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… Expand

Figures from this paper

Extreme isolation of WN3/O3 stars and implications for their evolutionary origin as the elusive stripped binaries
Recent surveys of the Magellanic Clouds have revealed a subtype of Wolf–Rayet (WR) star with peculiar properties. WN3/O3 spectra exhibit both WR-like emission and O3 V-like absorption – but at lowerExpand
The Quintuplet cluster - II. Analysis of the WN stars
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, WRExpand
The Galactic WC and WO stars: The impact of revised distances from Gaia DR2 and their role as massive black hole progenitors
Wolf-Rayet stars of the carbon sequence (WC stars) are an important cornerstone in the late evolution of massive stars before their core collapse. As core-helium burning, hydrogen-free objects withExpand
Do Wolf-Rayet stars have similar locations in hosts as type Ib/c supernovae and long gamma-ray bursts?
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 potentialExpand
Two extremely luminous WN stars in the Galactic center with circumstellar emission from dust and gas
Context. The central region of our Galaxy contains a large population of young massive stars. These stars are concentrated in three large star clusters, as well as being scattered in the field.Expand
A Galactic O2 If*/WN6 star possibly ejected from its birthplace in NGC 3603
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 luminosityExpand
Luminous blue variables are antisocial: their isolation implies that they are kicked mass gainers in binary evolution
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 briefExpand
The Galactic WC stars Stellar parameters from spectral analyses indicate a new evolutionary sequence
[Abridged] [...] AIMS: We aim to establish the stellar parameters and mass-loss rates of the Galactic WC stars. These data provide the empirical basis of studies of (i) the role of WC stars in theExpand
The Galactic hybrid Wolf-Rayet WN 7o/CE + O7V((f)) binary system WR 145
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 theExpand
Properties of Wolf-Rayet Stars
  • P. Crowther
  • Physics
  • Proceedings 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 andExpand
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 66 REFERENCES
Hydrogen in the atmosphere of the evolved WN3 Wolf–Rayet star WR 3: defying an evolutionary paradigm?
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 aExpand
Star Formation in R136: A Cluster of O3 Stars Revealed by Hubble Space Telescope Spectroscopy*
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 SpaceExpand
On the role of continuum-driven eruptions in the evolution of very massive stars and Population III stars
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. InExpand
On the Evolutionary Phase and Mass Loss of the Wolf-Rayet-like Stars in R136a*
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, threeExpand
Wolf—Rayet binaries in the Magellanic Clouds and implications for massive-star evolution — I. Small Magellanic Cloud
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 SmallExpand
Quantitative spectroscopy of Wolf—Rayet stars in HD 97950 and R136a — the cores of giant H ii regions
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)Expand
The spectrum of the very massive binary system WR 20a (WN6ha + WN6ha): Fundamental parameters and wind interactions
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. FromExpand
Observational and Evolutionary Aspects of Wolf-Rayet Stars
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)Expand
Implications of the metallicity dependence of Wolf-Rayet winds
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 howExpand
Lower mass loss rates in O-type stars: Spectral signatures of dense clumps in the wind of two Galactic O4 stars
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 aExpand
...
1
2
3
4
5
...