Astronomers have finally unmasked the black hole that made a star fake a supernova for years.
NASA's Chandra X-ray Observatory observed the outburst of AT 2016blu in March 2026 and found an unseen companion on an elliptical 113-day orbit around the luminous blue variable. The compact object, either a neutron star or a stellar-mass black hole, pulls material from the unstable star, forming an accretion disk that emits X-rays and makes the system appear to erupt like a supernova. Chandra's X-ray data suggested the star's repeated outbursts were powered by periodic high-energy blasts that heated surrounding gas. Calculations suggest at least 440 trillion pounds of material are stolen by the compact object each year, possibly two orders of magnitude more.