Prof. Viktor Ambartsumian (1908-1996) is one of the greatest scientists of the XX century, the greatest Soviet astrophysicist and the founder of the theoretical astrophysics school in the USSR that has fundamentally contributed to various fields of astronomy and astrophysics, cosmogony, theoretical physics, mathematics, and philosophy. His revolutionary works on stellar evolution and activity of galactic nuclei turned over the development of astrophysics and gave life to our previously unchanged Universe.
Ambartsumian was also a great organizer of science, an important political and public figure. He was the founder of the astrophysics departments at the Leningrad (St. Petersburg) and Yerevan State Universities, the Byurakan Astrophysical Observatory (BAO), journal Astrofizika (Astrophysics), one of the founders of the Armenian Academy of Sciences. Ambartsumian was the Director of BAO in 1946-1988, the President of the Armenian Academy of Sciences in 1947-1993, the President of the International Astronomical Union in 1961-1964 and the President of the International Council of Scientific Unions (ICSU) in 1968-1972.
Victor Ambartsumian was born on September 18, 1908, in Tbilisi. Ambartsumian played a significant role in different fields, in particular, in the theory of multiple light scattering. The invariance principle, formulated in these works for the first time, had a wide application in a number of other fields of science.
Ambartsumian’s investigations on the problem of stellar evolution brought in 1947 to the revealing of stellar systems of new type - stellar associations. The existence of stellar associations in the Galaxy, dynamically non-stable and disintegrating systems, was the first observational evidence in favour of continuing at present star-formation in it.
Ambartsumian put forward a hypothesis about the joint origin of the diffuse matter and stars of dense matter of unknown nature – protostars. Ambartsumian’s studies of early stages of evolution of stars and stellar systems are rather significant. It was shown that in the early stages of evolution, the instability of state reveals itself, being the regular phase of the cosmogonic processes.
Among these results the conclusions about the existence of stellar systems of positive total energy in the Galaxy, non-thermal nature of ultraviolet stellar radiation of T Tauri type and flare stars, are to be mentioned. New principle results were achieved by V. Ambartsumian in the study of evolution of galaxies. It was shown for the first time that the central regions of galaxies - their nuclei, play a decisive role in the phenomena of instability, observed in galaxies.
Besides the stars and diffuse matter they must contain dense massive bodies of unknown nature. The activity of galactic nuclei defines their evolution. At present the active galactic nuclei (AGN) are the most intensively studied objects in extragalactic astronomy.
Ambartsumian was awarded governmental prizes, orders and medals of a number of countries։
Victor Ambartsumian died on August 12, 1996 in Byurakan.
In 2010, Viktor Ambartsumian International Science Prize was created. It is one of the important awards in astronomy/astrophysics and related sciences. It is being awarded to outstanding scientists having significant contributions in physical-mathematical sciences from any country and nationality.