Detecting two major solar systems

Astronomers said yesterday they have just obtained evidence of two very large solar systems - giant stars surrounded by large disks of dust in forming planets.

The illustration compares the size of a giant star and the disk of dust surrounding it compared to the solar system.(Photo: NASA )

These cloud disks of dust surrounding stars are thought to signal the formation of future planetary systems.

Our sun is surrounded by the Kuiper belt, a disc consisting of dust, comets and other objects.

Astronomers say this latest discovery is "surprising" because such big stars are thought to be non-existent in the formation of planets.

" Our data shows that planetary formation may be more difficult than one might think, occurring around even the biggest stars ," said Joel Kastner of the Rochester Research Institute.

These new stars are thought to be 30-70 times larger than the sun. Because of their size, the scientists thought that the dust disks surrounding them would be larger than the Kuiper belt, and could be up to 10 times larger.

These new stars were discovered by NASA's Spitzer telescope on a survey of 60 bright stars.

In November last year, another group of scientists also discovered what they believed to be a miniature solar system. This group discovered a cloud of dust surrounding a brown dwarf - a type of star that is dying, larger than a planet but smaller than a regular star.

WALL VY