Massive stars near the Eddington-limit, pulsations & mass-loss

Abstract

AbstractVery massive stars (in excess of ~ 100 M⊙) and massive stars in pre-SN phases at the end of their evolution are continuously approaching the Eddington limit. According to our theoretical predictions their high Eddington factors lead to a peculiar sub-photospheric structure and enhanced mass-loss. Their proximity to the Eddington limit is thus likely the reason why these objects appear as LBVs and WR stars. Here we discuss how our predictions relate to the characteristics of strange-mode pulsations, and how rotating massive stars at low metallicities can produce spectroscopic signatures that have recently been observed in a sample of star-forming galaxies at redshifts z ≈ 2 – 4.