A Black hole is a region of space from which nothing, including light, can escape. According to the general theory of relativity, it is the result of the curving of space-time caused by being composed of dense mass. Around a black hole, there is a position of no return, called the event horizon. Stellar black holes are made when the center of the very big star falls in upon itself, or collapses. When this happens, it causes a supernova. A supernova is an exploding star that blasts part of the star into space. Scientists think supermassive black holes were made at the same time as the galaxy they are in. Around a black hole, there is a position of no return, called the event horizon. It is called “Black” because it absorbs all the light that hits it, reflecting nothing, just like a perfect black body in thermodynamics. The name also said to be taken from the black hole incidence happened in Calcutta. Under the theory of quantum mechanics black holes have a temperature and emit Hawking radiation, which makes them slowly get smaller.