Masses from line profile fits. For comparison we also show a canonical zero-age HB from Moehler et al. (2003). In the upper plot we also show results from FORS2 observations of hot HB stars in M 80, NGC 5986 (Moni Bidin et al. 2009), NGC 6752 (Moni Bidin et al. 2007), and M 22 (Salgado et al. 2013). In the lower plot we also provide the results obtained from FLAMES and FORS2 observations of hot HB stars in ω Cen (Moehler et al. 2011, small squares; Moni Bidin et al. 2011, small triangles).