000001988 001__ 1988
000001988 005__ 20160701171656.0
000001988 0247_ $$2DOI$$a10.1051/0004-6361:200809367
000001988 037__ $$aASTROimport-145
000001988 100__ $$avan Loo, S.
000001988 245__ $$aNon-thermal radio emission from O-type stars. III. Is Cygnus OB2 No. 9 a wind-colliding binary?
000001988 260__ $$c2008
000001988 520__ $$aThe star Cyg OB2 No. 9 is a well-known non-thermal radio emitter. Recent theoretical work suggests that all such O-stars should be in a binary or a multiple system. However, there is no spectroscopic evidence of a binary component. Re-analysis of radio observations from the VLA of this system over 25 years has revealed that the non-thermal emission varies with a period of 2.35±0.02 yr. This is interpreted as a strong suggestion of a binary system, with the non-thermal emission arising in a wind-collision region. We derived some preliminary orbital parameters for this putative binary and revised the mass-loss rate of the primary star downward from previous estimates. Appendix A is only available in electronic form at http://www.aanda.org 
000001988 700__ $$a Blomme, R.
000001988 700__ $$a Dougherty, S. M.
000001988 700__ $$a Runacres, M. C.
000001988 773__ $$c585-590$$i2$$pAstronomy and Astrophysics$$v483$$y2008
000001988 85642 $$ahttp://esoads.eso.org/abs/2008A%26A...483..585V
000001988 905__ $$apublished in
000001988 980__ $$aREFERD