For the past 12 months, scientists have been studying a 50-second burst of energy from over a billion light-years away that could change how we understand how stars live and die. In December 2021, a massive blast of energy hit the Earth’s atmosphere.
Its source was a gamma-ray burst – one of the most powerful explosions in the universe – but not just any gamma ray burst. One scientist said at the time that the event – named GRB 211211A – “looks unlike anything else we have seen before”.
The event was detected in December 2021 by NASA’s Neil Gehrels Swift Observatory and the Fermi Gamma-ray Space Telescope. The gamma-ray burst was significantly longer than average, which might normally suggest it had been produced by the collapse of a massive star into a supernova.
But several clues, in particular the unusually high proportion of infra-red light, hinted that this was no ordinary supernova. A study recently published in scientific journal Nature explains that the massive wave of energy had come from a kilonova. These comparatively rare cosmic events – which normally last far less than a minute – are the result of a collision between two ultra-dense neutron stars. They produce heavier elements such as gold and platinum.
Dr. Matt Nicholl, an Associate Professor at the University of Birmingham, said in a statement: “We found that this one event produced about 1,000 times the mass of the Earth in very heavy elements. This supports the idea that these kilonovae are the main factories of gold in the Universe”.
Dr Benjamin Gompertz, Assistant Professor at the University of Birmingham, said it was a “remarkable” event. He said: “We don’t expect mergers to last more than about two seconds. Somehow, this one powered a jet for almost a full minute. It’s possible the behaviour could be explained by a long-lasting neutron star, but we can’t rule out that what we saw was a neutron star being ripped apart by a black hole.”
Jillian Rastinejad, a doctoral candidate in the Northwestern University Department of Physics and Astronomy who led the research, said in a statement: “This event represents an exciting paradigm shift for gamma-ray-burst astronomy”. “This event looks unlike anything else we have seen before from a long gamma-ray burst,” she added. “Its gamma rays resemble those of bursts produced by the collapse of massive stars. (SOURCE)
