On September 5, 1908, Soviet astronomer and astrophysicist Viktor Amazaspovich Ambartsumian was born. Ambartsumian is well known as one of the founders of theoretical astrophysics. He worked in the field of physics of stars and nebulae, stellar astronomy, dynamics of stellar systems and cosmogony of stars and galaxies, and contributed to mathematical physics.
Victor Ambartsumian was the son of the prominent philologist and writer Hamazasp Asaturovich Ambartsumian, the translator of Homer’s Iliad into Armenian. He attended the University of Leningrad which is now Saint Petersburg State University to study astrophysics. Already one year later he was able to publish a scientific paper on solar activity. During his time as an undergraduate student, Ambartsumian would publish around 10 more papers. He later became a graduate student under A.A. Belopolskii at Pulkovo Observatory near Leningrad.
During the 1930s until the early 1940s, Victor Ambartsumian lectured at the University of Leningrad and he headed its Astrophysical Department. He made significant advances in his theory of the interaction of ultraviolet radiation from hot stars with the surrounding gas. He further managed to produce a series of scientific papers on the physics of gaseous clouds. Ambartsumian statistically analyzed stellar systems during the 1930s and also included their physical properties into his studies. It was found that his work was applicable to related issues including the evolution of double stars and star clusters.
Ambartsumian also dedicated a large amount of time to the research of inter-stellar matter in the Galaxy. He developed the concept that the light absorption in the Galaxy is caused by the presence of numerous dust nebulae or “absorbing clouds” in the inter-stellar space. On this basis, the fluctuation theory was later developed. Ambartsumian further observed the so-called continuous emission in the spectras of the young stars of the TAU Taurus type and their satellite non-stationary stars. These efforts contributed to important conclusions as regards the nature of the stellar energy sources.
Another field of Ambartsumian’s astrophysical research involved the evolution of galaxies. He developed a concept of activity of the galactic nuclei, to have a decisive role in the genesis and evolution of the galaxies and their systems. An important research of Ambartsumian and his followers was dedicated to the blue ejections from the nuclei of the gigantic galaxies, galaxy systems of new type, the so-called compact galaxies, etc.
In 1946, Victor Ambartsumian founded the Byurakan Observatory. He further became the second and longest-serving president of the Armenian Academy of Sciences and served as the president of the International Astronomical Union from 1961 to 1964. He was twice elected the President of the International Council of Scientific Unions.
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