Center for High Angular Resolution Astronomy, Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303, U.S.A.

We present an analysis of the kinematics of Be stars based on Hipparcos proper motions and published radial velocities. We find approximately 23 of the 344 stars in our sample have peculiar space motions greater than 40 km/s, and a similar number are found at large distances from the galactic plane (|z| > 1200 pc). We argue that these high velocity stars are either the result of a supernova that disrupted a binary or they were ejected by close encounters of binaries in young clusters. Be stars spun up by binary mass transfer will only appear as high velocity objects if there was significant mass loss during the supernova explosion of the initially more massive star, but the moderate peculiar velocities of Be X-ray binaries indicate that the progenitors lost most of their mass prior to the supernova (in accordance with model predictions). Whether all Be stars were spun up by binary mass transfer remains unknown, since the post-mass transfer companions are difficult to observe.

Submitted to ApJ
Preprints from gies@chara.gsu.edu