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Eminent Armenian scientist and astronomer, Prof. Victor Ambartsumian (also spelled Ambartsumyan and Ambarsumyan), Honorary President of the Armenian National Academy of Science, died on the 12th of August, 1996. He was an honorary or foreign member of academies of sciences of more than 25 countries and held honorary degrees from many well-known universities. The scientific community recognized his activities by electing him president of the International Council of Scientific Unions (1970-1974). His book Theoretical Astrophysics (1958, Pergamon Press) became a bible for a generation of astronomers.
Ambartsumian was born on 18 September 1908 in Tbilisi, Georgia, He wrote his first papers on "The New Sixteen-Year Period for Sunspots" and "Description of Nebulae in Connection with the Hypothesis on the Origin of the Universe" when he was only an 11-year old schoolboy. His talent was recognized very soon, and his father sent him to Leningrad where be obtained his higher education, receiving a first degree from Leningrad University and carrying out postgraduate studies at Pulkovo Observatory in 1928-1931. His first collaborators and friends were A. Kozyrev, D. Ivanenko, and M. Bronstein. During the short period 1928-30, while still a student, Ambartsumian published 22 papers in Astronomische Nachrichten, Zeitschrift für Physik, MNRAS, and other journals. One of these ( Z. Phys. 53, 690, 1929) was, in effect, the first paper in the theory of inverse spectral problems associated with the Sturm-Liouville operators.
Ambartsumian had broad research interests from the beginning. His work "The Quantization of Space" was reported at the International Conference in Odessa, where Summerfeld, Pauli, Jordan, Dirac, and many others were present. After the meeting, Pauli told him, "Colleague Ambartsumyan, at the moment the position of quantum electrodynamics appears hopeless. However, in a conversation with Mr. Tamm, I said that just a few ideas are needed like those of the English mathematician Ursell and yours to make the study of quantum mechanics possible again." In another paper, published in 1930 (when neutrons had not yet been discovered), Ambartsumian and Ivanenko argued against the presence of electrons in atomic nuclei. Soon he became a lecturer at Leningrad State University, and he was made a professor in 1934 at the age of 26. He then organized and headed the department of astrophysics at Leningrad (the first in the Soviet Union). His first PhD student was V.V. Sobolev (known for the Sobolev approximation in radiative transfer). It is commonly accepted that V.A. Ambartsumian was a father of the Soviet school of Theoretical Astrophysics. The most important steps in his scientific career can be given as:
Ambartsumian returned to Armenia from Leningrad, and in 1946 founded the Byurakan Astrophysical Observatory on the slopes of Mt. Aragats (4090 m above sea level), rising from the valley of Mt. Ararat. Soon he became President of the Armenian Academy of Science, serving from 1947 to 1993 and as honorary president thereafter. In 1985, about 20,000 scientists were working in this small republic of fewer than 3.5 million people, most of them in institutions part of the Academy system. Ambartsumian founded the journal Astrofizica (Astrophysics) and remained its editor-in-chief as well as director of Byurakan until the mid 1980’s.
It is generally recognized that Ambartsumian’s papers were very original and revolutionary, striking in their mathematical beauty and accuracy. Congratulating him on his 80th birthday, Chandrasekhar wrote: “The only other astronomer of this century who compares with Academician Ambartsumian in his constancy and devotion to astronomy is Prof. Jan Oort; but they would appear to be dissimilar in every other way. It will be a worthy theme for a historian of science of the 21st century to compare and contrast these two great men of science. He is an astronomer par excellence. There can be no more than two or three astronomers in this century who can look back on a life so worthily devoted to the progress of astronomy.” (Astrofizica 29, 408, 1989).
Photo (available in PDF version): Prof. V. A. Ambartsumian at the commissioning of the 2.6m telescope in Byurakan (courtesy Byurakan Observatory and Garik Israelian).
Obituary written by: Garik Israelian (IAC, Tenerife, Canary Islands, Spain)
BAAS Citation: BAAS, 1997, 29, 1446
SAO/NASA ADS Bibcode: 1997BAAS...29.1466I