This collection of papers describes the evolutionary path of stars of various masses. Observational data and theoretical modeling of the stellar atmosphere and the stellar interior and their interaction are presented, covering chemical peculiarities, mass loss, and explosion, all of which are strongly related to the hydrodynamic evolution of the interior. In particular the supernova SN 1987 A is discussed for the first time in detail, including the underground neutrino observations and the detection of X-rays from the supernova. The study of its progenitor, a B 3 supergiant, was related to...