Union Observatory

Union Observatory
Alternative namesJohannesburg Observatory Edit this at Wikidata
Observatory code 078 Edit this on Wikidata
LocationObservatory, Johannesburg, South Africa
Coordinates26°11′3″S 28°04′27″E / 26.18417°S 28.07417°E / -26.18417; 28.07417
Altitude1,808 metres (5,932 ft)
Established1903; 122 years ago (1903)
Closed1971
Websiteassa.saao.ac.za/sections/history/observatories/rep_obs/ Edit this at Wikidata
Union Observatory is located in South Africa
Union Observatory
Location of Union Observatory
[edit on Wikidata]
Photo of comet Mellish obtained with the Franklin Adams star camera of the Union Observatory on June 6, 1915, with an exposure of ninety minutes. The position of the comet was then R.A. 22h. 35m., declination 70° 18′ south.

Union Observatory, also known as Transvaal Observatory, Republic Observatory and Johannesburg Observatory (078), is a defunct astronomical observatory in Johannesburg, South Africa that operated from 1903 to 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]

History

The origins of the observatory began when Theodore Reunert of the South African Association for the Advancement of Science petitioned Alfred Milner Governor of the Transvaal Colony on 29 October 1902 for the establishment of a meteorological and astronomical observatory in Johannesburg.[4]: 17  Assistant Colonial Secretary W.H. Moor agreed to the project on 17 December 1902 with the budget increased from £1,350 to £5,629 due to equipment changes.[4]: 17 

On 1 April 1903, a new Meteorological Department was temporarily established in Johannesburg.[4]: 17  A location was sought for the new observatory and the Johannesburg Town Council made a decision on 12 May 1903, located within the municipal boundaries.[4]: 17  The land of eight acres, on a ridge west of the Indian War Memorial, was on the northern boundary of the farm Doornfontein, presently part of the suburb Observatory and was given as a gift by the Bezuidenhout family, with a further two acres sold for £500.[4]: 18  The land was given only for the use of science and a road, later called Observatory Avenue, was also to be built close to the site.[4]: 18  The observatory building was built and the formal opening took place on 17 January 1905 by Governor Milner, but had no astronomical equipment.[4]: 19 

In 1906 it was lent a Hamberg universal instrument (2 5/8-inch object glass) by Dr Oskar Backlund.[4]: 19  In September 1907 a 9-inch Grubb refractor was now used but repolished in 1908.[4]: 19  Mr J. Franklin-Adams gifted the observatory a 10-inch triple O.G. Cooke Star-Camera in 1909.[4]: 19  J.B. Rissik, Minister for Lands, permitted the purchase of a 26-inch refracting telescope from the Grubb Telescope Company in 1909.[4]: 19 

With the formation of the Union of South Africa in 1910, South Africa's two colonial observatories came under the control of the Minister of the Interior.[4]: 19  With the removal of the meteorological functions, the observatory was renamed Observatory of the Union of South Africa (Union Observatory) on 1 April 1912.[4]: 19  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. The Observatory's buildings at 18a Gill Street, Observatory, Johannesburg, still exist.[1]

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.[1]

The main-belt asteroid 1585 Union, discovered by Ernest Johnson in 1947, was named for the Union observatory.[5]

Leiden Southern Station

The Leiden Southern Station (081) was a collaboration between the Dutch Leiden Observatory and Union Observatory. From 1938 to 1954 it was an annex to the Union Observatory, and was moved to Hartbeespoort in 1954 due to light pollution. It operated until 1978.[7]

Discoveries

List of discovered minor planets

The Minor Planet Center credits Union Observatory ("Johannesburg"), as the site of 147 minor planet discoveries, made by the following list of astronomers:

