Fellow amateur astronomers, get ready to have your minds blown. Fast radio bursts (FRB) from space — the short-lived, incredibly powerful bursts of radio waves that have fascinated scientists and UFO enthusiasts alike since they were first detected in 2007 — just became a little less mysterious. In a paper published in Nature this month, an international team of astronomers claims they have pinpointed the origin of a single FRB.
The radio emissions are notoriously difficult to trace, partly because they're over in a matter of milliseconds. According to the Christian Science Monitor, FRBs are difficult to find unless a telescope happens to be pointing their way. Although scientists estimate they occur with relative frequency, just 18 FRBs have been observed directly since 2007, and they're almost always a one-time occurrence. Their one-hit-wonder status led many scientists to theorize that FRBs result from cataclysmic events like supernovas or the formation of a black hole.
In 2015, however, researchers discovered an FRB emanating from the same source as one measured in 2012. Nine more bursts, all emitted from the same location somewhere in deep space, occurred over the next six months. This burst, known as FRB 121102, was the first repeating FRB to be detected, and it provided researchers with an unprecedented opportunity to follow it to its origin.
In the paper describing their findings, researchers write that FRB 121102 originates from a dwarf galaxy about three billion light-years from Earth. As you've probably figured out from the name, the galaxy is far smaller than the Milky Way — in fact, it contains less than one percent of the mass of our galaxy. Their findings call into question what researchers thought they knew about FRBs.
In a statement, McGill University researcher Shriharsh Tendulkar expressed his surprise. "The host galaxy for this FRB appears to be a very humble and unassuming dwarf galaxy. .... One would generally expect most FRBs to come from large galaxies which have the largest numbers of stars and neutron stars — remnants of massive stars," he said. Basically, the collapse of a massive star might emit a strong radio burst, but it wouldn't cause a repeated signal like FRB 121102.
Tundulkar offered a possible alternative explanation. Apparently, the dwarf galaxy may have fewer stars than the Milky Way, but it's forming new neutron stars quickly. These kinds of galaxies are also linked to extreme events like superluminous supernovae and long gamma ray bursts. Such environments might be conducive to the creation of magnetars, aka highly magnetic dead stars. (How metal is that?) FRBs might be linked to any combination of these things; at the very least, it's an avenue worth exploration.
Researchers also noticed weaker, continuous radio emissions coming from the same general area as FRB 121102, which may have influenced its signals. In fact, according to the Christian Science Monitor, scientists think they might even be physically associated with each other.
Then there's the explanation you've been waiting for. Some people have claimed that these deep space radio waves could be communications from extraterrestrials. In that case, we'll have to wait and see what they're trying to tell us Earthlings — if it's warning about an alien invasion, I guess we'll find out the hard way.