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arXiv · 0801.1525

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

M. J. Ireland·A. Kraus·F. Martinache·J. P. Lloyd·P. G. Tuthill
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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 non-eclipsing binary with a 19 hour period. We find the mass of GJ 802B to be $0.063\pm0.005$M$_\sun$. GJ 802 has kinematics inconsistent with a young star and more consistent with the thick disk population, implying a system age of $\sim$10 GYr. However, model evolutionary tracks for GJ 802B predict system ages of $\sim$2 GYr, suggesting that brown dwarf evolutionary models may be underestimating luminosity for old brown dwarfs.

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M. J. Ireland, A. Kraus, F. Martinache, J. P. Lloyd, P. G. Tuthill. 2008-01-09. Dynamical Mass of GJ 802B: a brown dwarf in a triple system. https://doi.org/10.1086/529578

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