Zeenews Bureau
London: Joining the space explorer’s race, UK’s VISTA telescope, world’s largest telescope dedicated to mapping the sky, on Saturday released its first images.
The spectacular new images of the Flame Nebula, the centre of our Milky Way galaxy and the Fornax Galaxy Cluster show that it is working extremely well.
VISTA’s (the Visible and Infrared Survey Telescope for Astronomy) large mirror, wide field of view and very sensitive detectors will reveal a completely new view of the southern sky, a release of ESO’s Paranal Observatory said today.
VISTA’s main mirror is 4.1 metres across and is the most highly curved mirror of this size and quality ever made — its deviations from a perfect surface are less than a few thousandths of the thickness of a human hair — and its construction and polishing presented formidable challenges.
VISTA was conceived and developed by a consortium of 18 universities in the United Kingdom led by Queen Mary, University of London and became an in-kind contribution to ESO as part of the UK's accession agreement.
The telescope design and construction were project-managed by the Science and Technology Facilities Council's UK Astronomy Technology Centre.
“VISTA is a unique addition to ESO’s observatory on Cerro Paranal. It will play a pioneering role in surveying the southern sky at infrared wavelengths and will find many interesting targets for further study by the Very Large Telescope, ALMA and the future European Extremely Large Telescope,” says Tim de Zeeuw, the ESO Director General.
At the heart of VISTA is a 3-tonne camera containing 16 special detectors sensitive to infrared light, with a combined total of 67 million pixels. Observing at wavelengths longer than those visible with the human eye allows VISTA to study objects that are otherwise impossible to see in visible light because they are either too cool, obscured by dust clouds or because they are so far away that their light has been stretched beyond the visible range by the expansion of the Universe.
To avoid swamping the faint infrared radiation coming from space, the camera has to be cooled to -200 degrees Celsius and is sealed with the largest infrared-transparent window ever made.
Because VISTA is a large telescope that also has a large field of view it can both detect faint sources and also cover wide areas of sky quickly.
Each VISTA image captures a section of sky covering about ten times the area of the full Moon and it will be able to detect and catalogue objects over the whole southern sky with a sensitivity that is forty times greater than that achieved with earlier infrared sky surveys such as the highly successful Two Micron All-Sky Survey.
This jump in observational power — comparable to the step in sensitivity from the unaided eye to Galileo’s first telescope — will reveal vast numbers of new objects and allow the creation of far more complete inventories of rare and exotic objects in the southern sky.
First Published: Saturday, December 12, 2009, 12:11