The spectral variations of the O-type runaway supergiant HD 188209

Abstract

We report spectral time series of the late O-type runaway supergiant HD 188209. Radial velocity variations of photospheric absorption lines with a possible quasi-period ~ 6.4 days have been detected in high-resolution echelle spectra. Night-to-night variations in the position and strength of the central emission reversal of the Ha profile occuring over ill-defined time-scales have been observed. The fundamental parameters of the star have been derived using state-of-the-art plane--parallel and unified non-LTE model atmospheres, these last including the mass-loss rate. The derived helium abundance is moderately enhanced with respect to solar, and the stellar masses are lower than those predicted by the evolutionary models. The binary nature of this star is not suggested either from Hipparcos photometry or from radial velocity curves.

arXiv comment15 pages, 13 figures, MNRAS, accepted

Cited by in corpus (5)

• The Origin of Massive O-type Field Stars. Part I: A Search for Clusters
• Bright OB stars in the Galaxy.II. Wind variability in O supergiants as traced by H-alpha
• Kepler sheds new and unprecedented light on the variability of a blue supergiant: gravity waves in the O9.5Iab star HD 188209
• Radial dependence of line profile variability in seven O9--B0.5 stars
• First results from the LIFE project: discovery of two magnetic hot evolved stars