Weekly binned Fermi-LAT light curve of PKS 0346−27 in the energy range 0.1−300 GeV, showing flux (top panel) and photon index (bottom panel). The latter is only plotted for bins where it was possible to fit it as a free parameter (see Sect. 2.1). Filled blue points represent significant detections, downward grey arrows represent 95% confidence level upper limits. The detection threshold is set at TS > 9 and F/ΔF >  2. For ease of representation, the length of the arrows has been set as equal to the average error for significantly detected bins. The dashed line in the bottom plot indicates the average photon index during the quiescent state (see Table 3). A zoom-in of this light curve to the period after 2017.5 (MJD 57936.5) is shown in Fig. 4.