Related papers: RR Lyrae - Theory vs Observation

The results of nonlinear, convective models of RR Lyrae pulsators with metal content Z=0.0001 to 0.006 are discussed and several predicted relations connecting pulsational (period and amplitude of pulsation) and evolutionary parameters…

The purpose of the paper is to predict the temperature at the fundamental blue edge (FBE) of the instability strip for RR Lyrae (RRL) variables from the pulsation equation that relates temperature to period, luminosity, and mass. Modern…

We present new measurements of the metallicity of 131 RR Lyrae stars in the globular cluster Omega Centauri, using the hk index of the Caby photometric system. The hk method has distinct advantages over Delta-S and other techniques in…

We used moderately high-resolution, high S/N spectra to study the chemical composition of 10 field ab-type RR Lyrae stars. A new temperature scale was determined from literature Infrared Flux Method measures of subdwarfs and the Kurucz…

Infrared and optical absolute magnitudes are derived for the type II Cepheids kappa Pav and VY Pyx from revised Hipparcos parallaxes and for kappa Pav, V553 Cen and SW Tau from pulsation parallaxes. Phase-corrected JHK mags are given for…

Recent theoretical and observational findings breathed new life into the field of RR Lyrae stars. The ever more precise and complete measurements of the space asteroseismology missions revealed new details, such as the period doubling and…

We use theoretical models to establish a tight relationship for the absolute magnitudes of RR Lyrae stars as a function of their periods and Stroemgren pseudo-color c_0 = (u-v)_0 - (v-b)_0. Applying this to RR Lyr, and comparing the result…

Among the tens of thousands of known RR Lyrae stars there are only a handful that show indications of possible binarity. The question why this is the case is still unsolved, and has recently sparked several studies dedicated to the search…

It has recently been suggested that the discrepancy between the "long" and "short" distance moduli of the Large Magellanic Cloud (LMC), as inferred from the properties of the Cepheid and RR Lyrae variables, respectively, might be due to the…

We present our results of searching for differences in light curves of modulated and non-modulated RRab stars in the Galactic bulge. We examined a sample of more than 8000 stars. The most important results are that Blazhko stars have…

Purpose: RR Lyrae stars are important distance indicators. They are usually present in globular clusters where they were first discovered. The study of their properties and distribution in our Galaxy and external galaxies constitutes a…

An examination of the period-V amplitude relation for RRab stars (fundamental mode pulsators) with `normal' light curves in the Oosterhoff type I clusters M3 and M107 and in the Oosterhoff type II clusters M9 and M68 reveals that the V…

Classical Cepheid and RR Lyrae variables are fundamental tracers of cosmic distances and stellar evolution and pulsation. Light curve analysis and pulsation properties of these radially pulsating stars provide stringent tests for…

RR Lyrae stars (RRLs) are valuable probes of both Milky Way assembly and stellar-evolution physics. Using a sample 6,240 RRLs obtained in the first year of the Dark Energy Spectroscopic Instrument (DESI) survey, we investigate the…

We present the results of a photometric study of RR Lyrae variables in the field of the globular cluster M55. We have discovered nine new RR Lyrae stars, increasing the number of known variables in this cluster to 15 objects. Five of the…

We present B and V CCD photometry for variables in the cluster central region, adding new data for 32 variables and giving suitable light curves, mean magnitudes and corrected colors for 17 RR Lyrae. Implementing the data given in this…

We present CCD lightcurves for the three field RR Lyrae AQ Lyr, CN Lyr and AW Dra observed at the Teramo TNT telescope. Stellar temperatures have been derived from the observed mean colors, allowing a comparison with recent theoretical…

RR~Lyrae variables are widely used tracers of Galactic halo structure and kinematics, but they can also serve to constrain the distribution of the old stellar population in the Galactic bulge. With the aim of improving their near-infrared…

A photometric calibration of Kurucz static model atmospheres is used to obtain the following parameters of RR Lyrae stars: variation of stellar angular radius $\vartheta$, effective temperature $T_{\rm e}$, gravity $g_{\rm e}$ as a function…

In this paper we present new CCD investigations of RR Lyrae pulsators in the Oo.I globular cluster M5. B V curves of light for 15 RR Lyrae are presented. With the addition of further 11 curves of light by Storm, Carney and Beck (1991) one…