Synonyms for photon sphere

Most common

photon circle · last photon orbit

All synonyms

Noun

Definitions

1. n. 1

   Of a black hole, a spherical limit around a black hole at such distance that any photon meeting it tangentially is constrained to travel in a circular orbit; (more loosely) the region between this limit and the event horizon.

   The radius of the photon sphere is also the lower bound for any stable orbit.