Academician Mstislav V. Keldysh (On the 90th Anniversary of His Birth)

Solar System Research -     

On the 100-th anniversary of the birth of Academician V. A. Ambartsumian

A brief review is given of the applications of some methods, mainly developed at the Byurakan Observatory, to the statistics of flare stars. These developments originate in papers by Ambartsumian which led to the fundamental conclusion that a stage of flare activity is a natural stage in the evolution of red dwarf stars. In terms of their scientific value and novelty, the mathematical methods developed by Ambartsumian for solving specific astrophysical problems in the statistics of flare stars are just as significant as the astrophysical results obtained using these methods.     

Variable Star Status of Two Stars:V204 and I-I-39 in M3

The star I-I-42 (=vZ1390),a cluster member in M3,located near the red edge of the instability strip of the horizontal branch,was discovered by Roberts and Sandage as a low amplitude variable,it was designated as V204 in the "second catalogue of variable stars in globular clusters",but its coordinates given in all versions of this catalogue are wrong since 1955. We argue that V204 is indeed a low amplitude HB variable star,located near to the red edge of the instability strip,with a period of 0.74785d and an amplitude of about 0.04mag in V . We also find that the red cluster member star I-I-39 is a low amplitude variable with a period of 1.16d and amplitude of about 0.03mag in V which might be pulsating at the second overtone.