K2-99: a subgiant hosting a transiting warm Jupiter in an eccentric orbit and a long-period companion
Journal article, 2017

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 (circle dot) and radius 3.1 +/- 0.1 R-circle dot. The planet has a mass of 0.97 +/- 0.09 M-Jup and a radius 1.29 +/- 0.05 R-Jup. 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.

planets and satellites: individual: K2-99

planets and satellites: detection

planetary system


A. M. S. Smith

D. Gandolfi

O. Barragan

B. Bowler

S. Csizmadia

M. Endl

Malcolm Fridlund

Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics

S. Grziwa

E. W. Guenther

A. Hatzes

G. Nowak

S. Albrecht

R. Alonso

J. Cabrera

W. D. Cochran

H. J. Deeg

F. Cusano

P. Eigmuller

A. Erikson

D. Hidalgo

T. Hirano

M. C. Johnson

J. Korth

A. Mann

N. Narita

D. Nespral

E. Palle

M. Patzold

J. Prieto-Arranz

H. Rauer

I. Ribas

B. Tingley

V. Wolthoff

Monthly Notices of the Royal Astronomical Society

0035-8711 (ISSN) 1365-2966 (eISSN)

Vol. 464 3 2708-2716

Driving Forces

Sustainable development

Subject Categories

Astronomy, Astrophysics and Cosmology


Basic sciences


Onsala Space Observatory



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