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astro-ph1997
On the Production of Bright RR Lyrae Variables in Metal-Rich Globular Clusters
A. V. Sweigart, M. Catelan
Recent HST observations of the metal-rich bulge clusters NGC 6388 and NGC 6441 by Rich et al. (1997) have found that the horizontal branches (HBs) in these clusters slope upward wi…
astro-ph1997
Helium Mixing in Globular Cluster Stars
A. V. Sweigart
The observed abundance variations in globular cluster red giants indicate that these stars may be mixing helium from the hydrogen shell outward into the envelope, presumably as a r…