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Temperatures and radii of O stars

Published online by Cambridge University Press:  14 August 2015

A. B. Underhill
Affiliation:
∗Goddard Space Flight Center, Greenbelt, MD; temporarily at∗∗
L. Divan
Affiliation:
∗∗Institut d'Astrophysique, Paris, France
V. Doazan
Affiliation:
∗∗∗Observatoire de Paris, Paris, France
M.L. Prévot-Burnichon
Affiliation:
∗∗Institut d'Astrophysique, Paris, France

Abstract

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Angular diameters have been estimated for 18 O and 142 B stars using absolute intermediate-band photometry in the near infrared and they have been combined with integrated fluxes to yield effective temperatures. The effective temperatures of the O stars lie in the range 30000 K to about 47000 K. For a given subtype, the luminosity class I stars have lower effective temperatures than the main-sequence stars by about 1000 K. The absorption-line spectral types of the supergiants of types O and B reflect electron temperatures which are higher than can be maintained by the integrated flux which flows through the stellar atmosphere. Distances have been estimated for all the stars and linear diameters found. The average radius for an 08 to 09.5 supergiant is about 23.3 R; the radii for luminosity class III and Class V O stars lie in the range 6.8 to 10.7 R.

Type
Session 2: U.V. Spectroscopy
Copyright
Copyright © Reidel 1979 

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