Immensely powerful 'magnetar' is emitting wobbly radio signals in our galaxy — and scientists can't explain them

A magnetar that "woke up" in 2018 after years of radio silence emitted strange, wobbly radio signals — and scientists cannot explain them, new studies show. The findings suggest that the universe's most powerful magnets are even weirder than we initially realized.  

Magnetars are a rare, juvenile class of super-dense collapsed stars, known as neutron stars, with supercharged magnetic fields trillions of times greater than Earth's magnetic field. Magnetars are most likely birthed by supernovas but can also be created by neutron star collisions. The energy from these cosmic events makes magnetars some of the fastest-spinning objects ever discovered. But eventually, they lose energy and transition into regular neutron stars as their spin rate slows. Only around 30 magnetars have been detected to date.

Some magnetars occasionally explode violently as their complex magnetic fields unwind and snap, causing them to shoot out vast amounts of radiation into space in the form of X-rays, gamma rays and, most commonly, radio pulses. These outbursts, which can explode with the force of millions of suns, enable astronomers to spot the magnetars. But after several years, these outbursts diminish, and the rapidly spinning stars disappear from view once more.

In December 2018, a city-size magnetar named XTE J1810-197, which was first discovered in 2003, reappeared to astronomers thanks to one of these outbursts after more than a decade of radio silence. Ever since, the magnetar, which is located around 8,000 light-years from Earth, has continued to spit radio pulses toward our planet, enabling researchers to monitor the celestial object with some of the world's largest radio telescopes. 

In a pair of new studies, which were both published April 8 in the journal Nature Astronomy, researchers analyzed the radio pulses given off by XTE J1810-197 and discovered a weird "wobbling" in these signals. Further analysis revealed that these fluctuations could not be explained by any known magnetar behavior, suggesting something completely new was at play. 

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"Our findings demonstrate that exotic physical processes are involved in the production of the radio waves we can detect," Patrick Weltevrede, an astrophysicist at the University of Manchester in the U.K. and co-author of both new studies, said in a statement. But at present, the team cannot explain what these novel processes are.