On the effect of overshooting as predicted by the modelling of the pre-main sequence evolution of a 2 solar-mass star
arXiv:astro-ph/0606029 · doi:10.1111/j.1365-2966.2006.10636.x
Abstract
We discuss the effects of convective overshooting in the PMS evolution of intermediate mass stars, by analysing in detail the early evolution towards the main sequence of a 2 M_sun stellar model. These effects can be extremely important in the end of the PMS, when the abundances in CNO elements approach the equilibrium in the centre. We provide a possible physical explanation on why a moderate amount of overshooting produces, as the star approaches the ZAMS, an extra loop in the evolutionary tracks on the HR diagram. An interesting feature is that there is a very well defined amount of overshooting (for a given stellar mass and chemical composition) beyond which a loop is produced. For smaller amounts of overshooting such a loop does not take place and the evolutionary tracks are similar to the ones obtained by Iben (1965). The amount of overshooting needed to produce the loop decreases with stellar mass. We discuss the underlining physical reasons for the behaviour predicted by the evolution models and argue that it provides a crucial observational test for convective overshooting in the core of intermediate mass stars.
arXiv comment10 pages and 7 figures - to appear in MNRAS
References in corpus (6)
- Stellar Turbulent Convection: A Selfconsistent Model
- Simulations of core convection in rotating A-type stars: Differential rotation and overshooting
- Rotational Evolution of Solar-Like Stars in Clusters from Pre-Main Sequence to Main Sequence: Empirical Results
- A Theory of Non-Local Mixing Length Convection. III. Comparing Theory and Numerical Experiment
- The role of the time step and overshooting in the modelling of PMS evolution: the case of EK Cephei
- Time dependent mixing in He-burning cores: the case of NGC1866