New grids of stellar models including tidal-evolution constants up to carbon burning

Abstract

New stellar models spefically designed for the Small Magellanic Cloud are presented in this paper. In order to take into account the uncertainties in the metal content we computed two grids with different metallicities: Z = 0.002 and Z = 0.004. The covered mass range is from 0.8 up to 125 M ○. and the models are followed until the exhaustion of carbon in the core, for the more massive ones. We have introduced a recent measurement of the nuclear rate 14 N(p,γ) 15 O. A comparison among models with the old and new rate was carried out revealed that the former are slightly hotter than the first ones. Such differences depend on the mass range. The opacities, the equation of state, the remaining nuclear reactions rates, the core overshooting parameterization and the convective transport of energy are the same as discussed previously by us. We also give, besides the classical evolutionary models outputs, the internal structure constants needed to investigate apsidal motion and tidal evolution in close binaries. This aspect acquires importance in the light of recent investigations on circularization and synchronization levels in binary systems belonging to the Magellanic Clouds. The role of rotation can also be investigated through the gravity-darkening exponents which allow us to compute the brightness distribution of a given stellar surface.