Fast Radio Bursts (FRBs) are powerful extragalactic millisecond emissions of radio waves whose origin continues to be shrouded in mystery. Only recently have astronomers been able to trace them back to their galaxy. Now astronomers have not only traced the second-ever repeating FRB to where it came from, but discovered it's the closest one to us found yet.
The event is known as FRB 180916 and it appears to be coming from a spiral galaxy less than 500 million light-years away from Earth, researchers revealed in their study published in Nature. They also presented their results at the 235th meeting of the American Astronomical Society.
However, its vicinity is not the only peculiarity. FRBs can be divided into two categories: one-off emissions and repeating bursts. FRB 180916 is a repeating one and only the second repeating one whose location of origin has been confirmed. Though the location is puzzling experts.
“This is the closest FRB to Earth ever localized,” lead author Benito Marcote, from the Joint Institute for VLBI European Research Infrastructure Consortium, said in a statement. “Surprisingly, it was found in an environment radically different from that of the previous four localized FRBs — an environment that challenges our ideas of what the source of these bursts could be.”
The first repeating FRB followed back to its source was FRB 121102 in early 2018 and its repeated bursts likely come from a neutron star in a very distant dwarf galaxy. A non-repeating one was traced to the outskirts of a different galaxy, and another one pinpointed to an average spiral galaxy with no major distinguishing features.
“This object’s location is radically different from that of not only the previously located repeating FRB, but also all previously studied FRBs,” continued fellow lead author Kenzie Nimmo, PhD student at the University of Amsterdam. “This blurs the differences between repeating and non-repeating fast radio bursts. It may be that FRBs are produced in a large zoo of locations across the universe and just require some specific conditions to be visible.”
FRBs have only been studied in detail for less than a decade. In the last few years, astronomers have achieved incredible strides forward in this field in a short period of time, but the true nature of many of them and a complete picture still eludes us.