The UK Schmidt Telescope (UKST) is a survey telescope with an aperture of 1.2 metres and a very wide-angle field of view. The telescope was commissioned in 1973 and, until 1988, was operated by the Royal Observatory, Edinburgh. It became part of the AAO in June 1988.
The telescope was designed to photograph 6.6 x 6.6 degree areas of the night sky on plates 356 x 356 mm (14 x 14 inches) sqare in order to produce photgraphic aylases of the night sky. The UKST's initial task was the first deep, blue-light photographic survey of the southern skies, which was completed in the 1980s. It then undertook many other survey projects in different colours and in the near infrared, notably the Second Epoch Sky Survey in collaboration with Space Telescope Science Institute. The telescope's final photographic survey was the H-alpha Survey of the Milky Way and Magellanic Clouds using a special filter to isolate the light of glowing hydrogen. Its photographic work was completed in 2005 when the last H-alpha exposure was taken.
The excellent optics and wide field of the telescope are now exploited by the 6dF (6-degree Field) system, a multi-object fibre-optic spectrograph facility, which can obtain the spectra of more than 100 objects in a single field simultaneously. 6dF was commissioned in 2001, having been based on earlier prototypes such as the pioneering FLAIR system of the early 1980s.
The 6dF system was used from 2001 to 2005 to carry out the 6dF Galaxy Survey, which measured the redshifts of more than 120,000 galaxies over the whole southern sky, with more detailed measurements being made for the brightest 10,000 of them.
At present, the UKST is being operated by the AAO under funding from the international RAVE (RAdial Velocity Experiment) project. Using 6dF, RAVE aims to measure radial velocities (with an accuracy of ~1km/s) and physical parameters for up to a million stars in our Galaxy. Over 300,000 high-quality spectra have been obtained to date in this project.
The characteristics of UKST and the AAT complement each other perfectly and many AAT projects depend on the wide field capabilities of the UKST. For example, the telescopes of the Anglo-Australian Observatory have together discovered and confirmed a large number of distant quasars, the most energetic but often the most distant objects in the Universe.