The aftermath of nova Cen 2013 (V1369 Cen)

TL;DR

This study investigates the long-term aftermath of the 2013 nova Cen 2013 (V1369 Cen), revealing that the system has not yet fully relaxed five years post-eruption, with evidence of ongoing gas activity and a bloated white dwarf envelope.

Contribution

First detailed multi-wavelength spectroscopic analysis of a classical nova five years after eruption, providing insights into its relaxation process and binary system characteristics.

Findings

Binary orbital period of 3.76 hours identified

Evidence of an irradiated secondary star observed

No clear signature of an accretion disk detected

Abstract

Context: Classical nova progenitors are cataclysmic variables and very old novae are observed to match high mass transfer rate and (relatively) long orbital period systems. However, the aftermath of a classical nova has never been studied in detail. Aims: To probe the aftermath of a classical nova explosion in cataclysmic variables and observe as the binary system relaxes to quiescence. Methods: We used multi-wavelength time resolved optical and near-infrared spectroscopy for a bright, well studied classical nova five years after outburst. We were able to disentangle the contribution of the ejecta at this late epoch using its previous characterization, separating the ejecta emission from that of the binary system. Results: We determined the binary orbital period (P=3.76 hr), the system separation and mass ratio (q>=0.17 for an assumed white dwarf mass of 1.2 solar masses). We find evidence of an irradiated secondary star and no unambiguous signature of an accretion disk, although we identify a second emission line source tied to the white dwarf with an impact point. The data are consistent with a bloated white dwarf envelope and the presence of unsettled gas within the white dwarf Roche lobe. Conclusions: At more than 5 years after eruption, it appears that this classical nova has not yet relaxed.