The most luminous supernova ever recorded is ASASSN-15lh, at a distance of 3.82 gigalight-years. It was first detected in June 2015 and peaked at 570 billion L ☉, which is twice the bolometric luminosity of any other known supernova. The nature of this supernova is debated and several alternative explanations, such as tidal disruption of a star by a black hole, have been suggested.