This article was originally published at The Conversation. The publication contributed the article to Space.com's Expert Voices: Op-Ed & Insights. Marco Ajello is a professor of physics and astronomy at Clemson University in South Carolina, and where Jonathan Zrake is an assistant professor of physics.
Every galaxy has a supermassive black hole at its center, much like every egg has a yolk. But sometimes, hens lay eggs with two yolks. In a similar way, astrophysicists like us who study supermassive black holes expect to find binary systems – two supermassive black holes orbiting each other – at the hearts of some galaxies.
