Locations of the base of the convective zone (BCZ), expressed as a fractional stellar radius (R_BCZ/R_★) for 1 M_⊙ stellar models with different metallicities (Z). Each line corresponds to a distinct metallicity, with values indicated on the left side. The locations of the BCZ are shown at three evolutionary stages along the main sequence: the zero-age main sequence (ZAMS), intermediate-age main sequence (IAMS), and terminal-age main sequence (TAMS). The IAMS is defined as the evolutionary stage at which the stellar age corresponds to 50% of the total main-sequence lifetime (t/t_TAMS = 0.5). The figure illustrates the diversity in the depths of the convective zones and how they vary with both age and metallicity. For reference, the MESA standard solar model (computed with Z = 0.02) predicts R_BCZ/R_⊙ = 0.714 at the solar age of 4.61 Gyr.