Born: Port Kunda, Estonia, 23 October 1893
Died: Bangor, Co Down, N.Ireland, 10 September 1985
Children: Uno, Helgi, Tiiu, Elina, Inna, Maija
Addresses: 30 College Hill, Armagh; 99 Clifton Road, Bangor, Co Down
Distinctions: MRIA (1954). Medals: National Academy of Sciences (1960); Meteoritical Society (1968); American Association for the Advancement of Science (1972); Royal Astronomical Society (1975); Astronomical Society of the Pacific (1976). Honorary Degrees: Belfast (1968), Sheffield (1977)
Biography: E.J. Öpik was educated at Tallinn High School and Moscow Imperial University. After four years at Moscow Observatory he became Director of the Astronomy Department, Tashkent. From 1921-1944 he was an Associate Professor at Tartu University, and from 1930-34 visiting scientist at Harvard University. As a former volunteer to the White Russian army, he vehemently opposed the Bolshevik Revolution and, when Soviet occupation of Estonia was imminent, he moved, first to Hamburg, and lastly, in 1948, to Armagh Observatory where he remained until 1981.
Öpik was one of the most outstanding astrophysicists of his generation, with wide-ranging interests in the physical sciences. Among his many pioneering discoveries were: (1) the first computation of the density of a degenerate body, namely the white dwarf 40 Eri B, in 1915; (2) the first accurate determination of the distance of an extragalactic object (Andromeda Nebula) in 1922; (3) the prediction of the existence of a cloud of cometary bodies encircling the Solar System (1932), later known as the "Oort Cloud"; (4) the first composite theoretical models of dwarf stars like the Sun which showed how they evolve into giants (1938); (5) a new theory of the origin of the Ice Ages (1952).
Öpik made many contributions to our knowledge of the minor bodies of the Solar System and founded the meteor research group at Harvard. His statistical studies of Earth-crossing comets and asteroids are fundamental to our understanding of the motions of these objects and how they impact on Earth. His predictions of cratering on Mars were dramatically confirmed 15 years later by planetary probes. In recognition of his work, Minor Planet Öpik was named after him.
Öpik was prolific in his output and often controversial in his opinions. Many of his later publications appear in the Irish Astronomical Journal which he edited from 1950 till 1981.
See also: Histories of Armagh Observatory
Irish Astronomical Journal 10, Special Issue, 1972
Irish Astronomical Journal 17, No 4, 1986
Quarterly Journal Royal Astronomical Society 27, 508, 1986
Author details: John Butler, Armagh Observatory, N. Ireland
The Hierarchical Universe - the last talk by E.J. Öpik.
Last Revised: 2009 November 5th