Evolution of the Most Massive Stars

Abstract

We discuss the physics of the $ΩΓ$-- Limit, i.e. when the star is unbound as a result of {\emph{both}} rotation and radiation pressure. We suggest that the $ΩΓ$-- Limit is what makes the Humphreys--Davidson Limit. Stellar filiations are discussed, with an emphasis on the final stages, in particular on the final masses, their angular momentum and the chemical yields with account of rotation. A possible relation between WO stars and GRB is emphasized.