The region around the event horizon of a rotating black hole (a Kerr black hole) within which it is impossible for any object to remain stationary; also known as the stationary limit. Within the static limit, an object would be forced to spin with the black hole, as though in a whirlpool. The static limit touches the event horizon at the black hole's poles, where there are no rotational forces, but becomes larger than the event horizon towards the black hole's equator. The static limit is the outer boundary of the ergosphere. In a non-rotating black hole, the static limit coincides with the event horizon.
Subjects: Astronomy and Astrophysics.