Active OB stars: structure, evolution, mass loss and critical limits
[en] Proceedings IAU Symposium no. 272
[en] binaries: general ; stars: fundamental parameters ; stars: Wolf-Rayet ; stars: winds ; outflows
[en] We present the results from the spectroscopic follow-up of WR140 (WC7 + O4-5) during its last periastron passage in january 2009. This object is known as the archetype of colliding wind binaries and has a relatively large period (~=8 years) and eccentricity (~=0.89). We provide updated values for the orbital parameters, new estimates for the WR and O star masses and new constraints on the mass-loss rates.