Publications of Gregor Rauw
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See detailSearch for Interacting Winds in the WN7 + O Binary WR 22
Rauw, Grégor ULiege; Vreux, Jean-Marie ULiege; Gosset, Eric ULiege

in Revista Mexicana de Astronomia y Astrofisica Conference Series (1996, December 01)

We present new spectroscopic observations of the He I Lambda5876 line in WR22 which were obtained around periastron. These data show strong line profile variability. We use recently determined orbital ... [more ▼]

We present new spectroscopic observations of the He I Lambda5876 line in WR22 which were obtained around periastron. These data show strong line profile variability. We use recently determined orbital elements of WR22 to discuss the possibility of tidal interactions or of a colliding wind phenomenon affecting the outer parts of the Wolf-Rayet atmosphere. [less ▲]

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See detailExistence of a short period (3.5-4 hours) in the photometric variability of WR 66.
Rauw, Grégor ULiege; Gosset, Eric ULiege; Manfroid, Jean ULiege et al

in Astronomy and Astrophysics (1996), 306

We report here on an independent detection of a short period (~4hours) in the photometric variations of WR66, thus confirming in broad terms the discovery by Antokhin et al.. In addition, we present the ... [more ▼]

We report here on an independent detection of a short period (~4hours) in the photometric variations of WR66, thus confirming in broad terms the discovery by Antokhin et al.. In addition, we present the first spectroscopic variability analysis for this star. A few peculiarities of the spectrum of WR66 are also discussed. Finally, we perform a brief examination of different possible origins of the phenomenon. [less ▲]

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See detailWR22: the most massive Wolf-Rayet star ever weighed.
Rauw, Grégor ULiege; Vreux, Jean-Marie ULiege; Gosset, Eric ULiege et al

in Astronomy and Astrophysics (1996), 306

The results of an extensive spectroscopic campaign on the eclipsing binary WR22 are presented. A new radial velocity curve is deduced for the WN7 component, allowing us to improve the parameters of the ... [more ▼]

The results of an extensive spectroscopic campaign on the eclipsing binary WR22 are presented. A new radial velocity curve is deduced for the WN7 component, allowing us to improve the parameters of the orbit, formerly determined on the basis of photographic spectra. The high signal-to-noise ratio of our data also allows the detection of some weak absorption lines which, for the first time, can definitely be attributed to the companion. A study of their radial velocities gives a mass ratio of m_WR_/m_O_=2.78 leading to a minimum mass of 72M[SUB]sun[/SUB]_ for the WN7 star. The companion can be classified as a "late O" (O6.5-O8.5) star with a luminosity ratio of the system q=L_WR_^y^/L_O_^y^ at 5500A of about 8. The exceptionally high mass of the WN7 star and its high hydrogen mass-fraction suggest that WR22 is at the beginning of its Wolf-Rayet evolution. As a matter of fact, with such a high mass, WR22 most probably is still a hydrogen burning object. Therefore, the WN7 component is much closer to a main sequence O star with a "Wolf-Rayet clothing" than to the other members of the Wolf-Rayet family, which are rather highly evolved He-burning descendants of massive progenitors. [less ▲]

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See detailSpectropolarimetry of WR66
Lamy, H.; Hutsemekers, Damien ULiege; Rauw, Grégor ULiege

in Wolf-Rayet stars in the framework of stellar evolution ; 33rd Liege International Astrophysical Coll (1996)

We have carried out spectropolarimetric observations of the Wolf-Rayet star WR66 (WN8) with EFOSC1 mounted on the ESO 3.6m telescope of La Silla. The results indicate a polarization level of about 5 to 6 ... [more ▼]

We have carried out spectropolarimetric observations of the Wolf-Rayet star WR66 (WN8) with EFOSC1 mounted on the ESO 3.6m telescope of La Silla. The results indicate a polarization level of about 5 to 6 % in the continuum which is most probably due to interstellar polarization. [less ▲]

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See detailLine-profile variability and mass-transfer in the early type binary BD+40° 4220
Vreux, Jean-Marie ULiege; Rauw, Grégor ULiege; Bohannan, B. et al

in Liege International Astrophysical Colloquia (1996)

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See detailWolf-Rayet stars in the framework of stellar evolution.
Vreux, Jean-Marie ULiege; Detal, Alain ULiege; Fraipont-Caro, D. et al

Book (1996)

The following topics were dealt with: evolution of massive stars - theory; observational characteristics of Wolf-Rayet stars and related objects; evidences for evolutionary links - transition objects ... [more ▼]

The following topics were dealt with: evolution of massive stars - theory; observational characteristics of Wolf-Rayet stars and related objects; evidences for evolutionary links - transition objects; analysis of the observations - the models and their results; massive stars in starburst. [less ▲]

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See detailA new orbital solution for the WNL binary system WR12
Rauw, Grégor ULiege; Vreux, Jean-Marie ULiege; Gosset, Eric ULiege et al

in Liege International Astrophysical Colloquia (1996)

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See detailWR22 as a core hydrogen-burning Wolf-Rayet star
Rauw, Grégor ULiege; Vreux, Jean-Marie ULiege; Gosset, Eric ULiege et al

in Stellar evolution: what should be done; 32nd Liege International Astrophysical Coll. (1995)

The analysis of an extensive sample of high resolution spectra of the Wolf-Rayet binary WR22 recently allowed us to determine a minimum mass of 72 M_solar for the WN7 star. With such a high mass, WR22 is ... [more ▼]

The analysis of an extensive sample of high resolution spectra of the Wolf-Rayet binary WR22 recently allowed us to determine a minimum mass of 72 M_solar for the WN7 star. With such a high mass, WR22 is expected to be a core H-Burning star which has just evolved from a progenitor of at least 90-110 M_solar. [less ▲]

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See detailA seven year campaign on WR 22
Rauw, Grégor ULiege; Vreux, Jean-Marie ULiege; Gosset, Eric ULiege et al

in Wolf-Rayet Stars: Binaries; Colliding Winds; Evolution. International Astronomical Union. Symposium no. 163 (1995)

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See detailPhotometric monitoring of Wolf-Rayet stars: Strömgren uvby and narrow-band photometry
Gosset, Eric ULiege; Rauw, Grégor ULiege; Manfroid, Jean ULiege et al

in NATO ASIC Proc. 436: The Impact of Long-Term Monitoring on Variable Star Research: Astrophysics (1994)

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