Star Caught Eating Another Star, X-Ray Flare Shows
Illustration courtesy ESA/AOES Medialab
Published July 5, 2011
A tiny cannibal has been caught in the act, thanks to a superbright flash of x-rays spied by cosmic hunters.
The culprit is what’s known as a neutron star, the tiny but very dense corpse of a massive star that died in a supernova blast. Sitting 16,000 light-years away, this particular neutron star is normally among the faintest objects in the x-ray sky.
But during recent observations with the European Space Agency’s XMM-Newton space telescope, the star unexpectedly surged to 10,000 times its original brightness.
“A companion blue supergiant star is believed to have thrown off a gigantic clump of superheated gas from its surface, [which] got attracted by the intense gravitational field of the much smaller and denser neutron star orbiting nearby,” said study leader Enrico Bozzo, an astronomer with the ISDC Data Centre for Astrophysics in Geneva, Switzerland.
The lump of wayward stellar matter measured an estimated 9.9 million miles (16 million kilometers) across and took up about a hundred billion times the volume of the moon.
As it became part of the neutron star, the material was heated to millions of degrees, generating a brilliant x-ray flare that lasted for four hours.