New paper Accepted for publication in A&A available on ArXiv.

(Sana, de Koter, de Mink et al. 2012)

With 360 O-type stars the Tarantula Survey of massive stars (Evans et al 2011) is the largest homogeneous sample of massive stars analyzed to date. We determine the spectroscopic binary fraction and correct for biases finding an intrinsic binary fraction. Based on the distribution of orbital periods and mass ratios we estimate that over 50% of the current O star population in 30 Dor will exchange mass with its companion within a binary system.