Grids of rotating stellar models with masses between 1.0 and 3.0 Msun

Abstract

We calculated a grid of evolutionary tracks of rotating models with masses between 1.0 and 3.0 $M_{\odot }$ and a resolution $\hat{I}´M\le 0.02$ $M_{\odot }$, which can be used to study the effects of rotation on stellar evolutions and on the characteristics of star clusters. The value of $\sim$2.05 $M_{\odot }$ is a critical mass for the effects of rotation on stellar structure and evolution. For stars with $M>$ 2.05 $M_{\odot }$, rotation leads to an increase in the convective core and prolongs the lifetime of main sequence (MS); rotating models evolve slower 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 $<M/M_{\odot }<$ 2.05, rotation results in a decrease in the convective core and shortens the lifetime of MS; rotating models evolve faster than non-rotating ones. When the mass is located in the range of $\sim$1.7 - 2.0 $M_{\odot }$, the mixing caused by rotationally induced instabilities is not efficient; the hydrostatic effects dominate the effect on the evolution of these stars. For the models with masses between about 1.6 and 2.0 $M_{\odot }$, 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 the intermediate-age star clusters.

13 pages, 10 figures. Accepted for publication in RAA