Liisi Oterma (; 6 January 1915 – 4 April 2001) was a

Finnish Finnish may refer to: * Something or someone from, or related to Finland * Culture of Finland * Finnish people or Finns, the primary ethnic group in Finland * Finnish language, the national language of the Finnish people * Finnish cuisine See also ...

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets and galaxies – in either ...

, the first woman to get a

Ph.D. A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields. Because it is ...

degree in

astronomy Astronomy () is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, g ...

in Finland. She studied mathematics and astronomy at the

University of Turku sv, Åbo universitet , latin_name = Universitas Aboensis , image_name = University of Turku.svg , motto = ''Vapaan kansan lahja vapaalle tieteelle'' , established = 1920 , type ...

, and soon became

Yrjö Väisälä Yrjö Väisälä (; 6 September 1891 – 21 July 1971) was a Finnish astronomer and physicist. His main contributions were in the field of optics. He was also active in geodetics, astronomy and optical metrology. He had an affectionate ni ...

's assistant and worked on the search for minor planets. She obtained her masters degree in 1938. From 1941 to 1965, Oterma worked as an observer at the university's observatory. She obtained her PhD in 1955 with a dissertation on telescope optics. She was the first Finnish woman to obtain a PhD in astronomy. In 1959, Oterma became a docent of astronomy and from 1965 to 1978 a professor in University of Turku. In 1971, she succeeded Väisälä as the director of the

Tuorla Observatory Tuorla Observatory is the Department of Astronomy at the University of Turku, southwest Finland. It is the largest astronomical research institute in Finland. Together with the Space Research Laboratory at the Physics Department of the University ...

. She was director of the astronomical-optical research institute at the University of Turku from 1971-1975. Oterma was interested in languages and spoke German, French, Italian, Spanish, Esperanto, Hungarian, English and also Arabic, for example. Oterma's original plans were to study Sanskrit, but it was not offered at the University of Turku, and the choice was ultimately focused on astronomy. Oterma was quiet, modest in nature, and fearful of publicity. Anders Reiz, a professor at the Copenhagen Observatory, among others, said Oterma was “silent in eleven languages”. Oterma avoided appearing in photographs, and there are only a handful of pictures of her. She discovered or co-discovered several

comet A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena ...

s, including periodic comets 38P/Stephan-Oterma, 39P/Oterma and 139P/Väisälä–Oterma. She is also credited by the Minor Planet Center (MPC) with the discovery of 54

minor planet According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term ''mino ...

s between 1938 and 1953, and ranks 153rd on MPC's all-time discovery chart. The Hildian asteroid 1529 Oterma, discovered by Finnish astronomer

in 1938, was named in her honour.

Minor planets discovered

References

{{DEFAULTSORT:Oterma, Liisi 1915 births 2001 deaths 20th-century women scientists 20th-century astronomers Discoverers of asteroids Discoverers of comets * Finnish astronomers Women astronomers Astronomy-optics society