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A study of mass loss from the mid-ultraviolet spectrum of Alpha Cygni /A2 Ia/, Beta Orionis /B8 Ia/, and Eta Leonis /A0 Ib/Results are presented for a study of mass loss from A and late-B supergiants based on high-resolution mid-UV spectra obtained with the echelle spectrograph of the Balloon-borne Ultraviolet Stellar Spectrometer. Spectra of Alpha Cyg, Beta Ori, Eta Leo, and Alpha Lyr are compared in selected wavelength regions; particular attention is given to previous observations of each star, the Mg II and Fe II resonance lines, lines due to other ions, and evidence for mass ejection. The results indicate that mass loss from late-B and A supergiants is variable, that a considerable fraction of envelope material is ejected in 'puffs', and that the puffs may be due to photospheric instabilities. A mass-loss rate of about 1 hundred-millionth of a solar mass per year is derived for Alpha Cyg and shown to be two orders of magnitude smaller than the value determined from the observed IR excess. This discrepancy is attributed to excess ionization in the envelope.
Document ID
19780058389
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Lamers, H. J. G. L. M.
(Osservatorio Astronomico Trieste, Italy)
Stalio, R.
(Osservatorio Astronomico Trieste, Italy)
Kondo, Y.
(NASA Johnson Space Center Houston, Tex.; NASA, Goddard Space Flight Center, Greenbelt, Md., United States)
Date Acquired
August 9, 2013
Publication Date
July 1, 1978
Publication Information
Publication: Astrophysical Journal
Subject Category
Astrophysics
Report/Patent Number
PB-285050
Accession Number
78A42298
Distribution Limits
Public
Copyright
Other

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