Astronomers have detected a mysterious and extremely bright event, named AT2022tsd, in a galaxy approximately 4.4 billion light-years away.
AT2022tsd was first spotted on September 7, 2022 by astronomers using the Zwicky Transient Facility.
Nicknamed the ‘Tasmanian Devil,’ the event is a Luminous Fast Blue Optical Transient (LFBOT), a rare, extremely powerful event — more powerful than a supernova.
Previously detected LFBOTs evolved on timescales of just a few days, fading away rapidly.
However, AT2022tsd continued to explode with supernova-like energies many times, well after its initial burst and fade.
“An event like this has never been witnessed before,” said Professor Jeff Cooke, an astronomer at Swinburne University of Technology and the ARC Centre of Excellence in Gravitational Wave Discovery (OzGrav).
“When LFBOTs explode, they emit more energy than an entire galaxy of hundreds of billions of stars like the Sun.”
“The mechanism behind this massive amount of energy is currently unknown.”
“But in this case, after the initial burst and fade, the extreme explosions just kept happening, occurring very fast — over minutes, rather than weeks to months, as is the case for supernovae.”
“Amazingly, instead of fading steadily as one would expect, the source briefly brightened again, and again, and again,” said Dr. Anna Ho, an astronomer at Cornell University.
“LFBOTs are already a kind of weird, exotic event, so this was even weirder.”
“The data from the multiple observatories, including one with a high-speed camera, detected at least 14 irregular and highly-energetic bursts over a 120-day period.”
“However, these bursts are likely only a fraction of the total number.”
“AT2022tsd is puzzling. It pushes the limits of physics because of its extreme energy production, but also because of the short duration bursts,” Professor Cooke said.
“Light travels at a finite speed. As such, how fast a source can burst and fade away…
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