Viktor Amazaspovich Ambartsumian (; , Viktor Hamazaspi Hambardzumyan; 12 August 1996) was a Soviet and Armenian astrophysicist and science administrator. One of the 20th century's leading astronomers, he is widely regarded as the founder of theoretical astrophysics in the Soviet Union.
Educated at Leningrad State University (LSU) and the Pulkovo Observatory, Ambartsumian taught at LSU and founded the Soviet Union's first department of astrophysics there in 1934. He subsequently moved to Soviet Armenia, where he founded the Byurakan Observatory in 1946. It became his institutional base for the decades to come and a major center of astronomical research. He also co-founded the Armenian Academy of Sciences and led it for almost half a century—the entire post-war period. One commentator noted that "science in Armenia was synonymous with the name Ambartsumian." In 1965 Ambartsumian founded the journal Astrofizika and served as its editor for over 20 years.
Ambartsumian began retiring from the various positions he held only from the age of 80. He died at his house in Byurakan and was buried on the grounds of the observatory. He was awarded the title of National Hero of Armenia in 1994.
Background Ambartsumian was born in Tiflis (present-day Tbilisi, Georgia) on , to Armenian parents Hripsime Khakhanian (1885–1972) and Hamazasp Hambardzumyan (1880–1966). Hripsime's father was an Armenian Apostolic priest from Tskhinvali, while Hamazasp hailed from Vardenis (Basargechar). His ancestors had moved from Diyadin, what is now Turkey, to the southern shores of Lake Sevan in 1830, in the aftermath of the Russo-Turkish War. Hamazasp was an educated man of letters who studied law at Saint Petersburg University. He was also a writer and translator and notably translated Homer's Iliad into Armenian from Classical Greek. In 1912 he co-founded the Caucasian Society of Armenian Writers, which lasted until 1921. Ambartsumian was the secretary, while Hovhannes Tumanyan, the famed poet, served as its president. Ambartsumian knew Tumanyan personally. In 1922, after the 14-year-old boy described Sirius to him, Tumanyan wrote a short poem about the star.; excerpt
Ambartsumian's parents married in 1904. He had a brother, Levon, and sister, Gohar. Levon, a geophysics student, died at 23-24 while on an expedition in the Urals. Gohar (1907–1979) was a mathematician and Chair of Probability Theory and Mathematical Statistics at Yerevan State University towards the end of her life.
Education Ambartsumian developed an early interest in mathematics and was able to multiply by the age of 4. His interest in astronomy began with reading a Russian translation of a book by Ormsby M. Mitchel at 11. By his own account, he considered himself an astronomer by the age of 12. Between 1917 and 1924 he studied at Tiflis gymnasiums, where schooling was conducted in Russian and Armenian. In 1921 he transferred to gymnasium #4 to study under Nikolay Ignatievich Sudakov, a Moscow-educated astronomer, whom Ambartsumian called a "very serious teacher of astronomy." Ambartsumian worked with Sudakov at the school observatory the latter had built. At school, Ambartsumian wrote several papers on astronomy and delivered lectures on the origin of the Solar System and extraterrestrial life at "first in school and then in the various clubs and houses of culture" beginning at 12–13. In 1924 Ambartsumian delivered a lecture at Yerevan State University about the theory of relativity. He also met Ashot Hovhannisyan and Alexander Miasnikian, Armenia's communist leaders.
In 1924 Ambartsumian moved to Leningrad, where he began attending the Herzen Pedagogical Institute. Shakhbazyan suggests that his non-peasant, non-proletarian background prevented him from entering Leningrad State University (LSU). However, Ambartsumian explained in an interview that by the time he arrived in August, LSU's admissions were already closed. To avoid losing a year, he opted to study in the physics and mathematics department of the pedagogical institute. After one year, he transferred to LSU's physics and mathematics department. At university, Ambartsumian was interested in both astronomy and mathematics. "I loved mathematics, but at the same time I felt that my profession would be astronomy. Mathematics was like a hobby, but I did complete the full mathematics curriculum. Thus you could say that I graduated with a major in mathematics, but in fact it is recorded that I graduated as an astronomer," he said in an interview in 1987. At LSU among his professors were the physicist Orest Khvolson and mathematician Vladimir Smirnov. He studied alongside other major Soviet scientists such as Lev Landau, Sergei Sobolev, Sergey Khristianovich and George Gamow. In 1926 he published the first of his 16 scholarly papers as a student. He graduated in 1928, although he received his diploma only fifty years later—in 1978. His undergraduate thesis was "devoted to a study of radiative transfer radiative equilibrium." He completed his postgraduate studies at the Pulkovo Observatory under Aristarkh Belopolsky between 1928 and 1931.
Career
Leningrad After completing his postgraduate studies in 1931, Ambartsumian began working at the Pulkovo Observatory and teaching part-time at LSU. In 1931 Ambartsumian began reading the first course on theoretical astrophysics in the Soviet Union. He also served as Pulkovo's scientific secretary in 1931–32, which involved mostly administrative work. Ambartsumian later characterized Pulkovo as being a "very old institution, and for this reason there were certain elements of ossification and stagnation. Nevertheless, this was the best qualified astronomical institution in the Soviet Union."
