EPIC 219388192b-An Inhabitant of the Brown Dwarf Desert in the Ruprecht 147 Open Cluster
Journal article, 2017
We report the discovery of EPIC 219388192b, a transiting brown dwarf in a 5.3 day orbit around a member star of Ruprecht 147, the oldest nearby open cluster association, which was photometrically monitored by K2 during its Campaign 7. We combine the K2 time-series data with ground-based adaptive optics imaging and high-resolution spectroscopy to rule out false positive scenarios and determine the main parameters of the system. EPIC 219388192b has a radius of R-b= 0.937 +/- 0.032 R-Jup and mass of M-b= 36.84 +/- 0.97 M-Jup, yielding a mean density of 59.6 +/- 7.6 g cm(- 3). The host star is nearly a solar twin with mass M-star = 1.01 +/- 0.04 Me, radius R-star = 1.01 +/- 0.03 R-circle dot, effective temperature T-eff = 5850 +/- 85 K, and iron abundance [Fe/ H]. = 0.03 +/- 0.08 dex. Its age, spectroscopic distance, and reddening are consistent with those of Ruprecht 147, corroborating its cluster membership. EPIC 219388192b is the first mature brown dwarf with precise determinations of mass, radius, and age, and serves as benchmark for evolutionary models in the substellar regime.
photometric
stars : individual (EPIC 219388192)
techniques : spectroscopic
techniques : radial velocities
techniques : photometric
brown dwarfs
Author
G. Nowak
University of La Laguna
Instituto de Astrofísica de Canarias
E. Palle
University of La Laguna
Instituto de Astrofísica de Canarias
D. Gandolfi
Heidelberg-Königstuhl State Observatory
University of Turin
F. Dai
Massachusetts Institute of Technology (MIT)
A. F. Lanza
Istituto nazionale di astrofisica (INAF)
T. Hirano
Tokyo Institute of Technology
O. Barragán
University of Turin
A. Fukui
National Astronomical Observatory of Japan
H. Bruntt
Aarhus University
M. Endl
The University of Texas at Austin
W. D. Cochran
The University of Texas at Austin
P. G. P. Moroni
University of Pisa
National Institute for Nuclear Physics
J. Prieto-Arranz
Instituto de Astrofísica de Canarias
University of La Laguna
A. Kiilerich
Aarhus University
D. Nespral
Instituto de Astrofísica de Canarias
University of La Laguna
A. Hatzes
Thüringer Landessternwarte Tautenburg
S. Albrecht
Aarhus University
H. Deeg
Instituto de Astrofísica de Canarias
University of La Laguna
J. N. Winn
Princeton University
L. Yu
Massachusetts Institute of Technology (MIT)
M. Kuzuhara
National Astronomical Observatory of Japan
National Institutes of Natural Sciences
S. Grziwa
University of Cologne
A. M. S. Smith
German Aerospace Center (DLR)
E. W. Guenther
Thüringer Landessternwarte Tautenburg
V. Van Eylen
Leiden University
S. Csizmadia
German Aerospace Center (DLR)
Malcolm Fridlund
Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics
J. Cabrera
German Aerospace Center (DLR)
Philipp Eigmüller
German Aerospace Center (DLR)
A. Erikson
German Aerospace Center (DLR)
J. Korth
University of Cologne
N. Narita
University of Tokyo
National Institutes of Natural Sciences
National Astronomical Observatory of Japan
M. Patzold
University of Cologne
H. Rauer
Technische Universität Berlin
German Aerospace Center (DLR)
I. Ribas
Universitat Autonoma de Barcelona (UAB)
Astronomical Journal
0004-6256 (ISSN) 1538-3881 (eISSN)
Vol. 153 3 131Subject Categories
Astronomy, Astrophysics and Cosmology
DOI
10.3847/1538-3881/aa5cb6