2019MNRAS.488..525Z

It is still not known whether or not bimodal dust species (namely the silicate and amorphous carbon dust grains that are observed in a nova eruption) are formed in nova ejecta. Using the Modules for Experiments in Stellar Astrophysics code and considering the effects of the white dwarf mass, the mass-accretion rate and the chemical profile, which are described by a new parameter (the mixing depth), on the chemical abundances of nova ejecta, we investigate the possibility that bimodal dust species are produced in a nova eruption. We find that the C/O (the ratio of the carbon number density to the oxygen number density) of nova ejecta is affected by the mixing depth. For a model with a small mixing depth, the C/O of nova ejecta can evolve from greater than 1.0 to less than 1.0 over the course of an eruption, thereby providing the chemical conditions for the formation of bimodal dust species.