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EUV Radiation from B Stars: The Broad Implications for Stellar and Interstellar Astronomy

Published online by Cambridge University Press:  12 April 2016

Joseph P. Cassinelli
Joseph P. Cassinelli*
Affiliation:
Astronomy Department, University of Wisconsin, 475 N. Charter St., Madison, WI 53706, USA

Abstract

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Observations made with the Extreme Ultraviolet Explorer (EUVE) of the two bright stars ϵ CMa (B2 II) and β CMa (Bl II-III) are discussed. The photospheres show excess EUV radiation. The wind of ϵ CMa exhibits the Bowen Fluorescence mechanism, along with high ionization stages that help explain the nature of the wind shocks. The pulsation and beat phenomena exhibited by the variable star β CMa suggest that deposition of residual pulsation energy might heat and modify the structure of the atmospheres of early-type stars near the β Cephei strip. The possibility that many other B stars show a large excess Lyman continuum radiation is considered as a possible source of the ionization of the warm ionized medium (WIM) in the galactic ISM.

Type
VII. Photospheres and Winds of Early-Type Stars
Information
International Astronomical Union Colloquium , Volume 152: Astrophysics in the Extreme Ultraviolet , 1996 , pp. 367 - 374
Copyright
Copyright © Kluwer 1996

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