Distance to main progenitor at birth, r_birth, versus galactocentric distance at present time, r, of all star particles (excluding satellites) for 773 galaxies with virial mass of 10.4 < log(M₂₀₀/M_⊙) < 10.5 (left) and 165 galaxies with virial mass of 11.2 < log(M₂₀₀/M_⊙) < 11.3 (right), stacked. The dotted diagonal white line shows the 1:1 relation; i.e. stars at the same galactocentric distance as when they were born. The dashed vertical blue line indicates the median r_glx, which separates the main galaxy from the outskirts (the outer stellar halo). Stars born at r_birth > r_glx (above the dashed horizontal red line) are classified as accreted. Most in situ stars lie close to the 1:1 line, and most accreted stars end up in the inner regions of the galaxies. Consequently, the mass of stars in the stellar halo is one order of magnitude smaller than the accreted mass fraction. The 25th–75th percentiles of the half-mass stellar radius of the stacks of galaxies are shown with a green interval over the 1:1 line.