Photospheric velocity fields in the O-type stars

Abstract

view Abstract Citations (35) References (29) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Photospheric velocity fields in the O-type stars. Ebbets, D. Abstract The longstanding problem of line-broadening mechanisms in early-type stars has been reinvestigated. By analyzing either the He I 4471-A or the He II 4541-A line in both the wavelength and Fourier-transform domains, it is possible to measure the rotation and macroturbulence separately in individual stars. When the macroturbulence is assumed to have a Gaussian form, a velocity dispersion of about 30 km/s is found for the supergiants, but little or no turbulence is observed in the main-sequence stars. Radial-velocity measurements show a significant progression in the hydrogen Balmer lines for the supergiants, but no such effect is seen in the main-sequence stars. The turbulence and Balmer progression correlate well with each other, and with the stellar-wind velocities observed in the ultraviolet. Publication: The Astrophysical Journal Pub Date: January 1979 DOI: 10.1086/156759 Bibcode: 1979ApJ...227..510E Keywords: Atmospheric Turbulence; O Stars; Photosphere; Spectral Line Width; Stellar Atmospheres; Stellar Spectra; Supergiant Stars; Balmer Series; Early Stars; Fourier Transformation; Line Spectra; Radial Velocity; Spectrum Analysis; Stellar Rotation; Stellar Winds; Astrophysics; Line Broadening:Stellar Photospheres; Line Profiles:Stellar Photospheres; O Stars:Photospheres; Stellar Photospheres:Turbulence; Stellar Photospheres:Velocities full text sources ADS | data products SIMBAD (19)