The light curve includes 51,086 observations over 67 years.
Plateau outbursts are brighter and last longer than common outbursts.
Some outbursts end in standstills in which the brightness stays constant roughly one magnitude below maximum light for a few days to a thousand days. The average energy output in a standstill is larger than that during an outburst cycle. All outbursts follow a pattern, the plateau outburst cycle , where one or more common or anomalous outbursts occur in between two plateau outbursts or a plateau outburst and a standstill. Short quiescent durations lead to a higher outburst frequency and more energetic outbursts in intervals dominated by standstills than other lightcurve intervals. Our physical picture for Z Cam stars follows the standard disk instability mechanism for dwarf novae.