Explaining Prolonged Fluctuations in Light Curves of Classical Novae via Modeling

TL;DR

This paper investigates the physical mechanisms behind prolonged fluctuations in classical nova light curves, proposing that convective front dynamics in the white dwarf's envelope can explain these phenomena.

Contribution

It introduces nova eruption models that demonstrate how convective front movements can cause light curve fluctuations, highlighting the role of white dwarf mass and accretion duration.

Findings

Convective front approach and recession can produce light curve fluctuations.

Low mass white dwarfs and longer accretion phases favor these fluctuations.

The mechanism is linked to the nova cycle timescale.

Abstract

Fluctuations during a prolonged maximum have been observed in several nova eruptions, although it is not clear, and can not be deduced directly from observations, if the phenomenon is an actual physical reaction to some mechanism originating in the erupting white dwarf, if it is occurring in the expanding ejected shell or if 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 envelope and the time scale of the nova cycle, favors low mass WDs and long accretion phases.