1999A&A...347..127S

We analyze the orbital motion of the WN7+abs+O binary WR 22 based on 88 high resolution optical spectra obtained in 1996. We determine a period of P=80.336±0.0013d and a radial velocity semi-amplitude K_WR=70.6±0.8km/s for the Wolf-Rayet star. By averaging six HeI lines it is possible to detect the weak absorptions of the O companion. The spectral class of the O star is O9III (O8-O9.5) but the luminosity class is uncertain and brightness arguments indicate a luminosity class V. For the orbit of the O companion we derive K_O=190±10km/s. This leads to a mass ratio q=M_WR/M_O=2.69±0.14. We obtain masses of 55.3±7.3M_☉ and 20.6±1.7M_☉ for the WR and for the O star, respectively. Our mass determination revises down considerably the last published value for the mass of the Wolf-Rayet component but even with the new mass WR 22 remains ``the most massive Wolf-Rayet star ever weighed''.