In our society there's an upper class, middle class, and lower class. These days it seems like the middle class is dwindling, but anyway the point is theres a fairly continuous gradation among incomes and wealth from the very poor to the very rich. Apparently some scientists wondered the same about black holes, reports Science Daily.
Black holes generally come in two varieties. There are gigantic black holes with the mass of millions of suns or more located at the centers of large galaxies, and there are smallish black holes caused by the collapse of an individual star. Those might have masses in the range of a few times that our sun.
Some astronomers have been wondering if there was anything in between. Daniel Stern of NASA's Jet Propulsion lab says no.
"Some theories say that small black holes in globular clusters should sink down to the center and form a medium-sized one, but our discovery suggests this isn't true,"
But maybe the jury's still out on this one. Astrophysicists at UT-Austin think they've found a medium sized black hole in a star cluster called Omega Centauri. If their results hold up, there could be a black hole at the center of this start cluster with a mass of 40,000 suns.
Well if you ask me it makes sense that medium sized black holes could and would form. After all those hugely massive black holes in the center of large galaxies didn't start off huge, did they?