(Top-right panel) Continuum-subtracted Hα image of IC 1158. The 25th B-band magnitude elliptic contour is shown by a black solid line, along with the position of SN 2000cb (marked by a red star) and the center of the galaxy (marked by a red circle). The slit position is shown, and a color code is used to present the N2 metallicity measurements at the position of each H ii region that we inspected. (Top-left panel) Flux at the Hα wavelength along the slit, shown as a function of the distance from the SN location (marked by a dotted line, like the nucleus position). The N2 measurements are shown at the corresponding positions in the top sub-panel. (Bottom panel) Metallicity gradient IC 1158, see the bottom-panel caption of Fig. 6 for details.