Transcripts of 13237_TESS_TDE_Captions

[Music throughout]On January 21, 2019, for the very first time, NASA’s TESS saw a black hole destroy a star. This was a tidal disruption event, which occurs when a star passes too close to black hole. Extreme gravity causes the star to bulge and break apart into a stream of gas. The tail of the stream escapes into space, but the rest swings around to form an accretion disk. This event, called ASASSN-19bt for the All-Sky Automated Survey for Supernovae, which first identified it, happened in the TESS continuous viewing zone. TESS’s four cameras scan large sectors of the sky, and one constantly monitored this region for a full year. TESS saw ASASSN-19bt as soon as it started to brighten, days before other observatories spotted it. NASA’s Swift satellite quickly observed the outburst in visible light, UV, and, along with the European XMM-Newton satellite, X-rays. The UV measurements are the earliest recorded for a tidal disruption to date. They showed the event’s temperature dropped almost 50% in just a few days. Such a steep decrease has never been seen in a tidal disruption before. These outbursts are rare, happening only once every 10,000 to 100,000 years in a galaxy like our own. Future discoveries will help us learn even more about these uncommon cosmic blasts. [Music][Explore: Solar system & beyond] [NASA]