‘Unexpected’ black hole discovery shocks astronomers

Scientists have made a surprising new space discovery, with astronomers thinking they had “run out of sky” where objects like this could be hiding.

Scientists have made a surprising new discovery hidden away in another galaxy, after experts searched for an object of this nature for more than 50 years.

The fastest growing black hole of the last nine billion years was recently discovered by an international team led by astronomers at the Australian National University (ANU).

The black hole is so big that it consumes the equivalent of one Earth every second, shining 7000 times brighter than all the light from our own galaxy.

It has a mass of three billion suns, with other black holes of comparable size having stopped growing at this kind of rate billions of years ago.

The position of the black hole is shown by the purple cross inside the red circle. Picture: SkyMapper image

Lead researcher Dr Christopher Onken said the discovery was “unexpected”, describing it as a “very large” needle in a haystack.

“Astronomers have been hunting for objects like this for more than 50 years. They have found thousands of fainter ones, but this astonishingly bright one had slipped through unnoticed,” Dr Onken 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.”

The black hole is so prominent that anyone with a decent telescope and a “very dark backyard” can view it without much hassle.

This generated image of a black hole gives some idea of what the discovery may look like. Picture: iStock

Dr Chris Onken (left) and Samuel Lai. Picture: Jamie Kidston/ANU

The discovery was made as part of the SkyMapper project, which aims to produce a deep, multi-epoch, multi-colour digital survey of the entire southern sky for Australian astronomers.

Research about the discovery has been published to open-access archive arXiv and submitted to Publications of the Astronomical Society of Australia.

Co-author, Associate Professor Christian Wolf, said this discovery is such an outlier that it is highly unlikely that another black hole of this magnitude will be found again.

“We are fairly confident this record will not be broken. We have essentially run out of sky where objects like this could be hiding,” he said.

To give an idea of just how massive this black hole is, Samuel Lai, co-author and ANU PhD researcher, said it is about 500 times bigger than the black hole in our own galaxy.

“The orbits of the planets in our Solar System would all fit inside its event horizon – the black hole’s boundary from which nothing can escape,” he said.