Fast blue optical transient

In astronomy, a fast blue optical transient (FBOT) is a transient bright pulse lasting a very short time, caused by some very high-energy astrophysical process not yet understood. There have been a few FBOTs reported, the most famous being SN 2018cow (the "Cow" or AT2018cow) and, in March 2020, the ZTF18abvkwla (the "Koala"). More recently, in May 2020, a much more powerful FBOT (CRTS-CSS161010 J045834-081803, or CSS161010 for short) was reported. According to Deanne Coppejans, first author of the study, "This was unexpected ... We know of energetic explosions that can eject material at almost the speed of light, specifically gamma ray bursts, but they only launch a small amount of massabout 1 millionth the mass of the sun. CSS161010 launched 1 to 10 percent the mass of the sun at more than half the speed of lightevidence that this is a new class of transient."