WHAT ARE ROTATING BLACK HOLES?
A rotating black hole (Kerr black hole or Kerr-Newman black hole) is a black hole that possesses angular momentum. It is one of four possible types of black holes that could exist in the theory of gravitation called General Relativity. Black holes can be characterized by three (and only three) quantities M, J and Q, namely: mass M, (Schwarzschild black hole if J=0 and Q=0) angular momentum J (Kerr black hole if J not zero and Q=0) electric charge Q (charged black hole or Reissner-Nordstrøm black hole if Q not zero and J=0; or a Kerr-Newman black hole if both J and Q not zero). Rotating black holes are formed in the gravitational collapse of a massive spinning star or from the collapse of a collection of stars with an average non-zero angular momentum. As most stars rotate it is expected that most black holes in nature are rotating black holes. In late 2006, astronomers reported actual spin rates of black holes in Astrophysical Journal. A black hole in the Milky Way, GRS 1915+105, may r