In 1934 Ambartsumian was fired by Pulkovo director Boris Gerasimovich for alleged "laziness." Gerasimovich viewed Ambartsumian and other young astrophysicists as "undisciplined and in too much of a rush to publish untested theories and poorly documented research." Gerasimovich himself had a "tendency to non-cooperativeness." Gerasimovich was not taken seriously by them. When in 1934 Subrahmanyan Chandrasekhar visited Leningrad, he was told by Ambartsumian, "Look here, here is a set of papers by Gerasimovich. I turn to an arbitrary paper and to an arbitrary line. I am sure you will find a mistake." Chandrasekhar stated in 1977 that during his visit in 1934 Ambartsumian "was very free and very open. He was extremely critical of his seniors."
After leaving Pulkovo, Ambartsumian founded the first department of astrophysics in the Soviet Union at Leningrad State University in 1934. In 1934 he was named professor at LSU and in 1935 he was named doctor of physical-mathematical sciences without having to defend a thesis "based on his scientific work through that date." He headed the department until 1946 or 1947.
Between 1939 and 1941 Ambartsumian was the director of the Astronomical Observatory of LSU. He was simultaneously prorector (deputy president) of the university. Among his graduate students were Viktor Sobolev, Benjamin Markarian, Grigor Gurzadyan, and others. Ambartsumian considered Sobolev his "most brilliant graduate student."
Stalin's purges Many of Ambartsumian's colleagues and friends suffered during the Great Purge under Stalin, most notably Nikolai Aleksandrovich Kozyrev (1908–83), with whom he became close friends in the mid-1920s. Kozyrev was sentenced to ten years in a forced-labor camp, but survived the repressions. Others such as Matvei Petrovich Bronstein and Pulkovo director Boris Gerasimovich did not survive. Ambartsumian's relations with Kozyrev were "strained for the remainder of his life." McCutcheon notes that while in the West some have questioned Ambartsumian's possible role in the terror, "there is no hard evidence to suggest that he was guilty of anything more serious than surviving at a time when others did not."
World War II Ambartsumian led the evacuation of part of the faculty of Leningrad State University to Elabuga, Tatarstan in 1941, after the Nazi invasion of the Soviet Union. There a branch of LSU operated under Ambartsumian's leadership until 1944. He served as the dean of the branch.
Armenia In 1943 Ambartsumian moved with his family to Yerevan, Soviet Armenia, where he lived until the end of his life. In the same year, he co-founded the Armenian Academy of Sciences along with scientists and scholars Hovsep Orbeli, Hrachia Acharian, Artem Alikhanian, Abram Alikhanov, Manuk Abeghian and others. He served as vice president of the academy until 1947 and as president from 1947 to 1993.
Since 1943 Ambartsumian served as director of the Yerevan Astronomical Observatory. The small observatory was affiliated with Yerevan State University. Ambartsumian had secured a nine-inch telescope from Leningrad for the observatory. Ambartsumian said that before the war "this observatory did not rise significantly above the level of amateur variable star observations. During the war they also carried out photographic observations of variable stars using a small camera." In 1945–1946 Ambartsumian founded the department of astrophysics at Yerevan State University (YSU). He was named professor of astrophysics at YSU in 1947. He served as chair of the department until 1994.
In 1965 Ambartsumian founded the journal Astrofizika (Armenian: Աստղաֆիզիկա, Russian: Астрофизика), which has been published by the Armenian Academy of Sciences since then. It was originally published in Russian, subsequently articles in English began to appear. He served as its editor-in-chief until 1987. The journal has also been published since the first issue in English by Springer in the US as Astrophysics.
Byurakan
In 1946 Ambartsumian founded the Byurakan Astrophysical Observatory in the village of Byurakan, at an altittude of , on the slopes of Mount Aragats, some from Yerevan. The first buildings were completed in 1951, though the official inauguration took place in 1956. Observations began to be carried out simultaneous with the construction of the observatory. "Our instruments stood under the open sky, covered with tarpaulin," said Ambartsumian. Ambartsumian initially lived at a house in the village of Byurakan then build a house within the observatory grounds with the money awarded with the 1950 Stalin Prize. Ambartsumian directed the Byurakan Observatory until 1988 and was named its honorary director that year. From 1946 until his death in 1996, the Byurakan Observatory served as Ambartsumian's "institutional base."
In 1960 Ambartsumian secured a Schmidt telescope with 40І (102 cm) correcting plate and 52І (132 cm) mirror for Byurakan. The telescope was reportedly made by Carl Zeiss AG in Nazi Germany in the 1930s and was transferred to Leningrad as spoils of war. It was completed in Leningrad and sent to Armenia. Beginning with 1965, on Ambartsumian's initiative, Benjamin Markarian started the First Byurakan Survey that resulted in the discovery of the Markarian galaxies. A number of international symposiums and meetings were held at Byurakan under Ambartsumian's supervision. In 1968 the observatory was awarded the Order of Lenin, the Soviet Union's highest civilian order for its great merit to the development of science. In 1961 Ambartsumian supervised the establishment of an astrophysical station of Leningrad State University, his alma mater, within the grounds of the Byurakan Observatory. It is where graduate students of the LSU did their summer internships until the late 1980s. It was shut down in 1993.Chronology at Astronomy at St. Peteresburg University (in Russian). 1961: Начала создаваться Бюраканская станция.;1993: В октябре-ноябре Т.А. Полякова последней из сотрудников Астрономического института проводит наблюдения на нашей Бюраканской станции. С тех пор станция законсервирована.