# Liisi Oterma

Liisi Oterma (Finnish pronunciation:; 6 January 1915 – 4 April 2001) was a Finnish astronomer, the first woman to get a Ph.D. degree in astronomy in Finland.
She studied mathematics and astronomy at the University of Turku, and soon became Yrjö Väisälä's assistant and worked on the search for minor planets. She obtained her master's 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. 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 comets, 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 planets between 1938 and 1953, and ranks 153rd on MPC's all-time discovery chart.
The Hildian asteroid 1529 Oterma, discovered by Finnish astronomer Yrjö Väisälä in 1938, was named in her honour.

## Minor planets discovered

| 1504 Lappeenranta | March 23, 1939 |
| 1507 Vaasa | September 12, 1939 |
| 1522 Kokkola | November 18, 1938 |
| 1540 Kevola | November 16, 1938 |
| 1544 Vinterhansenia | October 15, 1941 |
| 1545 Thernöe | October 15, 1941 |
| 1558 Järnefelt | January 20, 1942 |
| 1559 Kustaanheimo | January 20, 1942 |
| 1679 Nevanlinna | March 18, 1941 |
| 1680 Per Brahe | February 12, 1942 |
| 1695 Walbeck | October 15, 1941 |
| 1705 Tapio | September 26, 1941 |
| 1758 Naantali | February 18, 1942 |
| 1882 Rauma | October 15, 1941 |
| 2064 Thomsen | September 8, 1942 |
| 2107 Ilmari | November 12, 1941 |
| 2159 Kukkamäki | October 16, 1941 |
| 2195 Tengström | September 27, 1941 |
| 2268 Szmytowna | November 6, 1942 |
| 2291 Kevo | March 19, 1941 |
| 2332 Kalm | April 4, 1940 |
| 2501 Lohja | April 14, 1942 |
| 2640 Hällström | March 18, 1941 |
| 2717 Tellervo | November 29, 1940 |
| 2774 Tenojoki | October 3, 1942 |
| 2803 Vilho | November 29, 1940 |
| 2804 Yrjö | April 19, 1941 |
| 2805 Kalle | October 15, 1941 |
| 2827 Vellamo | February 11, 1942 |
| 2828 Iku-Turso | February 18, 1942 |
| 2840 Kallavesi | October 15, 1941 |
| 2841 Puijo | February 26, 1943 |
| 2846 Ylppö | February 12, 1942 |
| 2857 NOT | February 17, 1942 |
| 2912 Lapalma | February 18, 1942 |
| 2946 Muchachos | October 15, 1941 |
| 2988 Korhonen | March 1, 1943 |
| 3132 Landgraf | November 29, 1940 |
| 3381 Mikkola | October 15, 1941 |
| 3497 Innanen | April 19, 1941 |
| 3597 Kakkuri | October 15, 1941 |
| 3811 Karma | October 13, 1953 |
| 3892 Dezsö | April 19, 1941 |
| 4133 Heureka | February 17, 1942 |
| 4163 Saaremaa | April 19, 1941 |
| 4227 Kaali | February 17, 1942 |
| (5216) 1941 HA | April 16, 1941 |
| (5534) 1941 UN | October 15, 1941 |
| (5611) 1943 DL | February 26, 1943 |
| (5985) 1942 RJ | September 7, 1942 |
| 6886 Grote | February 11, 1942 |
| 7267 Victormeen | February 23, 1943 |
| (11780) 1942 TB | October 3, 1942 |
| (15198) 1940 GJ | April 5, 1940 |