Astronomers find ultramassive black hole using new technique, call it 'extremely exciting'

Astronomers have used a novel method to find an ultramassive black hole, thought to be one of the largest ever detected. Researchers have rarely encountered a black hole with a mass more than 30 billion times that of the Sun, according to research published in the Royal Astronomical Society. The discovery, according to the researchers, is "extremely exciting" and creates "tantalising" opportunities for finding more black holes. 

The research, which was led by Durham University in the UK, employed a method called gravitational lensing, in which the light from a distant object is bent by using a neighbouring galaxy as a huge magnifying glass. They were able to use this to closely analyse how a black hole inside a galaxy that is hundreds of millions of light years away from Earth affects light.

First black hole discovered via gravitational lensing: Royal Astronomical Society

The size of the black hole was further confirmed using simulations performed on supercomputers and pictures taken by the Hubble Space Telescope. According to a press statement from the Royal Astronomical Society, this is the first black hole discovered via gravitational lensing, with the scientists modelling light passing across the universe hundreds of millions of times.

“This particular black hole, which is roughly 30 billion times the mass of our Sun, is one of the biggest ever detected and on the upper limit of how large we believe black holes can theoretically become, so it is an extremely exciting discovery,” stated James Nightingale, an observational cosmologist from Durham University's Department of Physics, the primary author of the study.

'Most of the biggest black holes are in active state,' says Nightingale

Nightingale added, “Most of the biggest black holes that we know about are in an active state, where matter pulled in close to the black hole heats up and releases energy in the form of light, X-rays, and other radiation.”

“However, gravitational lensing makes it possible to study inactive black holes, something not currently possible in distant galaxies. This approach could let us detect many more black holes beyond our local universe and reveal how these exotic objects evolved further back in cosmic time.”

Scientists have stated that the discovery is noteworthy as it “opens up the tantalising possibility that astronomers can discover far more inactive and ultramassive black holes than previously thought” and “investigate how they grew so large,” read the press release.

The backstory of such a specific finding began in 2004 after Alastair Edge, a research fellow at Durham University and a fellow astronomer, observed a large arc of a gravitational lens while looking through photographs of a galaxy survey.