ASASSN-19bt is a

tidal disruption event A tidal disruption event (TDE) is an astronomical phenomenon that occurs when a star approaches sufficiently close to a supermassive black hole (SMBH) to be pulled apart by the black hole's tidal force, experiencing spaghettification. A portion ...

, a star destroyed by a black hole, discovered by the

All Sky Automated Survey for SuperNovae The All Sky Automated Survey for SuperNovae (ASAS-SN) is an automated program to search for new supernovae and other astronomical transients, headed by astronomers from the Ohio State University, including Christopher Kochanek and Krzysztof Stanek ...

(ASAS-SN) project, with early-time, detailed observations by the

TESS Tess or TESS may refer to: Music * Tess (band), a Spanish pop band active from 2000 to 2005 * TESS (musician), a UK musician Film and theatre * ''Tess'' (1979 film), a 1979 film adaptation of '' Tess of the d'Urbervilles'' * ''Tess'' (2016 film ...

satellite. It was first detected on January 21, 2019, and reached peak brightness on March 4. The black hole is in the 16th magnitude galaxy 2MASX J07001137-6602251 in the constellation

Volans Volans is a constellation in the southern sky. It represents a flying fish; its name is a shortened form of its original name, Piscis Volans. Volans was one of twelve constellations created by Petrus Plancius from the observations of Pieter Dirk ...

at a redshift of 0.0262, around 375 million

light years A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

away. Observations in

UV light Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation i ...

made with NASA's

Neil Gehrels Swift Observatory Neil Gehrels Swift Observatory, previously called the Swift Gamma-Ray Burst Explorer, is a NASA three-telescope space observatory for studying gamma-ray bursts (GRBs) and monitoring the afterglow in X-ray, and UV/Visible light at the location o ...

showed a drop in the temperature of the tidal disruption from around 71,500 to 35,500 degrees Fahrenheit (40,000 to 20,000 degrees Celsius) 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.

References

{{2019 in space Black holes Astronomical events Volans (constellation) 2019 in space