Long-term monitoring of active stars. VI. UBV(RI)_c observations collected in Sep.-Oct. 1990
Abstract
In the framework of an extensive program focusing on the global properties and evolution of active stars, high-precision UBV(RI)_c 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. Based on data collected at the European Southern Observatory, La Silla, Chile. Tables and the complete data set are also available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr or via http://cdsweb.u-strasbg.fr/Abstract.html
- Publication:
-
Astronomy and Astrophysics Supplement Series
- Pub Date:
- February 1997
- DOI:
- 10.1051/aas:1997319
- Bibcode:
- 1997A&AS..121..369C
- Keywords:
-
- STARS: ACTIVITY;
- STARS: LATE-TYPE;
- STARS: VARIABLES