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Related papers: IC 4663: The first unambiguous [WN] Wolf-Rayet cen…

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We present a multi-wavelength characterisation of the planetary nebula (PN) NGC 6905 and its [Wolf-Rayet]-type ([WR]) central star (CSPN) HD 193949. Our Nordic Optical Telescope (NOT) Alhambra Faint Object Spectrograph and Camera (ALFOSC)…

Solar and Stellar Astrophysics · Physics 2021-11-03 V. M. A. Gómez-González , G. Rubio , J. A. Toalá , M. A. Guerrero , L. Sabin , H. Todt , V. Gómez-Llanos , G. Ramos-Larios , Y. D. Mayya

Classical Wolf-Rayet (WR) stars are hot, massive stars with depleted hydrogen. At low metallicities (Z), WN3-type WR stars have relatively thin winds and are major sources of ionizing flux. The detection of high-ionization emission lines in…

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 report the first-ever discovery of a Wolf-Rayet (WR) star in the Large Magellanic Cloud via detection of a circular shell with the Spitzer Space Telescope. Follow-up observations with Gemini-South resolved the central star of the shell…

Solar and Stellar Astrophysics · Physics 2015-06-19 V. V. Gvaramadze , A. -N. Chene , A. Y. Kniazev , O. Schnurr , T. Shenar , A. Sander , R. Hainich , N. Langer , W. -R. Hamann , Y. -H. Chu , R. A. Gruendl

Near infrared spectroscopy and photometry of the Wolf-Rayet Star WR 143 (HD 195177) were obtained in the $JHK$ photometric bands. High resolution spectra observed in the J and H bands exhibit narrow 1.083-micron He I line and the H I Pa…

Astrophysics · Physics 2015-06-24 Watson P. Varricatt , Nagarhalli M. Ashok

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…

Solar and Stellar Astrophysics · Physics 2017-05-31 Kathryn F. Neugent , Philip Massey , D. John Hillier , Nidia I. Morrell

We addressed the physical and kinematical properties of Wolf -- Rayet [WR] central stars (CSs) and their hosting planetary nebulae (PNe). The studied sample comprises all [WR] CSs that are currently known. The analysis is based on recent…

Solar and Stellar Astrophysics · Physics 2023-05-26 Zainab Awad , Alaa Ali

Aims: Following our comprehensive studies of the WR stars in the Milky Way, we now present spectroscopic analyses of almost all known WN stars in the LMC. Methods: For the quantitative analysis of the wind-dominated emission-line spectra,…

Solar and Stellar Astrophysics · Physics 2014-05-14 R. Hainich , U. Rühling , H. Todt , L. M. Oskinova , A. Liermann , G. Gräfener , C. Foellmi , O. Schnurr , W. -R. Hamann

In a search for new Galactic planetary nebulae from our systematic scans of the Anglo-Australian Observatory/United Kingdom Schmidt Telescope (AAO/UKST) Halpha survey of the Southern Galactic Plane, we have identified a Pop I Wolf-Rayet…

Astrophysics · Physics 2011-03-10 Martin Cohen , Quentin A. Parker , Anne J. Green

Three decades of searches have revealed 154 Wolf-Rayet (WR) stars in M31, with 62 of WC type, 92 of WN type and zero of transition type WN/C or WC/N. In apparent contrast, about two percent of the WR stars in the Galaxy, the LMC and M33…

Solar and Stellar Astrophysics · Physics 2015-12-09 Michael M. Shara , Joanna Mikolajewska , Nelson Caldwell , Krystian Ilkiewicz , Katarzyna Drozd , David Zurek

We present a homogeneous set of spectroscopic measurements secured with 4-meter class telescopes for a sample of 90 planetary nebulae (PNe) located in the direction of the Galactic bulge. We derive their plasma parameters and chemical…

Solar and Stellar Astrophysics · Physics 2015-05-13 S. K. Gorny , C. Chiappini , G. Stasinska , F. Cuisinier

This work aims to disentangle the morphological, kinematic, and chemical components of the nebula M1-67 to shed light on its process of formation around the central Wolf-Rayet (WR) star WR124. We have carried out integral field spectroscopy…

We report the serendipitous discovery of a ring nebula around a candidate Wolf-Rayet (WR) star, HBHA 4202-22, in Cygnus using the Spitzer Space Telescope archival data. Our spectroscopic follow-up observations confirmed the WR nature of…

The stellar properties of Sk41 (AB4, WN5h), the only known single Wolf-Rayet star in the SMC, are derived from ultraviolet (IUE), optical (AAT) and near-IR (NTT) spectroscopy. Contrary to expectations, the stellar properties of Sk41 are…

Astrophysics · Physics 2007-05-23 Paul A. Crowther

[WC]-type CSPNs are hydrogen-deficient Central Stars of Planetary Nebulae showing strong stellar winds and a carbon-rich chemistry. We have analyzed new high-resolution spectra of [WC]-type CSPNs with the Potsdam Wolf-Rayet (PoWR) non-LTE…

Astrophysics · Physics 2007-12-21 H. Todt , M. Peña , W. -R. Hamann , G. Gräfener

We present narrow band AAO/UKST HAlpha images and medium and low resolution optical spectra of a nebula shell putatively associated with the Wolf-Rayet star WR 60. We also present the first identification of this shell in the radio regime…

Astrophysics of Galaxies · Physics 2015-05-18 M. Stupar , Q. A. Parker , M. D. Filipovic

We have conducted a detailed multi-wavelength study of the peculiar nebula Abell 48 and its central star. We classify the nucleus as a helium-rich, hydrogen-deficient star of type [WN4-5]. The evidence for either a massive WN or a low-mass…

Solar and Stellar Astrophysics · Physics 2015-12-09 David J. Frew , Ivan S. Bojicic , Q. A. Parker , M. Stupar , S. Wachter , K. DePew , A. Danehkar , M. T. Fitzgerald , D. Douchin

The SMC harbours a class of hot nitrogen-sequence Wolf-Rayet stars (WNE) that display only relatively weak broad emission lines. This indicates low mass-loss rates and makes them also hard to detect. However, such stars are possible…

Astrophysics of Galaxies · Physics 2009-11-13 Manfred W. Pakull

We present a study of the peculiar Galactic emission line object NaSt1 (WR122, IRAS 18497+0056) which has previously been classified as a Wolf-Rayet (WR) star. Our spectroscopic dataset comprises Keck I-HIRES, WHT-ISIS and UKIRT-CGS4…

Astrophysics · Physics 2009-10-31 Paul A. Crowther , Linda J. Smith

Aims: We investigate the massive stellar content of the nearby dwarf irregular Wolf-Rayet galaxy IC 4662, and consider its global star forming properties in the context of other metal-poor galaxies, the SMC, IC 10 and NGC 1569. Methods:…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 P. A. Crowther , J. L. Bibby