A lithium depletion boundary age of 21 Myr for the Beta Pictoris moving group
Abstract
Optical spectroscopy is used to confirm membership for eight 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 6708 Å 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.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- February 2014
- DOI:
- 10.1093/mnrasl/slt141
- arXiv:
- arXiv:1310.2613
- Bibcode:
- 2014MNRAS.438L..11B
- Keywords:
-
- stars: kinematics and dynamics;
- stars: late-type;
- stars: pre-main sequence;
- open clusters and associations: individual: Beta Pictoris;
- solar neighbourhood;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- Accepted for MNRAS Letters