Theories state that some black holes could have formed within the first second of the Big Bang.
(Credit: NASA/ESA and G. Bacon (STScI))

All the black holes that astronomers have seen fall into one
of three categories: stellar-mass black holes, intermediate-mass black holes,
and supermassive black holes. Each is more massive than our Sun and formed at
least hundreds of thousands of years after the Big Bang, as our universe grew
and evolved.

But there is another type of black hole astronom