Structure and evolution of low-mass stars *
Gilles Chabrier and Isabelle Baraffe
Received 12 November 1996 / Accepted 11 April 1997
We present extensive calculations of the structure and the evolution of low-mass stars in the range 0.07-0.8 , for metallicities . These calculations are based on the most recent description of the microphysics characteristic of these dense and cool objects and on the latest generation of grainless non-grey atmosphere models. We examine the evolution of the different mechanical and thermal properties of these objects as a function of mass and metallicity. We also demonstrate the inaccuracy of grey models and relationships under these conditions. We provide detailed tables of the mass-radius-luminosity-effective temperature relations for various ages and metallicities, aimed at calibrating existing or future observations of low-mass stars and massive brown dwarfs. We derive new hydrogen-burning minimum masses, within the afore-mentioned metallicity range. These minimum masses are found to be smaller than previous estimates, a direct consequence of non-grey effects.
At last, we examine the evolution of the abundance of light elements, and B, as a function of age, mass and metallicity.
Key words: stars: low mass, brown dwarfs - stars: abundances
© European Southern Observatory (ESO) 1997
Online publication: April 6, 1998