paper, [@Chatterjee] have achieved sub-arsecond localisation of the FRB 121102 using radio interferometric observations from the Very Large Array. The source has been localised to a $m_{r^\prime} = 25.1$ AB mag low-metallicity, star-forming dwarf galaxy at $z = 0.19273(8)$ [@SriHarsh]. The precise localisation shows that the source is either co-located with a 180 $\upmu$Jy active galactic nucleus or an unresolved type of extragalactic source. However, the exact nature of the FRB progenitor is still unknown.

Despite concerted follow-up efforts for almost all FRBs, this remains the only FRB seen to repeat. These efforts have been quite substantial. For instance, $\approx80$ hrs of followup for the Lorimer burst [@Lorimer], $\approx80$ hrs for FRB 131104 [@Ravi] and $\approx110$ hrs of selected FRB positions [@Petroff_followup] at the Parkes radio telescope yielded no repeats. This suggests the possibility of there being two independent classes of FRBs – repeating and non-repeating – with two classes of possible progenitors [@nat_keane]. Progenitor theories include flaring magnetars [@Lyubarsky], giant pulses from pulsars [@Wasserman; @Connor], binary white dwarf mergers [@Kashiyama], neutron star mergers [@Totani] and collapsing supramassive neutron stars [@Falcke]. It is possible that the lack of repetition of pulses for the FRB discoveries at the Parkes radio telescope 