K2-139 b: a low-mass warm Jupiter on a 29-d orbit transiting an active K0 V star
Journal article, 2018
We announce the discovery of K2-139 b (EPIC 218916923 b), a transiting warm-Jupiter (Teq = 547 ± 25 K) on a 29-d orbit around an active (log R'_HK = -4.46 ± 0.06) K0V star in K2 Campaign 7. We derive the system's parameters by combining the K2 photometry with ground-based follow-up observations. With a mass of 0.387_-0.075^+0.083 M_J and radius of 0.808_-0.033^+0.034 R_J, K2-139 b is one of the transiting warm Jupiters with the lowest mass known to date. The planetary mean density of 0.91_-0.20^+0.24 g/cm^3 can be explained with a core of ~50 M⊕. Given the brightness of the host star (V = 11.653 mag), the relatively short transit duration (~5 h), and the expected amplitude of the Rossiter-McLaughlin effect (~25m/s), K2-139 is an ideal target to measure the spin-orbit angle of a planetary system hosting a warm Jupiter.
planets and satellites: detection
stars: fundamental parameters
planets and satellites: individual: K2-139 b (EPIC 218916923b)
planetary systems
Author
O. Barragán
University of Turin
D. Gandolfi
University of Turin
A. M. S. Smith
German Aerospace Center (DLR)
H. J. Deeg
University of La Laguna
Malcolm Fridlund
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Carina Persson
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
P. Donati
Istituto nazionale di astrofisica (INAF)
M. Endl
The University of Texas at Austin
Sz. Csizmadia
German Aerospace Center (DLR)
S. Grziwa
University of Cologne
D. Nespral
University of La Laguna
Artie P. Hatzes
Thüringer Landessternwarte Tautenburg
W. D. Cochran
The University of Texas at Austin
L. Fossati
Austrian Academy of Sciences
S. S. Brems
Heidelberg University
J. Cabrera
German Aerospace Center (DLR)
F. Cusano
Istituto nazionale di astrofisica (INAF)
Ph. Eigmüller
University of Turin
C. Eiroa
Universidad Autonoma de Madrid (UAM)
A. Erikson
German Aerospace Center (DLR)
E. W. Guenther
Thüringer Landessternwarte Tautenburg
J. Korth
University of Cologne
D. Lorenzo-Oliveira
University of Sao Paulo (USP)
L. Mancini
Max-Planck Institute for Radio Astronomy
Istituto nazionale di astrofisica (INAF)
University of Rome Tor Vergata
M. Pätzold
University of Cologne
J. Prieto-Arranz
University of La Laguna
H. Rauer
German Aerospace Center (DLR)
Technische Universität Berlin
I. Rebollido
Universidad Autonoma de Madrid (UAM)
J. Saario
Nordic Optical Telescope
O. V. Zakhozhay
National Academy of Sciences in Ukraine
Max-Planck Institute for Radio Astronomy
Monthly Notices of the Royal Astronomical Society
0035-8711 (ISSN) 1365-2966 (eISSN)
Vol. 475 2 1765-1776Exoplanets from space – CHEOPS and PLATO, ESA’s next two projects
Swedish National Space Board (174/18), 2017-01-01 -- 2022-12-31.
Subject Categories
Astronomy, Astrophysics and Cosmology
Roots
Basic sciences
DOI
10.1093/mnras/stx3207