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Chromospheric Ca II H and K and H-alpha emission in single and binary stars of spectral types F6-M2New observations of the Ca II H and K and H-epsilon region and/or the Balmer H-alpha line are presented for 100 mostly very active stars but also for weak or inactive stars with suspected activity. Correlations between chromospheric activity at Ca II H and K and H-alpha and effective surface temperature and rotation are identified, and several new stars with chromospheric Ca II H and K emission are discovered. No single activity-rotation relation can be derived for all luminosity classes, and there is clear evidence that evolved stars are generally more active than main-sequence stars of the same rotation period. Binary within the evolved stars appears to play no role, while main-sequence binary stars show generally higher levels of activity than their single counterparts. Chromospheric emission in the Ca II H and K lines depends on surface temperature in that flux declines with cooler temperature.
Document ID
19900037491
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Strassmeier, Klaus G.
(Vanderbilt Univ. Nashville, TN, United States)
Fekel, Francis C.
(Vanderbilt University Nashville, TN, United States)
Bopp, Bernard W.
(Dominion Astrophysical Observatory, Victoria, Canada; Toledo, University OH, United States)
Dempsey, Robert C.
(Toledo, University OH, United States)
Henry, Gregory W.
(McDonald Observatory, Austin, TX; Tennessee State University Nashville, United States)
Date Acquired
August 14, 2013
Publication Date
January 1, 1990
Publication Information
Publication: Astrophysical Journal Supplement Series
Volume: 72
ISSN: 0067-0049
Subject Category
Astrophysics
Accession Number
90A24546
Funding Number(s)
CONTRACT_GRANT: NAG8-111
CONTRACT_GRANT: NSF AST-85-20542
Distribution Limits
Public
Copyright
Other

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