Spectroscopic study of the short-period WN5o + O8.5V binary system WR127 (HD 186943)
Combined with previous information (orbital period P= 9.5550 d and inclination ), new optical spectroscopic data lead to improved circular orbits for this WR + O system, with mass 13.4 M⊙ of the WN5o star and 23.9 M⊙ of its O8.5V companion. These are normal for their spectral types. The WR/O mass ra...
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Published in | Monthly notices of the Royal Astronomical Society Vol. 411; no. 1; pp. 635 - 643 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Oxford, UK
Blackwell Publishing Ltd
01.02.2011
Oxford University Press |
Subjects | |
Online Access | Get full text |
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Summary: | Combined with previous information (orbital period P= 9.5550 d and inclination
), new optical spectroscopic data lead to improved circular orbits for this WR + O system, with mass 13.4 M⊙ of the WN5o star and 23.9 M⊙ of its O8.5V companion. These are normal for their spectral types. The WR/O mass ratio, q≃ 0.56, is reasonable for such a binary. The relatively large orbital separation between the two components (∼63 R⊙) implies that there is currently no interaction between the two stars beyond their colliding winds. Analysis of the excess line emission and absorption arising in the wind-wind collision zone yields the following parameters: streaming velocity v
strm= 1104 km s−1, cone opening half-angle θ≃ 59° and Coriolis angle shift
. Using probable values of mass-loss rate and terminal wind velocity for each star, a value of θ≃ 37° is obtained. The difference in θ is likely due to a combination of uncertainty in these parameters and radiative braking. Altogether, WR127 is a normal, detached and non-photospherically eclipsing binary system, although it does show atmospheric 'eclipses'. |
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Bibliography: | ArticleID:MNR17710 istex:8E5884EDFF41165B0CEFE2E390D08DE7032FF956 ark:/67375/WNG-C8KGTLFC-X ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0035-8711 1365-2966 |
DOI: | 10.1111/j.1365-2966.2010.17710.x |