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.

stars : individual (EPIC 219388192)

brown dwarfs

techniques : photometric

photometric

techniques : radial velocities

techniques : spectroscopic

Author

G. Nowak

University of La Laguna

Instituto Astrofisico de Canarias

E. Palle

Instituto Astrofisico de Canarias

University of La Laguna

D. Gandolfi

Heidelberg-Königstuhl State Observatory

University of Turin

F. Dai

Massachusetts Institute of Technology (MIT)

A. F. Lanza

Osservatorio Astrofisico di Catania

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

Istituto Nazionale Di Fisica Nucleare, Frascati

J. Prieto-Arranz

Instituto Astrofisico de Canarias

University of La Laguna

A. Kiilerich

Aarhus University

D. Nespral

University of La Laguna

Instituto Astrofisico de Canarias

A. Hatzes

Thüringer Landessternwarte Tautenburg

S. Albrecht

Aarhus University

H. Deeg

University of La Laguna

Instituto Astrofisico de Canarias

J. N. Winn

Princeton University

L. Yu

Massachusetts Institute of Technology (MIT)

M. Kuzuhara

National Institutes of Natural Sciences

National Astronomical Observatory of Japan

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

National Institutes of Natural Sciences

National Astronomical Observatory of Japan

University of Tokyo

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

Subject Categories

Astronomy, Astrophysics and Cosmology

DOI

10.3847/1538-3881/aa5cb6

More information

Latest update

9/10/2019