Discovery of rotational braking in the magnetic helium-strong star sigma orionis e

Citation data:

Astrophysical Journal Letters, ISSN: 2041-8213, Vol: 714, Issue: 2 PART 2, Page: L318-L322

Publication Year:
2010
Usage 26
Downloads 16
Abstract Views 10
Captures 8
Readers 8
Citations 49
Citation Indexes 49
arXiv Id:
1004.2038
DOI:
10.1088/2041-8205/714/2/l318
Repository URL:
https://works.swarthmore.edu/fac-physics/16; http://arxiv.org/abs/1004.2038
Author(s):
Townsend, R. H.D.; Oksala, M. E.; Cohen, David H.; Owocki, S. P.; Ud-Doula, A.
Publisher(s):
IOP Publishing
Tags:
Physics and Astronomy; Earth and Planetary Sciences; Astrophysics and Astronomy; Astrophysics - Solar and Stellar Astrophysics
article description
We present new U-band photometry of the magnetic helium-strong star σ Ori E, obtained over 2004-2009 using the SMARTS 0.9 m telescope at Cerro Tololo Inter-American Observatory. When combined with historical measurements, these data constrain the evolution of the star's 1.19 day rotation period over the past three decades. We are able to rule out a constant period at the p= 0.05% level, and instead find that the data are well described (p= 99.3%) by a period increasing linearly at a rate of 77 ms per year. This corresponds to a characteristic spin-down time of 1.34 Myr, in good agreement with theoretical predictions based on magnetohydrodynamical simulations of angular momentum loss from magnetic massive stars. We therefore conclude that the observations are consistent with σ Ori E undergoing rotational braking due to its magnetized line-driven wind. © 2010. The American Astronomical Society. All rights reserved.