A Seven Year Campaign on WR22

Rauw, Grégor; Vreux, Jean-Marie; Gosset, Éric; Hutsemékers, Damien; Magain, Pierre; Manfroid, Jean; Rémy, M.; Rochowicz, K.

doi:10.1007/978-94-011-0205-6_54

Cited by 20 publications

(38 citation statements)

References 5 publications

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“…From the observed variability, Antokhin et al (1995) suggest the possibles existence of a compact companion spiraling in towards the WR star. In contrast, Rauw et al (1996b) favor the non-radial pulsation aspect as proposed for many WN8. We conclude that the evidence of close binarity is insufficient.…”

Section: Comments On Individual Starsmentioning

confidence: 92%

“…From the diluted O star absorption lines visible in the composite spectrum, Rauw et al (1996b) estimate that the O star companion contributes about 1/8 to the the flux in the visual. We ignore this contribution in our spectral analysis.…”

Section: Comments On Individual Starsmentioning

confidence: 95%

“…Our models can fit the SED and the line spectrum perfectly. WR 12 is classified as WN8h+?, based on radial velocity variations (Niemela 1982;Rauw et al 1996a) and the eclipse lightcurve (Lamontagne et al 1996) with a period of 23.9 d. However, no lines from the companion are seen (SB1). As our models reproduce the line spectrum and the SED (the latter with anomalous reddening), we assume that the spectrum is not contaminated, but the star might have evolved in a close binary system.…”

Section: Comments On Individual Starsmentioning

confidence: 99%

“…With this revised distance, WR 22 becomes very luminous. Simple application of the mass-luminosity relation for helium stars yields a stellar mass of 74 M , while from the binary orbit the mass of the WR component has been determined to 72 M (Rauw et al 1996b) or 55 M (Schweickhardt et al 1999). …”

Section: Comments On Individual Starsmentioning

confidence: 99%

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The Galactic WN stars

Hamann¹,

Gräfener²,

Liermann³

2006

A&A

347

578

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Context. Very massive stars pass through the Wolf-Rayet (WR) stage before they finally explode. Details of their evolution have not yet been safely established, and their physics are not well understood. Their spectral analysis requires adequate model atmospheres, which have been developed step by step during the past decades and account in their recent version for line blanketing by the millions of lines from iron and iron-group elements. However, only very few WN stars have been re-analyzed by means of line-blanketed models yet. Aims. The quantitative spectral analysis of a large sample of Galactic WN stars with the most advanced generation of model atmospheres should provide an empirical basis for various studies about the origin, evolution, and physics of the Wolf-Rayet stars and their powerful winds. Methods. We analyze a large sample of Galactic WN stars by means of the Potsdam Wolf-Rayet (PoWR) model atmospheres, which account for iron line blanketing and clumping. The results are compared with a synthetic population, generated from the Geneva tracks for massive star evolution. Results. We obtain a homogeneous set of stellar and atmospheric parameters for the Galactic WN stars, partly revising earlier results. Conclusions. Comparing the results of our spectral analyses of the Galactic WN stars with the predictions of the Geneva evolutionary calculations, we conclude that there is rough qualitative agreement. However, the quantitative discrepancies are still severe, and there is no preference for the tracks that account for the effects of rotation. It seems that the evolution of massive stars is still not satisfactorily understood.

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Section: Comments On Individual Starsmentioning

confidence: 92%

Section: Comments On Individual Starsmentioning

confidence: 95%

Section: Comments On Individual Starsmentioning

confidence: 99%

Section: Comments On Individual Starsmentioning

confidence: 99%

See 2 more Smart Citations

The Galactic WN stars

Hamann¹,

Gräfener²,

Liermann³

2006

A&A

347

578

View full text Add to dashboard Cite

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“…Rauw et al (1996) derived a minimum mass of 72 M for this star. Since the system displays atmospheric eclipses when the WNha star passes in front of its secondary (Gosset et al 1991), the orbital inclination is pretty close to 90…”

Section: What Are the Most Massive Stars Known To Date?mentioning

confidence: 94%

Massive binaries and colliding winds

Rauw

2004

EAS Publications Series

Self Cite

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Abstract. In this contribution, I review recent results from observational investigations of early-type binaries of spectral types O and WolfRayet. These studies aim at an accurate determination of fundamental parameters such as masses and radii of the most massive stars. In addition, multi-wavelength analyses of wind collisions in massive binaries provide constraints on the properties of stellar winds of massive stars and shock physics of cosmic plasmas.

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