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On the Oosterhoff Classification of the Unusual, Metal-Rich Globular Clusters NGC 6388 and NGC 6441
M. Catelan, A. V. Sweigart, B. J. Pritzl +1
We discuss the Oosterhoff classification of the unusual, metal-rich globular clusters NGC 6388 and NGC 6441, on the basis of new evolutionary models computed for a range of metalli…
A New Formation Mechanism for the Hottest Horizontal-Branch Stars
Allen V. Sweigart, Thomas M. Brown, Thierry Lanz +2
Stars with very large mass loss on the red-giant branch can undergo the helium flash while descending the white-dwarf cooling curve. Under these conditions the flash convection zon…
Using M32 to Study Rapid Phases of Stellar Evolution
Thomas M. Brown, Henry C. Ferguson, Allen V. Sweigart +2
The compact elliptical galaxy M32 offers a unique testing ground for theories of stellar evolution. Because of its proximity, solar-blind UV observations can resolve the hot evolve…
The Origin of Hot Subluminous Horizontal-Branch Stars in Omega Centauri and NGC 2808
Allen V. Sweigart, Thomas M. Brown, Thierry Lanz +2
Hot subluminous stars lying up to 0.7 mag below the extreme horizontal branch (EHB) are found in the UV color-magnitude diagrams of omega Cen and NGC 2808. Such stars are unexplain…