Six seconds comet collision

The 192 light years distant star 49 Cetin is surrounded by a huge ring of comets, which occurs about every six seconds in a collision. With these circumstances, two American astronomers solve an unsolved problem for 17 years: the star is surrounded by a cloud of unusual carbon monoxide. The comet collisions release the gas, the researchers said in the journal "Astrophysical Journal."

"49 Cetin is probably 40 million years old - and the question is, how can the average in every other way star at this age have so much gas in its vicinity," says Benjamin Zuckerman of the University of California in Los Angeles problem together. Young stars are surrounded by rotating disks of gas and dust, which can occur in planets. But already some ten million years after the birth of a star's radiation is strong enough to blow out the gas from the young system. Zuckerman in his observations, however, met in 1995 to a dense cloud of carbon monoxide by 49 Cetin.

Together with his colleague Inseam song he now presents a solution to the puzzle. Then 49 Cetin is surrounded by a ring of comets similar to the Kuiper Belt in our solar system, but about 4000 times the mass contains. In a typical diameter of one to two kilometers, this results in a total of several hundred billion comets, the researchers said, "And these young comets contain almost certainly a lot more carbon monoxide than the old comets with us," says Zuckerman.

The calculations of Song and Zuckerman show that in such a comet-belt every six seconds, a collision occurs - a number that even the two astronomers were surprised: ". This tremendous rate we expected never ever" Scientists assume that the process stops since about ten million years and provides for supply of gas. Meanwhile, in another star - the 235 light years from HD 21997 - a similar cloud of gas discovered. Even for these 30 million years see Zuckerman star and her song scenario as best explanation of the phenomenon.