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

Journal
Date Issued
2017
Author(s)
Smith, A. M. S.
•
Gandolfi, D.
•
Barragán, O.
•
Bowler, B.
•
Csizmadia, Sz.
•
Endl, M.
•
Fridlund, M. C. V.
•
Grziwa, S.
•
Guenther, E.
•
Hatzes, A. P.
•
Nowak, G.
•
Albrecht, S.
•
Alonso, R.
•
Cabrera, J.
•
Cochran, W. D.
•
Deeg, H. J.
•
•
Eigmüller, Ph.
•
Erikson, A.
•
Hidalgo, D.
•
Hirano, T.
•
Johnson, M. C.
•
Korth, J.
•
Mann, A.
•
Narita, N.
•
Nespral, D.
•
Palle, E.
•
Pätzold, M.
•
Prieto-Arranz, J.
•
Rauer, H.
•
Ribas, I.
•
Tingley, B.
•
Wolthoff, V.
DOI
Abstract
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 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-1 d-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.
Volume
464
Issue
3
Start page
2708
Uri
Url
Issn Identifier
0035-8711
Ads BibCode
2017MNRAS.464.2708S
Rights
open.access
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