Skip to main content

Stuff of nightmares: Black holes one hundred billion times the mass of the sun

This computer-simulated image shows a supermassive black hole at the core of a galaxy. The black region in the center represents the black hole’s event horizon, where no light can escape the massive object’s gravitational grip. The black hole’s powerful gravity distorts space around it like a funhouse mirror. Light from background stars is stretched and smeared as the stars skim by the black hole.
This computer-simulated image shows a supermassive black hole at the core of a galaxy. The black region in the center represents the black hole’s event horizon, where no light can escape the massive object’s gravitational grip. The black hole’s powerful gravity distorts space around it like a funhouse mirror. Light from background stars is stretched and smeared as the stars skim by the black hole. NASA, ESA, and D. Coe, J. Anderson, and R. van der Marel (STScI)

If the idea of a black hole millions of times the mass of our sun makes you uncomfortable then we have bad news: Researchers have predicted that black holes could grow even larger than previously thought, reaching masses of hundreds of billions of times the mass of the sun. These aren’t merely supermassive black holes — they’re stupendously large black holes.

The biggest black holes discovered to date are the monsters that lie at the heart of galaxies, called supermassive black holes (SMBHs). These include Sagittarius A*, the black hole at the center of the Milky Way which is a relatively modest four million solar masses, and the famous black hole at the heart of Messier 87 which was imaged in 2019 and which has a mass of 6.5 million solar masses.

These SMBHs range in size up to 60 billion solar masses, which is the largest we currently know of. It was previously thought that this was around the upper limit on how large a black hole could get, as it is very hard for them to grow larger than this due to the limitations of the disk of matter around them, called the accretion disk.

But the new research questions this upper limit, by suggesting that even bigger stupendously large black holes (SLABs) could have formed in the early universe. These “primordial” SLABs wouldn’t form from the collapse of a massive star, like most black holes do, but would have been born even before galaxies started to form. That would let them be a range of sizes, up to billions of solar masses.

“We already know that black holes exist over a vast range of masses, with an SMBH of four million solar masses residing at the center of our own galaxy,” explained lead author Bernard Carr in a statement. “Whilst there isn’t currently evidence for the existence of SLABs, it’s conceivable that they could exist and they might also reside outside galaxies in intergalactic space, with interesting observational consequences. However, surprisingly, the idea of SLABs has largely been neglected until now.”

The researchers hope that this theory could propel research into SLABs, which could even be related to dark matter. Dark matter may have formed in the early universe, so learning about primordial black holes which also formed at this time could help unpick this puzzle.

The research is published in the journal Monthly Notices of the Royal Astronomical Society.

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
Astronomers just spotted the largest cosmic explosion ever seen
Artist’s impression of a black hole accretion.

Astronomers recently observed the largest cosmic explosion ever seen, far brighter than a supernova and lasting for much longer too. They believe that the outpouring of light is due to a supermassive black hole devouring a large cloud of gas.

Some of the brightest events seen in the sky are supernovae, which are huge explosions that occur when a massive star comes to the end of its life. But the recently observed event, called AT2021lwx, was 10 times brighter than any known supernova. Supernovae also typically last for a few months, but this event has been shining out for several years.

Read more
See the terrifying scale of a supermassive black hole in NASA visualization
Illustration of the black hole Sagittarius A* at the center of the Milky Way.

This week is black hole week, and NASA is celebrating by sharing some stunning visualizations of black holes, including a frankly disturbing visualization to help you picture just how large a supermassive black hole is. Supermassive black holes are found at the center of galaxies (including our own) and generally speaking, the bigger the galaxy, the bigger the black hole.

Illustration of the black hole Sagittarius A* at the center of the Milky Way. International Gemini Observatory/NOIRLab/NSF/AURA/J. da Silva/(Spaceengine) Acknowledgement: M. Zamani (NSF's NOIRLab)

Read more
Supermassive black hole spews out jet of matter in first-of-its-kind image
Scientists observing the compact radio core of M87 have discovered new details about the galaxy’s supermassive black hole. In this artist’s conception, the black hole’s massive jet is seen rising up from the centre of the black hole. The observations on which this illustration is based represent the first time that the jet and the black hole shadow have been imaged together, giving scientists new insights into how black holes can launch these powerful jets.

As well as pulling in anything which comes to close to them, black holes can occasionally expel matter at very high speeds. When clouds of dust and gas approach the event horizon of a black hole, some of it will fall inward, but some can be redirected outward in highly energetic bursts, resulting in dramatic jets of matter that shoot out at speeds approaching the speed of light. The jets can spread for thousands of light-years, with one jet emerging from each of the black hole's poles in a phenomenon thought to be related to the black hole's spin.

Scientists observing the compact radio core of M87 have discovered new details about the galaxy’s supermassive black hole. In this artist’s conception, the black hole’s massive jet of matter is seen rising up from the center of the black hole. The observations on which this illustration is based represent the first time that the jet and the black hole shadow have been imaged together, giving scientists new insights into how black holes can launch these powerful jets. S. Dagnello (NRAO/AUI/NSF)

Read more