The innermost stable circular orbit is 3 radii for a non-rotating black hole, less the faster it spins. https://en.m.wikipedia.org/wiki/Innermost_stable_circul

The innermost stable circular orbit is 3 radii for a non-rotating black hole, less the faster it spins. https://en.m.wikipedia.org/wiki/Innermost_stable_circular_orbit https://en.m.wikipedia.org/wiki/Innermost_stable_circular_or...