Upper panel. Spatially resolved star formation history for the central region of ESO381-20, as from BL stars of different ages (as indicated in the subpanels). The SFR per unit area is indicated on the colorbar, with the same color scale for all of the subsamples. The angular resolution of the maps is marked with a red rectangle in each subpanel. The center of the galaxy is indicated by a black cross. Just as a reference among different frames, we also overplot in red the ellipse corresponding to the projected major axis radius at the isophote level 25 mag arcsec^-1 in the I-band (taken from Sharina et al. 2008). Lower panel. Spatially resolved star formation history (via synthetic CMD modeling) of ESO381-20 within the last 1 Gyr. We select two subsamples of stars, found in the “inner” and in the “outer” regions of the galaxy, by looking at the density maps of the BL stars (Fig. 10, see text for details). The star formation rate for each region (normalized to the area of the considered region) as a function of time is plotted, with the oldest age being on the left side and the present day on the right edge of the (logarithmic) horizontal axis.