Nine years of data expose a recurring 433-day heartbeat in one of the sky’s brightest blazars

One of the most luminous blazars in the observable sky has been pulsing in optical light every 433 days — and that rhythm held for nine consecutive years. A new study drawing on nearly two decades of coordinated observations is calling it one of the most persistent optical quasi-periodic oscillations ever confirmed in an active galaxy. The leading explanations involve either a jet that is slowly precessing around a spinning supermassive black hole, or two supermassive black holes orbiting each other. New article on SKYCR.ORG 👇 🌌🔭