The Catania Automatic Photoelectric Telescope on Mt. Etna: A systematic study of magnetically active stars

A photometric monitoring of about 50 magnetically active stars, that are spread almost all over the H-R diagram, was initiated at the mountain station of Catania Observatory on Mt. Etna (1750-m a.s.l.) in 1992 with an 80-cm robotic telescope (APT-80) built by AutoScope Co. (USA). This systematic survey is now approaching its 10th year anniversary. For most of the stars, quite well defined solar-like spot maps have been derived from UBV data obtained in different epochs. These data have allowed us to investigate some relevant characteristics of spot activity and variability on stars, and to obtain clear evidence of long-term activity cycles, in the range from a few to about 10 years, on some of the observed targets. Starspot maps are constructed by using advanced tools, such as massive parallel computing and are based on Maximum Entropy and Tikhonov regularization criteria. Selected results are here presented. Our systematic observation program is still underway and a second APT80/2, equipped with a CCD camera, will pair the APT80/1 on the same site. Its operation is foreseen for mid 2002.