Wind variability of LBV stars

Israelian, G. L.
Bibliographical reference

Astrophysics and Space Science (ISSN 0004-640X), vol. 210, no. 1-2, p. 239-243 (IAU Colloquium 134)

Advertised on:
12
1993
Number of authors
1
IAC number of authors
0
Citations
0
Refereed citations
0
Description
General properties of Luminous Blue Variables (LBV) have been reviewed by Lamers (1987). The LBV's are all close to the Humphreys-Davidson luminosity upper limit. The semi periods of the photometric microvariations with Delta V is about 0.1m are about twice as large as for normal supergiants of the same L and Teff, and 4-20 times larger than the fundamental mode for radial pulsations. So, it is likely due to nonradial pulsations. During shell ejections, which accompanied by moderate photometric variations of Delta V is about 1m, Lbol remains constant. This fact has been explained by the quasiperiodic variations of Teff and the radius of pseudo-photosphere (Lamer 1986). LBV's are less stable than normal supergiants so that any internal instability has more effect on their envelopes. The nature of these instabilities remains unknown. We have found some interesting peculiarities which can throw light to this problem.