On the Role of the WNH Phase in the Evolution of Very Massive Stars: Enabling the LBV Instability with Feedback
@article{Smith2008OnTR, title={On the Role of the WNH Phase in the Evolution of Very Massive Stars: Enabling the LBV Instability with Feedback}, author={Nathan Smith and Peter S. Conti}, journal={The Astrophysical Journal}, year={2008}, volume={679}, pages={1467 - 1477} }
We propose the new designation “WNH” for luminous Wolf-Rayet (WR) stars of the nitrogen sequence with hydrogen in their spectra. These have been commonly referred to as WNL stars (WN7h, for example), but this new shorthand avoids confusion because there are late-type WN stars without hydrogen and early-type WN stars with hydrogen. Clearly differentiating WNH stars from H-poor WN stars is critical when discussing them as potential progenitors of Type Ib/c supernovae and gamma-ray bursts—the…
68 Citations
The Quintuplet cluster - II. Analysis of the WN stars
- Physics
- 2010
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 (WR 102d, WR 102i, WR…
Do Wolf-Rayet stars have similar locations in hosts as type Ib/c supernovae and long gamma-ray bursts?
- Physics
- 2010
Aims: We study the distribution of Wolf-Rayet (WR) stars and their subtypes with respect to their host galaxy light distribution. We thus want to investigate whether WR stars are potential…
Two extremely luminous WN stars in the Galactic center with circumstellar emission from dust and gas
- Physics
- 2008
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A Galactic O2 If*/WN6 star possibly ejected from its birthplace in NGC 3603
- Physics
- 2012
In this work we report the discovery of a new Galactic O2 If ∗ /WN6 star, a rare member of the extremely massive hydrogen core-burning group of stars that, because of their high intrinsic luminosity…
Luminous blue variables are antisocial: their isolation implies that they are kicked mass gainers in binary evolution
- Physics
- 2015
Based on their relatively isolated environments, we argue that LBVs must be primarily the product of binary evolution, challenging the traditional single-star view wherein LBVs mark a brief…
The Galactic hybrid Wolf-Rayet WN 7o/CE + O7V((f)) binary system WR 145
- Physics
- 2009
A spectroscopic study of the binary Wolf-Rayet (WR)+O system WR 145 is performed, in order to determine the radial velocity orbits of the individual stars, the angle of orbital inclination and the…
Properties of Wolf-Rayet Stars
- PhysicsProceedings of the International Astronomical Union
- 2007
Abstract A review of recent progress relating to Wolf-Rayet (WR) stars is presented. Topics include improved Milky Way statistics from near-IR surveys, different flavours of hydrogen-rich and…
A new and unusual LBV-like outburst from a Wolf–Rayet star in the outskirts of M33
- PhysicsMonthly Notices of the Royal Astronomical Society
- 2020
MCA-1B (also called UIT003) is a luminous hot star in the western outskirts of M33, classified over 20 yr ago with a spectral type of Ofpe/WN9 and identified then as a candidate luminous blue…
Core-collapse supernova progenitor constraints using the spatial distributions of massive stars in local galaxies
- Physics
- 2016
We study the spatial correlations between the H$\alpha$ emission and different types of massive stars in two local galaxies, the Large Magellanic Cloud (LMC) and Messier 33. We compare these to…
Two O2 If*/WN6 stars possibly ejected from the massive young Galactic cluster Westerlund 2
- Physics
- 2011
In this paper we report the identification of two new Galactic O2If*/WN6 stars (WR20aa and WR20c),ontheoutskirtsofthemassiveyoungstellarclusterWesterlund2.Themorphological similarity between the…
References
SHOWING 1-10 OF 70 REFERENCES
Hydrogen in the atmosphere of the evolved WN3 Wolf–Rayet star WR 3: defying an evolutionary paradigm?
- Physics
- 2004
WR 3 is the brightest very early-type WN star in the sky. Based on several years of timeresolved spectroscopy and precision photometry on various time-scales, we deduce that WR 3 is most likely a…
Star Formation in R136: A Cluster of O3 Stars Revealed by Hubble Space Telescope Spectroscopy
- Physics
- 1998
The R136 cluster in 30 Doradus is the prototype "super star cluster," and the only example sufficiently close that its massive star content can be studied directly. We have used the Hubble Space…
On the Role of Continuum-driven Eruptions in the Evolution of Very Massive Stars and Population III Stars
- Physics
- 2006
We suggest that the mass lost during the evolution of very massive stars may be dominated by optically thick, continuum-driven outbursts or explosions, instead of by steady line-driven winds. In…
On the Evolutionary Phase and Mass Loss of the Wolf-Rayet-like Stars in R136a
- Physics
- 1997
We report on a systematic study of the most massive stars, in which we analyzed the spectra of four very luminous stars in the Large Magellanic Cloud. The stars lie in the 30 Doradus complex, three…
Quantitative spectroscopy of Wolf—Rayet stars in HD 97950 and R136a — the cores of giant H ii regions
- Physics
- 1998
We present quantitative analyses of Wolf–Rayet stars in the cores of two giant H ii regions — HD 97950 in NGC 3603 and R136a in 30 Doradus — based on archive Hubble Space Telescope (HST)…
Wolf—Rayet binaries in the Magellanic Clouds and implications for massive-star evolution — I. Small Magellanic Cloud
- Physics
- 2003
We have carried out an intensive spectroscopic campaign to search for binaries via periodic radial velocity (RV) variations among all the nitrogen-rich WN Wolf‐Rayet (WR) stars in the Small…
The spectrum of the very massive binary system WR 20a (WN6ha + WN6ha): Fundamental parameters and wind interactions
- Physics
- 2005
We analyse the optical spectrum of the very massive binary system WR 20a (WN6ha + WN6ha). The most prominent emission lines, Hα and He λ 4686, display strong phase-locked profile variability. From…
Implications of the metallicity dependence of Wolf-Rayet winds
- Physics
- 2006
Aims. Recent theoretical predictions for the winds of Wolf-Rayet stars indicate that their mass-loss rates scale with the initial stellar metallicity in the local Universe. We aim to investigate how…
Lower mass loss rates in O-type stars: Spectral signatures of dense clumps in the wind of two Galactic O4 stars
- Physics
- 2004
We have analyzed the far-ultraviolet spectrum of two Galactic O4 stars, the O4If+ supergiant HD 190429A and the O4V((f)) dwarf HD 96715, using archival FUSE and IUE data. We have conducted a…
Observational and Evolutionary Aspects of Wolf-Rayet Stars
- Physics
- 1980
Many authorities proclaimed that all WR stars are members of close binary systems with OB type companions (see e.g. I.A.U. Symp.n°43). Arguing that fainter stars were less well studied Kuhi (1973)…