Related papers: Exploring M33 Through RR Lyrae Stars
We determine the fundamental stellar parameters of altogether 20 double-mode RR Lyrae (RRd) stars from the Galactic Field and the Large Magellanic Cloud, following our approach employed on the field RRd star BS Comae. The stars were…
We use the data of our extended catalog of spectroscopic determinations of elemental abundances in the atmospheres of Galactic-field RR Lyrae type variables to show that metal-rich RR Lyraes ($\rm{[Fe/H]} > -1.0$) have anomalous abundances…
The stellar halos of large galaxies represent a vital probe of the processes of galaxy evolution. They are the remnants of the initial bouts of star formation during the collapse of the proto-galactic cloud, coupled with imprint of ancient…
We have analyzed the data on 16,836 RR Lyrae (RR Lyr) variables observed toward the Galactic bulge during the third phase of the Optical Gravitational Lensing Experiment (OGLE-III), which took place in 2001-2009. Using these standard…
A small but significant radial gradient in the mean periods of LMC RR Lyrae variables is established from the OGLEIII survey data. This is interpreted as a metallicity gradient but other possibilities are discussed. Data on the ratio of…
We present new time-series CCD \emph{VR} photometry of the globular cluster NGC 5634. We aim to use the known RR Lyrae stars, members of the cluster, as indicators of mean metallicity and distance. Accurate coordinates, periods and an…
In order to study the Milky Way, RR Lyrae (RRL) variable stars identified by Gaia, ASAS-SN and ZTF sky survey projects have been analyzed as tracers in this work. Photometric and spectroscopic information of 3417 RRLs including proper…
We present new multicolour CCD photometry of the central part of the globular cluster M3, mapping the precise position of ~120 RR Lyrae stars (RRab, RRd, RRc) on the horizontal branch (HB). The location of the double-mode variables (RRd) is…
Using the theoretical stellar population synthesis models of BC96, Kong et al. (2003) showed that some BATC colors and color indices could be used to disentangle the age and metallicity effect. They found that there is a very good relation…
We present 947 radial velocities of RR Lyrae variable stars in four fields located toward the Galactic bulge, observed within the data from the ongoing Bulge RR Lyrae Radial Velocity Assay (BRAVA-RR). We show that these RR Lyrae stars…
We present the analysis of 26 nights of V and I time-series observations from 2011 and 2012 of the globular cluster M 30 (NGC 7099). We used our data to search for variable stars in this cluster and refine the periods of known variables; we…
RR Lyrae stars in the Milky Way are good tracers to study the kinematic behaviour and spatial distribution of older stellar populations. A recently established well documented sample of 217 RR Lyr stars with V<12.5 mag, has been used to…
The distance to the Galactic center inferred from OGLE RR Lyrae variables observed in the direction of the bulge is Ro=8.1+-0.6 kpc. An accurate determination of Ro is hindered by countless effects that include an ambiguous extinction law,…
Although roughly half of all stars are considered to be part of binary or multiple systems, there are only two confirmed cases of RR Lyrae pulsators with companions. One of them is TU Uma (Wade et al 1999) - a classical RR Lyrae star in a…
We present a detailed study of the variable star population of Eridanus II (Eri II), an ultra-faint dwarf galaxy that lies close to the Milky Way virial radius. We analyze multi-epoch $g,r,i$ ground-based data from Goodman and the Dark…
The new data for Cepheids and RR Lyrae stars of the Optical Gravitational Lensing Experiment (OGLE-III) survey allow us to study the three-dimensional distribution of stars corresponding to young (a few tens to a few hundreds of millions of…
Context. Nearly 150 tidal streams are known in the Milky Way, but full phase-space information exists for only a few. RR Lyrae stars (RRL), as standard candles, provide a powerful way to probe these structures, yet they have been identified…
A review is given of the possibilities for the study of the kinematics and metallicities of the old populations in galaxies of the Local Group using SALT/PFIS observations of RR Lyrae variables.
We present Hubble Space Telescope observations taken with the Advanced Camera for Surveys Wide Field Channel of two fields near M32 - between four and six kpc from the center of M31. The data cover a time baseline sufficient for the…
We report the detection of three RR Lyrae (RRL) stars (two RRc and one RRab) in the ultra-faint dwarf (UFD) galaxy Centaurus I (CenI) and two Milky Way (MW) $\delta$ Scuti/SX Phoenicis stars based on multi-epoch $giz$ DECam observations.…