Astronomers find multi-planet star system

Livermore, Calif. -- U.S. astronomers say they have, for the first time, obtained images of a multi-planet star system, much like ours.

Bruce Macintosh, an astrophysicist at the Lawrence Livermore National Laboratory, said the new planetary system orbits a dusty young star named HR8799, which is 140 light years away and about 1.5 times the size of our sun.

Macintosh said three planets, roughly 10, 10 and 7 times the mass of Jupiter, orbit the star and the size of the planets decreases with distance from the parent star, much as do the planets do in our system.

"Every extrasolar planet detected so far has been a wobble on a graph," said Macintosh. "These are the first pictures of an entire system. We've been trying to image planets for eight years with no luck and now we have pictures of three planets at once. This is a milestone in the search and characterization of planetary systems around stars."

And he said there's a very high probability there are more planets in the system that we haven't yet detected.

The discovery is reported in the online preprint journal Science Express.

Copyright 2008 by United Press International.