Rotation and Macroturbulence in Supergiant Stars

Abstract

AbstractA statistical investigation has been made of rotation and macroturbulence in early type la and lab supergiants. The principal results are: (1) At all spectral types in the range B0-A5 both rotation and macroturbulence contribute to the observed line broadening. In the early B stars rotation is as important a broadening agent as large-scale mass motion. In the middle B and A stars turbulence dominates but there still is an appreciable contribution from rotation. (2) In spite of the fact that the stars observed seem to be losing mass, there is no strong evidence for significant angular momentum loss.