Non-thermal radio emission from O-type stars III. Is Cyg OB2 No. 9 a wind-colliding binary?
Astrophysics
2009-11-13 v1
Abstract
The star Cyg OB2 No. 9 is a well-known non-thermal radio emitter. Recent theoretical work suggests that all such O-stars should be in a binary or a multiple system. However, there is no spectroscopic evidence of a binary component. Re-analysis of radio observations from the VLA of this system over 25 years has revealed that the non-thermal emission varies with a period of 2.35+-0.02 yr. This is interpreted as a strong suggestion of a binary system, with the non-thermal emission arising in a wind-collision region. We derived some preliminary orbital parameters for this putative binary and revised the mass-loss rate of the primary star downward from previous estimates.
Keywords
Cite
@article{arxiv.0803.2607,
title = {Non-thermal radio emission from O-type stars III. Is Cyg OB2 No. 9 a wind-colliding binary?},
author = {S. Van Loo and R. Blomme and S. M. Dougherty and M. C. Runacres},
journal= {arXiv preprint arXiv:0803.2607},
year = {2009}
}
Comments
13 pages, 5 figures, includes online data, accepted by A&A