English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Several [WC]-type central stars of planetary nebulae (PNe) are known to mimicthe spectroscopic appearance of massive carbon-rich or WC-type Wolf-Rayetstars. In stark contrast, no [WN]-type central stars have yet been identifiedas 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 unambiguousexample 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. Modelatmosphere analysis reveals the [WN3] star to have an exotic chemicalcomposition of helium (95%), hydrogen (<2%), nitrogen (0.8%), neon (0.2%) andoxygen (0.05%) by mass. Such an extreme helium-dominated composition cannot bepredicted by current evolutionary scenarios for hydrogen deficient [WC]-typecentral stars. Only with the discovery of IC4663 and its unusual compositioncan we now connect [WN] central stars to the O(He) central stars in a secondH-deficient and He-rich evolutionary sequence, [WN]->O(He), that exists inparallel to the carbon-rich [WC]->PG1159 sequence. This suggests a simplermechanism, perhaps a binary merger, can better explain H-deficiency in PNe andpotentially other H-deficient/He-rich stars. In this respect IC4663 is the bestsupported case for a possible merged binary central star of a PN.

IC4663: the first unambiguous [WN] Wolf-Rayet central star of a planetary nebula