What is a Black Hole?

A black hole is an region in space with such a powerful gravitational pull that nothing, not even light, can escape. Black holes are formed when a star collapses at the end of its life and becomes extremely dense. The gravitational field around a black hole is so strong that it warps space and time, creating a “point of no return” called the event horizon.

There are mainly three types of black holes:

• Stellar black holes: These are the most common type of black hole and are formed when a star collapses. They have masses that are typically several times that of our Sun and are typically a few miles in diameter.
• Intermediate black holes: These are more massive than stellar black holes but less big than supermassive black holes. They have masses hundreds or thousands of times greater than our Sun.
• Supermassive black holes: These are the largest type of black hole and are found at the centre of most galaxies. They have masses that are millions or billions of times that of our Sun.

Black holes are difficult to observe directly because they do not emit light, but their presence can be inferred through their effects on nearby objects. For example, a black hole can be detected if it is orbiting a companion star and pulling matter from the star into itself. The intense gravitational forces around a black hole can also cause jets of matter and energy to be emitted from its poles, which can be observed with telescopes.