Measured magnitudes versus the associated magnitude uncertainty (σ_mag) for both stars and lunar impact flashes in the I- and R-bands (left and right, respectively). In both panels the stellar measurements are presented as stars, while the validated impact flashes are shown as circles. For the I-band the suspected impact events (cyan crosses) are also shown. For the stars, the predicted model (Eq. (1)) is also presented (solid line; see Fig. 6). The dashed and dotted lines in each panel indicate the model prediction when the minimum and maximum value, respectively, of the background noise (STD_bkg) are considered for the case of the observations of 1 March, 2017 with the lower lunar phase ∼0.1 (Fig. 12) observed.