We report on the discovery of eight repeating fast radio burst ( FRB ) sources found using the Canadian Hydrogen Intensity Mapping Experiment ( CHIME ) telescope .
These sources span a dispersion measure ( DM ) range of 103.5 to 1281 pc cm ^ { -3 } .
They display varying degrees of activity : six sources were detected twice , another three times , and one ten times .
These eight repeating FRBs likely represent the bright and/or high-rate end of a distribution of infrequently repeating sources .
For all sources , we determine sky coordinates with uncertainties of \sim 10 ^ { \prime } .
FRB 180916.J0158+65 has a burst-averaged DM = 349.2 \pm 0.3 pc cm ^ { -3 } and a low DM excess over the modelled Galactic maximum ( as low as \sim 20 pc cm ^ { -3 } ) ; this source also has a Faraday rotation measure ( RM ) of -114.6 \pm 0.6 rad m ^ { -2 } , much lower than the RM measured for FRB 121102 .
FRB 181030.J1054+73 has the lowest DM for a repeater , 103.5 \pm 0.3 pc cm ^ { -3 } , with a DM excess of \sim 70 pc cm ^ { -3 } .
Both sources are interesting targets for multi-wavelength follow-up due to their apparent proximity .
The DM distribution of our repeater sample is statistically indistinguishable from that of the first 12 CHIME/FRB sources that have not repeated .
We find , with 4 \sigma significance , that repeater bursts are generally wider than those of CHIME/FRB bursts that have not repeated , suggesting different emission mechanisms .
Our repeater events show complex morphologies that are reminiscent of the first two discovered repeating FRBs .
The repetitive behavior of these sources will enable interferometric localizations and subsequent host galaxy identifications .