Flare stars in the Pleiades. VI

Results of photographic observations of stellar flares in the regions of the Pleiades made at the Biurakan and Abastumani Astrophysical Observatories from August 1976-December 1979 are presented. As of June, 1980 the total number of known flare stars in this region was 524 and the number of flares 1244. The distribution of flare stars with respect to the number of observed flares is represented by a mean frequency function (Ambartsumian and Mirzoyan, 1975). It is shown that all the unknown flare stars in the Pleiades system at present have very low mean flare frequencies. The total number of flare stars in the Pleiades is estimated to be about 1100. Synchronous photographic observations of stellar flares in the Pleiades were made in the UBV, during which time slow flares were observed in the flare stars 105 and 156. A study of the color and frequency characteristics of stellar flares in aggregates indicates that there is a physical relationship between the flare stars in the aggregates and UV Ceti stars in the neighborhood of the sun.