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Stellar Lyman-alpha emission and the local interstellar mediumThe UV spectra now available in the IUE archives have been systematically searched for the presence of Lyman-alpha emission in late-type stars. The results provide the first survey of the behavior of the Ly-alpha emission line across most of the cool half of the H-R diagram. The normalized Ly-alpha emission flux is strongest in the chromospherically active RS CVn stars and in the dMe stars. The range of normalized flux values is much smaller among F-type stars than in stars of later spectral type. A dropoff appears in the flux levels of stars at B-V less than 0.30 mag. The measurements are used to search for evidence of possible high column density clouds in the local ISM. The cloud previously identified toward Alpha Oph may be seen in the reduced flux observed toward Beta Oph.
Document ID
19910035812
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Landsman, Wayne
(ST Systems Corp. Greenbelt, MD, United States)
Simon, Theodore
(Hawaii, University Honolulu, United States)
Date Acquired
August 15, 2013
Publication Date
January 10, 1991
Publication Information
Publication: Astrophysical Journal, Part 2 - Letters
Volume: 366
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
91A20435
Funding Number(s)
CONTRACT_GRANT: NAS5-30446
CONTRACT_GRANT: NAG5-146
Distribution Limits
Public
Copyright
Other

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