Byurakan Astrophysical Observatory: 75 years of outstanding achievements

Abstract

The Byurakan Astrophysical Observatory (BAO) is one of the most famous observatories of the Soviet Union and may be of the world. It was founded in 1946 by the outstanding scientist Viktor Ambartsumian (1908-1996) and became the leader of studies on instability phenomena in the Universe. Many discoveries have been carried out at BAO related to stars, star clusters and other systems, nebulae, galaxies and systems of galaxies. BAO has two major instruments; 1m Schmidt and 2.6m classical telescopes. Together with V. Ambartsumian, outstanding scientists Beniamin Markarian, Grigor Gurzadyan, Marat Arakelian and others have worked at BAO. Many important international meetings and schools for young astronomers have been held. Many important people, including State authorities, Nobel Prize Winners and others have visited BAO. BAO has statuses of RA National Value, Regional Astronomical Centre, it has UNESCO Documentary Heritage item, its garden is recognized as Dendrarium, and there is RA National Hero Viktor Ambartsumian's house-museum.

The Pleiades flare stars in the Gaia era

“…The first indication that flare activity could be possibly used as a reliable criterion for determining the membership of stars in stellar systems was obtained from the discussion of the distribution of FSs in the Pleiades cluster region. Namely, the space distribution of FSs in the Pleiades cluster showed (e.g., Chavushian, 1979, Chavushian et al, 1999, 2004, Hambaryan, 1998, Mirzoyan, 1976, 1983 that the concentration of FSs around the center of the Pleiades cluster is the same, i.e. the surface density of FSs decreases upon distance from the center of cluster, irrespective their proper motion or membership probability.…”