LALANDE 21185, a star almost so close to the Sun that it is a neighbour in galactic terms, has two planets orbiting it - the closest that such bodies have been found new research suggests.
The dim "red dwarf" star is the fourth closest to the Earth. It is 200 times less bright than the Sun, has only one third of its mass and lies slightly more than eight lightyears away. Previously, it had been thought that the nearest stars apart from the Sun to have planets were at least 40 light years away.
"We're pretty sure that there's something there, but it's a little early to say exactly what," according to Prof George Gatewood, who told a meeting this week of the American Astronomical Society in Wisconsin, of his discovery.
The analysis suggests that there are two planets orbiting the star, each roughly the size of Jupiter - the heaviest planet in our solar system. Prof Gatewood calculated that one circles Lalande 21185 every 30 years at a distance of about 900 million miles (about the same distance as Saturn) and the other lies closer, a few 100 million miles from the star, orbiting it every six years.
Other stars have been pinpointed as having orbiting planets, but never so close. Last October, astronomers reckoned they had detected one around 51 Pegasi, 40 light years away, and in January spotted variations in the behaviour of Beta Pictoris, 50 light years away.
"These are the first ones that are really like our solar system," said Mr Steve Maran, an astronomer at Nasa's Goddard Space Flight Centre in Maryland.
Prof Gatewood found the planets by tracking the star's motions on the sky down to the object's tiniest twitch. The method is so precise that it could tell if an astronaut on the moon switched a flashlight from one hand to the other.
The planets' existence has not been confirmed by independent astronomers, but Mr Maran said the results suggest planets are the most likely explanation for the star's movements.