Grids of rotating stellar models with masses between 1.0 and 3.0 M⊙

Abstract

We calculated a grid of evolutionary tracks of rotating models with masses between 1.0 and 3.0 M⊙ and resolution δM ≤ 0.02 M⊙, which can be used to study the effects of rotation on stellar evolution and on the characteristics of star clusters. The value of ∼ 2.05 M⊙ is a critical mass for the effects of rotation on stellar structure and evolution. For stars with M > 2.05 M⊙, rotation leads to an increase in the convective core and prolongs their lifetime on the main sequence (MS); rotating models evolve more slowly than non-rotating ones; the effects of rotation on the evolution of these stars are similar to those of convective core overshooting. However for stars with 1.1 < M/M⊙ < 2.05, rotation results in a decrease in the convective core and shortens the duration of the MS stage; rotating models evolve faster than non-rotating ones. When the mass has values in the range ∼ 1.7–2.0 M⊙, the mixing caused by rotationally induced instabilities is not efficient; the hydrostatic effects dominate processes associated with the evolution of these stars. For models with masses between about 1.6 and 2.0 M⊙, rotating models always exhibit lower effective temperatures than non-rotating ones at the same age during the MS stage. For a given age, the lower the mass, the smaller the change in the effective temperature. Thus rotations could lead to a color spread near the MS turnoff in the color-magnitude diagram for intermediate-age star clusters.