The massive star binary fraction in young open clusters – I. NGC 6231 revisited

@article{Sana2008TheMS,
  title={The massive star binary fraction in young open clusters – I. NGC 6231 revisited},
  author={Hugues Sana and Eric Gosset and Ya{\"e}l Naz{\'e} and Gregor Rauw and N. Linder},
  journal={Monthly Notices of the Royal Astronomical Society},
  year={2008},
  volume={386},
  pages={447-460}
}
We present the results of a long-term high-resolution spectroscopy campaign on the O-type stars in NGC 6231. We revise the spectral classification and multiplicity of these objects and we constrain the fundamental properties of the O-star population. Almost three quarters of the O-type stars in the cluster are members of a binary system. The minimum binary fraction is 0.63, with half the O-type binaries having an orbital period of the order of a few days. The eccentricities of all the short… 

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The multiplicity of massive stars

  • H. SanaC. Evans
  • Physics
    Proceedings of the International Astronomical Union
  • 2010
Abstract Binaries are excellent astrophysical laboratories that provide us with direct measurements of fundamental stellar parameters. Compared to single isolated stars, multiplicity induces new
...

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