Constraints on Mixing Processes from Abundance Anomalies

Abundance anomalies in the Sun, main sequence F, A and B stars, turnoff Pop II stars, the horizontal branch and white dwarfs are caused at least partly by particle transport processes. Detailed evolutionary models have been calculated for most of those objects taking into account the gravitational settling, thermal diffusion and radiative accelerations of 28 isotopes (24 atomic species). These will be used together with the observed abundances to put constraints on the mixing that rotationnally induced turbulence may lead to. The link between abundance anomalies and rotation on the HB is explained by the variation with log g of the ratio of the Eddington-Sweet and atomic diffusion velocities.