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| Paper: |
Analysis of High-Resolution Ultraviolet Spectra of PG1159-035 taken with HST and FUSE |
| Volume: |
372, 15th European Workshop on White Dwarfs |
| Page: |
231 |
| Authors: |
Jahn, D.; Reiff, E.; Rauch, T.; Werner, K.; Kruk, J.W.; Herwig, F. |
| Abstract: |
PG 1159−035 is the prototype of the PG1159 spectral class which consists of extremely hot hydrogen-deficient (pre-)white dwarfs. It is also the prototype of the GW Vir variables, which are non-radial g-mode pulsators. We analyse high-resolution UV spectra in order to constrain its photospheric parameters. For the first time we determine the abundance of silicon and sulphur. Sulphur is found to be strongly subsolar, which cannot be explained by post-AGB evolutionary models. We re-determine the nitrogen abundance which is 1 dex lower than previously estimated. This weakens the role of nitrogen as a distinctive feature for pulsators and non-pulsators in the GW Vir instability strip. We find an iron deficiency, which is in accordance with results for other PG1159 stars and probably due to s-process neutron captures on iron seed nuclei. However, its extent is unexplained by stellar models. |
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