Miszalski, B., Crowther, P.A., de Marco, O. et al. (4 more authors) (2013) IC4663: the first unambiguous [WN] Wolf-Rayet central star of a planetary nebula. In: Astronomical Society of the Pacific Conference Series. 18th European White Dwarf Workshop, 13-17 Aug 2012, Cracow, Poland. Astronomical Society of the Pacific , pp. 281-286.
Abstract
Several [WC]-type central stars of planetary nebulae (PNe) are known to mimic the spectroscopic appearance of massive carbon-rich or WC-type Wolf-Rayet stars. In stark contrast, no [WN]-type central stars have yet been identified as clear-cut analogues of the common nitrogen-rich or WN-type Wolf-Rayet stars. We have identified the [WN3] central star of IC4663 to be the first unambiguous example in PNe. The low luminosity nucleus and an asymptotic giant branch (AGB) halo surrounding the main nebula prove the bona-fide PN nature of IC4663. Model atmosphere analysis reveals the [WN3] star to have an exotic chemical composition of helium (95%), hydrogen (<2%), nitrogen (0.8%), neon (0.2%) and oxygen (0.05%) by mass. Such an extreme helium-dominated composition cannot be predicted by current evolutionary scenarios for hydrogen deficient [WC]-type central stars. Only with the discovery of IC4663 and its unusual composition can we now connect [WN] central stars to the O(He) central stars in a second H-deficient and He-rich evolutionary sequence, [WN]->O(He), that exists in parallel to the carbon-rich [WC]->PG1159 sequence. This suggests a simpler mechanism, perhaps a binary merger, can better explain H-deficiency in PNe and potentially other H-deficient/He-rich stars. In this respect IC4663 is the best supported case for a possible merged binary central star of a PN.
Metadata
Item Type: | Proceedings Paper |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2013 Astronomical Society of the Pacific. |
Keywords: | Solar and Stellar Astrophysics |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 20 Nov 2017 10:33 |
Last Modified: | 22 Feb 2018 16:02 |
Published Version: | http://www.aspbooks.org/publications/469/281.pdf |
Status: | Published |
Publisher: | Astronomical Society of the Pacific |
Refereed: | Yes |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:124239 |