Peak magnitudedecline rate relation. The absolute peak magnitude in the 400 nm band, M(400), is plotted vs. ΔM₁₀(400), ΔM₂₀(400), and ΔM₃₀(400). The latter three values are measures of the light curve decline (in magnitudes) during the first 10, 20, and 30 days after maximum. The left-hand column of plots shows only the 2005ap-like events (pure sample), and the right-hand column shows all SLSN. The dashed red line is the fit of the extended sample, and the black of the complete sample (see Section 2 for the sample definitions). The SNe magnitudes and the corresponding ΔM_day(400) are reported in Table 1, and the parameters of the linear regression fits (black line) are listed in Table 3.