SwSt 1: an O-rich planetary nebula around a C-rich central star
Abstract
The hydrogen-deficient carbon-rich [WCL] type central star HD167362 and its oxygen-rich planetary nebula (PN) SwSt~1 are investigated. The nebular chemistry might indicate a recent origin for the carbon-rich stellar spectrum. Its stellar and nebular properties might therefore provide further understanding of the origin of the [WCL] central star class. The UV-IR stellar spectra are modelled with state of the codes and show ~40kK central star with a wind and a C/O~3, indicative of efficient third dredge-up. The synthetic stellar flux distribution is used to model the high density, compact PN, which has a solar C/O ratio, is still enshrouded by 1200K and 230K dust shells and, reported here for the first time, in molecular hydrogen. Although it appears that the change in C/O ratio has been recent, the published spectroscopy since 1895 has been re-examined and no clear spectral change is seen. If an event occurred that has turned it into a hydrogen-deficient central star, it did not happen in the last 100 years.
Cite
@article{arxiv.astro-ph/0108246,
title = {SwSt 1: an O-rich planetary nebula around a C-rich central star},
author = {O. De Marco and P. A. Crowther and M. J. Barlow and G. C. Clayton and A. deKoter},
journal= {arXiv preprint arXiv:astro-ph/0108246},
year = {2009}
}
Comments
31 pages, 19 figures (some are gif files), MNRAS in press