It is a mass, located in a specific area of outer space, which, due to its large size, generates large amounts of gravity, which allows it to keep all cosmic material within itself. These masses are believed to exist in and around most galaxies that separate them from each other. In 2016, some waves emitted by a black hole that emerged as the merger of two others were detected, about 1,337 million light years from Earth.
Not much has yet been known about this type of matter, but it is known that its origin is in a star; These evolve depending on the mass they have and during most of their life, they burn a certain amount of hydrogen, when it ends, a series of adjustments take place inside them. The star could end up having a mass less than or greater than 1.4 times the mass of the sun; if it is smaller, it would only be a white dwarf, on the contrary, if it is larger, it could be considered a neutron star, that is, a black hole. However, other theories suggest that these are formed as a product of the attractive force exerted on itself by a white dwarf, which in turn comes from a red giant.
Black holes can be classified according to their mass and according to their physical properties. When the mass of this is taken into account, they can be called: supermassive black holes, stellar mass or micro black holes. However, if only its most important physical characteristics are taken into account, it can be said that they are: without electric charge or rotation (Schwarzschild black hole), with rotation but without electric charge (Reissner-Nordstrøm), with electric charge but without rotation (Kerr), with electric charge and rotation (Kerr-Newman).
