Flux density monitoring. The top panel shows the single-dish radio flux densities as observed within the Michigan monitoring program. Flux densities observed at 4.8 (red), 8.0 (blue), and 14.5 GHz (green) are shown. Superimposed is the R-band light-curve (black data points) obtained with the Abastumani optical telescope. Note that the two y-axes are labeled differently (the left y-axis describes the radio flux density, the right y-axis the optical magnitude). Please also note that the optical data cover the time between 2000 Jun. 03 and 2012 Feb. 02. The plot at the bottom is an expansion of the plot at the top.