CO production rates and reduced nuclear magnitudes in December 2007 and April-May 2010. The times of outbursts A and D are marked by dot-dashed lines. Outbursts E and F are also shown. The R nuclear magnitudes are measured inside an aperture with a diameter of 10″ (Spanish amateur data reported in Tables D.1 and D.2; homepage of M. Kidger). The relation between the CO and magnitude scales is log₁₀(Q(CO)) = 29.25−0.062 m_R(1, r_h, 0), consistent with Eq. (2).