Results 81 to 90 of about 720,446 (211)

A constant upper luminosity limit of cool supergiant stars down to the extremely low metallicity of I Zw 18

Astronomy & Astrophysics
Stellar wind mass loss of massive stars is often assumed to depend on their metallicity Z. Therefore, evolutionary models predict that massive stars in lower-Z environments are able to retain more of their hydrogen-rich layers and evolve into brighter ...
Schootemeijer Abel, Götberg Ylva, Langer Norbert, Bortolini Giacomo, Hirschauer Alec S., Patrick Lee   +5 more
doaj   +1 more source

The Transport of Angular Momentum for Massive Stars. I. Formation of Slowly Rotating Early-type Nitrogen-sequence Wolf–Rayet Stars

The Astrophysical Journal
The evolutionary scenario of early-type nitrogen-sequence Wolf–Rayet (WNE) stars predicts a slowly rotating subclass that typically forms after the red supergiant phase.
Jijuan Si, Yan Li, Xue-Feng Li, Zhi Li
doaj   +1 more source

Wolf-Rayet central stars of planetary nebulae

, 2015
A significant number of the central stars of planetary nebulae (CSPNe) are hydrogen-deficient, showing a chemical composition of helium, carbon, and oxygen.
Todt, Helge Tobias (Dr.), Hamann, Wolf-Rainer (Prof. Dr.)   +1 more
core  

Deep Optical Images of the Ejecta Nebula around the Wolf–Rayet Star WR 8 (HD 62910)

The Astronomical Journal
We report the results of deep H α and [O iii ] images of the bright WN6/WC4 Wolf–Rayet (WR) star WR 8 (HD 62910). These data show considerably more surrounding nebulosity than seen in prior imaging. The brighter portions of the nebula span $\simeq {6}^{{\
Robert A. Fesen, Daniel Patnaude, Wei-Hao Wang, You-Hua Chu, Jason Sun, Manuel C. Peitsch, Martin Pugh, Scott Garrod, Michael Selby, Alex Woronow   +9 more
doaj   +1 more source

Ultraviolet classification of Wolf-Rayet stars [PDF]

Symposium - International Astronomical Union, 1995
The ultraviolet spectra of 94 WR stars obtained from Vilspa IUE archive are used here to look for classification criteria in the UV region alone. We have tried to select as many single and SB1 type stars as possible in the Galaxy and the LMC to get the complete, flux-calibrated spectra between 1150 and 3250 Å. Altogether 56 (34 of WN and 22 of WC type)
openaire   +1 more source

On the bipolarity of Wolf-Rayet nebulae

, 2021
Wolf-Rayet stars are amongst the rarest but also most intriguing massive stars. Their extreme stellar winds induce famous multiwavelength circumstellar gas nebulae of various morphologies, spanning from circles and rings to bipolar shapes.
Meyer, Dominique M.-A. (Dr. rer. nat.)
core   +1 more source

Chemical Abundance Ratios of Nitrogen-rich Galaxies Identified at z ∼ 6–12: Observational Demographics and Models

The Astrophysical Journal
We present chemical abundance ratios of eight nitrogen-rich ([N/O] > 0.3) galaxies at z  ∼ 6–12 identified by the first 4 yr of JWST observations, and compare these ratios with chemical evolution models.
Kuria Watanabe, Masami Ouchi, Kimihiko Nakajima, Nozomu Tominaga, Yuichi Harikane, Miho N. Ishigaki, Yuki Isobe, Minami Nakane, Moka Nishigaki, Ken’ichi Nomoto, Yoshiaki Ono, Masato Onodera, Akihiro Suzuki, Koh Takahashi, Yui Takeda, Hiroto Yanagisawa   +15 more
doaj   +1 more source

Rotation and Wolf-Rayet Star Formation [PDF]

International Astronomical Union Colloquium, 1999
AbstractNew results for 60 M⊙ stellar models with different rotation rates are presented. Some effects of rotation on Wolf-Rayet star formation are discussed.
openaire   +1 more source

A wind environment and Lorentz factors of tens explain gamma-ray bursts X-ray plateau. [PDF]

Nat Commun, 2022
Dereli-Bégué H, Pe'er A, Ryde F, Oates SR, Zhang B, Dainotti MG.   +5 more
europepmc   +1 more source

Atmospheric Diagnostics of Wolf-Rayet Stars [PDF]

International Astronomical Union Colloquium, 1988
Wolf-Rayet (WR) stars are the descendants of massive stars that have lost their hydrogen rich envelope. Recently more accurate data on WR stars have become available: mass-loss rates (van der Hucht et al. 1986), radii and luminosities (Underhill 1983, Nussbaumer et al.
openaire   +1 more source