Willem de Sitter
Willem de Sitter studied mathematics at Groningen University and then joined the Groningen astronomical laboratory. He worked at the Cape Observatory in South Africa (1897-1899) then, in 1908, de Sitter was appointed to the chair of astronomy at Leiden University. He was director of the Leiden Observatory from 1919 until his death.
De Sitter contributed to our understanding of Cosmology. One of his accomplishments was to have co-authored a paper with Albert Einstein in 1932 in which they argued that there might be large amounts of matter which does not emit light, now commonly referred to as dark matter.
De Sitter was also famous for his research on the planet Jupiter.
- James Craig Watson Medal (1929)
- Bruce Medal (1931)
- Gold Medal of the Royal Astronomical Society (1931)
Named after him
- Bruce Medal page
- Awarding of Bruce Medal: PASP 43 (1931) 125
- Awarding of RAS gold medal: MNRAS 91 (1931) 422
- AN 253 (1934) 495/496 (one line)
- JRASC 29 (1935) 1
- MNRAS 95 (1935) 343
- Obs 58 (1935) 22
- PASP 46 (1934) 368 (one paragraph)
- PASP 47 (1935) 65