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Related papers: A new Wolf-Rayet star in Cygnus

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The Cygnus OB2 Association contains some of the most luminous OB stars in our Galaxy, the brightest of which are also among the most luminous in X-rays. We have obtained a Chandra High Energy Transmission Grating Spectrometer (HETGS)…

Astrophysics · Physics 2009-11-10 W. L. Waldron , J. P. Cassinelli , N. A. Miller , J. J. MacFarlane , J. C. Reiter

We present the first radio--continuum detection of the circumstellar shell around the well-known WN8 type Wolf-Rayet star WR16 at 943.5\,MHz using the \ac{ASKAP} \ac{EMU} survey. At this frequency, the shell has a measured flux density of…

We report the detection of 7 new Wolf-Rayet (WR) star locations in M81 using the Multi-Object Spectrograph of the OSIRIS instrument at Gran Telescopio Canarias. These detections are the result of a follow-up of an earlier study using the…

Solar and Stellar Astrophysics · Physics 2020-02-19 V. M. A. Gómez-González , Y. D. Mayya , D. Rosa-González , L. H. Rodríguez-Merino , J. A. Toalá , C. Alvarez

We report the discovery of fifteen previously unknown Wolf-Rayet (WR) stars found as part of an infrared broad-band study of candidate WR stars in the Galaxy. We have derived an empirically-based selection algorithm which has selected ~5000…

Astrophysics · Physics 2008-11-26 L. J. Hadfield , S. D. Van Dyk , P. W. Morris , J. D. Smith , A. P. Marston , D. E. Peterson

Wolf-Rayet stars (WR) have been detected in the NW region of the metal-poor starburst galaxy IZw 18. The integrated luminosity and FWHM of the bumps at 4650 A and 5808 A are consistent with the presence of a few individual stars of WC4 or…

Astrophysics · Physics 2007-05-23 F. Legrand , D. Kunth , J. -R. Roy , J. M. Mas-Hesse , J. R. Walsh

Over the years, directed surveys and incidental spectroscopy have identified 12 Wolf-Rayet (WR) stars in the SMC and 139 in the LMC, numbers which are often described as "essentially} complete." Yet, new WRs are discovered in the LMC almost…

Solar and Stellar Astrophysics · Physics 2015-06-19 Philip Massey , Kathryn F. Neugent , Nidia Morrell , D. John Hillier

We summarize new X-ray detections of four nitrogen-type Wolf-Rayet (WR) stars obtained in a limited survey aimed at establishing the X-ray properties of WN stars across their full range of spectral subtypes. None of the detected stars is so…

Solar and Stellar Astrophysics · Physics 2015-05-14 S. L. Skinner , S. A. Zhekov , M. Guedel , W. Schmutz , K. R. Sokal

We are conducting a high angular resolution imaging survey of Galactic Wolf-Rayet stars using the Wide Field and Planetary Camera 2 aboard the Hubble Space Telescope. We have found a small stellar cluster associated with the faint, close…

We present results from the first attempts to derive various physical characteristics of the dusty Wolf-Rayet star WR 48a based on a multi-wavelength view of its observational properties. This is done on the basis of new optical and…

We report new results of a campaign to find Wolf-Rayet and O (WR/O) stars and high-mass X-ray binaries (HMXBs) in the Galactic center. We searched for candidates by cross-correlating the 2MASS catalog with a deep Chandra catalog of X-ray…

Astrophysics · Physics 2011-02-11 Jon C. Mauerhan , Michael P. Muno , Mark Morris

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…

Solar and Stellar Astrophysics · Physics 2010-11-29 A. Liermann , W. -R. Hamann , L. M. Oskinova , H. Todt , K. Butler

Context: The ESO Public Survey "VISTA Variables in the V\'ia L\'actea" (VVV) provides deep multi-epoch infrared observations for an unprecedented 562 sq. degrees of the Galactic bulge, and adjacent regions of the disk. In this survey nearly…

The massive interacting close binary system V729 Cyg (OIa+O/WN9), plausibly progenitor of a Wolf-Rayet system, is studied using new observations gathered over 65 nights and earlier published data. Radial velocity and five colour light…

Solar and Stellar Astrophysics · Physics 2015-06-18 B. Yasarsoy , K. Yakut

We report the discovery of 5 massive Wolf-Rayet (WR) stars resulting from a programme of follow-up spectroscopy of candidate emission line stars in the AAO/UKST Southern Galactic Plane H-alpha survey. The 6195-6775 angstrom spectra of the…

We use ultraviolet space-based (FUSE, HST) and optical/IR ground-based (2.3m MSSSO, NTT) spectroscopy to determine the physical parameters of six WC4-type Wolf-Rayet stars in the Large Magellanic Cloud. Stellar parameters are revised…

Astrophysics · Physics 2009-11-07 Paul A. Crowther , Luc Dessart , D. John Hillier , Jay B. Abbott , Alex W. Fullerton

We report the results of a survey of radio continuum emission of Galactic Wolf-Rayet stars north of declination -46 degrees. The observations were obtained at 8.46 GHz (3.6cm) using the Very Large Array (VLA), with an angular resolution of…

Astrophysics · Physics 2009-11-10 C. Cappa , W. M. Goss , K. A. van der Hucht

We report the discovery of two previously unknown WN3 stars in the Large Magellanic Cloud. Both are bright (15th magnitude), isolated, and located in regions covered in earlier surveys, although both are relatively weak-lined. We suggest…

Solar and Stellar Astrophysics · Physics 2015-06-05 Ian D. Howarth , Nolan R. Walborn

Wolf-Rayet stars are evolved massive stars, and the relative number of WC-type and WN-type WRs should vary with the metallicity of the host galaxy, providing a sensitive test of stellar evolutionary theory. However, past studies of the WR…

Solar and Stellar Astrophysics · Physics 2015-06-11 Kathryn F. Neugent , Philip Massey , Cyril Georgy

In this paper we derive stellar parameters for the Wolf-Rayet star in the gamma Velorum binary system (WR11), from a detailed non-LTE model of its optical and infrared spectra. Compared to the study of Schaerer et al., the parameters of the…

Two optically obscured Wolf-Rayet (WR) stars have been recently discovered by means of their infrared (IR) circumstellar shells, which show signatures of interaction with each other. Following the systematics of the WR star catalogues,…

Solar and Stellar Astrophysics · Physics 2012-12-18 Sonja Burgemeister , Vasilii V. Gvaramadze , Guy S. Stringfellow , Alexei Y. Kniazev , Helge Todt , Wolf-Rainer Hamann