Multiple short bursts of radio waves have been found coming from a single location far beyond the Milky Way Galaxy, Cornell astronomers have discovered. It's the first time researchers have found these enigmatic "fast radio bursts" to repeat, indicating that the waves are coming from a powerful source located many light years away.
Fast radio bursts, or FRBs, have long been a mystery for astronomers. Only 17 have ever been found, and they usually appear as isolated events — flashes of radio waves in the sky that only last for milliseconds at a time. Scientists had theorized that the flashes were caused by events as exotic as the smashing together of neutron stars, but Cornell's discovery indicates that whatever produces the burst isn't destroyed in the process. Shami Chatterjee, a senior researcher at Cornell, said that the FRB in question in the paper did not have an explosive origin. "So, either there's an odd coincidence," Chatterjee said, "or maybe there are different types of FRBs. Either way, it seems we've broken this enigmatic phenomenon wide open."
Fast radio bursts don't necessarily have an explosive origin
The detection of FRBs has only occurred fairly recently. The first was spotted in 2007, after digging through data already collected by telescopes on Earth, and it was only last year that scientists caught a burst reaching our planet as it arrived. Astronomers know these bursts are coming from distant places in the Universe, but they've had difficulty pinpointing exactly where FRBs come from. The discovery of the most recent FRB — published in Nature last week — came from a galaxy 1.9 billion parsecs (6 billion light years) away, but the data wasn't detailed enough for scientists to figure out from exactly where it emanated.
Now we know that some of the FRBs discovered so far repeat their blasts of radio waves, we can start to work out either exactly what's causing their galaxy-spanning yelps, or classify them into different categories. Cornell professor James Cordes says that the phenomon is not necessarily the result of a huge cosmic explosion, but neutron stars may still be the culprit. "We're detecting these FRBs from very far away, which means that they are intrinsically very bright," Cordes said. "Only a few astrophysical sources can produce bursts like this, and we think they are most likely neutron stars in other galaxies."