A New Evolutionary Picture for CVs and LMXBs II. The Impact of Thermal-Timescale Mass Transfer

Abstract

Depending on the outcome of pre-CV formation, mass transfer may set in under thermally unstable conditions in a significant number of systems. Full computations have shown that such an early phase of thermal-timescale mass transfer usually leads to ordinary looking CVs, but these do also show some unusual properties (e.g. chemical anomalies in later stages). Rather than investigating the common envelope evolution leading to pre-CVs, we study the properties of multiple evolutionary tracks starting with a phase of thermal-timescale mass transfer. Apart from fitting unusual CVs (like AE Aqr), global properties of the CV population as a whole give indications that this is indeed the channel where many CVs come from.