Article (Scientific journals)
WR22: the most massive Wolf-Rayet star ever weighed.
Rauw, Grégor; Vreux, Jean-Marie; Gosset, Eric et al.
1996In Astronomy and Astrophysics, 306, p. 771-782
Peer Reviewed verified by ORBi
 

Files


Full Text
1996A+A...306..771R.pdf
Publisher postprint (1.82 MB)
Request a copy

All documents in ORBi are protected by a user license.

Send to



Details



Keywords :
STARS: INDIVIDUAL: WR22; STARS: WOLF-RAYET; BINARIES: SPECTROSCOPIC; BINARIES: ECLIPSING; STARS: FUNDAMENTAL PARAMETERS
Abstract :
[en] 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.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Rauw, Grégor  ;  Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Groupe d'astrophysique des hautes énergies (GAPHE) - Sciences spatiales
Vreux, Jean-Marie ;  Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO)
Gosset, Eric ;  Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Groupe d'astrophysique des hautes énergies (GAPHE)
Hutsemekers, Damien ;  Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astroph. extragalactique et observations spatiales (AEOS)
Magain, Pierre  ;  Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique et traitement de l'image
Rochowicz, K.
Language :
English
Title :
WR22: the most massive Wolf-Rayet star ever weighed.
Publication date :
01 February 1996
Journal title :
Astronomy and Astrophysics
ISSN :
0004-6361
eISSN :
1432-0746
Publisher :
EDP Sciences, Les Ulis, France
Volume :
306
Pages :
771-782
Peer reviewed :
Peer Reviewed verified by ORBi
Available on ORBi :
since 02 July 2009

Statistics


Number of views
71 (2 by ULiège)
Number of downloads
0 (0 by ULiège)

Bibliography


Similar publications



Contact ORBi