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arXiv · 1310.2613

A lithium depletion boundary age of 21 Myr for the Beta Pictoris moving group

A. S Binks·R. D. Jeffries
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Abstract

Optical spectroscopy is used to confirm membership for 8 low-mass candidates in the young Beta Pic moving group (BPMG) via their radial velocities, chromospheric activity and kinematic parallaxes. We searched for the presence of the Li I 6708A resonance feature and combined the results with literature measurements of other BPMG members to find the age-dependent lithium depletion boundary (LDB) -- the luminosity at which Li remains unburned in a coeval group. The LDB age of the BPMG is 21 +/- 4 Myr and insensitive to the choice of low-mass evolutionary models. This age is more precise, likely to be more accurate, and much older than that commonly assumed for the BPMG. As a result, substellar and planetary companions of BPMG members will be more massive than previously thought.

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A. S Binks, R. D. Jeffries. 2013-10-09. A lithium depletion boundary age of 21 Myr for the Beta Pictoris moving group. https://doi.org/10.1093/mnrasl%2Fslt141

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