Astronomers may have found the most massive black hole in universe

Gargantuan object is around 36 million times more massive than our sun

Astronomers have discovered what could be the biggest known black hole in the universe.

The gargantuan black hole, around 36 billion times more massive than our sun, is close to the theoretical upper limit of what is possible in the universe, according to a new study published in the journal Monthly Notices of the Royal Astronomical Society.

“This is amongst the top 10 most massive black holes ever discovered, and quite possibly the most massive,” Thomas Collett, a co-author of the study from the University of Portsmouth, said.

The black hole lies about five billion light years away in one of the universe’s largest known galaxies, the Cosmic Horseshoe, which is so massive it distorts spacetime and warps the passing light of a background galaxy.

Scientists had to develop a new method to discover and accurately estimate the size of the behemoth.

“Most of the other black hole mass measurements are indirect and have quite large uncertainties, so we really don't know for sure which is biggest,” Dr Collett said.

“However, we’ve got much more certainty about the mass of this black hole thanks to our new method.”

The monster black hole was detected by looking for signs of gravitational lensing, a phenomenon in which a massive object's gravity bends and distorts light from a background source, effectively acting like a lens.

Researchers also used a gold-standard method to study the motion of stars within the galaxy and the speed and way they moved around to detect and estimate the size of the black hole.

This method, however, doesn't work as well when estimating the size of a black hole outside of the very nearby universe. But applying gravitational lensing helped researchers “push much further out into the universe”.

Newly discovered ultramassive blackhole lies at the centre of the Cosmic Horseshoe galaxy (NASA/ESA)

“Our approach, combining strong lensing with stellar dynamics, offers a more direct and robust measurement, even for these distant systems,” said Carlos Melo, another author of the study from the Universidade Federal do Rio Grande do Sul in Brazil.

“What is particularly exciting is that this method allows us to detect and measure the mass of these hidden ultramassive black holes across the universe, even when they are completely silent.”

The supermassive blackhole was likely formed during the merging of two galaxies.

The Cosmic Horseshoe galaxy is a fossil group, meaning it is at an end state after two neighbouring galaxies collapsed down to a single extremely massive entity, with no bright companions.

“It is likely that all of the supermassive black holes that were originally in the companion galaxies have also now merged to form the ultramassive black hole that we have detected,” Dr Collett said.

“So we're seeing the end state of galaxy formation and the end state of black hole formation.”

Researchers hope to apply their new method to data collected by the European Space Agency’s Euclid telescope to find more supermassive black holes and their hosts in order to better understand how black holes stop galaxies from forming stars.