Black hole

Definition

A black hole is a region in space where the gravitational pull is so strong that nothing, not even light, can escape from it. They are formed from the remnants of massive stars after they undergo supernova explosions.

5 Must Know Facts For Your Next Test

1. Black holes possess an event horizon, which is the boundary beyond which nothing can return.
2. The singularity at the center of a black hole is a point of infinite density.
3. Stellar-mass black holes form from the collapse of massive stars, while supermassive black holes exist at the centers of galaxies.
4. Hawking radiation predicts that black holes can slowly lose mass and energy over time.
5. Observational evidence for black holes includes gravitational waves and X-ray emissions from accretion disks around them.

Review Questions

• What is the event horizon of a black hole?
• How do stellar-mass black holes form?
• What type of evidence do astronomers use to detect black holes?

Related terms

Event Horizon:

The boundary around a black hole beyond which no light or other radiation can escape.

Singularity:

A point at the center of a black hole where density becomes infinite and current laws of physics cannot describe its conditions.

Supernova:

A powerful explosion that occurs when a massive star exhausts its nuclear fuel and collapses under its own gravity.