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Tiny telescope spots new Jupiter-sized planet

WASHINGTON - Astronomers have used a network of small telescopes to discover a planet circling a far-off star.

"This discovery demonstrates that even humble telescopes can make huge contributions to planet searches," said Guillermo Torres of the Harvard-Smithsonian Center for Astrophysics in a release.

Planet hunters normally detect a planet by measuring changes in the composition of a star's light caused by the planet's gravitational tug.

In this case, American and Spanish researchers looked for dimming as the planet transited, or passed in front of its star.

A telescope with a diameter of about 10 centimetres, or about the size of some backyard instruments, detected the dimming about 5,000 light-years away in the constellation Lyra. (A light-year is about 9.5 trillion kilometres, the distance light travels in a year.)

The telescope was part of a network called the Trans-Atlantic Exoplanet Survey or TrES, which synchronizes three small telescopes to search for extrasolar planets orbiting bright stars.

Observations from the larger lenses at the W.M. Keck Observatory in Hawaii confirmed the discovery.

The newfound planet, called TrES-1, has a mass about three-quarters that of Jupiter and about the same diameter.

TrES-1 orbits its star approximately every three days from a distance of 6.4 million kilometres, much closer and faster than the planet Mercury in our solar system, the researchers said.

A study describing the discovery appears in the online edition of Astrophysical Journal Letters.

[original article]

Posted by thinkum at August 26, 2004 03:27 PM