# Spinning Kerr black hole shape?

Okay, can somebody explain if a Kerr black hole has an oblate event horizon, or does it have a spherical event horizon and an oblate ergosphere?

### 3 Answers

- nebLv 75 months agoFavourite answer
A Kerr black hole is symmetric about the axis of rotation, but both the event horizon and the ergosphere are not spherical.

The event horizon is not spherical (slightly oblate) for horribly complex reasons even though it might appear to be symmetrical due to the absence of the polar coordinate as part of the equation for the event horizon. It, of course, is not the same as the event horizon of a Schwarzschild black hole due to the additional angular momentum term.

The equation for the ergosphere is much more obvious since it explicitly contains the polar coordinate as part of the function, so it is not spherical (oblate).

- SpacemanLv 75 months ago
Try the following references . . .

Source(s): https://en.wikipedia.org/wiki/Rotating_black_hole https://en.wikipedia.org/wiki/Kerr_metric https://en.wikipedia.org/wiki/Ring_singularity - CarolOklaLv 75 months ago
The event horizon is shaped like a ring, not a sphere or an oblate spheroid.

Source(s): Google search on " what is the shape of a spinning Kerr event horizon