Observational evidence for a correlation between macroturbulent broadening and line-profile variations in OB Supergiants

Abstract

The spectra of O and B supergiants are known to be affected by a significant form of extra line broadening (usually referred to as macroturbulence) in addition to that produced by stellar rotation. Recent analyses of high resolution spectra have shown that the interpretation of this line broadening as a consequence of large scale turbulent motions would imply highly supersonic velocity fields in photospheric regions, making this scenario quite improbable. Stellar oscillations have been proposed as a likely alternative explanation. As part of a long term observational project, we are investigating the macroturbulent broadening in O and B supergiants and its possible connection with spectroscopic variability phenomena and stellar oscillations. In this letter, we present the first encouraging results of our project, namely firm observational evidence for a strong correlation between the extra broadening and photospheric line-profile variations in a sample of 13 supergiants with spectral types ranging from O9.5 to B8.

8 pages, 3 figures, accepted for publication in ApJL

References in corpus (6)

• Abundance analysis of prime B-type targets for asteroseismology I. Nitrogen excess in slowly-rotating beta Cephei stars
• Statistical properties of a sample of periodically variable B-type supergiants - Evidence for opacity-driven gravity-mode oscillations
• Most Detects G- and P-Modes in the B Supergiant HD 163899 (B2Ib/II)
• Solar-like oscillations in a massive star
• The superimposed photospheric and stellar wind variability of the O-type supergiant alpha Cam
• Wind structure of late B supergiants I. Multi-line analyses of near-surface and wind structure in HD 199 478 (B8 Iae)

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