William Stephen Finsen FRAS[2] (28 July 1905 – 16 May 1979) was a South African astronomer. He discovered a number of double stars and took many photographs of Mars. He developed the Finsen eyepiece interferometer to measure very close double stars. He was the final director of Union Observatory in South Africa from 1957 to 1965 (it was renamed Republic Observatory in 1961).[3]
William Stephen Finsen | |
|---|---|
| Born | 28 July 1905 |
| Died | 16 May 1979 (aged 73) Johannesburg, South Africa |
| Alma mater | University of Cape Town[1] |
| Known for | Finsen eyepiece interferometer |
| Spouse | Gertrude Ada Camerer (m.1928) |
| Scientific career | |
| Fields | Astronomy |
| Institutions | Union Observatory, South Africa |
Biography
editFinsen was born in 1905 in Johannesburg, Transvaal Colony to Danish parents John Valgard Finsen & Marie Finsen (née Jensen).[4] He was the nephew of the Nobel prize winner Niels Ryberg Finsen.[5][6] He obtained a DSc in Astronomy from the University of Cape Town and spent almost 50 years working at the Union Observatory in Johannesburg.[1] He succeeded Willem Hendrik van den Bos as director of the observatory from 1957 to 1965, during which time it changed name to the Republic Observatory (1961).[3]
Both Finsen and van den Bos were vocally opposed to South African government's plan to close and amalgamate the Republic Observatory with the Cape Observatory (Cape Town) and the Radcliffe Observatory (Pretoria) into the South African Astronomical Observatory at Sutherland, Northern Cape in 1974, as they feared it would lead to termination of the well-established programmes of observation of binary stars and asteroids. Their fears would later be proven correct as those programmes were terminated.[7]
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Finsen invented an eyepiece interferometer which allowed measurement of very close double stars. His original device was used for many years at the astronomy department of the University of South Africa.[8] Finsen examined more than 8 000 stars, discovered 73 double stars and took 54 000 photographs of Mars. They were considered the best photographs of Mars prior to the first space probe pictures in 1965.[9][10] Finsen continued his observations of double stars after his official retirement from the observatory.[1]
During the second world war Finsen produced some basic films on astronomy which were used to train navigators. He also designed the Finsen Sun Compass to be used by armoured vehicle drivers in the desert campaigns. The standard magnetic compasses were useless owing to the large amount of metal in the vehicles.[1]
Finsen also developed a stomach contents sampler at the request of a specialist physician. Shaped like a pill, once swallowed the small device would open inside the patient's stomach after a pre-determined time and sample the stomach contents.[1]
Tweedledee and Tweedledum
editΦ 332 (Finsen 332) is a tiny and difficult double-double star at 18:45 / 5°30', named Tweedledee and Tweedledum by Finsen, who was, by the time of his 1953 discovery, struck by the nearly identical position angles and separations of it.[11][12][13]
Membership, awards and recognition
edit- The asteroid 1794 Finsen is named after him. Finsen first observed the asteroid in 1937.
- The geological feature Finsen Dorsum on the asteroid 433 Eros is named after him. Finsen had detected Eros' elongated shape.[14]
- President of the ASSA 1949–1950[1]
- Awarded the Gill Medal in 1967.[1]
- Fellow of the Royal Astronomical Society – proposed in 1925 by Robert T. A. Innes[2]
References
edit- ^ a b c d e f g Overbeek, M. D. (1997). "W. S. Finsen: More Than a Double Star Astronomer". Monthly Notes of the Astron. Soc. Southern Africa. 56: 74. Bibcode:1997MNSSA..56...74O.
- ^ a b "Society Business: Candidates proposed; Fellows elected". Monthly Notices of the Royal Astronomical Society. 86: 62. 11 December 1925. Bibcode:1925MNRAS..86...61.. doi:10.1093/mnras/86.2.61.
- ^ a b Hockey, Thomas (2009). The Biographical Encyclopedia of Astronomers. Springer Publishing. doi:10.1007/978-0-387-30400-7_455. ISBN 978-0-387-31022-0.
- ^ "William Stephen Finsen (1905–1979)". Ancestry.com. Retrieved 23 August 2019.
- ^ "Tórshavn (Thorshavn) sókn, Streymoy (Strømø), Færøerne / Kirkebøger / Kirkebog 1852 - 1875 Tórshavn (Thorshavn) / Opslag Nr. 24 - Fødte Mænd 1860-1861". danishfamilysearch.dk. Retrieved 17 July 2023.
- ^ "Tórshavn (Thorshavn) sókn, Streymoy (Strømø), Færøerne / Kirkebøger / Kirkebog 1868 - 1882 Tórshavn (Thorshavn) / Opslag Nr. 14 - Fødte Mænd". danishfamilysearch.dk. Retrieved 17 July 2023.
- ^ Docobo, J. A.; Andrade, M. (26 October 2012). "Dynamical and physical properties of 22 binaries discovered by W. S. Finsen". Monthly Notices of the Royal Astronomical Society. 428 (1): 321–339. doi:10.1093/mnras/sts045. ISSN 0035-8711.
- ^ "Eyepieces". ASSA. 10 October 2012. Retrieved 23 August 2019.
- ^ "Interesting Aspects about Astronomers". ASSA. 10 October 2012. Retrieved 23 August 2019.
- ^ "History – Astronomers – FinsenWS". saao.ac.za. 22 September 2004. Archived from the original on 22 September 2004. Retrieved 23 August 2019.
- ^ Sky Catalogue 2000.0, Volume 2: Double Stars, Variable Stars, and Nonstellar Objects (edited by Alan Hirshfeld and Roger W. Sinnott, 1985), Chapter 3: Glossary of Selected Astronomical Names.
- ^ Sky and Telescope, November 1961, page 263.
- ^ Deep-Sky Name Index 2000.0 - Hugh C. Maddocks (Foxon-Maddocks Associates, 1991).
- ^ "Planetary Names: Dorsum, dorsa: Finsen Dorsum on Eros". Planetary Names. Retrieved 23 August 2019.