Answer:
How Do Black Holes Form?
Scientists think the smallest black holes formed when the universe began.
Stellar black holes are made when the center of a very big star falls in upon itself, or collapses. When this happens, it causes a supernova. A supernova is an exploding star that blasts part of the star into space.
Explanation:
As the name suggests, supermassive black holes contain between a million and a billion times more mass than a typical stellar black hole. Although there are only a handful of confirmed supermassive black holes (most are too far away to be observed), they are thought to exist at the centre of most large galaxies, including the centre of our own galaxy, the Milky Way.
