EPIC 219388192b—An Inhabitant of the Brown Dwarf Desert in the Ruprecht 147 Open Cluster

Nowak, G.; Palle, E.; Gandolfi, Davide; Dai, Fei; Lanza, Antonino F.; Hirano, Teruyuki; Barragán, Oscar; Fukui, Akihiko; Bruntt, Hans; Endl, Michael; Cochran, William D.; Prada Moroni, Pier G.; Prieto-Arranz, J.; Kiilerich, Amanda; Nespral, D.; Hatzes, Artie P.; Albrecht, Simon; Deeg, H. J.; Winn, Joshua N.; Yu, Liang; Kuzuhara, Masayuki; Grziwa, Sascha; Smith, Alexis M. S.; Guenther, Eike W.; Van Eylen, Vincent; Csizmadia, Szilard; Fridlund, Malcolm; Cabrera, Juan; Eigmüller, Philipp; Erikson, Anders; Korth, Judith; Narita, Norio; Pätzold, Martin; Rauer, Heike; Ribas, Ignasi
Bibliographical reference

The Astronomical Journal, Volume 153, Issue 3, article id. 131, 11 pp. (2017).

Advertised on:
3
2017
Number of authors
35
IAC number of authors
5
Citations
39
Refereed citations
39
Description
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 M ⊙, radius {R}\star =1.01+/- 0.03 R ⊙, 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.
Related projects
Projects' name image
Exoplanets and Astrobiology
The search for life in the universe has been driven by recent discoveries of planets around other stars (known as exoplanets), becoming one of the most active fields in modern astrophysics. The growing number of new exoplanets discovered in recent years and the recent advance on the study of their atmospheres are not only providing new valuable
Enric
Pallé Bago