 1422 ± 14 days. The inner planet has a mass of 0.806 0.069  MJ and a radius of 1.126 0.077  RJ, yielding a density of 0.70 0.16  g cm-3. Unlike most planetary systems that include only a single hot Jupiter, HATS-59b,c includes, in addition to the transiting hot Jupiter, a massive outer companion. The architecture of this system is valuable for understanding planet migration.