## The rigidly rotating magnetosphere of $\sigma$ Ori E

R. H. D. Townsend$^{1}$, S. P. Owocki$^{1}$ and D. Groote$^{2}$

1 - Bartol Research Institute, University of Delaware, Newark, DE 19716, USA; 2 - Hamburger Sternwarte, Gojenbergsweg 112, 21029 Hamburg, Germany

We attempt to characterize the observed variability of the magnetic
helium-strong star $\sigma$ 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$\alpha$ emission-line profile, and longitudinal field strength,
confirming that it furnishes an essentially correct, quantitative
description of the star's magnetically controlled circumstellar
environment.

Reference: ApJL
Status: Manuscript has been accepted