OBSERVATIONAL EVIDENCE FOR GLOBAL OSCILLATIONS IN BE STAR DISKS

From a long-term spectroscopic observing campaign of Be stars we have found that their emission line profiles separate into two classes, the second of which is very asymmetric. The sign of asymmetry changes on a timescale of a few years. We show that these line profiles and the w ell-known enigmatic V/R variations observed in some Be stars are two a spects of the same phenomenon, one-armed global oscillations in a Kepl erian disk. We present model profiles and a line fit to support this h ypothesis and find good overall agreement.