Bright star Vega may have its own family of planets

Astronomers have discovered evidence of an asteroid belt surrounding the star like the one that circles the Sun which suggestes Vega is likely to have a solar system containing rocky planets similar to Earth or Mars.

In our own system, the asteroid belt beyond the orbit of Mars is maintained by the gravity of rocky planets and gas giants such as Jupiter and Saturn.

Scientists believe Vega has an inner asteroid belt and outer belt of debris separated by a gap, the 'Daily Mail' reported.

The same pattern is seen around the Sun.

A distant band of rock and ice, called the Kuiper belt, orbits the Sun near the edge of the Solar System.

"Our findings echo recent results showing multiple-planet systems are common beyond our Sun," astronomer Dr Kate Su, from the Steward Observatory at the Arizona University in the US, said.

Vega, known as the Harp Star, is the brightest star in the constellation Lyra.

It is relatively close at a distance of just 25 light years, and around 600 million years old - much younger than the Sun.

The discovery was made using the Herschel and Spitzer space telescopes. Detectors on the telescopes measured infrared light emitted by warm and cold bands of dust around the star.

Scientists suspect hidden planets are sweeping the region between the bands free of dust.

Vega may have several undetected planets up to the size of Jupiter, they believe.

The limits of current planet detection techniques make it difficult to spot small rocky planets, or larger worlds in outlying orbits.

Similar bands of debris were found to surround another star, Fomalhaut, which is known to have at least one candidate planet.

"Overall, the large gap between the warm and the cold belts is a signpost that points to multiple planets likely orbiting Vega and Fomalhaut," said Su.

The study was presented at the American Astronomical Society's annual meeting in Long Beach, California.