Related papers: A WC/WO star exploding within an expanding carbon-…

Analyses of supernovae (SNe) have revealed two main types of progenitors: exploding white dwarfs and collapsing massive stars. We present SN2002bj, which stands out as different from any SN reported to date. Its light curve rises and…

Recently, a soft black-body component was observed in the early X-ray afterglow of GRB 060218, which was interpreted as shock breakout from the thick wind of the progenitor Wolf-Rayet (WR) star of the underlying Type Ic SN 2006aj. In this…

We present new atmosphere models for Wolf-Rayet stars that include a self-consistent solution of the wind hydrodynamics. We demonstrate that the formation of optically thick WR winds can be explained by radiative driving on Fe line…

Here we examine 12 Galactic clusters and OB associations containing Wolf-Rayet stars (W-Rs) and/or Luminous Blue Variables (LBVs), in order to assess the progentor masses of these evolved massive stars. We find that in the Milky Way,…

The study of core-collapse supernova remnants (SNRs) presents a fascinating puzzle, with intricate morphologies and a non-uniform distribution of stellar debris. Particularly, young remnants (aged less than 5000 years) hold immense value as…

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…

Chemically homogeneously evolving stars have been proposed to account for several exotic phenomena, including gravitational-wave emissions and gamma-ray bursts. Here we study whether these stars can explain the metal-poor dwarf galaxy I…

Several supernova remnants and young neutron stars were recently discovered relatively high above the Galactic plane. One possibility is that they originate from runaway OB stars born in the Galactic disk. Understanding their origin will…

Supernovae (SNe) are thought to arise from two different physical processes. The cores of massive, short-lived stars undergo gravitational core collapse and typically eject a few solar masses during their explosion. These are thought to…

Supernova (SN) 2008D/XRT 080109 is considered to be the only direct detection of a shock breakout from a regular SN to date. While a breakout interpretation was favored by several papers, inconsistencies remain between the observations and…

Classical Wolf-Rayet stars are descendants of massive OB-type stars that have lost their hydrogen-rich envelopes, and are in the final stages of stellar evolution, possibly exploding as type Ib/c supernovae. It is understood that 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…

[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…

We present multi-wavelength observations of SN2014C during the first 500 days. These observations represent the first solid detection of a young extragalactic stripped-envelope SN out to high-energy X-rays. SN2014C was the explosion of an…

There is observational evidence that supports the existence of Very Massive Stars in the local universe. First, very massive stars (Mini<=320 M) have been observed in the Large Magellanic Cloud . Second, there are observed SNe that bear the…

As part of a search for Wolf-Rayet (WR) stars in the Magellanic Clouds, we have discovered a new type of WR star in the Large Magellanic Cloud (LMC). These stars have both strong emission lines, as well as He ii and Balmer absorption lines…

We find that applying a theoretical wind mass-loss rate from Monte Carlo radiative transfer models for hydrogen-deficient stars results in significantly more leftover hydrogen following stable mass transfer through Roche-lobe overflow than…

We present mass-loss predictions from Monte Carlo radiative transfer models for helium (He) stars as a function of stellar mass, down to 2 Msun. Our study includes both massive Wolf-Rayet (WR) stars and low-mass He stars that have lost…

We compute the remaining amounts of hydrogen in red giant donors to see whether the conflict between theory and observations can be overcome. By considering the mass-stripping effect from an optically thick wind and the effect of thermally…

Neon abundances are derived in four Galactic WC stars -- gamma Vel (WR11, WC8+O7.5III), HD156385 (WR90, WC7), HD192103 (WR135, WC8), and WR146 (WC5+O8) - using mid-infrared fine structure lines obtained with ISO/SWS. Stellar parameters for…