Monster black holes may lurk all around us: study

A photo released by the European Space Agency/Hubble shows the elliptical galaxy NGC 1600, 200 million light-years away — at the centre of the image and highlighted in the box (AFP Photo/) (ESA/Hubble/AFP)

Paris (AFP) - Astronomers have stumbled upon a supermassive black hole in an unexpected corner of the Universe, implying these galactic monsters are much more common than once thought, a study said Wednesday.

The giant, with an estimated mass 17 billion times that of our Sun, was discovered in a relative desert, astronomers from the University of California, Berkeley, wrote in the journal Nature.

"While finding a gigantic black hole in a massive galaxy in a crowded area of the Universe is to be expected -- like running across a skyscraper in Manhattan -- it seemed less likely they could be found in the Universe's small towns," said a university statement.

Big, star-rich galaxies where supermassive black holes had previously been found, are very rare.

Smaller ones like the NGC 1600 galaxy housing the newly-discovered whopper, are much more common, but were not previously thought to be appropriate hosts.

"So the question now is: 'Is this the tip of an iceberg?'" said study co-author Chung-Pei Ma.

"Maybe there are a lot more monster black holes out there that don't live in a skyscraper in Manhattan, but in a tall building somewhere in the Midwestern plains."

A supermassive black hole can have a mass of about a million Suns up to billions. Smaller, "ordinary" black holes range between tens to hundreds of Sun masses.

Black holes are very dense regions in spacetime with a gravitational force so strong that even light cannot escape it -- making them invisible.

Formed when massive stars implode at the end of their lives, black holes normally lurk dormant and undetected at the centres of galaxies.

They can sometimes be detected by their gravitational effect on the orbits of stars around them, and occasionally by their spectacular feeding frenzies -- guzzling gas and dust, sometimes entire stars, and spitting out jets of debris.

Much less is known about the origins of the supermassive variety.

The largest supermassive black hole spotted to date tipped the scales at about 21 billion solar masses, said the study authors.