Related papers: A New RR Lyrae Metallicity Calibration
We present the detection of 6,371 RR Lyrae (RRL) stars distributed across ~14,000 deg^2 of the sky from the combined data of the Sloan Digital Sky Survey (SDSS), the Panoramic Survey Telescope and Rapid Response System 1 (PS1), and the…
We report the first extensive model atmosphere and detailed chemical abundance study of eight RR Lyrae variable stars of c subclass throughout their pulsation cycles. Atmospheric parameters effective temperature, surface gravity,…
RR Lyrae (RRL) variable stars are cornerstone distance indicators. In particular, double-mode RR Lyrae (RRd) stars enable period--luminosity relations (PLRs) that are less sensitive to metallicity, reducing systematic biases in distance…
We present new spectroscopic metal abundances for 74 RR Lyrae stars in omega Cen obtained with FLAMES. The well-known metallicity spread is visible among the RR Lyrae variables. The metal-intermediate (MInt) RR Lyrae stars ([Fe/H] ~ -1.2)…
The mass-metallicity relation (MZR) is a fundamental scale law of galaxies. It is observed to evolve with redshift in unresolved galaxies up to z>6. However, observational constraints limits our view at such early epochs to galaxies with…
The stellar metallicity is a direct measure of the amount of metals present in a galaxy, as a large part of the metals lie in its stars. In this paper we investigate new stellar metallicity indicators suitable for high-z galaxies studying…
Metallicity is a fundamental parameter that contributes to the physical characteristics of a star. However, the low temperatures and complex molecules present in M dwarf atmospheres make it difficult to measure their metallicities using…
Context. Reliable metallicity values for M dwarfs are important for studies of the chemical evolution and advancement of planet formation theory in low-mass environments. Historically the determination of stellar parameters of low-mass…
We present an improved analysis of halo substructure traced by RR Lyrae stars in the SDSS stripe 82 region. With the addition of SDSS-II data, a revised selection method based on new ugriz light curve templates results in a sample of 483 RR…
We present template radial velocity curves of $ab$-type RR Lyrae stars constructed from high-precision measurements of ${\rm H\alpha}$, ${\rm H\beta}$, and ${\rm H\gamma}$ lines. Amplitude correlations between the Balmer line velocity…
We present photometry of 30 Galactic RR Lyrae variables taken with HST WFC3/IR for the Carnegie-Chicago Hubble Program. These measurements form the base of the distance ladder measurements that comprise a pure Population II base to a…
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…
We present mean horizontal branch absolute magnitudes and iron abundances for a sample of 39 globular clusters. These quantities were calculated in an unprecedented homogeneous fashion based on Fourier decomposition of ligt curves of RR…
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…
We present results for the QUEST RR Lyrae Survey at low galactic latitude, conducted entirely with observations obtained with the QUEST mosaic camera and the 1.0/1.5m J\"urgen Stock Schmidt telescope at the National Observatory of…
We use data from the Northern Sky Variability Survey (NSVS), obtained from the first generation Robotic Optical Transient Search Experiment (ROTSE-I), to identify and study RR Lyrae variable stars in the solar neighborhood. We initially…
We present a theoretical calibration of the RR Lyrae period-luminosity (PL) relation in the UBVRIJHK Johnsons-Cousins-Glass system. Our theoretical work is based on calculations of synthetic horizontal branches (HBs) for several different…
A probabilistic approach has been used in combination with the parallax data from Gaia (e)DR3 to calibrate Period-Luminosity-(Abundance) (PLZ) Relations covering a wide range of visual to Infrared observations of RR Lyrae stars. Absolute…
With the Delta a photometric system, it is possible to study very distant galactic and even extragalactic clusters with a high level of accuracy. This can be done with a classical color-magnitude diagram and appropriate isochrones. The new…
Using the stellar atmospheric parameters such as effective temperature and metallicity derived from SDSS spectra for 2200 main sequence (MS) stars which were also observed by Beijing - Arizona - Taiwan - Connecticut (BATC) photometric…