On the Galactic Nova Progenitor Population

TL;DR

This paper proposes a new classification scheme for Galactic novae based on the nature of their quiescent systems, supported by photometric surveys and light-curve analysis, with implications for supernova progenitors.

Contribution

It introduces a nova classification based on quiescent system properties and presents survey results linking secondary star evolution to nova types.

Findings

Evolved secondary stars are common in recurrent novae.

Photometric surveys can determine the secondary star's evolutionary state.

Light-curve analysis confirms the pre-maximum halt in nova outbursts.

Abstract

Of the 350 or more known Galactic classical novae, only a handful of them, the recurrent novae, have been observed in outburst more than once. At least eight of these recurrents are known to harbour evolved secondary stars, rather than the main sequence secondaries typical in classical novae. Here we present a selection of the work and rationale that led to the proposal of a new nova classification scheme based not on the outburst properties but on the nature of the quiescent system. Also outlined are the results of a photometric survey of a sample of quiescent Galactic novae, showing that the evolutionary state of the secondary can be easily determined and leading to a number of predictions. We discuss the implications of these results, including their relevance to extragalactic work and the proposed link to type Ia supernovae. We also present a summary of the work using the SMEI instrument to produce exquisite nova light-curves and confirmation of the pre-maximum halt.