Related papers: RR Lyrae variables in Galactic globular clusters V…
In order to test the prevailing paradigm of horizontal-branch (HB) stellar evolution, we use the large databases of measured RR Lyrae parameters for the globular cluster M3 (NGC 5272) recently provided by Bakos et al. and Corwin & Carney.…
We present some applications of our Synthetic Horizontal Branches (SHB) simulations, aimed to reproduce the peculiar period distributions of RR Lyrae belonging to the Galactic Globular Clusters M3 and M5. We show some evidence, supporting…
We present theoretical predictions concerning horizontal branch stars in globular clusters, including RR Lyrae variables, as derived from synthetic procedures collating evolutionary and pulsational constraints. On this basis, we explore the…
We present predicted relations connecting pulsational and evolutionary parameters, as based on a wide set of convective pulsating models of RR Lyrae stars with Z=0.001, Y=0.24 and mass and luminosity suitable for the ``old'' (age $>$ 8 Gyr)…
Evolutionary calculations of population II stars with chemical composition of the globular cluster M3 were carried out under various assumptions about the initial stellar mass ($0.809M_\odot\le M_\mathrm{ZAMS} \le 0.83M_\odot$) and the mass…
Up-to-date isochrones, zero-age horizontal branch (ZAHB) loci, and evolutionary tracks for core He-burning stars are applied to the color-magnitude diagrams (CMDs) of M3, M15, and M92, focusing in particular on their RR Lyrae populations.…
We compare theory and observations for fundamental RR Lyrae in the solar neighborhood and in both Oosterhoff type I (OoI) and type II (OoII) Galactic globular clusters (GGCs). The distribution of cluster RR_ab in the PA_V plane depends not…
We have applied the image subtraction method to the M3 dataset previously analyzed by Corwin & Carney (2001; CC01). The new analysis produced light curves and periods for 15 variables, bringing to 222 the total number of RR Lyrae stars in…
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…
In this paper we revisit observational data concerning RR Lyrae stars in Galactic globular clusters, presenting frequency histograms of fundamentalized periods for the 32 clusters having more than 12 pulsators with well recognized period…
We present a comprehensive photometric study of RR Lyrae stars in the M3 globular cluster, utilising a vast dataset of 3140 optical ($UBVRI$) CCD images spanning 35 years from astronomical data archives. We have successfully identified…
There is a growing evidence that several globular clusters must contain multiple stellar generations, differing in helium content. This hypothesis has helped to interpret peculiar unexplained features in their horizontal branches. In this…
New observations of variable stars in the globular cluster M3 reveal that the RR Lyrae variable V79 is a double-mode (RRd) variable with the first overtone mode dominating. In all previous studies, V79 was found to be a fundamental mode…
The period-change behaviour of 134 RR Lyrae stars in the globular cluster Messier 3 (M3) is investigated on the ~120-year time base of the photometric observations. The mean period-change rates (\beta \approx 0.01 d Myr^-1) of the…
We present a new set of horizontal-branch (HB) models computed with the MESA stellar evolution code. The models adopt $\alpha$-enhanced \cite{ags09} metals mixtures and include the gravitational settling of He. They are used in our HB…
We present time series data on the variable stars of the galactic globular cluster Messier 3 (M3). We give BVI light curves for 226 RR Lyrae, 2 SX Phe and 1 W Vir type variables, along with estimated fundamental photometric parameters such…
We have performed a detailed study of the pulsational and evolutionary characteristics of 133 RR Lyrae stars in the globular cluster NGC5272 (M3) using highly accurate BVI data taken on 5 separate epochs. M3 seems to contain no less than…
Paper I: "RR Lyrae Variables in Globular Clusters and the Second-Parameter Phenomenon" Authors: M. Catelan, A. V. Sweigart, J. Borissova Abstract: We propose to use RR Lyrae variables in globular clusters to probe the origin of the…
Double-mode RR Lyrae variables (i.e. radial variables which are simultaneously pulsating in both fundamental and first overtone modes) appear a fundamental tool for investigating the mass of old Population II Horizontal Branch (HB) stars.…
The grid of evolutionary tracks of population II stars with initial masses from $0.81M_\odot$ to $0.85M_\odot$ and chemical composition of the globular cluster M 3 is computed. Selected models of horizontal branch stars were used as initial…