© Omar Ould-Boukattine / ASTRON

FRBs are extremely energetic, extragalactic radio transients, but how high-energy can they be before hitting a limit? This is a key question in unraveling the emission physics and subsequent origins of FRBs. In a newly published paper in MNRAS (Ould-Boukattine et al. 2025, DOI: 10.1093/mnras/staf1937), we were able to constrain a limit on the maximum energy based on observations from a single source, the hyperactive repeater FRB 20220912A.

Observations were carried out as part of the HyperFlash project, which is a dedicated ultra-high-cadence FRB monitoring campaign in which 25-32-metre class radio telescopes in Europe aim to observe the brightest and rarest FRBs. The Westerbork RT-1 telescope is one of the main contributing telescopes in this program, having observed more than 6500 h in 2024 (75% of the year). See our previous Daily image of 14-01-2025.

In our paper, we find a limit on the maximum energy of FRB 20220912A that is consistent with limits inferred for apparently non-repeating FRB sources. This consistency may point toward a common physical mechanism underlying the energetics of both repeating and apparently non-repeating FRBs!

Additionally, based on the total observed radio energy, we estimate that the magnetic energy of a typical magnetar would be depleted in only ~2150 hours, notably shorter than the lifetime of a typical PhD thesis. This suggests that hyperactive repeaters could be intrinsically short-lived phenomena, unless their engines are somehow being refueled.