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The Galactic WC stars Stellar parameters from spectral analyses indicate a new evolutionary sequence
[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 theExpand
Early Magnetic B-Type Stars: X-ray Emission and Wind Properties
We present a comprehensive study of X-ray emission and wind properties of massive magnetic early B-type stars. Dedicated XMM-Newtonobservations were obtained for three early type B-type stars, ξ 1Expand
The Wolf-Rayet stars in the Large Magellanic Cloud - A comprehensive analysis of the WN class
Context. Massive stars, although being important building blocks of galaxies, are still not fully understood. This especially holds true for Wolf-Rayet (WR) stars with their strong mass loss, whoseExpand
The Galactic WN stars revisited. Impact of Gaia distances on fundamental stellar parameters
Comprehensive spectral analyses of the Galactic Wolf-Rayet stars of the nitrogen sequence (i.e.\ the WN subclass) have been performed in a previous paper. However, the distances of these objects wereExpand
The Quintuplet cluster - II. Analysis of the WN stars
Based on K-band integral-field spectroscopy, we analyze four Wolf-Rayet stars of the nitrogen sequence (WN) found in the inner part of the Quintuplet cluster. All WN stars (WR 102d, WR 102i, WRExpand
The Galactic WC and WO stars: The impact of revised distances from Gaia DR2 and their role as massive black hole progenitors
Wolf-Rayet stars of the carbon sequence (WC stars) are an important cornerstone in the late evolution of massive stars before their core collapse. As core-helium burning, hydrogen-free objects withExpand
On the Weak-wind Problem in Massive Stars: X-Ray Spectra Reveal a Massive Hot Wind in μ Columbae
United States. National Aeronautics and Space Administration (Chandra X-ray Observatory (U.S.) Award GO1-12017B)
Wolf-Rayet stars in the Small Magellanic Cloud: II. Analysis of the binaries
Massive WR stars are evolved massive stars characterized by strong mass-loss. Hypothetically, they can form either as single stars or as mass donors in close binaries. About 40% of the known WR starsExpand
Wolf-Rayet stars in the Small Magellanic Cloud: I. Analysis of the single WN stars
Wolf-Rayet (WR) stars have a severe impact on their environments owing to their strong ionizing radiation fields and powerful stellar winds. Since these winds are considered to be driven by radiationExpand
The central star of the planetary nebula PB 8: a Wolf-Rayet-type wind of an unusual WN/WC chemical composition
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 majorityExpand