Space is full of mysteries, and among the most intriguing at the moment are fast radio bursts (FRBs). These strange signals are extremely bright but gone in a flash, and only a few dozen of them have been recorded since they were first discovered about a decade ago. Now, astronomers at Australia's Parkes Observatory have recorded three new signals in relatively quick succession – one of which is the brightest FRB ever detected.
FRBs first came to the attention of the scientific community in 2007, when Parkes researchers studying archival data came across a short, sharp spike in readings taken six years earlier. Similar anomalies were later found in other data readouts and in 2015, an FRB was finally caught in the act.
Over 30 of them have been detected since, and while the majority of them are once-off events, one of them is confusing things further by shouting into the void on a regular basis. Scientists still aren't sure what their source is, but the theories cover everything from neutron stars to alien spacecraft.
FRBs were detected by the radio telescope at Parkes on March 1, 9 and 11. It's strange enough for multiple signals to come through that close together, but the middle one of the three was particularly weird. With a signal-to-noise ratio of 411, that event was the brightest fast radio burst detected so far by quite a wide margin. The ratios of most other FRBs hover between about 10 and 40, with the next highest reaching a peak of 90.
The astronomers encouraged further observations of the location, but unfortunately it took place too close to the Sun for an immediate follow-up.
The universe might not be able to hold onto the mystery for too much longer though. It's thought that FRBs must be occurring on a daily basis – we just need to be looking in the right direction at the right time to see them. With more and more observatories training their eyes on the skies, new reports should come in thick and fast over the next few years, providing new data to crack the case.
Sources: Astronomer's Telegram, FRB Catalogue (Petroff et al., 2016), via Phys.org