Title

Discovery of a wide companion near the deuterium-burning mass limit in the upper scorpius association

Authors

Authors

V. J. S. Bejar; M. R. Z. Osorio; A. Perez-Garrido; C. Alvarez; E. L. Marti; R. Rebolo; I. Villo-Perez;A. Diaz-Sanchez

Comments

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Abbreviated Journal Title

Astrophys. J. Lett.

Keywords

binaries : general; planetary systems; stars : individual (UScoCTIO; 108); stars : low-mass, brown dwarfs; stars : pre-main-sequence; EXTRASOLAR GIANT PLANETS; YOUNG BROWN DWARFS; SIGMA-ORIONIS CLUSTER; OB; ASSOCIATION; ULTRACOOL DWARFS; BINARY; STARS; SPECTROSCOPY; CANDIDATES; PHOTOMETRY; Astronomy & Astrophysics

Abstract

We present the discovery of a companion near the deuterium-burning mass limit located at a very wide distance, at an angular separation of 4.6 '' +/- 0.1 '' (projected distance of similar to 670 AU) from UScoCTIO 108, a brown dwarf of the very young Upper Scorpius association. Optical and near- infrared photometry and spectroscopy confirm the cool nature of both objects, with spectral types of M7 and M9.5, respectively, and that they are bona fide members of the association, showing low gravity and features of youth. Their masses, estimated from the comparison of their bolometric luminosities and theoretical models for the age range of the association, are 60 +/- 20 and 14(-8)(+2) M(Jup), respectively. The existence of this object around a brown dwarf at this wide orbit suggests that the companion is unlikely to have formed in a disk based on current planet formation models. Because this system is rather weakly bound, they probably did not form through dynamical ejection of stellar embryos.

Journal Title

Astrophysical Journal Letters

Volume

673

Issue/Number

2

Publication Date

1-1-2008

Document Type

Article

Language

English

First Page

L185

Last Page

L189

WOS Identifier

WOS:000255233000020

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