¹ Bartol Research Institute, University of Delaware, Newark, DE 19711, USA
² Hamburger Sternwarte, Gojenbergsweg 112, 21029 Hamburg, Germany

We attempt to characterize the observed variability of the magnetic helium-strong star  Ori E in terms of a recently developed rigidly rotating magnetosphere model. This model predicts the accumulation of circumstellar plasma in two co-rotating clouds, situated in magnetohydrostatic equilibrium at the intersection between magnetic and rotational equators. We find that the model can reproduce well the periodic modulations observed in the star's light curve, H emission-line profile, and longitudinal field strength, confirming that it furnishes an essentially correct, quantitative description of the star's magnetically controlled circumstellar environment.

Accepted by ApJL
Offprints from rhdt@bartol.udel.edu
Or on the web at http://www.star.ucl.ac.uk/~rhdt/publications/