Bartol Research Institute, University of Delaware, Newark, DE 19716, USA

I review the basic concepts of the Rigidly Rotating Magnetosphere model for the circumstellar plasma distribution around the helium-strong star  Ori E. I demonstrate that the model can furnish a good fit to the photometric, spectroscopic and magnetic variability exhibited by this star, and argue that the variability of other helium-strong stars may be amenable to a similar interpretation.

To appear in "Active OB Stars: Laboratories for Stellar & Circumstellar Physics", ASP Conf. Ser. 2005, S. Stefl, S. P. Owocki, & A. Okazaki, eds.
Preprints from rhdt@bartol.udel.edu
Or on the web at http://www.star.ucl.ac.uk/~rhdt/publications/