CMD showing empirical IS limits (red points) separately for 1O (left panel) and F-mode (right panel) LMC Cepheids. Fits for the blue and red edges, considering a break at P ∼ 3 days, are shown as solid lines. Gray shaded areas mark the blue loop extent (delimited by its bluest extreme and the tip of the RGB) for evolutionary tracks with masses from 3 to 7 M_⊙, and for Z = 0.006, 0.008, and 0.009. The upper limits for the areas are defined by the evolutionary tracks for 7 M_⊙ and would extend further up if tracks with higher masses are considered. The I-band absolute magnitude distributions of the 1O and F LMC Cepheids are shown on the right side of each panel.