In 2019, the Event Horizon Telescope gave us the first-ever image of a singularity, peering at light emitted just outside the boundary of the supermassive black hole M87. Now, by sifting through the data from that image, researchers have picked out an even more elusive feature hidden inside the vortex of light, giving us our first glimpse of a phenomenon unique to black holes that scientists call a “photon ring.”
