Union Observatory

Union Observatory
Alternative names	Johannesburg Observatory
Observatory code	078
Location	Observatory, Johannesburg, South Africa
Coordinates	26°11′3″S 28°04′27″E / 26.18417°S 28.07417°E
Altitude	1,808 metres (5,932 ft)
Established	1903
Closed	1971
Website	assa.saao.ac.za/sections/history/observatories/rep_obs/
	Location of Union Observatory
	[edit on Wikidata]

Union Observatory also known as Johannesburg Observatory (078) is a defunct astronomical observatory in Johannesburg, South Africa that was operated between 1903 and 1971. It is located on Observatory Ridge, the city's highest point at 1,808 metres altitude in the suburb Observatory.^[1]^[2]

The observatory and its former annex, the § Leiden Southern Station, are known for the discovery of 6,000 double stars and for Proxima Centauri, made by astronomer Robert Innes. At the observatory, 578 identifications of minor planet were made, a record number at the time.^[1] The Minor Planet Center credits the observatory as the site where 147 minor planets were discovered by astronomers Harry Wood, Cyril Jackson, Hendrik van Gent, Ernest Johnson, Ejnar Hertzsprung, Jacobus Bruwer and Joseph Churms (see § List of discovered minor planets).^[3]

^ ^a ^b Cite error: The named reference ASSA-new was invoked but never defined (see the help page).
^ Cite error: The named reference ASSA-archive-full was invoked but never defined (see the help page).
^ Cite error: The named reference MPC-Discoverers was invoked but never defined (see the help page).

[ASSA-new-1] Cite error: The named reference ASSA-new was invoked but never defined (see the help page).

[ASSA-archive-full-2] Cite error: The named reference ASSA-archive-full was invoked but never defined (see the help page).

[MPC-Discoverers-3] Cite error: The named reference MPC-Discoverers was invoked but never defined (see the help page).

[1]

[2]

[3]