Explaining prolonged fluctuations in light curves of classical novae via modelling.

Fluctuations during a prolonged maximum have been observed in several nova eruptions, although it is not clear, and cannot be deduced directly from observations, whether the phenomenon is an actual physical reaction to some mechanism originating in the erupting white dwarf, whether it is occurring in the expanding ejected shell, or whether it is a form of interaction with the red dwarf companion. A handful of erupting nova models are investigated in this work, in order to assess the possibility of this sort of feature being an actual part of the eruption itself. The results explain that the mechanism that may produce these fluctuations is the repeated approach and recession of the convective front from the surface. The efficiency of this mechanism, being dependent on the mass of the WD (white dwarf) envelope and the time-scale of the nova cycle, favours low-mass WDs and long accretion phases. [ABSTRACT FROM AUTHOR]