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Long-term behaviour of starspots. III - Active longitudes on the long-period RS CVn star HK LacertaeThirteen years of photometry were used to study active longitudes on the surface of HK Lacertae. The decaying and forming phenomena of active areas in the years of 1980-1981, 1983-1984, and 1988-1989 are shown. New activity centers suddenly occur near the same orbital phase (0.6) and have lifetimes of several (greater than 6) years. The average rotational period of HK Lac is 24.2852 d; compared to the orbital period of 24.4284 d, this implies a 32 degree/year drift of the active areas on the stellar surface. Two possible interpretations for the period difference are discussed: pseudosynchronism and rigidity of magnetic patterns. The active longitudes on HK Lac are compared with similar phenomena found on the sun.
Document ID
19920033229
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Olah, K.
(Konkoly Observatory Budapest, Hungary)
Hall, D. S.
(Dyer Observatory Nashville, TN, United States)
Henry, G. W.
(Tennessee State University Nashville, United States)
Date Acquired
August 15, 2013
Publication Date
November 1, 1991
Publication Information
Publication: Astronomy and Astrophysics
Volume: 251
Issue: 2
ISSN: 0004-6361
Subject Category
Astrophysics
Accession Number
92A15853
Funding Number(s)
CONTRACT_GRANT: NSF AST-84-14594
CONTRACT_GRANT: NAG8-111
Distribution Limits
Public
Copyright
Other

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