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10 April 2014 11:44 am ,
Vol. 344 ,
The Pyrenean ibex, an impressive mountain goat that lived in the central Pyrenees in Spain, went extinct in 2000. But a...
Tight budgets are forcing NASA to consider turning off one or more planetary science projects that have completed their...
Ebola is not a stranger to West Africa—an outbreak in the 1990s killed chimpanzees and sickened one researcher. But the...
In an as-yet-unpublished report, an international panel of geoscientists has concluded that a pair of deadly...
Tropical disease experts tried and failed before to eradicate yaws, a rare disfiguring disease of poor countries. Now,...
Since 2002, researchers have reported that agricultural communities in the hot and humid Pacific Coast of Central...
Balkan endemic kidney disease surfaced in the 1950s and for decades defied attempts to finger the cause. It occurred...
- 10 April 2014 11:44 am , Vol. 344 , #6180
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A Supreme Star Guide
21 August 1998 7:00 pm
When astronomers crank up a huge, powerful optical telescope, they don't just point and shoot. First, they must select targets from detailed imaging surveys of chunks of the sky, performed by other, wide-field telescopes. Now, the first of a new generation of optical surveys is available to help them decide where to look. Thanks to the use of sensitive electronic cameras, the new survey will offer the deepest--the furthest away from Earth in both space and time--and most detailed guide yet for astronomers using the European Southern Observatory's (ESO's) Very Large Telescope (VLT), under construction in northern Chile. The survey will also be useful to other large telescopes in Australia, Chile, and Hawaii.
Last year, ESO astronomers surveyed four patches of southern sky--each 2 degrees by 3 degrees, or 30 times the size of the full moon--in unprecedented detail, using ESO's 3.5-meter New Technology Telescope at La Silla, Chile. The patches yielded an inventory of about 1 million galaxies and 250 distant galaxy clusters, providing a wealth of observation targets for astronomers who will start using the first of VLT's four identical 8.2-meter telescopes when it comes on line next year.
The ESO Imaging Survey, the results of which were released earlier this month, is 10 times as sensitive as is the 1990 British-Australian survey of the southern sky, called the APM Galaxy Survey, which was based on digitized photographic plates. "Being able to select fainter objects means that you will be able to probe further back into the history of the universe," says APM survey head Steve Maddox of Cambridge University.