HST/COS observations of the WZ Sge-like SU UMa variable GZ Cet have been scheduled for 2013 September 13. (Similar observations for the SU UMa variable BB Ari have been scheduled for the week of September 23-30.) Please see AAVSO Special Notice #369 for details.
Your observations of these CVs are essential to making a final decision as to whether the HST/COS observations will be allowed to take place.
Many thanks and good observing - Elizabeth Waagen, AAVSO HQ