Theoretical Instability Domains of Massive Stars

Massive stars are characterized by a large radiation over gas pressure ratio. With increasing stellar initial mass, they suffer stronger stellar winds, and the induced mass-loss affects the evolution and internal structure on the main sequence and on the post-main sequence. Recent ground-based observations and space missions have shown the presence of pulsations in massive stars, such as acoustic and gravity modes excited by the κ-mechanism and even solar-like oscillations. Strange modes could also be excited in the most massive stars (Aerts et al. 2010). We computed evolutionary tracks and non-adiabatic frequencies for initial masses ranging from 15 to 70 M[SUB]&sun;[/SUB] on the main sequence and on the post-main sequence taking mass loss into account and we discuss in this paper the results for 25 M[SUB]&sun;[/SUB] models.