leiden_obs

Leiden Southern Station (Hartebeespoort)

Leiden Southern Station 1954 – 1978
Terrain run by Tshwane University of Technology since 1 January 2004 as Toppieshoek Outdoor Recreation and Leadership Development Centre
Current Information:
Current  Information
The  Observatory closed in 1978 when Leiden University translocated its Southern Station to the European Southern Observatory in Chile. Two telescopes remain in situ and are curated by the Tshwane University of Technology. There is a current initiative to restore and conserve this site for its astronomical history as a heritage site together with the Broederstroom Archaeological Site (a declared Heritage Site) located on the same property.
In Brief:
Noted  for:
Variable star observation
.
Summary:
Needing an observing site with a better climate than that available in the Netherlands, an agreement was reached late in 1923 between the Leiden University Observatory (founded 1633) and Union (Republic) Observatories, whereby the facilities of the two institutions were made available to each other. In search of light pollution-free skies, the three Leiden telescopes moved from Johannesburg to state land near Hartbeespoort Dam in 1953. In  time light pollution, air pollution and the new observatory situated at Sutherland were factors in closing the Observatory in 1978. This facility and its telescopes were used primarily by astronomers from the Netherlands.
Historical background:

History:

  • Due to very close ties with Leiden University Observatory in the Netherlands (founded in 1633), an agreement  of co-operation was reached in 1923 between the Union and  Leiden Observatories. Astronomers from each establishment were  free to make use of the facilities of the other. Since the night skies in the Transvaal were infinitely better than those in the Netherlands, the flow of visiting astronomers was virtually one way. (Moore, p.107;  Van Herk)
  • Initially, the Leiden observers made use of the Franklin-Adams telescope.
  • By 1929 the Leiden Observatory had decided to commission a telescope and permanent staff to the Union Observatory in Johannesburg. Due to various delays in its construction, the telescope, known as the Rockefeller twin astrograph telescope, was only installed in Johannesburg in 1938. The Union government provided funds for a building at the Union Observatory to house this telescope. The first astronomer was Enjar Hertzsprung (Hertzsprung – Russel Diagram)
  • The Leiden observers concentrated on the study of variable stars. By 1957 they had accumulated 12 000 photographic plates taken at the Union Observatory. (Jamieson).
  • With  growing light pollution in Johannesburg, in 1953 it was decided to establish an outstation at Hartbeespoort. This became known as the Leiden Southern Station.
  • The agreement was that the Hartbeespoort facility was operated by Leiden Observers, but it was an official outstation of the Union  (later Republic) Observatory, and as such came under Finsen’s jurisdiction even though it was virtually autonomous.
  • Some  of the Union Observatory instruments were also moved to the site.
  • By  the time of the move to the Hartbeespoort, the Flux Collector telescope arrived and was installed at Hartbeespoort. This was the first fully automated telescope (what is referred to today as a ‘’Go To Telescope’’) in southern Africa.
  • After the Republic Observatory closed, the Leiden Southern Station continued to operate until it was transferred to the European Southern Observatory (ESO) in La Silla, Chile, in 1978 because of light pollution.
  • The Flux Collector was translocated to the ESO and the Franklin-Adamas and Rockefeller Twin Astrograph were donated to the CSIR and from them to the South African Department of Education in 1982.
Astronomers:
• Willem de Sitter, a renowned astronomer in Leiden, a colleague of Albert Einstein and one of the pioneers of Relativity Theory, met Robert Innes while both were stationed at the Royal Observatory in Cape Town. Later, when Innes became director of the Union Observatory and De Sitter became Director of the Leiden University Observatory, they agreed to share facilities.
• Enjar Hertzsprung was the first astronomer to be sent by Leiden to the Union Observatory. He, independently from Henry Norris Russel, around 1913, had first put forward the idea that later became known as the Hertzsprung-Russel Diagram. (Mitton) Herzsprung commissioned the building of the Rockefeller Twin Astrograph to use in South Africa.
• Hendrik van Gent (1899-1947) was a variable star observer who worked mainly on the Franklin-Adams telescope, which was the property of the Union Observatory.
• Willem van den Bos, arrived in Johannesburg from Leiden to work on double stars. He remained in South Africa and became the Director of the Union Observatory.
• Adriaan Wessellink was Superintendent of the Station from 1946-1950 while it was based at the Union Observatory in Johannesburg.
• Theo Walraven, inventor of the 5-colour photometer, initially used in conjunction with the Rockefeller twin astrograph and subsequently with the Flux Collector. He was Director of the Leiden Southern Station while it was at Hartbeespoort.
• Arnout van Genderen made extensive use of the Light Collector and Walraven’s photometer during his residence at the Leiden Southern Station at Hartbeespoort from 1972 to 1978. His principal work was based on variable double star observations. He incidentally discovered the early Iron Age archaeological site at the station which became a national monument. https://www.universiteitleiden.nl/en/news/2020/01/twinkle-twinkle-giant-star
• Jan Willem Pel worked at the Leiden Southern Station during three residencies between 1968 and 1978. He completed his PhD on variable star observations during this time.
• Jan Lub was based at the Leiden Southern Station in the 1970s. He went on to study the molecular interstellar medium, galaxy centres, star formation, dwarf galaxies, and Magellanic clouds.
Programmes:
Variable star observation.

Instruments:
There were three telescopes at this site, two of which remain in their original housing.
• Rockefeller Twin 16-inch astrograph, 1938. First installed at the Union Observatory, Johannesburg, and moved to Hartbeespoort in 1957.
• Franklin-Adams 10-inch telescope. First installed at the Union Observatory, Johannesburg, and moved to Hartbeespoort in 1954.
• Flux Collector 36-inch, 1957, moved to La Silla, European Southern Observatory in 1978. Specifically designed for photo-electric photometry.

Sources:

Pictorial  Sources:

Bibliography:

• Glass, I.S., ‘’The Franklin-Adams Telescope’’, MNASSA Monthly Notes of the Astronomical Society of South Africa 74, nos. 5 & 6, June 2015. https://hdl.handle.net/10520/EJC172751
• Hilton, A.S., “Small astronomical observatories and unusual telescopes of Gauteng (Presidential address).” MNASSA Monthly Notes of the Astronomical Society of South Africa 56, nos. 9 & 10, October 1997.
• Jamieson, A., “The Johannesburg Observatory glass plate story”, MNASSA: Monthly Notes of the Astronomical Society of South Africa 81, no. 5, 2022.
• Mitton,  J., A Concise Dictionary of Astronomy. Oxford: Oxford University Press, 1991.
• Moore, P. and Collins, P., The Astronomy of Southern Africa. Cape Town: Howard Timmins, 1977. Chapter 6.
• Schoenmaker, A.A.A., “De Rockefeller dubbele astrograaf van het Leids Zuidelijk Station” Sterrewacht Leiden (unpublished manuscript)
• Smits, P., “A Brief History of Astronomy in Southern Africa”. (Unpublished)
• Van Herk, G., Kleibrink, H. and Bijleveld, W., “The Leiden Southern Station”, MNASSA: Monthly Notes of the Astronomical Society of South Africa 47, no. 3,1988.
• Vermeulen, D.J., Living amongst the stars at the Johannesburg Observatory. Johannesburg: Chris Van Rensburg Publications, 2006.

Acknowledgement:
Many thanks to Jane and Vincent Carruthers who helped to research and write this page.
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Source: Hollenbach

Source: Hollenbach