Contrast curves. Top: 5-σ contrast curve, which gives the K₁-contrast as a function of angular separation. Full lines represent O-type stars and dashed lines B-type stars. Middle: absolute K-band magnitude that is reached as a function of separation (5-σ). Linestyles are the same as top figure. Bottom: contrast curves translated to mass ratios. Linestyles are the same as top and middle figures.