Planet is found circling star 8 light years from Earth Solar system is closest to ours, shows similarities

June 12, 1996|By LOS ANGELES TIMES

Astronomers report they have discovered a solar system far closer to our sun than any of the previous half-dozen planet discoveries. And the new planetary system has features strikingly similar to our own.

Evidence presented yesterday at the American Astronomical Society meeting in Madison, Wis., suggests that the fourth-nearest star from our sun has a Jupiter-sized companion orbiting at about the distance of Saturn -- and possibly a second, smaller, planet at the distance of the asteroid belt.

If confirmed, the new planet -- just over 8 light years from Earth in the direction of the Big Dipper -- adds another piece of evidence confirming centuries of speculation that planets are common, and that astronomers don't have to look much beyond their own backyards to find them.

Some of these, astronomers hope, might harbor the potential for life.

"It's the beginning of a whole new field," said George Gatewood of the Allegheny Observatory in Pittsburgh, who discovered the planet orbiting a fast-moving star called Lelande 21185. "We've just lifted up the corner of the first page of the book."

After decades of false hopes and dashed promises, astronomers have discovered a string of oddball planetary systems since the fall of 1995.

Gatewood's planetary system, in contrast, looks more like our own. The planet weighs in with Jupiter's mass and appears to circle its star at a similar distance. Both possible planets also orbit in the same pancake-flat plane favored by Earth's planetary companions.

Traveling at light speed (an impossibility), one could make the nearly 50 trillion-mile journey to Lelande 21185 in just over eight years. Prospects for life are dim, however, because all large planets previously discovered are mostly gas, lacking any land. In addition, the star itself is too faint to generate enough heat to support life.

The latest discovery was not the result of space-age technology as much as persistence and patience. The Pittsburgh observatory had been keeping track of Lelande 21185 more than six decades with a 30-inch telescope -- small by modern standards.

By plotting the star's course through the heavens, the observatory was able to discern a small wobble in its motion -- the star was being pulled side to side by the gravitational influence of the planet. Only recently did the telescope get new optics that allowed Gatewood to see the star with 10 times the previous precision.

Pub Date: 6/12/96

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