Structure of a Kerr (Rotating) Black Hole

Structure of a Kerr (Rotating) Black Hole
Rotating black holes are only slightly more complex than nonrotating ones. The singularity of a Kerr black hole is located
in an infinitely thin ring around the center of the hole. It appears as an arc in this cutaway drawing. The event horizon
is again a spherical surface. There is also a doughnut-shaped region, called the ergoregion, just outside the event horizon, in
which nothing can remain at rest. Space in the ergoregion is being curved or pulled around by the rotating black hole.