Spectroscopic monitoring of OBA stars

摘要: We have been using the fiber-linked echelle spectrograph described by Mandel (these proceedings) at various telescopes, both in conditions of central Europe and excellent La Silla. Our main objects study were early-type stars, mainly supergiants. studies show that variability stars displays a large variety phenomena. The variations are generally irregular. There exceptions, however, as surprising case θ1Ori C. Most on several widely-different time-scales, which makes their particularly difficult. Spherical symmetry may be violated many cases, suggested, e.g., variable blue red-shifted emission components.