EPIC 212803289: a subGiant With a Warm Jupiter and Possibly a Brown Dwarf

EPIC 212803289: a subgiant hosting a transiting warm Jupiter in an eccentric orbit and a long-period companion

Authors:

Smith et al

Abstract:

We report the discovery from K2 of a transiting planet in an 18.25-d, eccentric (0.19± 0.04) orbit around EPIC 212803289, an 11th magnitude subgiant in Virgo. We confirm the planetary nature of the companion with radial velocities, and determine that the star is a metal-rich ([Fe/H] = 0.20±0.05) subgiant, with mass 1.60+0.14−0.10 M⊙ and radius 3.1±0.1 R⊙. The planet has a mass of 0.97±0.09 MJup and a radius 1.29±0.05 RJup. A measured systemic radial acceleration of −2.12±0.04 ms−1d−1 offers compelling evidence for the existence of a third body in the system, perhaps a brown dwarf orbiting with a period of several hundred days.