A US researcher has noticed a black hole taking more than a decade to devour a star. Most black holes only require one year to eat stars.
University of New Hampshire scientist Dacheng Lin and his team noted a black hole has been eating at a star since July 2005 and is still going. This is the longest known event of a star being devoured by a black hole.
"We have witnessed a star's spectacular and prolonged demise," said Lin in a statement. "Dozens of tidal disruption events have been detected since the 1990's, but none that remained bright for nearly as long as this one."
The observation was noted Monday in the Nature Astronomy journal. The astronomic event is taking place in a host galaxy 1.8 billion light years away. According to the Chandra X-ray Observatory, NASA's flagship telescope for detecting x-rays around the universe, the black hole, also known as XJ1500+0154, is located in the center of the host galaxy, the expected location for a supermassive black hole. Supermassive black holes are found at the centers of almost all large galaxies in the observable universe.
The XJ1500+0154 black hole emitted its greatest x-ray brightness in June 2008, and has since reduced in brightness. The data also indicates the radiation surrounding the black hole has surpassed the so-called Eddington limit, a balance between the outgoing pressure of radiation from hot gas and the inward gravitational pull of the black hole. The limit explains the luminosity of black holes.
"For most of the time we've been looking at this object, it has been growing rapidly. This tells us something unusual - like a star twice as heavy as our sun - is being fed into the black hole," said co-author James Guillochon from the Harvard-Smithsonian Center for Astrophysics.
The black hole is expected to continue eating away at the star for several more years to come.