Night-wise light curves for energy thresholds of 1 and 5 TeV. Red squares indicate integral fluxes > 1 TeV relative to the integral flux above 1 TeV obtained from Aharonian et al. (2006). Error bars depict 1σ statistical errors. The dashed red line is the fit of a constant to this light curve, and the hatched red area marks the 1σ statistical error. The equivalent data for an energy threshold of 5 TeV are presented in blue. For reference, the Fermi-LAT synchrotron light curve as published in Mayer et al. (2013) is shown in magenta. Each bin corresponds to 6 h of observations. The flux is scaled to the average quiescent synchrotron photon flux as reported in Buehler et al. (2012) ((6.1 ± 0.2) × 10^-7 cm^-2 s^-1).