system
Given the following post, respond as if you're commenting on Reddit:
human
How close to a perfect sphere is a black hole?

Is there much variation in the surface of a black hole? I'd imagine because of its relatively small size and huge mass black holes would be very close to a perfect sphere.
gpt
A black hole with zero angular momentum has perfect spherical symmetry. But any realistic black hole will likely have *some* angular momentum. In that case, it's not longer spherically symmetric but rather axially symmetric about the axis of rotation.