NASAAstrophysicsSep 25, 20261 min
Circling the Black Hole at the Photon Sphere

Astroboat summary
You currently sit at the black hole’s photon sphere, where light can travel endlessly in a circle due to the star’s great gravitational pull. The apparent position of the photon sphere is always easy to spot – it is the apparent dividing line between black hole and sky.
Why it matters
Astrophysics updates show how observations refine our picture of stars, galaxies, and the wider universe.