New evidence deepens the mystery of fast radio bursts (FRBs), the brief flashes of radio emission stemming from unknown sources beyond our galaxy. Scientists have now discovered faint repeat bursts from one of the brightest FRBs, previously thought to have been a one-off event.
To Repeat or Not to Repeat
It was over a decade ago that scientists noticed the first enigmatic, millisecond-duration burst of radio waves from outside of the Milky Way. Since then, we’ve discovered about 100 FRB sources and even identified the host galaxies for several of them. Nonetheless, we still don’t know what causes FRBs, or even whether they’re all the same type of phenomenon.
FRB 121102, the first fast radio burst found to repeat, was also the first to be localized in the sky. [Gemini Observatory/AURA/NSF/NRC]FRB properties span a wide range, but one of the biggest distinguishing features has been repetition. While most discovered FRBs have been one-off events — a single bright flash and no evidence of any additional emission from the same region either before or after — around ten FRBs have been found to repeat.
We successfully localized one repeating FRB to a distant low-mass, low-metallicity dwarf galaxy. The two non-repeating bursts ...