Dynamical mass of GJ 802B: A brown dwarf in a triple system

被引：71

作者：

Ireland, M. J. ^{[1
]}

Kraus, A. ^{[2
]}

Martinache, F. ^{[3
]}

Lloyd, J. P. ^{[3
]}

Tuthill, P. G. ^{[4
]}

机构：

[1] CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA

[2] CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA

[3] Cornell Univ, Ithaca, NY 14853 USA

[4] Univ Sydney, Sch Phys, Sydney, NSW 2006, Australia

来源：

ASTROPHYSICAL JOURNAL | 2008年 / 678卷 / 01期

基金：

美国国家科学基金会;

关键词：

stars : low-mass; brown dwarfs;

D O I：

10.1086/529578

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We report a dynamical measurement of the mass of the brown dwarf GJ 802B using aperture-masking interferometry and astrometry. In addition, we report the discovery that GJ 802A is itself a close spectroscopic noneclipsing binary with a 19 hr period. We find the mass of GJ 802B to be 0: 063 +/- 0: 005M(circle dot). GJ 802 has kinematics inconsistent with a young star and more consistent with the thick-disk population, implying a system age of similar to 10 Gyr. However, model evolutionary tracks for GJ 802B predict system ages of similar to 2 Gyr, suggesting that brown dwarf evolutionary models may be underestimating luminosity for old brown dwarfs.

引用

页码：463 / 471

页数：9

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