The globular cluster Omega Centauri - The origin of the mysterious correlation between the RR Lyrae luminosity and Fe/H

Journal Article · Sat Jun 01 04:00:00 EDT 1991 · Astrophysical Journal; (United States)

DOI:https://doi.org/10.1086/186047· OSTI ID:5314647

Lee, Young-Wook ^[1]

---

1. Yale University, New Haven, CT (USA)

The observed correlation between the RR Lyrae luminosity and Fe/H for all Omega Cen RR Lyrae stars for which Fe/H has been determined by the delta-S method is considered, and emphasis is placed on the lack of luminosity variation among the variables in Omega Cen. Model calculations are shown to suggest that the observed 'flat' correlation between the RR Lyrae luminosity and Fe/H for stars having Fe/H forbidden line less than -1.4 can be reproduced if the HB stars in Omega Cen obey the nonmonotonic behavior of the HB morphology with decreasing Fe/H similar to that observed in the Galactic globular cluster system. This is considered to be a natural consequence of recent HB evolutionary models suggesting that the RR Lyrae mean luminosity depends on HB morphology as well as metallicity. 21 refs.

• OSTI ID: 5314647
• Journal Information: Astrophysical Journal; (United States), Journal Name: Astrophysical Journal; (United States) Vol. 373; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
CEPHEIDS
CHEMICAL COMPOSITION
CORRELATIONS
ELEMENT ABUNDANCE
ELEMENTS
GIANT STARS
IRON
LUMINOSITY
MATHEMATICAL MODELS
METALS
OPTICAL PROPERTIES
ORIGIN
OSCILLATIONS
PHYSICAL PROPERTIES
PULSATING VARIABLE STARS
SPECTROPHOTOMETRY
STAR CLUSTERS
STAR EVOLUTION
STAR MODELS
STARS
TRANSITION ELEMENTS
VARIABLE STARS