The Astrophysical Journal · 1982 · 15 citations · 0 references
Natural SciencesAstronomyPhysicsExtragalactic AstronomyGalactic AstronomyStellar AstronomyGalactic HaloGlobular ClustersRed GiantsStar ClustersStellar PopulationsStellar StructureElemental AbundancesGlobular Cluster PopulationsMetal-rich Host StarsRed Giant Branch StarsRed Giant StarsRr Lyrae StarsStar Cluster MetallicityStellar Metallicities
The spectroscopic metallicity index (delta S) is determined for RR Lyrae stars in 13 globular clusters, and Fe/H values are obtained for 22 globular clusters. It is shown that: (1) published Ca and Fe abundances for red giants in globular clusters are consistent with a one-to-one relationship between Ca/H and Fe/H; (2) several globular clusters have delta S Fe abundances significantly higher than Fe/H = -1.2; (3) the second parameter phenomenon may be more widespread among the metal-rich globular clusters of the inner galactic halo than has been hitherto believed; and (4) there are no clear-cut examples in which giant-branch morphology does not correlate with Fe/H.