Undereddened

A good rectification of the 2200 A dip, which is clearly visible in the undereddened spectrum, is obtained for 0.4<E_(B-V)<0.5.

The linear fit gives A = 0.067 ± 10⁻³; B = 6.77 ± 0.04; σ = 0.17 for the undereddened sample with (B − V) > −0.09 and |(d− < d >)| ≤ 1.5Σ.

Note that Jones et al. 1992 actually consider 17 type ab RR Lyrae stars, but we are unable to reconstruct the undereddened photometry for one of these, SS Leo, from their sources, Liu & Janes 1990 and Jones, Carney, & Latham 1988.