Average activity level (pEW′(Hα)) as a function of the mass of the 98 sample stars, colour-coded with the J magnitude. Large data points indicate that a signal (FAP ≤ 10%) related to the activity of the star was found in at least one parameter, while small data points indicate non-detections. Stars with no known planetary companions are indicated with circles, while those with confirmed planetary companions are indicated with triangles.