SALT observations of southern post-novae

TL;DR

This paper presents optical observations of 22 southern post-novae, analyzing their spectra and nebular remnants to understand their evolution and structure, including the discovery of an expanding shell around V382 Vel.

Contribution

First comprehensive optical spectral and imaging analysis of southern post-novae, revealing nebular structures and emission line evolution.

Findings

Emission line equivalent widths decrease with time since outburst.

Average continuum power-law exponent is 2.37.

Detected an expanding shell around V382 Vel with 12 arcsec diameter.

Abstract

We report on recent optical observations of the stellar and the nebular remnants of 22 southern post-novae. In this study, for each of our targets, we obtained and analysed long-slit spectra in the spectral range 3500-6600 A and in H$\alpha$+NII narrow-band images. The changes in the emission lines' equivalent widths with the time since the outburst agree with earlier published results of other authors. We estimated an average value $\alpha$=2.37 for the exponent of the power law fitted to the post-novae continua. Our observations clearly show the two-component structure of the V842 Cen expanding nebulae, owing to the different velocities of the ejected matter. We discovered an expanding shell around V382 Vel with an outer diameter of about 12 arcsec.