### Kerr black hole

**(Kerr object, Kerr BH, rotating black hole)**
(spinning black hole with no charge)

The term **Kerr black hole** refers to a particular black hole model that
includes the effects of its mass and rotation but not charge,
and the term is likely sometimes used for actual **rotating black holes**
that have significant rotation and little electric charge.
The model was developed in the 1960s, decades subsequent to the
development of models dealing with mass and mass plus charge.
It is generally assumed that charged black holes rapidly lose
their charge given their additional attraction of the opposite
charge, and practically speaking, the *Kerr black hole* concept
is a practical model for actual black holes.
The **Kerr metric** is the metric devised for the model,
and **Kerr spacetime** refers to the spacetime model it defines.

Rotation is a significant complication to general relativity (GR) based models,
introducing **frame dragging**, the ergosphere, and revealing
the potential for the Penrose process and Blandford-Znajek mechanism
and affecting other characteristics such as the photon sphere
and innermost stable circular orbit.

The **Kerr-Newman black hole** is an extension to the *Kerr black hole*
model that accommodates electric charge, also developed in the 1960s.
The earlier (1920s) models that accommodated only mass and only mass
with charge where the **Schwarzschild black hole** and the
**Reissner-Nordström black hole**.

While the Kerr black hole is based upon GR, it can be valid for
some theoretical modifications to GR, so determining that an actual
black hole shows characteristics of a Kerr black hole does not
necessarily distinguish GR from some amended version of GR.

(*black hole type,models*)
**Further reading:**

http://en.wikipedia.org/wiki/Rotating_black_hole

http://en.wikipedia.org/wiki/Kerr_metric

**Referenced by pages:**

black hole model

Kerr-NUT spacetime

gravitational singularity

Taub-NUT spacetime

Taub spacetime

Index