Nasa finds 'cannibal' star that ate its neighbour
Published 16/09/2010 | 11:19
A 'cannibal' star suspected of eating its neighbour has been found by Nasa.
The billion-year-old red giant, called BP Piscium, is thought to have gobbled up a young star whose remnants are still visible.
BP Piscium is a more evolved version of our Sun located 1,000 light-years away in the constellation of Pisces. It has been found with the help of Nasa's Chandra X-ray observatory.
Scientists begun studying it 15 years ago and were bemused by its unusual appearance.
It is orbited by a disc of dusty matter that usually betokens planets beginning to form around young stars.
But young stars are born in clusters and BP Piscium is isolated, leading astronomers to believe that it is in fact a red giant – a star in a late stage of evolution.
They concluded that the disc of dusty matter is formed of the remnants of a young star that it has recently consumed and “digested”.
Professor Joel Kastner of the Rochester Institute of Technology, New York, said the researchers had discovered a rare case of “stellar cannibalism”.
The scientists believe that the star ate its neigbour shortly after it started expanding into its "red giant" phase, the late stage of stellar evolution.
He said: "Our working speculation is that we are observing the star right at the point at which it has swallowed its companion and hence formed a disc.
“Some of the material that used to be its companion has fallen on to the star and some has been shot out at high speeds, and that's what we're seeing."
The scientists believe that the Earth could one day fall victim to the same fate of BP Piscium’s unfortunate neighbour.
David Rodriguez from University of California, Los Angeles, said: "BP Psc shows us that stars like our Sun may live quietly for billions of years, but when they go, they just might take a star or planet or two with them.”