On Omega Centauri and its RRc stars

Journal Article · Sat Sep 01 04:00:00 EDT 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/169101· OSTI ID:6406902

Simon, N R ^[1]

---

1. Nebraska Univ., Lincoln (USA)

Masses, absolute temperatures, and luminosities are derived for a large sample of RRc stars in the globular cluster Omega Centauri, interpreting the observed periods, relative luminosities, and Fourier phases in terms of linear and hydrodynamic pulsation models. The resulting masses agree with those of the RRd stars in other clusters and the derived parameters pass a number of other tests which are independent of their derivation. The results disagree with current horizontal branch models and also imply that the canonical slope of the log T(e) versus B-V relation is too steep by a factor of two. It is shown that the disagreement between the RRd masses and those based on horizontal branch calculations cannot be reconciled by reasonable changes in metallicity or opacity. No correlation between the masses of the Omega Cen RRc stars and their metallicities is found, and it is shown that this cannot be due to the late redward evolution by the RR Lyrae stars of lower mass. 38 refs.

• OSTI ID: 6406902
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 360; 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
CANONICAL DIMENSION
GIANT STARS
LUMINOSITY
MASS
MATHEMATICAL MODELS
OPTICAL PROPERTIES
OSCILLATIONS
PHYSICAL PROPERTIES
SCALE DIMENSION
STAR CLUSTERS
STAR MODELS
STARS
VARIABLE STARS