important; height: 675px;
715 Transvaalia 22 April 1911 list [A]
758 Mancunia 18 May 1912 list [A]
790 Pretoria 16 January 1912 list [A]
982 Franklina 21 May 1922 list [A]
1032 Pafuri 30 May 1924 list [A]
1096 Reunerta 21 July 1928 list [A]
1116 Catriona 5 April 1929 list [B]
1132 Hollandia 13 September 1929 list [C]
1133 Lugduna 13 September 1929 list [C]
1165 Imprinetta 24 April 1930 list [C]
1186 Turnera 1 August 1929 list [B]
1193 Africa 24 April 1931 list [B]
1194 Aletta 13 May 1931 list [B]
1195 Orangia 24 May 1931 list [B]
1196 Sheba 21 May 1931 list [B]
1197 Rhodesia 9 June 1931 list [B]
1225 Ariane 23 April 1930 list [C]
1226 Golia 22 April 1930 list [C]
1241 Dysona 4 March 1932 list [A]
1242 Zambesia 28 April 1932 list [B]
1243 Pamela 7 May 1932 list [B]
1244 Deira 25 May 1932 list [B]
1245 Calvinia 26 May 1932 list [B]
1246 Chaka 23 July 1932 list [B]
1248 Jugurtha 1 September 1932 list [B]
important; height: 675px;
1264 Letaba 21 April 1933 list [B]
1267 Geertruida 23 April 1930 list [C]
1268 Libya 29 April 1930 list [B]
1278 Kenya 15 June 1933 list [B]
1279 Uganda 15 June 1933 list [B]
1282 Utopia 17 August 1933 list [B]
1305 Pongola 19 July 1928 list [A]
1318 Nerina 24 March 1934 list [B]
1319 Disa 19 March 1934 list [B]
1320 Impala 13 May 1934 list [B]
1321 Majuba 7 May 1934 list [B]
1323 Tugela 19 May 1934 list [B]
1324 Knysna 15 June 1934 list [B]
1325 Inanda 14 July 1934 list [B]
1326 Losaka 14 July 1934 list [B]
1327 Namaqua 7 September 1934 list [B]
1336 Zeelandia 9 September 1934 list [C]
1337 Gerarda 9 September 1934 list [C]
1342 Brabantia 13 February 1935 list [C]
1349 Bechuana 13 June 1934 list [B]
1353 Maartje 13 February 1935 list [C]
1354 Botha 3 April 1935 list [B]
1355 Magoeba 30 April 1935 list [B]
1356 Nyanza 3 May 1935 list [B]
1357 Khama 2 July 1935 list [B]
important; height: 675px;
1358 Gaika 21 July 1935 list [B]
1359 Prieska 22 July 1935 list [B]
1360 Tarka 22 July 1935 list [B]
1362 Griqua 31 July 1935 list [B]
1367 Nongoma 3 July 1934 list [B]
1368 Numidia 30 April 1935 list [B]
1383 Limburgia 9 September 1934 list [C]
1384 Kniertje 9 September 1934 list [C]
1385 Gelria 24 May 1935 list [C]
1389 Onnie 28 September 1935 list [C]
1393 Sofala 25 May 1936 list [B]
1394 Algoa 12 June 1936 list [B]
1396 Outeniqua 9 August 1936 list [B]
1397 Umtata 9 August 1936 list [B]
1427 Ruvuma 16 May 1937 list [B]
1428 Mombasa 5 July 1937 list [B]
1429 Pemba 2 July 1937 list [B]
1430 Somalia 5 July 1937 list [B]
1431 Luanda 29 July 1937 list [B]
1432 Ethiopia 1 August 1937 list [B]
1456 Saldanha 2 July 1937 list [B]
1467 Mashona 30 July 1938 list [B]
1468 Zomba 23 July 1938 list [B]
1474 Beira 20 August 1935 list [B]
1490 Limpopo 14 June 1936 list [B]
important; height: 675px;
1505 Koranna 21 April 1939 list [B]
1506 Xosa 15 May 1939 list [B]
1568 Aisleen 21 August 1946 list [D]
1580 Betulia 22 May 1950 list [D]
1585 Union 7 September 1947 list [D]
1595 Tanga 19 June 1930 list [B][A]
1607 Mavis 3 September 1950 list [D]
1609 Brenda 10 July 1951 list [D]
1618 Dawn 5 July 1948 list [D]
1623 Vivian 9 August 1948 list [D]
1627 Ivar 25 September 1929 list [E]
1634 Ndola 19 August 1935 list [B]
1638 Ruanda 3 May 1935 list [B]
1641 Tana 25 July 1935 list [B]
1658 Innes 13 July 1953 list [F]
1660 Wood 7 April 1953 list [F]
1663 van den Bos 4 August 1926 list [A]
1666 van Gent 22 July 1930 list [C]
1667 Pels 16 September 1930 list [C]
1670 Minnaert 9 September 1934 list [C]
1676 Kariba 15 June 1939 list [B]
1686 De Sitter 28 September 1935 list [C]
1689 Floris-Jan 16 September 1930 list [C]
1693 Hertzsprung 5 May 1935 list [C]
1694 Kaiser 29 September 1934 list [C]
important; height: 675px;
1701 Okavango 6 July 1953 list [G]
1702 Kalahari 7 July 1924 list [E]
1712 Angola 28 May 1935 list [B]
1731 Smuts 9 August 1948 list [D]
1738 Oosterhoff 16 September 1930 list [C]
1752 van Herk 22 July 1930 list [C]
1753 Mieke 10 May 1934 list [C]
1760 Sandra 10 April 1950 list [D]
1784 Benguella 30 June 1935 list [B]
1816 Liberia 29 January 1936 list [B]
1817 Katanga 20 June 1939 list [B]
1819 Laputa 9 August 1948 list [D]
1879 Broederstroom 16 October 1935 list [C]
1885 Herero 9 August 1948 list [D]
1914 Hartbeespoortdam 28 September 1930 list [C]
1922 Zulu 25 April 1949 list [D]
1925 Franklin-Adams 9 September 1934 list [C]
1945 Wesselink 22 July 1930 list [C]
1946 Walraven 8 August 1931 list [C]
1948 Kampala 3 April 1935 list [B]
1949 Messina 8 July 1936 list [B]
1986 Plaut 28 September 1935 list [C]
2019 van Albada 28 September 1935 list [C]
2025 Nortia 6 June 1953 list [G]
2066 Palala 4 June 1934 list [B]
important; height: 595px;
2193 Jackson 18 May 1926 list [A]
2203 van Rhijn 28 September 1935 list [C]
2378 Pannekoek 13 February 1935 list [C]
2546 Libitina 23 March 1950 list [D]
2651 Karen 28 August 1949 list [D]
2718 Handley 30 July 1951 list [D]
2801 Huygens 28 September 1935 list [C]
2825 Crosby 19 September 1938 list [B]
2829 Bobhope 9 August 1948 list [D]
2831 Stevin 17 September 1930 list [C]
2865 Laurel 31 July 1935 list [B]
2945 Zanstra 28 September 1935 list [C]
3184 Raab 22 August 1949 list [D]
3284 Niebuhr 13 July 1953 list [F]
3300 McGlasson 10 July 1928 list [A]
3768 Monroe 5 September 1937 list [B]
4296 van Woerkom 28 September 1935 list [C]
4359 Berlage 28 September 1935 list [C]
4511 Rembrandt 28 September 1935 list [C]
5038 Overbeek 31 May 1948 list [D]
(5452) 1937 NN 5 July 1937 list [B]
7102 Neilbone 12 July 1936 list [B]

