One of the more mysterious phenomena discovered in space is fast radio bursts, or FRBs, strange pulses of extremely bright energy a few milliseconds long which sometimes repeat in distinct patterns. No one is sure exactly what causes these bursts, though astronomers think they may be related to the rapid rotation of neutron stars, and some fringe thinkers have suggested they are evidence of extraterrestrial intelligence. And now, an FRB has been discovered in our own galaxy for the first time.
A cooperative effort of astronomers from the Massachusetts Institute of Technology (MIT), McGill University, and more identified FRBs within the Milky Way and were even able to pinpoint their source. Previous bursts had been so far away it was impossible to identify their origin, but the new study was able to identify the source of the bursts, which can be blasts of more than 100 million times the power of the sun.
“There’s this great mystery as to what would produce these great outbursts of energy, which until now we’ve seen coming from halfway across the universe,” said Kiyoshi Masui, assistant professor of physics at MIT, who led the team’s analysis of the FRB’s brightness. “This is the first time we’ve been able to tie one of these exotic fast radio bursts to a single astrophysical object.”
The bursts are coming from a type of neutron star called a magnetar, which has a very large and powerful magnetic field. Astronomers are still working to understand how the magnetar produces FRBs, but it’s thought to be related to the way magnetars produce radio waves. Normally, when gas moves through magnetic fields of black holes, for example, it emits energy as radio waves. But magnetars may be different, with a mass of electrons interacting with a magnetic field at once to create a pulse. Researchers are still figuring out the mechanics of how this happens.
Still, a valuable step forward has been taken in understanding these strange signals. “Before this event, a wide variety of scenarios could explain the origin of FRBs,” said Chris Bochenek, a doctoral student in astrophysics at Caltech who led one study of the radio event. “While there may still be exciting twists in the story of FRBs in the future, for me, right now, I think it’s fair to say that most FRBs come from magnetars until proven otherwise.”
