The field brown dwarf LP 944-20 and the Castor moving group
Departament d'Astronomia i Meteorologia, Av. Diagonal, 647, 08028 Barcelona, Spain
Corresponding author: email@example.com
Accepted: 23 December 2002
A reliable age estimation for the field brown dwarf LP 944-20 is accomplished through the analysis of its kinematic properties. The space velocities of this star strongly suggest its membership in the so-called Castor moving group. LP 944-20 can be sensibly assumed to have the group's age, which is estimated to be ~320 Myr, and metal content, which is found to be roughly solar. With these new constrains and the available photometry and lithium abundance, current brown dwarf models are put to a test. Using the IR magnitudes and the lithium diagnostics, the models are able to provide a reasonable description of the brown dwarf's properties (to within a few sigma) but yield an age which is roughly 50% larger than our estimate. Possible reasons for this discrepancy are discussed.
Key words: stars: low-mass, brown dwarfs / stars: fundamental parameters / stars: kinematics / stars: individual: LP 944-20
© ESO, 2003