Searching for nova shells around cataclysmic variables - II. A second campaign

We report on our second campaign to search for old nova shells around cataclysmic variables (CVs). Our aim was to test the theory that nova eruptions cause cycles in the mass transfer rates of CVs. These mass transfer cycles change the behaviour of CVs during their intereruption periods. We examined Ha images of 47 objects and found no new shells around any of the targets. Combining our latest results with those of our previous campaign (Sahman et al.), and the searches by Schmidtobreick et al. and Pagnotta & Zurek, we estimate that the nova-like phase of the mass transfer cycle lasts similar to 3000 yr.

Automated summary

This paper reports on the second campaign to search for old nova shells around cataclysmic variables (CVs). No new shells were found based on the examination of Ha images of 47 objects. Combining the latest results with previous studies, the nova-like phase of the mass transfer cycle is estimated to last about 3000 years.