Notes. The first column indicates the region, the second column the number of stars that are assigned to the region, and the third column the observed binary fraction . The last two columns give the detection probability p_detect and bias-corrected binary fraction f_cl. “ALL” refers to all the stars studied in this work, that is MS + TO + Be + BSS stars and the BSGs. ^(#)These detection probabilities and bias-corrected binary fractions are valid under the adopted parent orbital parameter distributions discussed in Sect. 4.3. The quoted 1σ errors contain both the statistical uncertainties due to the sample size and those due to random drawing of the index of the parent distributions. ^(†)While providing the detection probability also for Be stars and BSS, we do not propagate it further to compute the intrinsic binary fraction of these groups of stars as the fraction of BiPs among them is probably significant. ^(‡)Detection probability computed assuming a linearly variable period index from π = −0.25 ± .25 at the upper mass range to +0.25 ± .25 at the lower mass range. ^(*)From Patrick et al. (2020), including both RSGs in the core and in the outskirts, based on higher-quality ESO-HARPS data with longer time coverage.