Title: The metal abundances of RR Lyrae stars in the globular clusters NGC 3201, NGC 4590, and NGC 6171
Abstract: The ΔS metal abundance index has been measured for RR Lyrae stars in the globular cluster NGC 3201, NGC 4590, and NGC 6171. The abundance of NGC 3201 was found to be [Fe/H] = - 1.33 ± 0.15 on Butler's scale, with no evidence of star-to-star variation among nine stars studied. The results for NGC 4590 and NGC 6171 (two stars each) were [Fe II] = - 1.96 and - 0.84, respectively. The result for NGC 6171 is in good agreement with previous ΔS determinations.