Inverse of the quality function, 1/χ², vs. T_eff of the period-to-period fits in the ℓ = 1 case, for the five sets of periods considered for NGC 246: Sector 3 (upper left panel), Sector 30 (upper right panel), the 17 periods from the combination of both sectors (middle panel), and the two subsets of the combination of both sectors with 11 periods (lower left panel) and 14 periods (lower right panel). The vertical gray strip indicates the spectroscopic values of T_eff and the corresponding uncertainty for this star.