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The European team spent four years using the European Southern Observatory in Chile to look for planets at Alpha Centauri B and its sister stars Alpha Centauri A and Proxima Centauri. They used a technique that finds other worlds by looking for subtle changes in a star’s speed as it races through the galaxy.

Part of the problem is that the star is so close and so bright _ though not as bright as the sun _ that it made it harder to look for planets, said study lead author Xavier Dumusque of the Geneva Observatory.

One astronomer who wasn’t part of the research team, wondered in a companion article in Nature if the team had enough evidence to back such an extraordinary claim. But other astronomers said they had no doubt and Udry said the team calculated that there was only a 1-in-1,000 chance that they were wrong about the planet and that something else was causing the signal they saw.

Finding such a planet close by required a significant stroke of good luck, said University of California Santa Cruz astronomer Greg Laughlin.

Dumusque described what it might be like on this odd and still unnamed hot planet. Its closest star is so near that it would always hang huge in the sky. And whichever side of the planet faced the star would be broiling hot, with the other side icy cold.

Because of the mass of the planet, it’s likely a rocky surface like Earth, Dumusque said. But the rocks would be “more like lava, like a lava planet.”

“If there are any inhabitants there, they’re made of asbestos,” joked Shostak.


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