Black Holes Could Get So Humongous, Astronomers Came Up With a New Size Category - ScienceAlert

Such hypothetical black holes - larger than 100 billion times the mass of the Sun - have been explored in a new paper which names them SLABs, an acronym that stands for "Stupendously LArge Black holeS".

"We already know that black holes exist over a vast range of masses, with a supermassive black hole of 4 million solar masses residing at the centre of our own galaxy," explained astronomer Bernard Carr of Queen Mary University London.

There are stellar-mass black holes; those are black holes that are around the mass of a star, up to around 100 solar masses.

The next category up is intermediate mass black holes, and how large they get seems to depend on who you talk to.

The chonkiest black holes we've detected are ultramassive, more than 10 billion (but less than 100 billion) solar masses.

This model has an upper limit of around 50 billion solar masses - that's the limit at which the object's prodigious mass would require an accretion disc so massive it would fragment under its own gravity.

These would not be subject to the size constraints of black holes from collapsed stars, and could be extremely small or, well, stupendously large.

So, based on the primordial black hole model, the team calculated exactly how stupendously large these black holes could be, between 100 billion and 1 quintillion (that's 18 zeroes) solar masses.