MOST Observations of σ Ori E: Challenging the Centrifugal Breakout Narrative

Author(s)

R. H. D. Townsend, Th. Rivinius, J. F. Rowe, A. F. J. Moffat, J. M. Matthews, D. Bohlender, C. Neiner, J. H. Telting, D. B. Guenther, T. Kallinger, R. Kuschnig, S. M. Rucinski, D. Sasselov, W. W. Weiss

Abstract

We present results from three weeks' photometric monitoring of the

magnetic helium-strong star σ Ori E using the Microvariability and

Oscillations of Stars microsatellite. The star's light curve is

dominated by twice-per-rotation eclipse-like dimmings arising when

magnetospheric clouds transit across and occult the stellar disk.

However, no evidence is found for any abrupt centrifugal breakout of

plasma from the magnetosphere, either in the residual flux or in the

depths of the light minima. Motivated by this finding we compare the

observationally inferred magnetospheric mass against that predicted by a

breakout analysis. The large discrepancy between the values leads us to

argue that centrifugal breakout does not play a significant role in

establishing the magnetospheric mass budget of σ Ori E.

Organisation(s)

Department of Astrophysics

External organisation(s)

Harvard-Smithsonian Center for Astrophysics, University of Wisconsin, Madison, European Southern Observatory (Germany), National Aeronautics & Space Administration (NASA), University of Montreal, National Research Council Canada (NRC-CNRC), Nordic Optical Telescope, Saint Mary's University, University of Toronto, University of British Columbia (UBC), Université Paris VII - Paris-Diderot

Journal

The Astrophysical Journal

Volume

769

No. of pages

5

DOI

https://doi.org/10.1088/0004-637X/769/1/33

Publication date

05-2013

Peer reviewed

Yes

Austrian Fields of Science 2012

103004 Astrophysics, 103003 Astronomy

Keywords

Portal url

https://ucrisportal.univie.ac.at/en/publications/1929f31d-8c3a-4ae4-91f8-89dc0e08ecac