next previous
Up: Abstract

A&A Supplement series, Vol 122, February 1997, 368-378

Received April 22; accepted June 6, 1996

Long-term monitoring of active stars.

VI. tex2html_wrap_inline1666 observations collected in Sep.-Oct. 1990giftex2html_wrap_inline1668gif

G. Cutispoto tex2html_wrap1682 - G. Leto tex2html_wrap1684

Send offprint request: G. Cutispoto

tex2html_wrap1686  Osservatorio Astrofisico di Catania, V.le A.Doria 6, I-95125 Catania, Italy
tex2html_wrap1688  Istituto di Rastronomia, C.P. 141, I-96017, Noto (SR), Italy


In the framework of an extensive program focusing on the global properties and evolution of active stars, high-precision tex2html_wrap_inline1670 photometry of 9 selected stars, collected at the European Southern Observatory over the intervals 7-17 September and 30 September - 10 October 1990, is presented. Significant evolution of the light curves, period variations and evidence for long-term variability of the global degree of spottedness are found. Some of the spectral classifications are discussed. These observations contribute to the establishment of a time-extended photometric database which can give important clues on topics such as the stability of the spotted areas, differential rotation, solar-like cycles and the correlation between inhomogeneities at different atmospheric levels.

keywords: stars: activity -- stars: late-type -- stars: variables

Copyright by the European Southern Observatory (ESO)