The peculiar dust shell of Nova DZ Cru (2003)

TL;DR

This paper reports mid-infrared observations of Nova DZ Cru revealing a dust shell likely composed of hydrogenated amorphous carbon, with potential evolution from aliphatic to aromatic structures or complete destruction over time.

Contribution

It provides detailed Spitzer observations of DZ Cru's dust shell and proposes a new interpretation of its composition and evolution post-eruption.

Findings

Dust shell observed 4 years after eruption

Likely composed of hydrogenated amorphous carbon

Possible transformation from aliphatic to aromatic structures

Abstract

We present Spitzer Space Telescope observations of the "peculiar variable" DZ Cru, identified by Rushton et al. (2008, MNRAS, 386, 289) as a classical nova. A dust shell, on which are superimposed a number of features, is prominent in the 5-35micron range some 4 years after eruption. We suggest that the dust in DZ Cru is primarily hydrogenated amorphous carbon in which aliphatic bands currently predominate, and which may either become predominantly aromatic as the dust is photo-processed by ultraviolet radiation from the stellar remnant, or more likely completely destroyed.