Historical Event: The Farthest Black Hole Ever Was Seen Consuming a Star

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An unexpected visible light source was discovered by a survey telescope last year, prompting an alarm to the European Southern Observatory’s Very Large Telescope (ESO’s VLT). The VLT and other telescopes were quickly redirected to the source, which turned out to be a supermassive black hole in an extremely faraway galaxy that had just consumed a star and was shooting out the debris in a jet. With the VLT’s help, we now know it to be the furthest such occurrence ever witnessed. It’s the first time a jet like this has been seen in visible light, and it’s especially exciting since the jet is pointed practically directly at Earth.

A tidal disruption event occurs when a star wanders too near to a black hole and is torn apart by the tremendous tidal forces of the black hole (TDE). About 1% of these events result in plasma and radiation jets being expelled from the black hole’s poles as it rotates. Black hole pioneer John Wheeler first described jetted-TDEs in 1971, comparing them to a tube of toothpaste squeezed so tightly that it squirts out both ends.

In this pursuit, numerous telescopes, including the Zwicky Transient Facility (ZTF) in the United States, conduct frequent surveys of the sky for signals of transient, or fleeting, phenomena that may be examined in more depth by larger telescopes, like ESO’s VLT in Chile. In order to preserve and process crucial information from the ZTF survey and to notify us about abnormal occurrences in real time, scientists devised an open-source data pipeline.

The ZTF discovered a new source of visible light in February of last year. The AT2022cmc event resembled gamma-ray bursts, the most intense known sources of light in the Universe. In order to get a better look at the mysterious source and maybe get a glimpse of the very unusual event, scientists activated a number of telescopes located all around the world. The VLT at ESO was among those that made swift observations of this novel occurrence using the X-shooter instrument. The light from AT2022cmc started its trip when the universe was just a third of its present age, according to the VLT data, making it the most distant source yet detected for such occurrences.

Twenty-one telescopes located on different continents gathered data in many different wavelengths of light, from ultra-high-energy gamma rays to radio waves. The group compared these findings to previously established phenomena such as stellar collapses and kilonovae. However, the results could only be explained by the presence of a rare jetted-TDE directed in our direction.

AT2022cmc is the most distant TDE ever discovered, as determined by the VLT distance measurement, but that’s not the only record it sets. This is the first jetted-TDE to be discovered via an optical scan; the few previously known examples were all found using high energy gamma-ray and X-ray instruments. This offers a novel method for identifying jetted-TDEs, paving the path for more research into these very uncommon phenomena and for investigating the harsh environs around black holes.