Large Asteroid Belt Discovered Around Vega Star
Astronomers have discovered a large asteroid belt around the star Vega, which is the second brightest star in the northern celestial hemisphere.
By detecting infrared light emitted by distinct bands around Vega, NASA's Spitzer Space Telescope and the European Space Agency's Herschel Space Observatory detected the asteroid belt around the star.
Based on the observations, scientists also confirmed the existence of inner warm belts and outer cool belts around Vega similar to another star called Fomalhaut. The warm and cool belts are separated by a gap, a design which is similar to the asteroid and Kuiper belts in our solar system.
Scientists suggest that the gap is likely maintained by multiple planets. The asteroid belt in our solar system lies between the orbits of Mars and Jupiter. It is called the main belt and comprises mostly of metal and rock. The Kuiper belt is a disc-shaped region of icy objects located beyond the orbit of Neptune - billions of miles from the sun.
"Our findings echo recent results showing multiple-planet systems are common beyond our sun," Kate Su, lead author of the paper from the University of Arizona, Tucson, said in a statement.
Apart from having similar warm and cool belts, both the Vega and Fomalhaut stars have some other common aspects. Both stars are about twice the mass of our sun and are located close by, at a distance of 25 light years away. Their age dates back to 400 million years, but scientists suggest that Vega could be about 600 million years old.
The inner belt of the stars could not be viewed in visible light, as glare from the stars outshine them. The distance between the inner and outer belt of both the stars corresponds to the distance between the asteroid belt and the Kuiper belt in our solar system. The outer belt is 10 times farther from its host star than the inner belt.
Jupiter-sized or smaller planets are likely filling the gap between the inner and outer belts, which researchers hope to find out about.
The study paper was presented Tuesday at the American Astronomical Society meeting in Long Beach, Calif.
The details of the study will appear in The Astrophysical Journal.