If I recall correctly, the photon sphere orbit is unstable, so there may not be a ton of photons there. “Unstable” in this sense means that photons in adjacent orbits tend to diverge away from the photon sphere orbit rather than toward it.
For Schwarzchild holes, the lowest circular orbit for massive objects is at 3 event horizons, which is above the photon sphere. There are unstable circular orbits down to 2 horizons. Black home rotation reduces this altitude for prograde orbits asymptotically down to 1 horizon.
Buddahriffic@lemmy.world 1 week ago
Hell, forget the photon sphere, even. Know that jet of energy black holes are thought to sprew out at their poles due to the material falling in to them? Imagine what that material is doing inside the event horizon. Whatever it is, it’ll be pretty violent, enough to call the moon slamming into the earth “relatively peaceful”. It would probably be more pleasant hanging out in the core of the sun than even an AU away from a black hole’s event horizon (and I mean on the outside).
Also, the event horizon is where light cannot escape. The “spacecraft event horizon”, or the orbital plane surrounding a black hole where a spacecraft couldn’t escape it is going to be much farther out, unless we can figure out ftl travel.