AAS 200th meeting, Albuquerque, NM, June 2002
Session 11. Nearby Stars and Low Mass Dwarfs
Display, Monday, June 3, 2002, 9:20am-6:30pm, SW Exhibit Hall

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[11.06] Deuterium Burning and Lithium Burning in Brown Dwarfs

J. A. Milsom, A. Burrows (University of Arizona)

We present here the results of evolutionary models on deuterium and lithium burning in sub-stellar mass objects. We demonstrate that the lower mass limits for which deuterium burning and lithium burning become important depend sensitively upon the object's metallicity, the object's helium mass fraction, and the specific atmospheric model and boundary conditions being employed. The mass for which the sub-stellar object burns 50% of its deuterium can vary from ~11.9 MJup to ~14.1MJup as the metallicity is varied from z=1 to z=0.001. Similarly, the mass for which 50% of the lithium is burned varies by ~0.01 MSun as the helium mass fraction is varied from 0.22 to 0.32. These considerations are important for observers using ``lithium tests'' or ``deuterium tests'' to determine the masses and/or ages of specific objects and are mildly relevant to those who would use the ``deuterium limit" to demarcate the boundary between planets and brown dwarfs.

We are happy to acknowledge support from NASA under grants NAG5-10760 and NAG5-10629.


The author(s) of this abstract have provided an email address for comments about the abstract: milsom@physics.arizona.edu

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Bulletin of the American Astronomical Society, 34
© 2002. The American Astronomical Soceity.