Upper panel: Linear least-squares fits to the three dipole periods of EC 20058 marked with an asterisk and the four quadrupole periods marked with two asterisks in Table 11. The derived period spacings from these fits are ΔΠ_ℓ = 1 = 41.4115 ± 0.3864 s and ΔΠ_ℓ = 1 = 23.795 ± 0.284 s, respectively. Middle panel: Residuals of the ℓ = 1 period distribution relative to the dipole mean period spacing. Lower panel: Residuals of the ℓ = 2 period distribution relative to the quadrupole mean period spacing. Modes with consecutive radial order are connected with a thin black line.