Hertzsprung-Russell diagram for the sample of ULLYSES target O-type stars in N11 B. Evolutionary tracks (continuous lines) and isochrones (dotted lines) from Brott et al. (2011) and Köhler et al. (2015) with LMC composition are displayed. The ULLYSES targets (cyan circles) are identified with the PGMW # from Parker et al. (1992). The stars have ages of between 2 and 4.5 Myr, and evolutionary masses of 25– 45 M_⊙. The ZAMS line, and the completeness threshold of V> 16 mag are displayed (red line). Typical uncertainties are indicated.