system
Given the following post, respond as if you're commenting on Reddit:
human
Do black holes have equatorial bulge?
gpt
There isn't really a shape to a black hole. The horizon is topologically a sphere, and that's about all you can really say. The actual shape could be spherical, or ellipsoidal, or some odd looking blob thing. It depends on the observer. A non rotating, uncharged black hole is perfectly spherically symmetric, but this just implies there is a class of observers for which the horizon is a perfect sphere. An observer that is boosted with respect to the black hole will not observe a sphere.

There's also the issue of what you would see versus what is actually true in your frame. You cannot directly see the horizon and must infer its shape from nearby radiation. For instance, a Schwarzschild black hole as seen from a stationary observer looks spherical, but it looks bigger than it actually is. This is because there are photons that are captured by the black hole beyond the cross section of the black hole. Nearby matter may also distort radiation and the black hole itself acts as a gravitational lens.