Early-type stars in the young open cluster NGC 2244 and in the Monoceros OB2 association. I. The mul

  title={Early-type stars in the young open cluster NGC 2244 and in the Monoceros OB2 association. I. The mul},
  author={Laurent Mahy and Ya{\"e}l Naz{\'e} and Gregor Rauw and Eric Gosset and Micha{\"e}l De Becker and Hugues Sana and Philippe R. J. Eenens},
  journal={Astronomy and Astrophysics},
Aims. We present the results obtained from a long-term spectroscopic campaign devoted to the multiplicity of O-type stars in the young open cluster NGC 2244 and in the Mon OB2 association. Methods. Our spectroscopic monitoring was performed over several years, allowing us to probe different time-scales. For each star, several spectral diagnostic tools are applied, in order to s earch for line shifts and profile variations. We also measure the projected rotational velocity and revisit the… 
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