Colour−magnitude diagram (CMD) of the MCPS stars (Zaritsky et al. 2004) within 100 pc (~6.9′) of the central position of two remnants, MCSNR J0528−6727 (left) and MCSNR J0534−6955 (right). Geneva stellar evolution tracks (Lejeune & Schaerer 2001) are shown as red lines, for metallicity of 0.4 Z_⊙ and initial masses of 3, 5 M_⊙ (dashed lines) and 10, 15, 20, 25, and 40 M_⊙ (solid lines), from bottom to top. The green dashed line shows the criteria used to identify the OB stars (V< 16 and B−V< 0). Stars satisfying these criteria are shown as blue dots.