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[Music throughout] A high-energy

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outburst seen in April 2020 confirmed the surprising range

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of supermagnetized objects called magnetars.

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This blast of X-rays and gamma rays triggered instruments on several spacecraft.

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The eruption was over in the blink of an eye and originated

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from a galaxy about 11 million light-years away.

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Magnetars are part of the family of compact objects known as neutron stars,

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the crushed, leftover cores of exploded stars.

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What makes magnetars special are their incredibly strong

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magnetic fields — up to 1,000 times stronger than a typical neutron

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star’s. Sudden changes to this ultrastrong field are thought

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to drive brief, enormously powerful outbursts called giant flares.

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One giant flare in our own galaxy affected Earth’s upper

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atmosphere — from 28,000 light-years away.

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On April 15th, detectors on NASA’s

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Fermi, Swift, Mars Odyssey and Wind missions, as well as

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on the European Space Agency’s INTEGRAL satellite, picked up a

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rapid surge of X-rays and gamma rays. Using the arrival times of

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the signal at different spacecraft, astronomers pinned the burst to

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NGC 253, a bright, nearby galaxy.

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From start to finish, the event lasted 140 milliseconds — as

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fast as a finger snap. Astronomers see

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gamma-ray bursts, or GRBs, almost every day. We know that

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at least some of the shortest GRBs come from merging neutron stars

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more than 100 million light-years away. The April blast

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initially looked similar to these events. But a GRB located

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in our own galactic neighborhood should have appeared much brighter.

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As astronomers explored this new burst in detail, they

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found it looked less like a short GRB and more like a magnetar

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giant flare. Astronomers have recorded two such

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flares inside our own galaxy and a third in a satellite galaxy.

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All of these bursts displayed a spikey tail as they faded out.

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The spikes form as the flare's hot spot spins in and out of view,

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like a lighthouse beam. Current instruments can’t detect

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this feature in flares located at great distances, but other

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characteristics, such as their extremely fast rise in brightness, are

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unmatched by short GRBs. This fueled

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astronomers’ growing suspicions that short GRBs associated with galaxies

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in our neighborhood might really be magnetar giant flares.

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Now, the precise localization of the 2020 event

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to the disk of the Sculptor galaxy has unmasked them at last.

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Astronomers suspect that a few percent of observed short GRBs

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may in fact be giant flares — high-powered eruptions

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in our galactic back yard produced by the strongest

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magnets in the cosmos.

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NASA