Recurrent Novae at Quiescence: Systems with Giant Secondaries

TL;DR

This paper studies the spectroscopic and photometric behavior of recurrent novae with giant secondaries during quiescence, revealing variability linked to accretion processes and wind envelope changes.

Contribution

It provides detailed observations and analysis of variability mechanisms in recurrent novae with giant secondaries at quiescence, highlighting the role of accretion rate fluctuations and wind envelope dynamics.

Findings

Hot component variability is uncorrelated with orbital motion.

Spectral features are consistent with a white dwarf+accretion disc in a wind envelope.

Variability likely caused by accretion rate fluctuations and wind column density changes.

Abstract

Spectroscopic and photometric behaviour of the class of recurrent novae with giant secondaries (T Coronae Borealis, RS Ophiuchi, V3890 Sagittarii and V745 Scorpii) at quiescence are presented in this study. The hot component in these systems is variable, with the variability manifesting as variability in the ultraviolet luminosity, the ultraviolet and optical emission line fluxes and in the UBV/visual magnitudes. The variations are uncorrelated with the binary orbital motion. The observed ultraviolet+optical spectral characteristics of the hot component in these systems can be explained by a white dwarf+accretion disc embedded in an envelope of wind from the M giant secondary. We suggest the observed variations are a result of (a) fluctuations in the mass accretion rate; (b) changes in the column density of the absorbing, optically thick, wind envelope.