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Related papers: Wolf-Rayet stars probed by AMBER/VLTI

200 papers

Massive, early type stars have been detected as radio sources for many decades. Their thermal winds radiate free-free continuum and in binary systems hosting a colliding-wind region, non-thermal emission has also been detected. To date, the…

Solar and Stellar Astrophysics · Physics 2020-07-22 Paula Benaglia , Michäel De Becker , C. H. Ishwara-Chandra , Huib Intema , Natacha L. Isequilla

We investigate the spatial distribution of chemical abundances in a sample of low metallicity Wolf-Rayet (WR) galaxies selected from the SDSS. We used the integral field spectroscopy technique in the optical spectral range (3700-6850 AA)…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Enrique Perez-Montero , Carolina Kehrig , Jarle Brinchmann , Jose M. Vilchez , Daniel Kunth , Florence Durret

The mass-loss rates of massive helium stars are one of the major uncertainties in modern astrophysics. Regardless of whether they were stripped by a binary companion or managed to peel off their outer layers by themselves, the influence and…

Solar and Stellar Astrophysics · Physics 2020-10-21 Andreas A. C. Sander , Jorick S. Vink

Early-type Wolf-Rayet(WR) stellar models harbor a super-Eddington layer in their outer envelopes due to a prominent iron opacity bump. In the past few decades, one-dimensional hydrostatic and time-steady hydrodynamic models have suggested a…

Solar and Stellar Astrophysics · Physics 2019-04-04 Stephen Ro

We present the analysis of the optical variability of the early, nitrogen-rich Wolf-Rayet (WR) star WR7. The analysis of multi-sector Transiting Exoplanet Survey Satellite (TESS) light curves and high-resolution spectroscopic observations…

Solar and Stellar Astrophysics · Physics 2022-06-08 J. A. Toalá , D. Bowman , T. Van Reeth , H. Todt , K. Dsilva , T. Shenar , G. Koenigsberger , S. Estrada-Dorado , L. M. Oskinova , W. -R. Hamann

Wolf-Rayet (WR) stars, as they are advanced stages of the life of massive stars, provide a good test for various physical processes involved in the modelling of massive stars, such as rotation and mass loss. In this paper, we show the…

Solar and Stellar Astrophysics · Physics 2015-08-20 Cyril Georgy , Sylvia Ekström , Raphael Hirschi , Georges Meynet , José Groh , Patrick Eggenberger

While the search for exoplanets around main sequence stars more massive than the Sun have found relatively few such objects, surveys performed around giant stars have led to the discovery of more than 30 new exoplanets. The interest in…

Solar and Stellar Astrophysics · Physics 2015-06-03 F. Cusano , C. Paladini , A. Richichi , E. W. Guenther , B. Aringer , K. Biazzo , R. Molinaro , L. Pasquini , A. P. Hatzes

We measure transverse proper motion velocities of LMC Wolf-Rayet (WR) stars using Gaia DR3 astrometry. The combined velocity distribution of WNh, O If*/WN, and WNL very massive stars ($>100\ M_\odot$; VMS) shows both slow, unejected objects…

Solar and Stellar Astrophysics · Physics 2026-05-19 Caden Burkhardt , Fiona Han , M. S. Oey , Natalia Ivanova , Mathieu Renzo

Wolf-Rayet (WR) stars in the Magellanic Clouds (MCs) are ideal for studying the production of X-ray emission by their strong fast stellar winds. We have started a systematic survey for X-ray emission from WR stars in the MCs using archival…

Astrophysics · Physics 2009-11-13 Martin A. Guerrero , You-Hua Chu

Analyzing the spectra from Wolf-Rayet stars requires adequate non-LTE modeling of their expanding atmosphere. The numerical schemes for solving the radiative transfer in the co-moving frame of reference have been developed by Mihalas and…

Solar and Stellar Astrophysics · Physics 2014-11-20 W. -R. Hamann , G. Graefener , L. M. Oskinova , A. Feldmeier

Wolf-Rayet stars are advanced evolutionary stages of massive stars. Despite their large mass-loss rates and high wind velocities, none of them display a bow shock, although a fraction of them are classified as runaway. Our 2.5-D numerical…

Solar and Stellar Astrophysics · Physics 2020-07-22 D. M. -A. Meyer , L. M. Oskinova , M. Pohl , M. Petrov

We report the discovery of a starburst-driven wind (superwind) from the starburst nucleus galaxy Mrk 1259. The estimated number ratio of Wolf-Rayet (WR) to O stars amounts to ~0.09. While the nuclear emission-line region is due to usual…

Astrophysics · Physics 2009-10-30 Y. Ohyama , Y. Taniguchi , R. Terlevich

We report the discovery of a new Wolf-Rayet star in the direction of Cygnus. The star is strongly reddened but quite bright in the infrared, with J = 9.22, H = 8.08 and K = 7.09 (2MASS). On the basis of its H + K spectrum, we have…

Astrophysics · Physics 2009-11-07 A. Pasquali , F. Comeron , R. Gredel , J. Torra , F. Figueras

We attempt to determine the driver for clumping in hot-star winds by extending the measure of the spectral variability level of Galactic Wolf-Rayet stars to by far the hottest known among them, the WN2 star WR 2 and the WO2 stars WR 102 and…

Solar and Stellar Astrophysics · Physics 2020-11-18 André-Nicolas Chené , Nicole St-Louis , Anthony F. J. Moffat , Kenneth G. Gayley

Among different types of massive stars in advanced evolutionary stages is the enigmatic WN8h type. There are only a few Wolf-Rayet (WR) stars with this spectral type in our Galaxy. It has long been suggested that WN8h-type stars are the…

High Energy Astrophysical Phenomena · Physics 2018-12-12 J. A. Toala , L. M. Oskinova , W. -R. Hamann , R. Ignace , A. A. C. Sander , T. Shenar , H. Todt , Y. -H. Chu , M. A. Guerrero , R. Hainich , J. M. Torrejon

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…

Much of the carbonaceous dust observed in the early universe may originate from colliding wind binaries (CWBs) hosting hot, luminous Wolf-Rayet (WR) stars. Downstream of the shock between the stellar winds there exists a suitable…

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…

Solar and Stellar Astrophysics · Physics 2015-05-28 J. A. Toalá , S. J. Arthur

Massive Wolf-Rayet (WR) stars dominate the radiative and mechanical energy budget of galaxies and probe a critical phase in the evolution of massive stars prior to core-collapse. It is not known whether core He-burning WR stars (classical…

The late evolutionary stages of stellar evolution are a key ingredient for our understanding in many fields of astrophysics, including stellar evolution and the enrichment of the interstellar medium (ISM) via stellar yields. Already the…

Solar and Stellar Astrophysics · Physics 2016-12-14 C. Paladini