A rotating black hole is a black hole that possesses angular momentum. A black hole is a theoretical region of space in which the Gravitational field is so powerful that nothing not even Electromagnetic radiation (e A black hole is a theoretical region of space in which the Gravitational field is so powerful that nothing not even Electromagnetic radiation (e In Physics, the angular momentum of a particle about an origin is a vector quantity equal to the mass of the particle multiplied by the Cross product of the position

## Types of black holes

There are four known, exact, black hole solutions to Einstein's equations. A black hole is a theoretical region of space in which the Gravitational field is so powerful that nothing not even Electromagnetic radiation (e These equations describe gravity in General Relativity. General relativity or the general theory of relativity is the geometric theory of Gravitation published by Albert Einstein in 1916 Two of these (Kerr black hole or Kerr-Newman black hole) are rotating. It is generally believed that all black holes will eventually be similar to a stationary black hole and that stationary black holes can be characterized by three (and only three) quantities M, J and Q, namely:

• mass M,
• angular momentum J,
• electric charge Q. Mass is a fundamental concept in Physics, roughly corresponding to the Intuitive idea of how much Matter there is in an object In Physics, the angular momentum of a particle about an origin is a vector quantity equal to the mass of the particle multiplied by the Cross product of the position Electric charge is a fundamental conserved property of some Subatomic particles which determines their Electromagnetic interaction.

In terms of these properties, the four types of stationary black holes can be defined as follows:

 Non-rotating (J = 0) Rotating (J ≠ 0) Uncharged (Q = 0) Schwarzschild Kerr Charged (Q ≠ 0) Reissner-Nordström Kerr-Newman

## Formation

Rotating black holes are formed in the gravitational collapse of a massive spinning star or from the collapse of a collection of stars or gas with an average non-zero angular momentum. In Einstein's theory of General relativity, the Schwarzschild solution (or the Schwarzschild vacuum) describes the Gravitational field outside In General relativity, the Kerr metric (or Kerr vacuum) describes the geometry of Spacetime around a rotating massive body In Physics and Astronomy, the Reissner-Nordström metric is a solution to the Einstein field equations in empty space which corresponds to the gravitational The Kerr-Newman metric is a solution of Einstein's General relativity field equation that describes the spacetime geometry in the region surrounding a charged Gravitational collapse in Astronomy is the inward fall of a massive body under the influence of the force of Gravity. A star is a massive luminous ball of plasma. The nearest star to Earth is the Sun, which is the source of most of the Energy on Earth As most stars rotate it is expected that most black holes in nature are rotating black holes. In late 2006, astronomers reported estimates of the spin rates of black holes in Astrophysical Journal. The Astrophysical Journal (abbreviated to ApJ or Astrophys J) is a Scientific journal covering Astronomy and Astrophysics. A black hole in the Milky Way, GRS 1915+105, may rotate 1,150 times per second,[1] approaching the theoretical upper limit. GRS 1915+105 or V1487 Aquilae is an X-ray binary star system which features a regular star and a Black hole.

### Relation with gamma ray bursts

The formation of a rotating black hole by a collapsar is thought to be observed as the emission of gamma ray bursts. Hypernova (pl hypernovae) refers to an exceptionally large Star that collapses at the end of its lifespan—for example a collapsar, or a large Gamma-ray bursts ( GRB s are the most luminous electromagnetic events occurring in the Universe since the Big Bang.

## Conversion to a Schwarzschild black hole

A rotating black hole can produce large amounts of energy at the expense of its rotational energy. In that case a rotating black hole gradually reduces to a Schwarzschild black hole, the minimum configuration from which no further energy can be extracted.

## Kerr metric, Kerr-Newman metric

For more details on this topic, see Kerr metric. In General relativity, the Kerr metric (or Kerr vacuum) describes the geometry of Spacetime around a rotating massive body
For more details on this topic, see Kerr-Newman metric. The Kerr-Newman metric is a solution of Einstein's General relativity field equation that describes the spacetime geometry in the region surrounding a charged

A rotating black hole is a solution of Einstein's field equation. The Einstein field equations ( EFE) or Einstein's equations are a set of ten equations in Einstein 's theory of General relativity in which the There are two, known exact solutions, the Kerr metric and the Kerr-Newman metric, which are believed to be representative of all rotating black hole solutions, in the exterior region. In General relativity, the Kerr metric (or Kerr vacuum) describes the geometry of Spacetime around a rotating massive body The Kerr-Newman metric is a solution of Einstein's General relativity field equation that describes the spacetime geometry in the region surrounding a charged