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Solar plages and the interpretation of stellar Ca 2 H and K line variations in late type dwarfsApproximately a dozen late type dwarf stars have been observed by Wilson (1978) to undergo cyclic variability in Ca II H and K line emission which seems analogous to the solar activity cycle. What might be learned about these stars from solar analogies? The Ca II K index is estimated variation of the Sun viewed as a star, and compared with the observed range of Wilson's stellar observations. Results indicate trends of increasing relative variation H-K(max)/H-K(min) with later spectral type, due to decreasing dilutional contribution of residual photospheric flux to a 1 A band at line center, and of increasing relative variation with decreasing relative time of rise to maximum tau rise/tau reminiscent of the observed solar correlation of a quick rise to sunspot maximum with a strong cycle.
Document ID
Document Type
Conference Paper
Cook, J. W. (Hulburt (E. O.) Center for Space Research Washington, DC, United States)
Date Acquired
August 11, 2013
Publication Date
January 1, 1981
Publication Information
Publication: Smithsonian Astrophysics Observatory 2nd Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, Vol. 1
Subject Category
Distribution Limits
Work of the US Gov. Public Use Permitted.

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IDRelationTitle19830012575Analytic PrimarySecond Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, volume 1