The Anglo-Australian Planet Search. XXIII. Two New Jupiter Analogs

We report the discovery of two long-period giant planets from the Anglo-Australian Planet Search. HD 154857c is in a multiple-planet system, while HD 114613b appears to be solitary. HD 114613b has an orbital period P = 10.5 yr, and a minimum mass msin i of 0.48 M _Jup; HD 154857c has P = 9.5 yr and msin i = 2.6 M _Jup. These new data confirm the planetary nature of the previously unconstrained long-period object in the HD 154857 system. We have performed detailed dynamical stability simulations which show that the HD 154857 two-planet system is stable on timescales of at least 10⁸ yr. These results highlight the continued importance of "legacy" surveys with long observational baselines; these ongoing campaigns are critical for determining the population of Jupiter analogs, and hence of those planetary systems with architectures most like our own solar system.