Press Release

NAS RA V. Ambartsumian Byurakan Astrophysical Observatory (BAO)
Press release 18.09.2025

VIKTOR AMBARTSUMIAN’S 117TH BIRTHDAY

On 18th of September, we celebrate the 117th birthday of the eminent Armenian scientist Viktor Ambartsumian and Astronomy Day in Armenia.

Viktor Ambartsumian’s birthday, September 18, has been officially celebrated as Astronomy Day in Armenia since 2009, according to a decision by the Government of Armenia.

Academician Viktor Ambartsumian (1908–1996) was one of the greatest scientists of the 20th century, a leading astrophysicist of the Soviet era, and the founder of the school of theoretical astrophysics in the USSR. He made fundamental contributions to astronomy and astrophysics, cosmogony, theoretical physics, mathematics, and philosophy. His groundbreaking work on stellar evolution and the activity of galactic nuclei was revolutionary for astrophysics, transforming our understanding of the Universe. Ambartsumian was also a visionary in the organization of science and an influential political and public figure.

He founded the departments of astrophysics at Leningrad (Saint Petersburg) and Yerevan State Universities, the Byurakan Astrophysical Observatory (BAO), the journal “Astrophysics”, and was one of the founders of the National Academy of Sciences of Armenia.

Ambartsumian achieved pioneering results in the study of galaxy evolution, demonstrating for the first time that the central regions of galaxies—their nuclei—play a decisive role in observed instabilities. Beyond stars and diffuse matter, these regions must contain dense bodies of unknown nature. The activity of galactic nuclei determines the evolution of galaxies. Today, active galactic nuclei (AGN) are among the most intensively studied objects in extragalactic astronomy.

His research on stellar evolution led in 1947 to the discovery of a new type of stellar system—stellar associations. The presence of dynamically unstable and dissolving systems in galaxies provided the first observational evidence of ongoing star formation within them.

V. Ambartsumian passed away on August 12, 1996, in Byurakan. In 2010, the Viktor Ambartsumian International Scientific Prize was established, becoming one of the most prestigious awards in astronomy, astrophysics, and related fields. It honors outstanding scientists worldwide for their significant contributions to physical and mathematical sciences, regardless of nationality.

Lilit Darbinyan