相关论文: Wolf-Rayet Central Stars of Planetary Nebulae: The…

We present spectra of 32 previously unpublished confirmed and candidate Wolf-Rayet ([WR]) and weak emission-line (WELS) central stars of planetary nebulae (CSPNe). Eighteen stars have been discovered in the Macquarie/AAO/Strasbourg H-Alpha…

We addressed the physical and kinematical properties of Wolf -- Rayet [WR] central stars (CSs) and their hosting planetary nebulae (PNe). The studied sample comprises all [WR] CSs that are currently known. The analysis is based on recent…

The Wolf-Rayet (WR) phenomenon is widespread in astronomy. It involves classical WRs, very massive stars (VMS), WR central stars of planetary nebula CSPN [WRs], and supernovae (SNe). But what is the root cause for a certain type of object…

We present high resolution spectrophotometric data for 34 galactic planetary nebulae with [WC] nuclei (WRPNe).The sample includes PNe with early and late [WC] stars and some WELS. Physical conditions and chemical abundances have been…

Wolf-Rayet (WR) stars comprise a class of stars whose spectra are dominated by strong, broad emission lines that are associated with copious mass loss. In the massive-star regime, roughly 90% of the known WR stars are thought to have…

High resolution spectra are used to analyze the galactic kinematics and distribution of a sample of planetary nebulae with [WR] and 'wel' central star ([WR]PN and WLPN). The circular and peculiar velocities (Vpec) of the objects were…

Wolf-Rayet (WR) stars are the evolved descendants of massive O-type stars and are considered to be progenitor candidates for Type Ib/c core-collapse supernovae (SNe). Recent results of our HST/WFC3 survey of Wolf-Rayet stars in M101 are…

Nearly 50 post-common-envelope (post-CE) close binary central stars of planetary nebulae (CSPNe) are now known. Most contain either main sequence or white dwarf (WD) companions that orbit the WD primary in around 0.1-1.0 days. Only…

The evolution of central stars of planetary nebulae was so far documented in just a few cases. However, spectra collected a few decades ago may provide a good reference for studying the evolution of central stars using the 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…

We construct a speculative scenario for the evolution of Wolf-Rayet central stars of planetary nebula. It is clear from the latest infra-red observations that a new perspective has to be adopted: the simultaneous presence of carbon- and…

Over a hundred planetary nebulae (PNe) are known to have H-deficient central stars that mimic the spectroscopic appearance of massive Wolf-Rayet stars. The formation of these low-mass Wolf-Rayet stars, denoted [WR] stars, remains poorly…

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…

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…

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…

[WC]-type CSPNs are hydrogen-deficient Central Stars of Planetary Nebulae showing strong stellar winds and a carbon-rich chemistry. We have analyzed new high-resolution spectra of [WC]-type CSPNs with the Potsdam Wolf-Rayet (PoWR) non-LTE…

Wolf-Rayet stars (WRs) are evolved massive stars in the brief stage before they undergo core collapse. Not only are they rare, but they also can be particularly difficult to find due to the high extinction in the Galactic plane. This paper…

We summarize past and current surveys for Wolf-Rayet stars among the Local Group galaxies, emphasizing both the how and the why. Such studies are invaluable for helping us learn about massive star evolution, and for providing sensitive…

Massive Wolf-Rayet (WR) stars comprise a spectroscopic class characterized by high temperatures (Teff > ~30 kK) and powerful and rapid stellar winds. Hydrogen-rich WR stars represent the most massive stars in existence (M > ~100 Msun),…

% context About 2500 planetary nebulae are known in our Galaxy but only 224 have central stars with reported spectral types in the Strasbourg-ESO Catalogue of Galactic Planetary Nebulae (Acker et al. 1992; Acker et al. 1996) % aims We have…