Abstract
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 ±0.005 M ⊙. GJ 802 has kinematics inconsistent with a young star and more consistent with the thick-disk population, implying a system age of ∼10 Gyr. However, model evolutionary tracks for GJ 802B predict system ages of ∼2 Gyr, suggesting that brown dwarf evolutionary models may be underestimating luminosity for old brown dwarfs.
Original language | English |
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Pages (from-to) | 463-471 |
Number of pages | 9 |
Journal | Astrophysical Journal |
Volume | 678 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1 May 2008 |
Externally published | Yes |