2001/08/14 by Orsola De Marco, O. De Marco, P. A. Crowther +5 · 2 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1046/j.1365-8711.2001.04887.x
published as Mon.Not.Roy.Astron.Soc. 328 (2001) 527 · 31 pages, 19 figures (some are gif files), MNRAS in press
arxiv created 2001/08/14 · openalex publication_date 2001/12/01 · arxiv updated 2009/12/01 · openalex created_date 2020/11/23 · openalex updated_date 2026/08/01
The hydrogen-deficient [WCL] type central star HD167362 and its planetary nebula (PN) SwSt 1 are investigated. The central star has a carbon-rich emission line spectrum and yet the nebula exhibits a 10-µm emission feature from warm silicate dust, perhaps indicating a recent origin for the carbon-rich stellar spectrum. Its stellar and nebular properties might therefore provide further understanding as to the origin of the [WCL] central star class. The central star optical and UV spectra are modelled with state of the art non-LTE codes for expanding atmospheres, from which the stellar parameters are determined. Using the Sobolev approximation code isa-Wind, we find Teff=40000 K, log ( ˙ M/M ⊙ yr −1)=–6.72, L=8900 L ⊙ (for a distance of 2.0 kpc), and v∞ ≃ 900 km s −1. The abundance mass fractions for helium, carbon and oxygen is determined to be 37%, 51 % and 12%, respectively. From this we derive C/O=4.3 (by mass), confirming that the star suffered efficient third dredge-up. The nitrogen abundance is close to zero, while an upper limit of <10 % by mass is established for H. The model uses a composite