Aussie astronomers discover rapidly expanding black hole

Australian astronomers have discovered what they believe to be the fastest-growing black hole of the past 9 billion years, estimated to be consuming the equivalent of one Earth every second.

The team located an extremely bright quasar, which is a luminous object powered by a supermassive black hole, using the SkyMapper Southern Sky Survey, a telescope at Siding Spring Observatory in the north of the state of New South Wales.

Black holes are immensely dense areas where gravity is so strong that everything around them, including light, gets drawn into their vortexes. This means the holes are not actually visible, so astronomers track them due to all the matter swirling around them.

Lead researcher Christopher Onken from the Australian National University described their latest find, named J1144, as being a "very large, unexpected needle in the haystack".

Onken said J1144 shines about 7,000 times brighter than all the light from the Milky Way and has the mass of 3 billion suns, making its presence visible to even backyard astronomers, which raises the question of why it remained unknown for so long.

"Astronomers have been hunting for objects like this for more than 50 years," he said. "They have found thousands of fainter ones, but this astonishingly bright one had slipped through unnoticed," he told Xinhua on Wednesday, adding that there had been a "little gap" in the night skies that had not been fully studied before.

"Historically, people have avoided looking very close to the plane of the Milky Way because there's so many stars, there's so many contaminants, that it'd be very hard to find anything more distant," Onken told the Guardian newspaper also on Wednesday.

Onken told Xinhua that astronomers knew of about 9,000 black holes, with his team having discovered about 80 so far.

"We're very excited about this one, it is unlike others we have found," he said. "Now we want to know why this one is different -- did something catastrophic happen? Perhaps two big galaxies crashed into each other, funnelling a whole lot of material onto the black hole to feed it."

Their report on J1144 has been published on the arXiv.org website.