The Photosphere -- Wind Connection in HD 64760
Abstract
The intrinsically fast rotating early-type B supergiant HD 64760 (B0.5 Ib) exhibits the most striking and clearly systematic wind structure of all known O and early B supergiant stars studied in the UV tep{1995ApJ...452L..61P}. With the discovery of strictly periodic and sinusoidal modulations of the UV resonance lines at periods of 1.2 and 2.4 days tep{1997A&A...327..699F}, HD 64760 has become a key object in the study of spatially structured hot star winds and their connection to the stellar surface.
We present the results from extended optical spectroscopic time series observations, which allows one to probe the transition zone between the photosphere and the base of the stellar wind. The confirmation of the periodic 2.4-day signal in the Hα line tep{2002A&A...382.1032K} suggests that the prominent wind modulation as probed by the UV resonance lines at high outflow velocities is rooted to the base of the wind. The possible connections of the wind structure with the very recently discovered multi-periodic non-radial pulsations in the photosphere tep{2005astro.ph.10511K} is discussed in some detail.- Publication:
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Active OB-Stars: Laboratories for Stellare and Circumstellar Physics
- Pub Date:
- March 2007
- Bibcode:
- 2007ASPC..361..179K