¹ Bartol Research Institute, University of Delaware, Newark DE 19350
² Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ UK

The characteristic signature of Be stars is the Balmer line emission understood to arise in a circumstellar disk. Unlike the accretion disks of protostars or mass-exchange binary systems, the evolved and generally single or wide-binary status of Be stars seems to require that its disk must form from mass ejection (a.k.a. decretion) from the star itself. In this paper, I use analogies with launching orbital satellites to discuss two candidate processes (radiation, pulsation) for driving such orbital mass ejection, with particular emphasis on the role of the rapid, possibly near-critical, rotation of Be stars in facilitating the formation of their signature disks.

to appear in Stellar Rotation, Proceedings IAU Symposium No. 215, 2003, André Maeder & Philippe Eenens, eds.
Preprints from owocki@bartol.udel.edu