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Paper: |
The Carbon Abundance in the Wolf-Rayet Shell Nebula NGC 6888 |
Volume: |
348, Astrophysics in the Far Ultraviolet: Five Years of Discovery with FUSE |
Page: |
334 |
Authors: |
Moore, B.D.; Dufour, R.J.; Sankrit, R.; Aufdenberg, J.P. |
Abstract: |
We present FUSE observations of HD 192163, the Wolf-Rayet star responsible for the shell nebula NGC 6888. In particular we focus on the spectrum over 974- 979 Å, which we use to probe the carbon abundance within a rarefied shell external to the visible nebula. Absorption in the C III 977 Å line permits an estimate of the C2+ column density from the circumstellar material. Using a model for the shell in conjunction with previous study of the nebula, we infer a total carbon abundance of 12+log(C/H) = 7.6±0.3, about one-tenth the solar value. Comparison with models of the chemical evolution of massive stars shows agreement with the expected mass of the progenitor star, but only for models with high stellar rotation rates. |
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