Bibcode
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
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.