Exploring the diffusion-induced nova scenario

We propose an scenario for the formation of DA white dwarfs with very thin He‐buffers. For these stars we explore the possible ocurrence of diffusion‐induced CNO‐flashes in white dwarfs, during their early cooling stage. Then we calculate the consequent white dwarf cooling evolution by means of a consistent treatment of element diffusion and nuclear burning.We find that diffusion induced novas do occur in physically sounding white dwarf models. In particular, we find that these flashes do occur in some low‐mass (M≲0.6 M⊙) and low metallicity (ZZAMS≲0.001) remnants about 106–107 yr after departing from the AGB. We discuss observable predictions of these models, in particular eruption lightcurves and chemical compositions.