The alien girdle is quite close to its star, known as HD69830, and is much thicker than the asteroid belt seen between the orbits of Mars and Jupiter.More info about the found at BBC
The scientists hope to use the Spitzer data to learn about planet formation.
Spitzer telescope spots asteroid belt

NASA's Spitzer infrared telescope found a star 41 light-years from Earth with what appears to be a belt of asteroids orbiting the star. Scientists say this it the first time such a band of rocky material has been found around a star of similar age and size to our Sun.