You might have noticed that Z UMa has just recently reached a peak in its brightness and this peak was brighter than previous peaks for the last four years (see the attached screen shot from the BAAVSS database). I am going to stick my neck out here and make a bit of a prediction! I think we will see more of this in the next four years with more sharply defined peaks and troughs and a wider range in magnitudes. My reasoning is the interplay between the two periods of pulsation that this star shows. If you look back to 2016-2017 there was a period then when the amplitude of variation died away somewhat and there was evidence for double peaks in the pulsation prior to this. Then the variation recovered and there were more sharply defined peaks and troughs. I think we are now seeing a repeat of this behaviour.
Why do I think this? Well, I am not sure I believe that the second, less prominent, pulsation period in this star is dying away. I think that this modulation of the amplitude and the double peaks (see above) is evidence that the two pulsation periods in this star are still operating together and causing the modulations to the primary pulsation period that we see. Over the next four years we will probably see these sharply defined peaks because the two periods are acting in concert and then after this they will go out of phase and we will see the return of the double peaks and the lower amplitude range. We shall see! For more on this read my previous posts on this subject.
