Title: Formation Of Black Holes
Course: Relativity > Section: Module 25: Formation Of Black Holes

Formation of Black Holes

Black holes typically form from the remnants of massive stars after they undergo a supernova explosion. Here’s a step-by-step explanation of the formation process:

1. Stellar Evolution:
  - A star spends most of its life fusing hydrogen into helium in its core. When it exhausts its hydrogen supply, the core contracts and heats up, allowing it to start fusing helium into heavier elements.
2. Supernova Explosion:
  - When a massive star (more than about 20 times the mass of the Sun) runs out of nuclear fuel, it can no longer support itself against gravitational collapse. The core contracts while the outer layers collapse inward, leading to a massive explosion known as a supernova.
3. Formation of a Black Hole:
  - If the remaining core after the supernova explosion is more than about 3 times the mass of the Sun, it can collapse into a black hole. The gravitational pull becomes so strong that it creates a singularity — a point of infinite density — wrapped within an event horizon, beyond which no information or matter can return.

Properties of Black Holes