Related papers: Determining element abundances of [WC]-type Centra…

A considerable fraction of the central stars of planetary nebulae (CSPNe) are hydrogen-deficient. As a rule, these CSPNe exhibit a chemical composition of helium, carbon, and oxygen with the majority showing Wolf-Rayet-like emission line…

While most of the low-mass stars stay hydrogen-rich on their surface throughout their evolution, a considerable fraction of white dwarfs as well as central stars of planetary nebulae have a hydrogen-deficient surface composition. The…

According to previous spectral analyses of Wolf-Rayet type central stars, late [WC] subtypes show systematically higher carbon-to-helium abundance ratios than early [WC] subtypes. If this were true, it would rule out that these stars form…

Aims: Chemical compositions and other properties of planetary nebulae around central stars of spectral types [WC], [WO], and wels are compared with those of `normal' central stars, in order to clarify the evolutionary status of each type…

We report on an on-going analysis of high-resolution UV spectra of hot hydrogen-rich central stars of planetary nebulae (CSPN), obtained with the Hubble Space Telescope and FUSE. Since UV spectra of many CSPN are dominated by Fe and Ni…

We review the properties of carbon-sequence ([WC]) Wolf-Rayet central stars of planetary nebulae (CSPNe). Differences between the subtype distribution of [WC] stars and their massive WC cousins are discussed. We conclude that [WO]-type…

The hydrogen-deficient carbon-rich [WCL] type central star HD167362 and its oxygen-rich planetary nebula (PN) SwSt~1 are investigated. The nebular chemistry might indicate a recent origin for the carbon-rich stellar spectrum. Its stellar…

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…

Over the past decade, the number of planetary nebula central stars (CSPN) known to exhibit the Wolf-Rayet (WR) phenomenon has grown substantially. Many of these discoveries have resulted from the Macquarie/AAO/Strasbourg Ha (MASH) PN…

[Abridged] [...] AIMS: We aim to establish the stellar parameters and mass-loss rates of the Galactic WC stars. These data provide the empirical basis of studies of (i) the role of WC stars in the evolution of massive stars, (ii) the…

The central star (CSPN) of the planetary nebula M 1-25 (PN G 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…

The radiation field of central stars of planetary nebulae (CSPNe) is crucial for determining the physical conditions of planetary nebulae (PNe). Many studies in the literature model PNe using the blackbody approximation (bb) or…

Planetary nebulae represent a potential late stage of stellar evolution, however the central stars (CSPNe) are relatively faint and therefore pertinent information is merely available for <20% of the Galactic sample. Consequently, the…

A considerable fraction of the central stars of planetary nebulae (CSPNe) are hydrogen-deficient. Almost all of these H-deficient central stars (CSs) display spectra with strong carbon and helium lines. Most of them exhibit emission line…

We present a brief review on the formation and evolution of hydrogen deficient central stars of planetary nebulae. We include a detailed description of the main observable features of both the central stars and their surrounding nebulae and…

Context. At least 492 central stars of Galactic planetary nebulae (CSPNs) have been assigned spectral types. Since many CSPNs are faint, these classification efforts are frequently made at low spectral resolution. However, the stellar…

Classical Wolf-Rayet (WR) stars mark an important stage in the late evolution of massive stars. As hydrogen-poor massive stars, these objects have lost their outer layers, while still losing further mass through strong winds indicated by…

The striking broad emission line spectroscopic appearance of Wolf-Rayet (WR) stars has long defied analysis, due to the extreme physical conditions within their line and continuum forming regions. Recently, model atmosphere studies have…

We observed seven central stars of planetary nebulae (CSPN) in the Large Magellanic Cloud (LMC) with the Far Ultraviolet Spectroscopic Explorer (FUSE), and performed a model-based analysis of these spectra in conjunction with Hubble Space…

The progress over the last years in modelling the atmospheres and winds of PN central stars is reviewed. We discuss the effect of the inclusion of the blanketing by millions of metal lines in NLTE on the diagnostics of photospheric and…