Researchers find 'lonely planets'
Japanese astronomers claim to have found free-floating "planets" orbiting no detectable star.
Writing in Nature, they say they have found 10 Jupiter-sized objects, which they could not connect to any solar system.
The objects revealed themselves by bending the light of more distant stars, an effect called "gravitational microlensing".
Objects of large enough mass can bend light, as Einstein predicted. If a large planet passes before a more distant background star, it may act as a lens, bending and distorting the light of that star so that it may appear to brighten periodically.
This artist's impression shows how the researchers found the planets by looking for their effect on the light emitted by distant stars.
18 May 2011