Artist's representation: A black hole absorbs matter. © dpa/www.johnapaice.com/University of Southampton/John A. Paice
A research team observes the largest known explosion in space over a period of several years. Behind it is a black hole.
Southampton - Researchers have discovered an extraordinarily powerful explosion in the universe. The explosion, named zAT2021lwx, is more than ten times brighter than any previously known supernova and three times brighter than any previously known tidal star-rupture event in which a black hole "spaghetifies" a star. The phenomenon was discovered back in 2020 by the Zwicky Transient Facility (ZTF) in California, a telescope that scans the sky for momentarily brightening objects. The explosion has been going on for more than three years.
"We came across it by accident because our search algorithm pointed it out when looking for a type of supernova," explains Philip Wiseman (University of Southampton), who led the research. "Most supernovae and tidal star-rupture events only last a few months before disappearing. The fact that something shines brightly for over two years was immediately very unusual," the researcher said in a statement from his university.
Largest explosion in the universe observed by a team of researchers
The research team has determined the object's distance from Earth to be about eight billion light-years. "If you know the distance to the object and how bright it appears to us, you can calculate the brightness of the object at its source," says Sebastian Hönig, a co-author of the study, which was published in the journal Monthly Notices of the Royal Astronomical Society. "As soon as we made these calculations, we realized that it was extremely bright."
The only objects in the universe that are brighter than AT2021lwx are quasars. However, unlike a quasar, AT2021lwx appeared suddenly and unexpectedly, rather than having fluctuating brightness for an extended period of time. "If you look back over a decade, AT2021lwx hasn't been discovered and then suddenly it pops up with the brightness of the brightest objects in the universe, which is unprecedented," points out Mark Sullivan, another co-author of the study.
Black hole engulfs a huge cloud of gas - big explosion
The research team suspects that a huge cloud of gas or dust - thousands of times larger than our sun - has deviated from its course and ended up in a black hole. As a result, shock waves were generated and the observed explosion was triggered. Further observations in different wavelengths as well as computer simulations are to follow.
Last fall, the brightest gamma-ray burst ever measured was observed. The research group does not shy away from comparison with this: The gamma-ray burst GRB 221009A was brighter, but lasted only a fraction of the time that AT2021lwx lasted. The total energy released by the current explosion is therefore significantly higher, according to a statement on the study - making AT2021lwx the largest known explosion in space to date.
This article, written by the editors, used machine support. The article was carefully reviewed by editor Tanja Banner before publication.
