Astronomers discover black hole that contains 200,000 times mass of the Sun buried in gas - WION

The smallest, like 'the Unicorn,' are so-called stellar-mass black holes formed by the gravitational collapse of a single star.

There are gargantuan 'supermassive' black holes like the one at our galaxy's center, 26,000 light-years from Earth, which is four million times the sun's mass.

This is one of the first times that a heavily buried, or "obscured," supermassive black hole has been found in a dwarf galaxy.

"This black hole in Mrk 462 is among the smallest of the supermassive, or monster, black holes," said Jack Parker of Dartmouth College in New Hampshire, who led the study with colleague Ryan Hickox, also from Dartmouth

"Because buried black holes are even harder to detect than exposed ones, finding this example might mean there are a lot more dwarf galaxies out there with similar black holes," said Hickox. 

A large fraction of dwarf galaxies with supermassive black holes favours the idea that small black hole seeds from the earliest generation of stars grew astonishingly quickly to form the billion solar mass objects in the early universe

These expectations apply because the conditions necessary for the direct collapse from a giant cloud to a medium-sized black hole should be rare, so it is not expected that a large fraction of dwarf galaxies would contain supermassive black holes

"We can't make strong conclusions from one example, but this result should encourage much more extensive searches for buried black holes in dwarf galaxies," said Parker