The 3.9-metre Anglo-Australian Telescope (AAT) turns 25 on 16 October this year, and still continues to have a front-line role in astronomy.
On the 16 October 1974 when HRH Prince Charles inaugurated the AAT, it ranked among the three largest optical telescopes in the world. Now, 25 years later, it still plays a major role in astronomy. Its innovative science programs range from mapping the Universe in the largest ever survey of distant galaxies, to the discovery of planets around nearby stars. It is also enjoying increasing success in earning export dollars for Australia by building state-of-the-art equipment for the new generations of large telescopes being constructed overseas.
Twenty-five years of innovation and discovery
1974 27 April, first light, first images of stars recorded on photographic plates at the prime focus. 16 October, AAT inaugurated.
1975 The Image Dissector Scanner (IDS), the first digital electronic
imaging detector designed for astronomy, allows astronomers to collect
much more and better data than ever before.
1979 Studies of galaxy NGC 5291 show it to be an unusual gas-rich galaxy. Gas is being stripped from this galaxy and, as a by-product, a host of tiny companion galaxies is being formed.
1980 A novel infrared instrument, IRPS comes into full operation giving the AAT new power. Detailed IR observations of the Orion nebula are also made, revealing for the first time the violent early stages of star formation.
1981 Charge-coupled devices (CCDs) revolutionise light detection at the AAT and will eventually replace photography. Optical fibres for astronomy are pioneered at the AAO with the use of 25 fibres in a small field.
1982 AAT observations of a quasar (PKS 2000-330) reveal a redshift of 3.78, which made it the most distant known object in the Universe at the time.
1983 Infrared observations of the centre of our Galaxy show that the central object consists of several separate components, including congregations of young hot stars, a very tight cluster of cooler stars, and a central concentration of cooler stars probably circling a black hole.
1984 Discovery of clouds on the dark side of Venus. At certain wavelengths, clouds are backlit by the heat from the planet’s surface. A larger optical fibre mounting system covers the full field, greatly increasing the scope for multi-object work.
1985 The Low Dispersion Survey Spectrograph (LDSS) is first used. This revolutionary instrument allows multi-slit low-dispersion spectroscopy of very faint objects.
1986 Organic molecules are detected in the dusty material streaming out of comet Halley. Discovery of the first quasar with a redshift greater than four, the then most distant known object in the Universe.
1987 The AAT carries out observations to learn more about Supernova 1987a. There is an urgent need for a very high resolution spectrograph to study the Supernova, and the Peter Gillingham spectrograph is designed, built and in use within two months.
1988 The University College London Coudé Spectrograph (UCLES) is commissioned. It has the double advantage of very high resolution and broad wavelength coverage. The UK Schmidt Telescope becomes part of the AAO.
1989 Autofib, an automatic optical fibre positioner is used to show that the globular clusters around the elliptical galaxy Centaurus A are very similar to those in our own galaxy, despite the large differences in morphological type and luminosity between the two galaxies.
1990 The largest catalogue of galaxies ever produced is completed ---— over 2 million galaxies are identified from Schmidt plates. The 2dF project commences.
1991 IRIS (Infrared Imager Spectrograph) becomes the AAO’s first instrument to give two-dimensional imaging at IR wavelengths. It is the most complex instrument to have been built at the AAT. IRIS observations of a cluster of extremely hot, massive stars located near the Galactic Centre, suggest that a burst of star formation may have occurred a few million years ago.
1992 A new, large format Tektronix CCD is commissioned. This detector has twice the sensitivity of the best CCD previously available.
1993 IRIS observations of the northern outflow of Orion reveal unexpected jets. The jets are a result of an explosion about 1000 years ago.
1994 The comet Shoemaker-Levy 9 collides with Jupiter. IRIS observations reveal details of the collisions and later changes at the impact sites.
1995 The Two-degree Field (2dF) facility for the AAT is officially opened.
1996 The Taurus tunable filter uses a unique system to enable astronomers to tune into very narrow parts of the spectrum. This is particularly helpful for observing objects that emit their light at a specific wavelength rather than across a broad range.
1997 Observations at the AAT detect the first isolated brown dwarf in our galaxy. Brown dwarfs are star-like objects which are not massive enough to burn nuclear fuel and so are extremely faint and difficult to detect.
1998 The new H-alpha filter on the UKST enables a new survey to be undertaken in H-alpha light. More than 300 new planetary nebulae are identified. The AAO is recognised as world leader in optical fibres for astronomy when the European Southern Observatory contracts the AAO to build a fibre positioner for the Very Large Telescope (VLT) in Chile.
1999 2dF in regular use. More galaxy and quasar redshifts (50 000 &
growing) measured than any other instrument in the world.
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