Karastergiou, A.Rajwade, K. M.Mickaliger, M. B.2021-02-082021-02-082020Karastergiou, A. et al. (2020). Possible periodic activity in the repeating FRB 121102. Monthly Notices of the Royal Astronomical Society, 495(4), 3551–35581365-2966https://doi.org/10.1093/mnras/staa1237http://hdl.handle.net/10566/5856The discovery that at least some Fast Radio Bursts (FRBs) repeat has ruled out cataclysmic events as the progenitors of these particular bursts. FRB 121102 is the most well-studied repeating FRB but despite extensive monitoring of the source, no underlying pattern in the repetition has previously been identified. Here, we present the results from a radio monitoring campaign of FRB 121102 using the 76 m Lovell telescope. Using the pulses detected in the Lovell data along with pulses from the literature, we report a detection of periodic behaviour of the source over the span of 5 yr of data. We predict that the source is currently ‘off’ and that it should turn ‘on’ for the approximate MJD range 59002−59089 (2020 June 2 to 2020 August 28). This result, along with the recent detection of periodicity from another repeating FRB, highlights the need for long-term monitoring of repeating FRBs at a high cadence.enSurveysBinaries: generalRadio continuum: transientsFast Radio Bursts (FRBs)Article