dc.contributor.author |
Parthasarathy, M |
|
dc.contributor.author |
Acker, A |
|
dc.contributor.author |
Stenholm, B |
|
dc.date.accessioned |
2008-08-18T11:20:22Z |
|
dc.date.available |
2008-08-18T11:20:22Z |
|
dc.date.issued |
1998-01 |
|
dc.identifier.citation |
Astronomy and Astrophysics, Vol. 329, No. 1, pp. L9 - L12 |
en |
dc.identifier.issn |
0004-6361 |
|
dc.identifier.uri |
http://hdl.handle.net/2248/3191 |
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dc.description.abstract |
The characteristics of the spectra of weak emission line stars (WELS) are found to be very similar to that of [WC]-PG1159 and PG1159 objects. On the basis of the spectra we find 31 WELS central stars of planetary nebulae to be in fact [WC]-PG1159 stars. These stars mark the transition from the [WC] central stars of planetary nebulae to the PG1159 (pre-)white dwarfs. The evolutionary sequence appears to be [WC late ] - [WC early ] - WELS = [WC]-PG1159 - PG1159. The presence of nebulae and dust shells around these stars and also the significant percentage of [WC]-PG1159 stars among the [WC] central stars of PN indicates that late He-flash scenario may not be the principal mechanism for their post-AGB evolution towards the non-DA white dwarf stage. We found 4 hybrid central stars. They display a HeII/CIV 4650 - 4686 Angstroms trough very similar to that of PG1159 stars. However, their spectra show stellar Balmer lines indicating that they are relatively hydrogen-rich in contrast to the PG1159 stars. Based on observations obtained at the European Southern Observatory (ESO), La Silla, Chile. |
en |
dc.format.extent |
169799 bytes |
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dc.format.mimetype |
application/pdf |
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dc.language.iso |
en |
en |
dc.publisher |
European Southern Observatory |
en |
dc.relation.uri |
http://aa.springer.de/bibs/8329001/23000l9/small.htm |
en |
dc.subject |
Stars: Post-AGB |
en |
dc.subject |
Stars: Carbon |
en |
dc.subject |
Stars: Evolution |
en |
dc.subject |
ISM: Planetary Nebulae |
en |
dc.subject |
Stars: Emission-Line |
en |
dc.title |
Weak emission line [WELS] central stars of planetary nebulae are [WC]-PG1159 stars |
en |
dc.type |
Article |
en |