Stunning: This illustration shows plasma shooting out of the black hole after it devours a star. Such an event took place four billion light years from Earth
Known as 'relativistic jets', they can reach hundreds of thousands of light years in length.
Most galaxies have super-massive black holes - regions of space that suck in everything nearby with their strong gravitation pull - at their core, with masses of millions or even billions of suns.
Scientists were first alerted to the phenomenon in March after Nasa's Swift telescope detected several bursts of X-rays from a quiet patch of sky.
Teams from both Pennsylvania State University and the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, said the bursts could be the remnants of a star pulled apart when it came too close to a black hole located 3.9billion light years away.
Dr David Burrows, from Pennsylvania State University which controls Swift, said chemical analysis of the bright flash's ultraviolet light show it comes from material being sucked into a black hole the size of a million suns.
Writing in Nature, they concluded that the Swift satellite just happened to be in the path of the jet of star remains that were shot out at 99.5 per cent the speed of light.
Dr Burrows said: 'Incredibly, this source is still producing X-rays and may remain bright enough for the Swift satellite to observe into next year. It behaves unlike anything we've seen before.'
The swallowing of a star by a black hole only happens once every one hundred million years in a galaxy. The black hole is now believed to be even more powerful because of the additional mass from the swallowed star.
The absorption of large mass such as stars or even other black holes is what gives black holes growth and spawn the existence of super-massive black holes.Super-massive black holes could contain up to billions of solar masses. By comparison, the sun is just one solar mass and the Earth is 1/332,950th of a solar mass.