Temperature Scale and Iron Abundances of Very Hot Central Stars of Planetary Nebulae (invited review)

@inproceedings{Werner2002TemperatureSA,
  title={Temperature Scale and Iron Abundances of Very Hot Central Stars of Planetary Nebulae (invited review)},
  author={Klaus Werner and Jochen L. Deetjen and Stefan Dreizler and T Rauch and Jeffrey W. Kruk},
  year={2002}
}
The determination of effective temperatures of very hot central stars (Teff>70000K) by model atmosphere analyses of optical H and He line profiles is afflicted with considerable uncertainty, primarily due to the lack of neutral helium lines. Ionization balances of metals, accessible only with UV lines, allow more precise temperature estimates. The potential of iron lines is pointed out. At the same time iron and other metal abundances, hardly investigated until today, may be derived from UV… Expand

Figures from this paper

Element Abundance Determination in Hot Evolved Stars
The hydrogen-deficiency in extremely hot post-AGB stars of spectral class PG1159 is probably caused by a (very) late helium-shell flash or a AGB final thermal pulse that consumes the hydrogenExpand
The Elemental Abundances in Bare Planetary Nebula Central Stars and the Shell Burning in AGB Stars
We review the observed properties of extremely hot, hydrogen-deficient post-asymptotic giant branch (AGB) stars of spectral type (WC) and PG1159. Their H deficiency is probably caused by a (very)Expand
AGB star intershell abundances inferred from UV spectra of extremely hot post-AGB stars
The hydrogen-deficiency in extremely hot post-AGB stars of spectral class PG1159 is probably caused by a (very) late helium-shell flash or a AGB final thermal pulse that consumes the hydrogenExpand
Iron abundance in hot hydrogen-deficient central stars and white dwarfs from FUSE, HST, and IUE spectroscopy
We present a rst systematic investigation of the iron abundance in very hot (Te 50 000 K) hydrogen- decient post-AGB stars. Our sample comprises 16 PG 1159 stars and four DO white dwarfs. We useExpand
Chandra and FUSE spectroscopy of the hot bare stellar core H 1504+65 ⋆
H 1504+65 is an extremely hot hydrogen-deficient white dwarf with an effective temperature close to 200 000 K. We present new FUV and soft X-ray spectra obtained with FUSE and Chandra, which confirmExpand
Metal abundances in PG1159 stars from Chandra and FUSE spectroscopy
We investigate FUSE spectra of three PG1159 stars and do not find any evidence for iron lines. From a comparison with NLTE models we conclude a deficiency of 1-1.5 dex. We speculate that iron wasExpand
Hot star extension to the Hubble Space Telescope stellar spectral library
Context. Libraries of stellar spectra find many uses in astrophysics, from photometric calibration to stellar population synthesis. Aims. We present low resolution spectra of 40 stars from 0.2 μmExpand
Discovery of magnetic fields in central stars of planetary nebulae
For the first time we have directly detected magnetic fields in central stars of planetary nebulae by means of spectro- polarimetry with FORS1 at the VLT. In all four objects of our sample we foundExpand
High-resolution FUSE and HST ultraviolet spectroscopy of the white dwarf central star of Sh 2-216
Context. We perform a comprehensive spectral analysis of LS V +46°21  in order to compare its photospheric properties to theoretical predictions from stellar evolution theory as well as fromExpand
Comprehensive modelling of the planetary nebula LMC-SMP 61 and its [WC]-type central star
We present a comprehensive study of the Magellanic Cloud planetary nebula SMP 61 and of its nucleus, a Wolf- Rayet type star classified [WC 5-6]. The observational material consists of HST STISExpand

References

SHOWING 1-10 OF 22 REFERENCES
Spectroscopic studies of very old hot stars. I - NGC 246 and its exciting star
The planetary nebula NGC 246 and its exciting stars were studied, using an image-tube spectrograph at the Cassegrain focus of a 36-inch telescope. Observations of the central star indicate that itExpand
The central star of S 216
Optical and high-resolution ultraviolet spectra of LS V+46 21, the postulated central star of the large, nearby planetary nebula S 216, have been analysed. From modelling the line profiles, this starExpand
Properties of atmospheres and winds of H-deficient central stars and related objects
According to latest results presented at this workshop, it appears that thesurface chemistry of hydrogen-deficient post-AGB stars can now be explained byevolutionary calculations involving a lateExpand
Internal mixing and surface abundance of [WC]-CSPN
Recent advances in constructing stellar evolution models of hydrogen-deficient post-asymptotic giant branch (AGB) stars are presented. Hydrogen-deficiency can originate from mixing and subsequentExpand
Winds in the atmospheres of central stars of Planetary Nebulae (Invited Review)
For this review we have chosen to concentrate on recent progress concerning the model atmosphere analysis of stellar winds in central stars of planetary nebulae (CSPNs). Since there is another reviewExpand
Spectral analysis of the sdO K 648 , the exciting star of the planetary nebula Ps 1 in the globular cluster M 15 ( NGC 7078 )
We present a spectral analysis of the sdO central star K 648 based on medium-resolution optical and high-resolution UV spectra. The photospheric parameters are determined by means of state-of-the-artExpand
Late stages of stellar evolution. II: Mass loss and the transition of asymptotic giant branch stars into hot remnants
We have computed the transition of asymptotic branch giants of 0.8 and 1.0 M/sub sun/ into remnants of 0.565, 0.553, and 0.546 M/sub sun/ by means of mass loss which removed the stellar envelopes inExpand
White Dwarf Central Stars
Planetary nebula nuclei on lower luminosity, diagonal tracks in the HR, Diagrams are degenerate dwarf stars close to their final radii. For several reasons, these stars have until recently beenExpand
Nucleosynthesis in asymptotic giant branch stars: Relevance for galactic enrichment and solar system formation
▪ Abstract We present a review of nucleosynthesis in AGB stars outlining the development of theoretical models and their relationship to observations. We focus on the new high resolution codes with...
On the ultraviolet iron spectrum of pre-white dwarfs
Detection de nombreuses raies de FeV, VI, VII dans les spectres IUE de deux etoiles centrales et plusieurs sous-naines tres chaudes. Les intensites de ces raies varient fortement d'une etoile aExpand
...
1
2
3
...