Max Planck Institute for Radio Astronomy

An international team of researchers led by the Max Planck Institute for Radio Astronomy has found compelling evidence of two supermassive black holes locked in a tight orbit at the centre of the galaxy Markarian 501. Analysing over two decades of radio observations revealed a hidden second jet and an Einstein ring, pointing to a binary system whose components are so close they could merge in as little as 100 years. If confirmed, this would be one of the closest known supermassive black hole binaries, offering an unprecedented window into their final growth stages.