|Location||Observatory, Johannesburg, South Africa|
|Altitude||1,808 m (5,932 ft)|
Known as the Transvaal Observatory until 1912, it became the Republic Observatory in 1961. Well remembered for the quality of its Directors, work done on minor planets and the discovery of Proxima Centauri, growing light pollution problems in Johannesburg led to its closure in 1971-1972.
At that time the South African government decided to amalgamate all astronomical research into one body, which later became known as the South African Astronomical Observatory (SAAO); it has its headquarters in Cape Town and has Sutherland as its outstation. The main Cape telescopes were moved to Sutherland, and the Radcliffe Observatory at Pretoria was also dismantled.
Union Observatory went through a number of name changes:
- Transvaal Meteorological Department 1903 – 1909
- Transvaal Observatory 1909 – 1912
- Union Observatory 1912 – 1961
- Republic Observatory 1961 – 1971,
Its directors were:
- Robert Innes 1903–1927
- Harry Edwin Wood 1927–1941
- Willem Hendrik van den Bos 1941–1956
- William Stephen Finsen 1957–1965
- Jan Hers 1965–1971
- "Johannesburg: Physical and human geography". Encyclopaedia Britannica. Retrieved 2 January 2012.
- Republic Observatory, in Astronomical Society of Southern Africa
- Republic Observatory, Popularly known as Johannesburg or Union Observatory at the Wayback Machine (archived September 20, 2004)
- Johannesburg Centre at the Wayback Machine (archived August 3, 2008)