![]() ![]() So that allowed Fong’s and Troja’s research groups to independently continue closely observing the burst in great detail using telescopes on the ground, the teams report in Nature.Īs the weeks wore on and no supernova appeared, the researchers grew confused. “We thought it was a run-of-the-mill long gamma-ray burst,” says astrophysicist Wen-fai Fong of Northwestern University in Evanston, Ill. NASA’s Swift and Fermi space telescopes detected the explosion on December 11, 2021, in a galaxy about 1.1 billion light-years away. “It has the kilonova, which is the smoking gun.” “Although we suspected it was possible that extended emission GRBs were mergers … this is the first confirmation,” says astrophysicist Benjamin Gompertz of the University of Birmingham in England, who describes observations of the burst in Nature Astronomy. Zamani/International Gemini Observatory/NOIRLab/NSF/AURA, NASA, ESA This shows the glow of a kilonova that followed the oddball gamma-ray burst called GRB 211211A, in images from the Gemini North telescope and the Hubble Space Telescope. There’s no such mystery about GRB 211211A: The burst lasted more than 50 seconds and was clearly accompanied by a kilonova, the characteristic glow of new elements being forged after a neutron star smashup. ![]() “There were some outliers which we did not know how to interpret.” “We always knew there was an overlap,” says astrophysicist Chryssa Kouveliotou of George Washington University in Washington, D.C., who wrote the 1993 paper that introduced the two GRB categories, but was not involved in the new work. And some long-duration GRBs dating back to 2006 lacked a supernova after the fact, raising questions about their origins. A surprisingly short GRB in 2020 seemed to come from a massive star’s implosion ( SN: 8/2/21). Or a pair of dense stellar corpses called neutron stars could collide, merge and form a new black hole, releasing a short gamma-ray burst of two seconds or less.īut there had been some outliers. The collapse of a massive star just before it explodes in a supernova could make a long gamma-ray burst, lasting more than two seconds ( SN: 10/28/22). Prior to the discovery of this burst, astronomers mostly thought that there were just two ways to produce a GRB. This burst, called GRB 211211A, is the first that unambiguously breaks the binary, Troja and others report December 7 in five papers in Nature and Nature Astronomy. “This is the red flag that tells us, nope, it’s not. “We had this black-and-white vision of the universe,” says astrophysicist Eleonora Troja of the Tor Vergata University of Rome. But about a year ago, two NASA space telescopes caught a short GRB in long GRB’s clothing: It lasted a long time but originated from a short GRB source. Each type has been linked to different cosmic events. These events could be devastating for our technological civilization.Astronomers have spotted a bright gamma-ray burst that upends previous theories of how these energetic cosmic eruptions occur.įor decades, astronomers thought that GRBs came in two flavors, long and short - that is, lasting longer than two seconds or winking out more quickly. The biggest current threat is probably a solar proton event, which occurs when the Sun releases high numbers of energetic protons that can disrupt communications and affect power grids. (See the November 27, 2018, issue of the journal Astrobiology, and “Could a supernova explain an ancient mass extinction?” on page 11 of Astronomy’s April 2019 issue.) A supernova within about 25 light-years would probably cause a major mass extinction, which has likely happened one or more times in the past 500 million years. We think that may have happened about 2.6 million years ago, and possibly contributed to an extinction event at the end of the Pliocene era that took out marine megafauna. We might see a little bit of damage to the ozone layer, or some small increase of radiation on the ground on Earth, but these would be too small to matter.īased on the latest work with my collaborators, a massive star would need to be within about 150 light-years to cause measurable damage. Betelgeuse is about 500 light-years away, not near enough to cause serious damage. ![]()
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