For around 67 days, the source is silent. Then, for around 90 days, it wakes up again, spitting out repeated millisecond radio flares before falling silent, and the whole 157-day cycle repeats.
However, fast radio bursts are extremely mysterious, and there was no guarantee that the cycle would continue. So it’s pretty exciting that the source has flared up again, right on cue – consistent with predictions of its activity cycle.
This suggests that there’s significant value in monitoring known fast radio burst sources – but also in continuing to watch FRB 121102 to try to understand what could be causing the phenomenon.
A quick refresher: fast radio bursts are, as the name suggests, bursts of radio waves that are very fast, just a few milliseconds long, coming from galaxies millions to billions of light-years away. But they’re also extremely powerful; within those milliseconds, they can discharge as much power as hundreds of millions of Suns.
Most of the tim