Bibcode
DOI
Magazzu, Antonio; Martin, Eduardo L.; Rebolo, Rafael
Bibliographical reference
Astrophysical Journal, Part 2 - Letters (ISSN 0004-637X), vol. 404, no. 1, p. L17-L20.
Advertised on:
2
1993
Journal
Citations
129
Refereed citations
108
Description
We describe a spectroscopic test capable of providing direct
confirmation of the substellar nature of brown dwarf candidates. While
the conditions for substantial lithium burning are reached even in very
low-mass stars, in substellar objects with less than 0.06 solar mass
such conditions are never attained and Li is expected to be preserved.
Therefore, the detection of lithium in the spectrum of a brown dwarf
candidate would be of great interest to confirm its substellar mass. We
report on a search for the Li I 670.8 nm resonance doublet in some very
low-mass dwarfs and brown dwarf candidates, namely, GL 65 (A and B), GL
406, GL 234AB, GL 569B, and GL 473AB. We do not detect the lithium
feature in any of the spectra of this work. This implies that the
objects in our sample have suffered from heavy Li depletion (more than
four orders of magnitude in most cases). These objects consequently
present masses higher than 0.06 solar mass and appear to be older than
about 10 exp 8 yr.