Newly Discovered Wolf-Rayet and Weak Emission-Line Central Stars of Planetary Nebulae

TL;DR

This study reports 32 new Wolf-Rayet and weak emission-line central stars of planetary nebulae, increasing the known population by about 30%, and provides spectral classifications to aid understanding of their evolution.

Contribution

It presents the discovery and spectral classification of 32 new CSPNe with [WR] and WELS characteristics, expanding the known sample and enabling detailed evolutionary analysis.

Findings

Increased the known [WR] CSPNe by ~30%.

Identified 22 probable [WR]s and 10 WELS.

Enhanced understanding of [WR] subclass distribution and evolution.

Abstract

We present spectra of 32 previously unpublished confirmed and candidate Wolf-Rayet ([WR]) and weak emission-line (WELS) central stars of planetary nebulae (CSPNe). Eighteen stars have been discovered in the Macquarie/AAO/Strasbourg H-Alpha (MASH) PN survey sample, and we have also uncovered 14 confirmed and candidate [WR]s and WELS among the CSPNe of previously known PNe. Spectral classifications have been undertaken using both the Acker & Neiner and Crowther, De Marco & Barlow schemes. Twenty-two members in this sample are identified as probable [WR]s; the remaining 10 appear to be WELS. Observations undertaken as part of the MASH spectroscopic survey have now increased the number of known [WR]s by ~30 per cent. This will permit a better analysis of [WR] subclass distribution, metallicity effects, and evolutionary sequences in these uncommon objects.