Related papers: EWOCS-V: Is Wd1-72 a recent post-interaction WR+O …
BAT99 126 is a multiple system in the Large Magellanic Cloud containing a Wolf-Rayet (WR) star, which has a reported spectroscopic (orbital) period of 25.5 days and a photometric (orbital) period of 1.55 days, and hence is potentially one…
Context. Oxygen sequence Wolf-Rayet (WO) stars represent a very rare stage in the evolution of massive stars. Their spectra show strong emission lines of helium-burning products, in particular highly ionized carbon and oxygen. The…
Since close WR+O binaries are the result of a strong interaction of both stars in massive close binary systems, they can be used to constrain the highly uncertain mass and angular momentum budget during the major mass transfer phase. We…
Examination of the temporal variability properties of several strong optical recombination lines in a large sample of Galactic Wolf-Rayet (WR) stars reveals possible trends, especially in the more homogeneous WC than the diverse WN…
We present the first visual orbit for the nitrogen-rich Wolf-Rayet binary, WR 133 (WN5o + O9I) based on observations made with the CHARA Array and the MIRC-X combiner. This orbit represents the first visual orbit for a WN star and only the…
Understanding the evolution of massive binary stars requires accurate estimates of their masses. This understanding is critically important because massive star evolution can potentially lead to gravitational wave sources such as binary…
Context. Massive-binary evolution models predict that some systems will go through an evolutionary phase where the original primary has become a supernova and left a compact object behind that then orbits a Wolf-Rayet (hereafter, WR) star.…
White dwarfs (WDs) are the stellar core remnants of low mass stars. They are typically divided into three main composition groups: Oxygen Neon (ONe), Carbon Oxygen (CO) and Helium (He) WDs. The evolution of binary systems can significantly…
The Wolf-Rayet (WR) binary system WR140 is a close (0.9-16.7 mas) binary star consisting of an O5 primary and WC7 companion and is known as the archetype of episodic dust-producing WRs. Dust in WR binaries is known to form in a confined…
We present high-resolution infrared (2--18 micron) images of the archetypal periodic dust-making Wolf-Rayet binary system WR140 (HD 193793) taken between 2001 and 2005, and multi-colour (J -- [19.5]) photometry observed between 1989 and…
BAT99-129 is a rare, short-period eclipsing Wolf-Rayet binary in the Large Magellanic Cloud. We present here medium-resolution NTT/EMMI spectra that allow us to disentangle the spectra of the two components and find the orbital parameters…
Wolf-Rayet stars are amongst the rarest but also most intriguing massive stars. Their extreme stellar winds induce famous multi-wavelength circumstellar gas nebulae of various morphologies, spanning from circles and rings to bipolar shapes.…
Context: Comprehensive studies of Wolf-Rayet stars were performed in the past for the Galactic and the LMC population. The results revealed significant differences, but also unexpected similarities between the WR populations of these…
Classical Wolf-Rayet (WR) stars are massive, hydrogen depleted, post main-sequence stars that exhibit emission-line dominated spectra. For a given metallicity Z, stars exceeding a certain initial mass M_single(Z) can reach the WR phase…
Infrared imaging of the colliding-wind binary Apep has revealed a spectacular dust plume with complicated internal dynamics that challenges standard colliding-wind binary physics. Such challenges can be potentially resolved if a…
Our dedicated XMM-Newton monitoring, as well as archival Chandra and Swift datasets, were used to examine the behaviour of the WN5h+O3V binary WR21a at high energies. For most of the orbit, the X-ray emission exhibits few variations.…
Wolf-Rayet (WR) stars are luminous massive blue stars thought to be immediate precursors to the supernova terminating their brief lives. The existence of dust shells around such stars has been enigmatic since their discovery some 30 years…
We investigate Wolf-Rayet (WR) stars as a source of feedback contributing to the removal of natal material in the early evolution of massive star clusters. Despite previous work suggesting that massive star clusters clear out their natal…
Context. Very massive clusters and regions of intense star formation such as the center of our Milky Way contain young, hydrogen-burning stars very close to the Eddington Limit. Formally classified as hydrogen-rich Wolf-Rayet stars, the…
The Wolf-Rayet nebula M1-67 around WR124 is located above the Galactic plane in a region mostly empty of interstellar medium, which makes it the perfect target to study the mass-loss episodes associated with the late stages of massive star…