Lorena Hernández-García

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.

At the centers of many galaxies lurk supermassive black holes. From time to time they 'scream' — unleashing powerful X-ray flares. Scientists have long puzzled over the nature of these 'quasi-periodic eruptions'.