CPD for M 48 compared with younger (400 Myr; dotted, blue online) and older (500 Myr; dashed, red online) rotational isochrones. Neither the 400 Myr nor the 500 Myr isochrone provide a good match to the data, passing significantly below or above the core group of stars with 0.6 < (B − V)₀< 0.9. The cluster’s rotational age is clearly within this (400, 500) Myr interval. (For clarity, the (central) P₀ = 1.1 d isochrones for the three separate ages are emphasized.)