martes, 16 de septiembre de 2008

Historic snapshot of a planet beyond the solar system


After years of searching, astronomers may finally have recorded the first image of a planet orbiting a sunlike star beyond the solar system. The body, about eight times Jupiter’s mass, lies exceptionally far from its presumed parent star — roughly 11 times Neptune’s average distance from the sun.

“If this object is a planet at such a wide separation it would challenge our conceptions of planet and companion formation,” says theorist Adam Burrows of Princeton University.

In an article posted online September 10, codiscoverers David Lafrenière, Ray Jayawardhana and Marten H. van Kerkwijk of the University of Toronto caution there’s a small chance that the object, small enough to be classified as a planet, merely resides in the same part of the sky as the star but is not gravitationally bound to it.

But if the body does turn out to orbit the young sunlike star, which has the unwieldy name 1RXS J160929.1-210524, it could pose a problem for planet formation theories. A widely accepted model suggests that the planet-forming disks of gas, dust and ice that surround newborn stars concentrate most of their material close to their stars.

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