Z CamPaign Update December 2013
Let me begin by thanking all the observers who have contributed data to the Z CamPaign up to now. Your dedication and persistence has paid off admirably, and none of the results I am about to share with you would have been possible otherwise. We passed the four year mark in September 2013. As a direct result of this observing campaign there have been eight papers published, accepted or submitted for publication.
To summarize the findings to date, we now know of 21 bona fide Z Cam systems. We have eliminated 29 impostors, stars that at one time or another were listed as or suspected of being Z Cam stars in the literature.
There are still things to be learned from continued monitoring of the bona fide Z Cam stars. We're finding some unusual and unexpected behaviors. For one- outbursts from standstills- which turned out to be more common that any of us thought at the beginning of this campaign in 2009. Many Z Cam stars also exhibit deep VY Scl-type fading episodes. In recent years Michael Shara has found ancient nova shells around two Z Cams (Z Cam and AT Cnc) bolstering the hibernating novae theory. I've become more convinced than ever that Z Cams represent a relatively short period in the life cycle of CVs as they evolve. Now it appears that CVs can and do evolve from one type to another. We can't have too much data on these rare star systems. What's more, we still have a list of 20 suspects that will require more intensive long-term monitoring to determine once and for all their variability type. I expect to be writing summaries and papers from this campaign for several years to come.
So, before we look forward, I'd like to look back on the four years of the campaign so far and highlight all the fantastic work you have done.