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NASAAstrophysicsSep 25, 20261 min

Circling the Black Hole at the Photon Sphere

Circling the Black Hole at the Photon Sphere source image

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.