New telescope in search of extrasolar planets

Started by Desdemone, April 21, 2004, 02:06:24 AM

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A hunt for new worlds was launched yesterday by a British-led project that aims to uncover thousands of alien planets, providing a massive boost for the search for extraterrestrial life.

 

The idea that myriad alien worlds and life might exist throughout the universe seems increasingly plausible to many scientists.

To date, the search for these so called "extrasolar planets" has been dominated by a team led by Prof Geoff Marcy of the University of California, Berkeley. So far, the tally is 123, all "gas giants" similar to our own Jupiter.

Yesterday Europe launched a new planet hunt with the inauguration of SuperWASP at the Roque de Los Muchachos Observatory in the Canary Islands.

"SuperWASP is the most ambitious project of its kind," according to the project's principal investigator, Dr Don Pollacco of Queen's University Belfast, where the prototype telescope was developed. A second is planned for the southern hemisphere.

Thanks to its five cameras, its extremely wide field of view, combined with its ability to measure brightness very precisely, allows it to view large areas of the sky and accurately monitor the brightnesses of hundreds of thousands of stars.

"That is why SuperWASP is world-beating," said Dr Alan Fitzsimmons of Queen's University Belfast. "It surveys more of the sky down to a fainter brightness than any comparable instrument."

If any of the surveyed stars has Jupiter-sized planets nearby, then they could move across the face of their parent star, as viewed from the Earth.

While no telescope could actually see the planet directly, its passage or transit, blocks out a small proportion of the parent star's light so that the star dims for a few hours.

"By some estimates, we expect to find 10 a month," said Dr Fitzsimmons.

The launch comes only a day after the first planet was discovered using another method, "gravitational microlensing".

In this development, akin to Sherlock Holmes using a magnifying glass to reveal hidden clues, a star or planet can act as a cosmic lens to magnify and brighten a more distant star lined up behind it.

The gravitational field of the foreground star bends and focuses light, like a glass lens bending and focusing starlight in a telescope.

Earlier this week, astronomers announced the first definitive discovery of a planet around a star beyond Earth's solar system using gravitational microlensing. The newly discovered star-planet system is 17,000 light years away, in the constellation Sagittarius.