When it comes to the mysteries of outer space, the closer we think we are to some answers, the more we find out just how much we have yet to discover. A series of bright flashes was recently spotted and has left scientists bewildered. Here's why.
The flashes, first spotted in January 2020, came from the direction of the constellation Ursa Major and are known as repeating fast radio bursts (FRB). But this isn't the first time researchers have come across such an event - these FRBs reminded scientists of flashes observed in the Crab Nebula, a well-known remnant from an old supernova. Although the stellar explosion resulting in the Crab Nebula was first recorded in 1054 AD, it wasn't until the 1960s when a fluctuating radio source was spotted coming from the location of the Crab Nebula. Astronomers then learned that the signal came from a pulsar, a type of neutron star with a strong magnetic field.
Although scientists were able to determine the cause of the FRBs coming from the Crab Nebula, those seen in M81 remain a mystery. Bursts like this are usually observed in galaxies with young stars, but the source of the recently-discovered signal being an old group of stars has left scientists puzzled. According to astronomers, one possible explanation is magnetars, supernova remnants with the strongest magnetic force in the universe. But although this possibility would make sense in the case of the M81 FRBs, the explanation remains a bit problematic. "We expect magnetars to be shiny and new, and definitely not surrounded by old stars," Jason Hessels, an astronomy professor at the University of Amsterdam, said in the statement. "If what we're looking at here really is a magnetar, then it can't have been formed from a young star exploding. There has to be another way."
Another interpretation is that the flashes might have been caused by a white dwarf, the dense core of a large, burnt-out star. Researchers suspect that a mass of this type may have gained even more electronic pressure from the gas of nearby stars, causing it to collapse into a magnetar. But even with these explanations, we're still not sure whether the flashes recently observed were caused by an unusual magnetar or other celestial event. What's for sure is that scientists have quite a lot of research to do before they're able to solve the mystery of the signal, or explain why it resembles the one from the Crab Nebula. Until then, stay tuned.