WZ Cas - variability on multiple time-scales We present results on our long-term velocity monitoring of the C-richsemi-regular variable WZ Cas with a Coravel instrument. Our findings arecompared with light changes of the star. We suggest that the two mainperiods, 366 and 186 d, are due to radial pulsation. Furthermore, wefind an interesting variation of the width and depth of thecross-correlation profile over a time-scale of at least 1000 d. Severalpossible explanations for this behaviour are discussed by comparison oftime-scales and expected variability amplitudes. The influence ofmovements of large convective cells on the line profiles seems to be themost likely explanation of some of the observed phenomena.
