Astronomers uncover closest pair of supermassive black holes yet

Astronomers suspected the NGC 7727 galaxy hosted the two black holes, but had not been able to confirm their presence until now.

Astronomers have observed the closest pair of supermassive black holes to Earth ever seen.

There is much less separation between the two objects than any other pair than has previously been spotted, and they will eventually merge into one giant black hole, researchers say.

Scientists determined the masses of the two objects by looking at how the gravitational pull of the black holes influences the motion of the stars around them.

The bigger black hole, located right at the core of the NGC 7727 galaxy, was found to have a mass almost 154 million times that of the Sun, while its companion is 6.3 million solar masses.

According to the researchers, this is the first time the masses have been measured in this way for a supermassive black hole pair.

They were able to to do this because of how close the system is to Earth, and due to the detailed observations they made using the Paranal Observatory in Chile with the Multi-Unit Spectroscopic Explorer (MUSE) on the European Southern Observatory’s Very Large Telescope (ESO’s VLT).

Located in the galaxy NGC 7727 in the constellation Aquarius, the supermassive black hole pair is about 89 million light-years away from Earth

Astronomers suspected NGC 7727 hosted the two black holes, but had not been able to confirm their presence until now.

Karina Voggel, Strasbourg Observatory, University of Strasbourg, said: “Our finding implies that there might be many more of these relics of galaxy mergers out there and they may contain many hidden massive black holes that still wait to be found.

“It could increase the total number of supermassive black holes known in the local Universe by 30%.”

Experts suggest the search for similarly hidden supermassive black hole pairs is expected to make a great leap forward with ESO’s Extremely Large Telescope (ELT), set to start operating later this decade in Chile’s Atacama Desert.

Co-author Steffen Mieske, an astronomer at ESO in Chile and Head of ESO Paranal Science Operations, said: “This detection of a supermassive black hole pair is just the beginning.”

Enjoy reading the Irish News?

Subscribe now to get full access