Comparative study of a [WC 6] nucleus with other emission-lines
nuclei of planetary nebulae.
Acker A., Gorny S.K., Cuisinier F.
1996, A&A 305,944
Abstract:
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The central star (CSPN) of the planetary nebula M 1-25 (PNG 4.9+4.9) is
classified as a [WC 6] star, the only CSPN of this subclass known at this
time. A comparison with the other emission-lines CSPN (the [WC]-class and
the 'weak emission-lines stars' or wels-class) shows that (1) the
characteristics of this [WC 6] star fit well inside the main properties of
the other [WC] CSPN; (2) the [WC] CSPN seem to evolve from the [WC 8-11]
(latter) to [WC 2-4] (earlier) subclasses, say from dense nebulae with cool
stars to more extended nebulae with hot nuclei, as for other CSPN; (3) on
the two-colour IRAS diagram, the [WC] and the wels CSPN form two
different groups: the progenitors of the [WC]-type CSPN seem to be carbon
stars evolving along post-AGB tracks, whereas the wels CSPN seem to
be related to OH/IR stars, some of them having possibly experienced a late
helium-flash.
Please send copy requests to:
acker@simbad.u-strasbg.fr
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