The population of M dwarfs observed at low radio frequencies

Coherent low-frequency (≲200 MHz) radio emission from stars encodes the conditions of the outer corona, mass-ejection events and space weather 1 – 5 . Previous low-frequency searches for radio-emitting stellar systems have lacked the sensitivity to detect the general population, instead largely focusing on targeted studies of anomalously active stars 5 – 9 . Here we present 19 detections of coherent radio emission associated with known M dwarfs from a blind flux-limited low-frequency survey. Our detections show that coherent radio emission is ubiquitous across the M dwarf main sequence, and that the radio luminosity is independent of known coronal and chromospheric activity indicators. While plasma emission can generate the low-frequency emission from the most chromospherically active stars of our sample 1 , 10 , the origin of the radio emission from the most quiescent sources is yet to be ascertained. Large-scale analogues of the magnetospheric processes seen in gas giant planets 3 , 11 , 12 probably drive the radio emission associated with these quiescent stars. The slowest-rotating stars of this sample are candidate systems to search for star–planet interaction signatures. The authors present 19 detections of coherent low-frequency radio emission from M dwarfs using the Low Frequency Array. The sample includes both chromospherically active and quiescent stars, but radio luminosities are independent of coronal and chromospheric activity indicators.