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Cosmic Cannibalism

BP Piscium may provide clues about the formation of exoplanets.

BP Piscium may provide clues about the formation of exoplanets.

By David Reneke

Dave Reneke brings news from the space and astronomy communities around the world.

The full text of this article can be purchased from Informit.

Cosmic Cannibalism
Nasa's Chandra X-ray observatory has found a star that might have gobbled up its neighbour – another star or a giant planet – shedding new light on the interaction between planets and stars.

The star, BP Piscium, is a more evolved version of our Sun, and is located about 1000 light years away in the constellation of Pisces. It appears to be a young star but in fact it may be a 1-billion-year-old red giant that “ate” its young companion, leaving remnants that are still visible today.

Researchers first started studying the star 15 years ago and were puzzled by its unusual look. Most young stars form in clusters but BP Piscium was isolated. The research team, led by Joel Kastner of the Rochester Institute of Technology in New York, noted that if the star was a young one it would have been a much stronger X-ray source. However, its rate of X-ray production is very similar to old, yet rapidly spinning, giant stars.

It also appears to have a dusty orbiting disc, which usually forms planets: a dead giveaway to longevity. Having considered all the evidence, the team decided that they were witnessing a rare case of stellar cannibalism.

“The giant star's companion has most probably fallen inside it and got digested,” said team member David Rodriguez from the University of California. “We've never actually...

The full text of this article can be purchased from Informit.

David Reneke is an astronomy lecturer and teacher, a feature writer for major Australian newspapers and magazines, and a science correspondent for ABC and commercial radio. Subscribe to David’s free Astro-Space newsletter at www.davidreneke.com