ASASSN-19bt

ASASSN-19bt was a tidal disruption event known for being the first such event discovered. It was discovered by the All [Sky Automated Survey for SuperNovae] project, with early-time, detailed observations by the TESS satellite. It was first detected on January 21, 2019, and reached peak brightness on March 4.
The black hole which caused the TDE has a mass of around 6 million suns and is in the 16th magnitude galaxy 2MASX J07001137-6602251 in the constellation Volans at a redshift of 0.0262, around 375 million light years away.
Observations in UV light made with NASA's Neil Gehrels Swift Observatory showed a drop in the temperature of the tidal disruption from around 71,500 to 35,500 degrees Fahrenheit over a few days. This is the first time such an early temperature drop has been seen in a tidal disruption event. The transient resulting from the tidal disruption event has been cataloged as AT 2019ahk.