Models of Achernar : evolution and atmospheres of a rapidly rotating B star

Abstract

I investigate the effects of varying internal angular momentum distributions on the SEDs of massive stars. Rapidly rotating stars are deformed by rotation, and the degree of deformation can give us a further constraint on stellar evolution models, possibly allowing us to constrain the internal angular momentum distribution of these stars. I have modelled three different internal angular momentum distributions: uniform rotation and two different power law distributions. I use a fully implicit 2D stellar evolution code to determine the variation in surface properties exactly. The variation in surface properties of these evolutionary models are then used as the input for atmospheric modelling. I have made a grid of atmospheric intensities at values of T eff and log g , which I then use to interpolate the intensities in the direction of the observer over the surface of the star to produce a synthetic spectral energy distribution. I have used Achernar as a test case for this modelling.