| Issue |
Astron. Astrophys. Suppl. Ser.
Volume 121, Number 2, February 1997
|
|
|---|---|---|
| Page(s) | 368 - 378 | |
| DOI | https://doi.org/10.1051/aas:1997319 | |
| Published online | 15 February 1997 | |
Long-term monitoring of active stars.*,**
VI. 
observations collected in
Sep.-Oct. 1990
1
Osservatorio Astrofisico di Catania, V.le A.Doria 6, I-95125 Catania, Italy e-mail: gcutispoto@astrct.ct.astro.it
2
Istituto di Rastronomia, C.P. 141, I-96017, Noto (SR), Italy
Send offprint request to: G. Cutispoto
Received:
22
April
1996
Accepted:
6
June
1996
In the framework of an extensive program focusing on the global properties and
evolution of active stars, high-precision 
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.
Key words: stars: activity / stars: late-type / stars: variables
© European Southern Observatory (ESO), 1997