Potential modification of the surface metallicity of MS stars after the engulfment of 1 M_⊕ of planetesimals (dashed line) or the accretion of 0.03 M_⋆ metal-free gas (plain), both resulting as a consequence of the formation of a solar-system analog. The pollution by 0.01 M_⊕ planetesimals is also shown by the thin dotted line. The stellar convective zone mass, M_CZ, is shown as a green dotted line. All values are evaluated at an age of 0.6 Gyr. The potential changes in composition due to planet formation are indicated in gray.