Related papers: Pinwheel nebula around WR 98a

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 (WR102d, WR102i, WR102hb, and WR102ea) are of spectral subtype…

The WN3/O3 Wolf-Rayet (WR) stars were discovered as part of our survey for WRs in the Magellanic Clouds. The WN3/O3s show the emission lines of a high-excitation WN star and the absorption lines of a hot O-type star, but our prior work has…

We discuss our most recent findings on the diffuse X-ray emission from Wolf-Rayet (WR) nebulae. The best-quality X-ray observations of these objects are those performed by XMM-Newton and Chandra towards S308, NGC2359, and NGC6888. Even…

We present new near-infrared (JHK) bispectrum speckle-interferometry monitoring of the carbon star IRC+10216 obtained between 1999 and 2001 with the SAO 6m telescope. The J-, H-, and K-band resolutions are 50mas, 56mas, and 73mas, resp. The…

We present first results of an experiment to combine data from Keck aperture masking and the Infrared-Optical Telescope Array (IOTA) to image the circumstellar environments of evolved stars with ~20 milliarcsecond resolution. The unique…

IC 10 X-1 is an eclipsing high mass X-ray binary (HMXB) containing a stellar-mass black hole (BH) and a Wolf-Rayet (WR) donor star with an orbital period of P = 34.9 hr. This binary belongs to a group of systems that can be the progenitors…

We study the evolution of the interstellar and circumstellar media around massive stars (M > 40M_{\odot}) from the main sequence through to the Wolf-Rayet stage by means of radiationhydrodynamic simulations. We use publicly available…

We investigate the morphology of the collision front between the stellar winds of binary components in two long-period binary systems, one consisting of a hydrogen rich Wolf-Rayet star (WNL) and an O-star and the other of a Luminous Blue…

Context: Nonthermal radio emission in massive stars is expected to arise in wind-wind collisions occurring inside a binary system. One such case, the O-type star Cyg OB2 #9, was proven to be a binary only four years ago, but the orbital…

We present a characterization of the dust in the Wolf-Rayet (WR) nebula RCW 58 around the WN8h star WR 40 using archival infrared (IR) observations from WISE and Herschel and radio observations from ATCA. We selected two clumps, free from…

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…

The recently discovered colliding-wind binary (CWB) Apep has been shown to emit luminously from radio to X-rays, with the emission driven by a binary composed of two Wolf-Rayet (WR) stars of one carbon-sequence (WC8) and one…

HDE228766 is a very massive binary system hosting a secondary component, which is probably in an intermediate evolutionary stage between an Of supergiant and an WN star. The wind of this star collides with the wind of its O8 II companion,…

Theory surrounding the origin of the dust-laden winds from evolved stars remains mired in controversy. Characterizing the formation loci and the dust distribution within approximately the first stellar radius above the surface is crucial…

We have discovered a detached pair of white dwarfs (WDs) with a 12.75 min orbital period and a 1,315 km/s radial velocity amplitude. We measure the full orbital parameters of the system using its light curve, which shows ellipsoidal…

We continue our numerical analysis of the morphological and energetic influence of massive stars on their ambient interstellar medium for a 35 solar mass star that evolves from the main sequence through red supergiant and Wolf-Rayet phases,…

Mid-infrared photometry of the Wolf-Rayet star HD 38030 in the Large Magellanic Cloud from the NEOWISE-R mission show it to have undergone a dust-formation episode in 2018 and the dust to have cooled in 2019-20. New spectroscopy with the…

Accurately quantifying the rates dM/dt at which massive stars lose mass is essential to any understanding of their evolution. All dM/dt estimates to date assume wind clumping factors; not allowing for clumping leads to overestimates of…

Massive stars that become stripped of their hydrogen envelope through binary interaction or winds can be observed either as Wolf-Rayet stars, if they have optically thick winds, or as transparent-wind stripped-envelope stars. We approximate…

Most massive stars reside in multiple systems that will interact over the course of their lifetime. Classical Wolf-Rayet (WR) stars represent the final end stages of stellar evolution at the upper-mass end. As part of a homogeneous,…