Photometric light curves for our ten targets (left panels), and for one of the reference stars used to compute the differential photometry for each target (right panels). The differential photometry (red circles and blue squares, respectively) has been shifted so that the average value corresponds to the mean Ks-magnitude of the objects. The horizontal dashed lines show the ± 1σ variation with respect to the average values for two comparison stars in the field of view of each target and reference star.