Last year, astronomers recorded the brightest supernova explosion ever seen. Follow up observations now suggest this cataclysmic event wasn’t a supernova at all, but rather, an extremely rare celestial phenomenon involving a supermassive black hole and a rather unfortunate star.
In 2015, astronomers participating in the the All Sky Automated Survey for SuperNovae (ASAS-SN) witnessed what they thought was an unusually bright supernova. Dubbed ASASSN-15lh, it was twice as bright as the previous record holder, shining 20 times brighter than the total light output of the entire Milky Way galaxy. A supernova is the brilliant, dying gasp of a large star that can no longer balance the tremendous forces keeping it together, producing a shockwave that blows the star’s outer shell into space with tremendous force.