A gigantic black hole within our own Milky Way galaxy has "woken up" after a 26-year hibernation - and dazzled astronomers with an incredible light show 50 times brighter than supernova remnant the Crab Nebula.

The V404 Cygni system, just 8,000 light years from earth, is comprised of a black hole 12 times the size of the sun and a nearby star, the black hole slowly "devouring" the smaller star in an incredible display of power. As debris from the star is slurped like spaghetti into the black hole it heats up, producing enormous flashes of light which are the brightest in the X-ray sky.

"The behaviour of this source is extraordinary at the moment, with repeated bright flashes of light on time scales shorter than an hour, something rarely seen in other black hole systems," said Erik Kuulkers, Integral project scientist at the European Space Agency (ESA).

V404 Cygni system
The V404 Cygni system is 8,000 light years from earth in the Cygnus constellation ESA

"In these moments, it becomes the brightest object in the X-ray sky – up to fifty times brighter than the Crab Nebula, normally one of the brightest sources in the high-energy sky."

This is the first time the system has been so active since 1989, when the system produced a similar display observed from the Mir space station and Japan's X-ray satellite Ginga.

"Many of us weren't yet professional astronomers back then," said Kuulkers, "and the instruments and facilities available at the time can't compare with the fleet of space telescopes and the vast network of ground-based observatories we can use today.

"It is definitely a 'once in a professional lifetime' opportunity."

Black holes are formed when giant stars collapse in on themselves, forming regions from where nothing can escape - not even light. And certainly not a little star just half the size of our own sun.