Bibcode
Herrero, A.; Kudritzki, R. P.; Vilchez, J. M.; Kunze, D.; Butler, K.; Haser, S.
Bibliographical reference
Astronomy and Astrophysics (ISSN 0004-6361), vol. 261, no. 1, p. 209-234.
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7
1992
Citations
416
Refereed citations
333
Description
We present the results of a spectroscopic analysis of 25 galactic
luminous OB stars. The gravities are in general lower than previously
assumed, especially for giants. The helium abundances are also higher
than normal in many cases. Using data from the spectroscopic analysis,
radii, luminosities and masses are derived. The observed wind terminal
velocities are used with the analytic approximation for the theory of
radiatively driven winds (Kudritzki et al., 1989) to obtain masses and
mass loss rates. The masses derived from the spectroscopic analysis and
those derived independently from the wind theory agree, except for a
small difference attributed to deficiencies in the physics of the model
atmospheres used. A comparison with evolutionary tracks indicates that
(1) evolution theory cannot explain the observed helium abundance
pattern and that (2) the masses derived from the spectroscopic analysis
(or the wind theory) are systematically lower than those derived from
evolutionary calculations.