Astronomy and Astrophysics Supplement Series, Vol. 120, November II 1996, 57-61
Grids of pre-main sequence stellar models. The accretion scenario at Z=0.001 and Z=0.020
Observatoire de Genève, CH-1290 Sauverny, Switzerland
Received February 12; accepted April 5, 1996
Abstract:I present and briefly discuss a new set of pre-main sequence (MS) evolutionary tracks computed in the framework of the accretion paradigm for star formation at metallicities Z=0.001 and Z=0.020. Improved birthlines are obtained from a time-dependent prescription for the accretion rate. These evolutionary sequences are better suited than the canonical approach which starts arbitrarily high on a luminous Hayashi adiabat, to interpret color-magnitude diagrams and ages of young stellar associations. They also constitute a (both physical and numerical) self-consistent extension to the post-MS stellar models previously published by the Geneva group (Schaller et al. 1992).
Key words: stars: evolution --- stars: pre-main sequence --- Hertzsprung-Russel (HR) diagram