QU Carinae: Type Ia supernova in the making?

Abstract

Variable Na I absorption lines have been reported in a number of Type Ia supernovae (SNeIa). The presence of this circumstellar material suggests that cataclysmic variables (CVs) with a giant donor star may be the progenitors of these SNeIa. We present echelle spectra of the CV QU Carinae which strengthen the connection between CVs of the V Sge class, the accretion wind evolution scenario, variable wind features, variable Na I absorption and SNeIa. This thread not only provides insight into the spectral peculiarities of QU Car, but also links SNeIa as a class with their parent systems.