Question

What is the proof for existence of black holes?

Answer 1

Black holes can be indirectly observed by their influence on nearby matter.

Explanation:

Black holes can't directly be observed with telescopes that detect light, X-rays or any other form of electromagnetic radiation. What we can do is conclude that black holes do exist and study them by their effect on nearby matter.

For example, if a black hole were to pass through a cloud of some sort of interstellar matter, it will cause the matter to be pulled inward in a known process called accretion.

Something similar can occur if a star passes too close to the black hole. If this happens, the black hole can tear apart the star as it pulls it closer to itself (the black hole).

As the matter that is being attracted to the black hole heats up and accelerates, it emits X-rays that leak and radiate into space.

(https://science.nasa.gov/astrophysics/focus-areas/black-holes)