Black Holes, how do they form?

Question

Do black holes form by when the massive star dies and all the gravity falls in on itself, or something else. Please let me know, I'm really desperate!!

Answer 1

There are several major types of black hole, and each forms differently:

• Quantum black holes - these aren't currently proven to exist, but many scientists think they are likely. These are microscopic black holes, which are believed to have formed in the Big Bang, though they can be created wherever there is enough energy.
• Stellar-mass black holes. These are the remains of dead stars, and the main type of black hole people talk about. They form when very large stars collapse to the point where even light cannot escape at the end of their lives.
• Supermassive black holes. These, as their name suggests, are extremely massive - with masses of millions to billions of times that of the Sun. Scientists aren't quite sure as to how these formed, but the main theory at the moment is that they started as several stellar-mass black holes, left behind by the first generation of stars, which fell into the centre of galaxies that were forming around them. As they did so, they came together, to form one large black hole. Another theory is that they started life as 'dark stars', a theoretical type of star held together by dark matter, which could be far larger than normal stars. These would have been extremely short-lived, and collapsed to create a supermassive black hole.