A black hole is observed reacting violently to a rapid force-feeding by its companion - an orbiting star.

British astronomers have observed violent red flashes, lasting just fractions of a second, during one of the brightest black hole outbursts in recent years.
Image Caption: An artist's impression of the 'feeding frenzy'

British astronomers have seen powerful flashes from a black hole as it struggles to swallow material from a nearby star.

The flashes, which are among the brightest seen from a black hole in recent years, were captured by a fast-imaging camera mounted on a telescope in the Canary Islands over a period of two weeks.

They came from a black hole called V404 Cygni, which is about 7,800 light years from Earth and was the first black hole to be discovered in our galaxy.

Each flash was blindingly intense and contained the power of 1,000 suns, according to British astronomers.

The flashes did not last long - some were as quick as 1/40th of a second, or about ten times faster than the blink of an eye.

It happened as V404 Cygni swallowed material from the star, but some was not sucked in and was "spewed out" into space instead.

Not even light can escape the gravity of a black hole, a region of space extremely dense with matter.

Dr Poshak Gandhi, associate professor at the University of Southampton, said: "The very high speed tells us that the region where this red light is being emitted must be very compact.

"Piecing together clues about the colour, speed, and the power of these flashes, we conclude that this light is being emitted from the base of the black hole jet. The origin of these jets is still unknown, although strong magnetic fields are suspected to play a role.

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"Furthermore, these red flashes were found to be strongest at the peak of the black hole's feeding frenzy.

"We speculate that when the black hole was being rapidly force-fed by its companion orbiting star, it reacted violently by spewing out some of the material as a fast-moving jet."

The study was by the universities of Southampton, Sheffield and Warwick along with partners in Europe, USA, United Arab Emirates and India.

It is published in the Monthly Notices of the Royal Astronomical Society.