Itai Linial

Astronomers are monitoring X-ray flares from the vicinity of a black hole at the center of a galaxy. These flares repeat with a certain rhythm, like heartbeats. Normally, as a star approaches a black hole, the rhythm speeds up — just as a pulse quickens when running. But at the black hole 'Ansky,' the rhythm is slowing down.

A black hole rips apart a star, and we see a dazzling flare. Then, a couple of years later, when everyone has forgotten about it, radio telescopes suddenly pick up a new signal, like an echo from the past.