AT2021lwx occurred nearly 8 billion years ago and was more than 10 times brighter than any known supernova explosion. The event was likely caused by the accretion of a giant molecular cloud on to a dormant supermassive black hole. An artist’s impression of a black hole accretion. Image credit: John A. Paice. AT2021lwx was first detected in 2020 by the Zwicky Transient Facility, and was subsequently detected by the Asteroid Terrestrial-impact Last...
