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Relations between broad-band linear polarization and Ca II H and K emission in late-type dwarf starsBroadband UBV linear polarization data acquired for a sample of late-type dwarfs are compared with contemporaneous measurements of Ca II H and K line core emission. A weighted average of the largest values of the polarization degree is shown to be the best parameter for chromospheric activity diagnosis. The average maximum polarization in the UV is found to increase from late-F to late-G stars. It is noted that polarization in the U band is considerably more sensitive to activity variations than that in the B or V bands. The results indicate that stellar magnetic fields and the resulting saturation in the Zeeman-sensitive absorption lines are the most probably source of linear polarization in late-type main-sequence stars.
Document ID
19880054383
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Huovelin, Juhani (Joint Inst. for Lab. Astrophysics Boulder, CO, United States)
Saar, Steven H. (Joint Institute for Laboratory Astrophysics Boulder, CO, United States)
Tuominen, Ilkka (Helsinki, University Observatory, Finland)
Date Acquired
August 13, 2013
Publication Date
June 15, 1988
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 329
ISSN: 0004-637X
Subject Category
ASTROPHYSICS
Funding Number(s)
CONTRACT_GRANT: NGL-06-003-057
Distribution Limits
Public
Copyright
Other