We report the results of optical spectroscopy of a candidate evolved massive star in the Cygnus X region, TYC 3159-6-1, revealed via detection of its curious circumstellar nebula in archival data of the Spitzer Space Telecope. We classify TYC 3159-6-1 as an O9.5-O9.7 Ib star and derive its fundamental parameters by using the stellar atmosphere code FASTWIND. The He and CNO abundances in the photosphere of TYC 3159-6-1 are consistent with the solar abundances, suggesting that the star only recently evolved off the main sequence. Proper motion and radial velocity measurements for TYC 3159-6-1 show that it is a runaway star. We propose that Dolidze 7 is its parent cluster. We discuss the origin of the nebula around TYC 3159-6-1 and suggest that it might be produced in several successive episodes of enhanced mass-loss rate (outbursts) caused by rotation of the star near the critical, \Omega-limit.
@article{arxiv.1310.7025,
title = {TYC 3159-6-1: a runaway blue supergiant},
author = {V. V. Gvaramadze and A. S. Miroshnichenko and N. Castro and N. Langer and S. V. Zharikov},
journal= {arXiv preprint arXiv:1310.7025},
year = {2015}
}
Comments
12 pages, 6 figures, accepted for publication in MNRAS