A brief History
When the AAT project was already well underway in 1970, the British decided to build a 1.2 metre Schmidt telescope on Siding Spring Mountain. The Schmidt type of telescope is named after its inventor, Bernhard Schmidt, who discovered in the early 1930s that it was possible to build a telescope with a very wide field of view by a suitable combination of a spherical mirror and corrector-plate lens. The first large telescope of this type was the 48 inch Schmidt on Palomar Mountain, which carried out a complete photographic survey of the sky accessible from Palomar, from the north pole to -33° declination, during the early 1950s. This survey was reproduced as a set of photographs, and the resultant sky survey has been a fundamental database for northern hemisphere astronomers for forty years.
The then Science Research Council (SRC) established the UK Schmidt Telescope Project in 1971 as an independent project with the design, construction and operation under the direction of V C Reddish. The SRC set up a special Unit at the Royal Observatory, Edinburgh (ROE). Sir Howard Grubb Parsons & Company Limited of Newcastle-upon-Tyne, which also won the contract for the AAT mirror and tube assembly, began work on the Schmidt Telescope in June 1971. In May 1973 the telescope was delivered to Siding Spring, and the first plate was taken in the following month. The telescope was formally opened on 17 August 1973 by Professor Bengt Strömgren, President of the International Astronomical Union, and after completing initial commissioning it entered service on 3 September, just three days behind schedule. When Professor Reddish became Director of the ROE in 1975, the Schmidt Unit became part of that Observatory.
At about the same time the European Southern Observatory (ESO) built a 1.0-metre Schmidt telescope alongside its new 3.6-metre telescope on La Silla in Chile. As the primary objective of both Schmidt telescopes was to map the southern sky, the SERC and ESO agreed to share the survey work, with the UK Schmidt taking plates in blue light and ESO the corresponding set of red photographs. The ESO/SERC Southern Sky Survey covers the sky from -17° to the south pole with a mosaic of 606 photographic plates in each colour. The survey plates were copied onto glass and film at the ESO Sky Atlas Laboratory, and the resulting Atlas has been distributed to some 170 institutions around the world. This atlas is now also widely available in digital form. The UK Schmidt also carried out a photographic near infrared survey of the Milky Way which has been widely distributed as an atlas made in the ROE Photolabs, and a new atlas of the equatorial strip of sky is now being produced.
In 1988 the SERC concluded negotiations with the Board for the Schmidt Telescope to become part of the Anglo-Australian Observatory, operated like the AAT under the AAO Director, and funded jointly by the two Governments. The Plate Library at ROE remains the ultimate destination of all Schmidt Telescope plates, and has a unique archive of over 10,000 sky photographs. Other facilities in the UK, the Photolabs at ROE and the high-speed measuring machines, remain closely linked with the Schmidt Telescope operations in Australia.
Further reading:
- Gascoigne, Proust & Robins, The Creation of the Anglo-Australian Observatory, Cambridge University Press, 1990
- Malin, A View of the Universe, Cambridge University Press, 1993
- Haynes, Haynes, Malin & McGee, Explorers of the Southern Sky, Cambridge University Press, 1996
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