K2-99 : A subgiant hosting a transiting warm Jupiter in an eccentric orbit and a long-period companion

Summary, in English

We report the discovery from K2 of a transiting planet in an 18.25-d, eccentric (0.19 ± 0.04) orbit around K2-99, an 11th magnitude subgiant in Virgo. We con- firm 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 m s-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.

• Author: A. M.S. Smith; D. Gandolfi; O. Barragán; B. Bowler; Sz Csizmadia; M. Endl; M. C.V. Fridlund; S. Grziwa; E. Guenther; A. P. Hatzes; G. Nowak; S. Albrecht; R. Alonso; J. Cabrera; W. D. Cochran; H. J. Deeg; F. Cusano; Ph Eigmüller; A. Erikson; D. Hidalgo; T. Hirano; M. C. Johnson; J. Korth; A. Mann; N. Narita; D. Nespral; E. Palle; M. Pätzold; J. Prieto-Arranz; H. Rauer; I. Ribas; B. Tingley; V. Wolthoff
• Publishing year: 2017-01-21
• Language: English
• Pages: 2708-2716
• Publication/Series: Monthly Notices of the Royal Astronomical Society
• Volume: 464
• Issue: 3
• Links: http://dx.doi.org/10.1093/mnras/stw2487
• Document type: Journal article
• Publisher: Oxford University Press
• Keywords: Planetary systems; Planets and satellites: detection; Planets and satellites: individual: K2-99
• Status: Published
• ISBN/ISSN/Other: ISSN: 0035-8711