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Rotationally Modulated Winds of BA-Type Supergiants

Published online by Cambridge University Press:  12 April 2016

Andreas Kaufer*
Affiliation:
Landessternwarte Heidelberg, Königstuhl 12, D-69117 Heidelberg, Germany

Abstract

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Extended spectroscopic monitoring programs with high resolution and coverage in wavelength and time have revealed a new picture of the winds and the circumstellar environments of late B- and early A-type supergiants. Dramatic line-profile variations (LPV) of the wind-sensitive Hα line with characteristic cyclical V/R variations indicate the presence of deviations of the envelopes from spherical symmetry. Time-series analysis of these LPVs suggest that the wind variations are caused by rotating surface structures which modulate the lower wind region. Occasionally observed high-velocity absorptions (HVA) indicate the presence of rotating extended and dense streakline or loop structures in the envelopes. The potential use of these circumstellar features to determine the true stellar rotation periods is discussed.

Type
Section I Observations of Non-spherical Winds
Copyright
Copyright © Springer-Verlag 1999

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