Weighing Melnick 34: the most massive binary system known

  title={Weighing Melnick 34: the most massive binary system known},
  author={Katie Tehrani and Paul A. Crowther and Joachim M. Bestenlehner and Stuart P. Littlefair and Andrew M. T. Pollock and Richard J. Parker and Olivier Schnurr},
  journal={Monthly Notices of the Royal Astronomical Society},
Here we confirm Melnick 34, an X-ray bright star in the 30 Doradus region of the Large Magellanic Cloud, as an SB2 binary comprising WN5h+WN5h components. We present orbital solutions using 26 epochs of VLT/UVES spectra and 22 epochs of archival Gemini/GMOS spectra. Radial-velocity monitoring and automated template fitting methods both reveal a similar high eccentricity system with a mass ratio close to unity, and an orbital period in agreement with the 155.1 +/- 1 day X-ray light curve period… 
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