On the Sandage period shift effect among field RR Lyrae stars

Journal Article · Thu Nov 01 04:00:00 EST 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/169326· OSTI ID:6316225

Lee, Y ^[1]

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1. Yale Univ., New Haven, CT (USA) Victoria Univ. (Canada)

The origin of the disagreement between the results of the synthetic horizontal branch (HB) model of Lee et al. (1990) and the Sandage (1990) analysis of Lub's (1977) data on a sample of field RR Lyrae stars is investigated, extending the original synthetic HB calculations of Lee et al. to all HB types over the metallicity range of the Galactic halo. It is shown that the period shifts of the RR Lyrae stars in globular clusters depend strongly on their HB type and metallicity. Results suggest that the disagreement between the slopes, Delta logP(Teff)/Delta Fe/H, obtained by Lee et al. and the ones obtained by Sandage can be explained by the fact that Lub's sample may have contained many highly evolved stars in the metallicity range of Fe/H between -2.0 and -1.6, since Lee's analysis did not include these stars. 48 refs.

• OSTI ID: 6316225
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 363; 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
CHEMICAL COMPOSITION
COMPARATIVE EVALUATIONS
DATA ANALYSIS
GIANT STARS
LUMINOSITY
MATHEMATICAL MODELS
OPTICAL PROPERTIES
OSCILLATIONS
PHYSICAL PROPERTIES
PULSATING VARIABLE STARS
STAR CLUSTERS
STAR EVOLUTION
STAR MODELS
STARS
VARIABLE STARS