The FAST radio telescope caught 233 bursts from the source FRB 20240114A — the one that flashes so often it's been dubbed hyperactive. Each burst resembles a series of short radio waves whose frequency steadily rises, like someone running a finger up a guitar string. But for 45 of these bursts, the rise is on average 2.5 times steeper: 245.6 megahertz per millisecond versus 98.1 for the rest.
This split doesn't look like chance. A statistical test gave a gap between the groups with a significance of 11.3 sigma, as if people's heights in a crowd clearly fell into 'short' and 'tall' with no in-between. Crucially, the split persists even when only single bursts are considered, not mixed with doublets. So it's not a measurement artifact.
The fast bursts in these two groups also differ in other ways: the 'fast' ones have a lower peak frequency (by 7%), shorter duration (by 29%), and occupy a separate cluster in feature space. Together, this hints that the bursts originate from two different zones in the neutron star's magnetosphere, like two musicians playing the same tune but in different octaves and tempos.
The split into two groups was so clear that the statistical 'gap' reached 11.3 sigma — in particle physics, 5 sigma is usually enough for a discovery.
In Carl Sagan's novel 'Contact,' the radio signal from space contained nested layers of information; here, nature itself splits the signal into two 'voices.'