Scientists have taken another step in understanding one of the biggest mysteries of the universe after astronomers were able to trace the signal of a mysterious repeating fast radio burst for the second time.
Fast radio bursts (or FRBs) are powerful millisecond-long bursts of radio waves in space. In fact, each one produce as much energy as the sun does over a century. FRBs were first spotted in 2007, but so far, scientists haven't been able to explain how such powerful transient radio bursts are possible.
"The big question is what can produce an FRB," Kenzie Nimmo, a doctoral student at the University of Amsterdam in the Netherlands, said at a news briefing at the 235th meeting of the American Astronomical Society in Honolulu, Hawaii, where the results of the study were presented.
Scientists have offered multiple explanations for the appearance of the explosive heavenly events including: supernovas (large stars that explode after they reach the end of their lifespan), magnetars (collapsed stellar corpses that emit strong magnetic fields) and even some who suggest the FRBs could be linked to alien signals.
While most of the FRBs observed by scientists over the years have been singular events, some FRB sources were observed to have sent out the short energetic radio signals multiple times.
The source of the newly discovered repeating FRB (which has the easy-to-remember name of 180916.J0158+65), was first observed by a global network of eight ground-based telescopes and is located in a dwarf galaxy with a high rate of star formation about a half-a-billion light years away. That's about seven times closer than the previous repeating FRB that was observed. The galaxy was found to have a persistent radio source that could explain the repeating FRB's origin.
"The FRB is among the closest yet seen, and we even speculated that it could be a more conventional object in the outskirts of our own galaxy," said Mohit Bhardwaj, study co-author and McGill University doctoral student. "However, the observation proved that it's in a relatively nearby galaxy, making it still a puzzling FRB but close enough to now study using many other telescopes."
FRB 180916.J0158+65 was discovered by the Canadian Hydrogen Intensity Mapping Experiment (CHIME) observatory, which is located in British Columbia. Follow-up observations were conducted by a network of telescopes in Europe, which helped scientists pinpoint exactly where the repeating FRB was originating from.
"The multiple flashes that we witnessed in the first repeating FRB arose from very particular and extreme conditions inside a very tiny [dwarf] galaxy," said Benito Marcote, lead study author from the Joint Institute for VLBI in Europe. "This discovery represented the first piece of the puzzle but it also raised more questions than it solved, such as whether there was a fundamental difference between repeating and non-repeating FRBs. Now, we have localized a second repeating FRB, which challenges our previous ideas on what the source of these bursts could be."
The study announcing the team's results was published Monday in the journal Nature, and its findings presented at the 235th annual meeting of the American Astronomical Society in Honolulu.
Researchers are hoping that additional data that's collected about FRBs may help them understand what this particular signal is trying to say.