|Organization||Australian Astronomical Observatory|
|Location||Siding Spring Observatory, Australia|
|First light||April 27, 1974|
|Diameter||3.9 m, 12.8 ft|
|Collecting area||12 m2, 129 ft2|
|Focal length||12.7 m, 42.7 ft|
The Anglo-Australian Telescope (AAT) is a 3.9 m equatorially mounted telescope operated by the Australian Astronomical Observatory and situated at the Siding Spring Observatory, Australia at an altitude of a little over 1100 m. In 2009, the telescope was ranked as the fifth highest-impact of the world's optical telescopes. In 2001-2003, it was considered the most scientifically productive 4 metre-class optical telescope in the world based on scientific publications using data from the telescope.
The telescope was commissioned in 1974 with a view to allowing high quality observations of the sky from the southern hemisphere (at the time, most major telescopes were located in the northern hemisphere). The AAT was credited with stimulating a resurgence in British optical astronomy. It was constructed by Australia and the United Kingdom but has been entirely funded by Australia since 2010. Observing time is available to astronomers worldwide.
The AAT was one of the last large telescopes built with an equatorial mount. More recent large telescopes have instead adopted the more compact and mechanically stable altazimuth mount. The AAT was however one of the very first telescopes to be fully computer-controlled, and set new standards for pointing and tracking accuracy.
A Joint Policy Committee started work on construction planning in August 1967. It took until September 1969 for plans to be finalised. The agreement initially committed the specification to a telescope design based on the Kitt Peak telescope until its deficiencies were known. Both the horseshoe mount and the gearing system needed improvements. Although the revised gear system was considerably more expensive it was significantly more accurate, lending itself well to unforeseen applications.
The mirror was made by Owens-Illinois in Toledo, Ohio. It was then transported to Newcastle, England where Sir Howard Grubb, Parsons and Co took two years to grind and polish the mirror's surface. Mitsubishi Electric built the mount which was constructed by August 1973. First light occurred on 27 April 1974. The telescope was officially opened by Prince Charles on 16 October 1974.
The telescope is housed with a seven-story, circular, concrete building. It was designed to withstand the high winds prevailing at that location. The slit is narrow. The dome is required to move with the telescope to avoid obstruction.
The AAT is equipped with a number of instruments, including :
- The Two Degree Field facility (2dF), a robotic optical fibre positioner for obtaining spectroscopy of up to 400 objects over a 2° field of view simultaneously.
- The University College London Échelle Spectrograph (UCLES), a high-resolution optical spectrograph which has been used to discover many extrasolar planets.
- IRIS2, a wide-field infrared camera and spectrograph.
HERMES will be commissioned in 2013. It is a new spectrograph to be used with the 2dF fibre positioner. HERMES will be used for the ‘Galactic Archaeology‘ (GA) Survey, which aims to reconstruct the history of our galaxy's formation from precise multi-element (~25) abundances of 1 million stars derived from HERMES spectra.
 Contemporaries on commissioning
The AAT was built just a little smaller and built later than the Mayall 4m, but the AAT views the southern sky.
Kitt Peak National Obs.
|1973||Nicholas U. Mayall|
Siding Spring Obs.
|1959||C. Donald Shane|
 See also
- Fred Watson (6 January 2009). "Across the universe". Sydney Morning Herald. Retrieved 8 November 2011.
- Tammy Plonter (11 September 2008). "Australian Telescope Leads the World In Astronomy Research". Universe Today.
- Home, R. W.; Roderick Weir Home (1990). Australian Science in the Making. Cambridge University Press. p. 364. ISBN 0521396409. Retrieved 15 April 2013.
- Nick Lomb (June 15, 2010). "Australia's largest optical telescope to become part of the Australian Astronomical Observatory on 1 July 2010 and to celebrate its 36th birthday". Sydney Observatory.
- Gregory, Jane (2005). Fred Hoyle's Universe. Oxford University Press. p. 225. ISBN 0191578460. Retrieved 15 April 2013.
- Haynes, Raymond (1996). Explorers of the Southern Sky: A History of Australian Astronomy. Cambridge University Press. pp. 382–394. ISBN 0521365759. Retrieved 15 April 2013.
- "HERMES project AAT". Department of Industry, Innovation, Climate Change, Science, Research and Tertiary Education. Retrieved 15 April 2013.
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