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[Music throughout]On January 21, 2019,

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for the very first time, NASA’s TESS saw a black hole destroy a star.

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This was a tidal disruption event, which occurs when a star

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passes too close to black hole. Extreme gravity causes

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the star to bulge and break apart into a stream of gas.

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The tail of the stream escapes into space, but the rest swings around

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to form an accretion disk. This event,

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called ASASSN-19bt for the All-Sky Automated

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Survey for Supernovae, which first identified it, happened in the TESS

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continuous viewing zone. TESS’s four cameras scan large

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sectors of the sky, and one constantly monitored this region for a full

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year. TESS saw ASASSN-19bt

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as soon as it started to brighten, days before other observatories

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spotted it. NASA’s Swift satellite

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quickly observed the outburst in visible light, UV,

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and, along with the European XMM-Newton satellite, X-rays.

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The UV measurements are the earliest recorded

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for a tidal disruption to date. They showed the event’s temperature

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dropped almost 50% in just a few days. Such a steep

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decrease has never been seen in a tidal disruption before.

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These outbursts are rare, happening only

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once every 10,000 to 100,000 years in a galaxy

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like our own. Future discoveries will help us

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learn even more about these uncommon cosmic blasts.

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[Music][Explore: Solar system & beyond]

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[NASA]