References

  1. ^ a b c d e f "Republic Observatory (known as Johannesburg or Union Observatory)". Astronomical Society of Southern Africa. 2016. Retrieved 29 December 2016.
  2. ^ "Republic Observatory (known as Johannesburg or Union Observatory)". Astronomical Society of Southern Africa. 2016. Archived from the original on 4 April 2016. Retrieved 29 December 2016.
  3. ^ "Minor Planet Discoverers (Alphabetically)c". Minor Planet Center. 4 September 2016. Retrieved 29 December 2016.
  4. ^ a b c d e f g h i j k l m Hers, J. (1987). "History of the Transvaal Observatory. I". Monthly Notes of the Astronomical Society of Southern Africa. 46: 17–19. Bibcode:1987MNSSA..46...17H. hdl:10520/AJA00248266_2102.
  5. ^ Schmadel, Lutz D. (2007). "(1585) Union". Dictionary of Minor Planet Names – (1585) Union. Springer Berlin Heidelberg. p. 125. doi:10.1007/978-3-540-29925-7_1586. ISBN 978-3-540-00238-3.
  6. ^ "Jan Hers". IAU – International Astronomical Union, individual members. Retrieved 29 December 2016.
  7. ^ "Leiden Southern Station (Hartebeespoort)". Astronomical Society of Southern Africa. 2016. Archived from the original on 27 August 2016. Retrieved 29 December 2016.