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Related papers: Toward more accurate RR Lyrae metallicities

200 papers

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…

We report the results of CCD V and r photometry of the globular cluster NGC 5466. The difference image analysis technique adopted in this work has resulted in accurate time series photometry even in crowded regions of the cluster enabling…

Astrophysics · Physics 2009-11-13 A. Arellano Ferro , V. Rojas Lopez , Sunetra Giridhar , D. M. Bramich

Analysis of cluster and field star uvby data demonstrates the existence of a previously undetected discrepancy in a widely used photometric metallicity calibration for G dwarfs. The discrepancy is systematic and strongly color-dependent,…

Astrophysics · Physics 2009-11-07 Bruce A. Twarog , Barbara J. Anthony-Twarog , Delora Tanner

Europium plays a key role in studies of nucleosynthesis in the rapid (r-) process of neutron capture nuclear reactions and the evolution of the r-process element abundances in galaxies. We refine the method for analyzing the Eu~II lines in…

Solar and Stellar Astrophysics · Physics 2026-04-27 L. I. Mashonkina , S. A. Yakovleva

Astronomy is entering an unprecedented era of Big Data science, driven by missions like the ESA's Gaia telescope, which aims to map the Milky Way in three dimensions. Gaia's vast dataset presents a monumental challenge for traditional…

Artificial Intelligence · Computer Science 2024-10-24 Lorenzo Monti , Tatiana Muraveva , Gisella Clementini , Alessia Garofalo

RR Lyrae stars have long been considered reliable tracers of old, metal-poor populations, primarily due to their prevalence in globular clusters and the Galactic halo. However, the discovery of a metal-rich subpopulation in the Galactic…

Solar and Stellar Astrophysics · Physics 2025-10-24 HanYuan Zhang , Giuliano Iorio , Vasily Belokurov , N. Wyn Evans , Alexey Bobrick , Valentina D'Orazi

NGC 362 is a bright southern globular cluster for which no extensive variability survey has ever been done. Time-series CCD photometric observations have been obtained. Light curves have been derived with both profile fitting photometry and…

Astrophysics · Physics 2009-10-08 P. Szekely , L. L. Kiss , R. Jackson , A. Derekas , B. Csak , K. Szatmary

In recent years a number of poorly studied chemical elements, such as phosphorus, sulphur, and strontium, have received special attention as important tracers of the Galactic chemical evolution. By exploiting the capabilities of the…

Solar and Stellar Astrophysics · Physics 2015-12-16 E. Caffau , S. Andrievsky , S. Korotin , L. Origlia , E. Oliva , N. Sanna , H. -G. Ludwig , P. Bonifacio

We present multi-epoch infrared photometry in the $K_s$-band for 74 bright RR Lyrae variable stars tied directly to the 2MASS photometric system. We systematize additional $K$-band photometry from the literature to the 2MASS system and…

Astrophysics of Galaxies · Physics 2019-08-21 Andrew C. Layden , Glenn P. Tiede , Brian Chaboyer , Curtis Bunner , Michael T. Smitka

We present new luminosity-metallicity (LZ; MV-[Fe/H] and MG-[Fe/H]) relations and, for the first time, empirical, Gaia three-band (G,GBP,GRP) period-Wesenheit-metallicity (PWZ) relations of RR Lyrae stars (RRLs) derived using a hierarchical…

Solar and Stellar Astrophysics · Physics 2022-03-30 A. Garofalo , H. E. Delgado , L. M. Sarro , G. Clementini , T. Muraveva , M. Marconi , V. Ripepi

The study of stellar parameters of planet-hosting stars, such as metallicity and chemical abundances, help us to understand the theory of planet formation and stellar evolution. Here, we present a catalogue of accurate stellar atmospheric…

Solar and Stellar Astrophysics · Physics 2015-03-11 S. Alves , L. Benamati , N. C. Santos , V. Zh. Adibekyan , S. G. Sousa , G. Israelian , J. R. De Medeiros , C. Lovis , S. Udry

We present the analysis of four new extremely metal poor turn-off stars thanks to high-resolution spectra obtained with the Subaru/HDS spectrograph. We determined the abundances and upper limits of Li, C, Mg, Ca, Sr, and Ba. Metallicities…

Solar and Stellar Astrophysics · Physics 2025-07-01 Takuma Suda , Patrick Francois , Shinya Wanajo , Elisabetta Caffau , Wako Aoki , Piercarlo Bonifacio

The abundance of {\alpha}-elements provides an important fossil signature in Galactic archaeology to trace the chemical evolution of the different disc populations. High-precision chemical abundances are crucial to improving our…

We compute the spatial velocity components and the galactic orbital elements for 209 metal-poor $([Fe/H] < -1.0)$ RRLyrae (ab) variable stars in the solar neighborhood using proper motions, radial velocities, and photometric distances…

Astrophysics · Physics 2009-11-07 T. V. Borkova , V. A. Marsakov

We present chemical abundances for 110 stars identified in objective-prism surveys as candidates to be very metal-poor. The abundances are derived from high S/N, intermediate-resolution spectra obtained with the Keck Observatory Echelle…

Astrophysics · Physics 2009-11-10 D. K. Lai , M. Bolte , J. A. Johnson , S. Lucatello

Spectroscopic determinations of Rubidium abundances were conducted by applying the spectrum fitting method to the Rb I 7800 line for an extensive sample of ~500 late-type dwarfs as well as giants (including Hyades cluster stars) belonging…

Solar and Stellar Astrophysics · Physics 2021-04-28 Yoichi Takeda

We apply the stellar locus method to synthetic $(BP-RP)_{XPSP}$ and $(BP-G)_{XPSP}$ colors derived from corrected Gaia BP/RP (XP) spectra to obtain precise estimates of metallicity for about 100 million stars in the Milky Way (34 million…

Solar and Stellar Astrophysics · Physics 2025-02-04 Bowen Huang , Haibo Yuan , Shuai Xu , Kai Xiao , Maosheng Xiang , Yang Huang , Timothy C. Beers

Knowledge of late K and M dwarf metallicities can be used to guide planet searches and constrain planet formation models. However, the determination of metallicities of late-type stars is difficult because visible wavelength spectra of…

Solar and Stellar Astrophysics · Physics 2014-05-16 Andrew W. Mann , John M. Brewer , Eric Gaidos , Sebastien Lepine , Eric J. Hilton

We present new theoretical period-luminosity-metallicity (PLZ) relations for RR Lyrae stars (RRL) at Spitzer and WISE wavelengths. The PLZ relations were derived using nonlinear, time-dependent convective hydrodynamical models for a broad…

We estimated iron and metallicity gradients in the radial and vertical directions with the F and G type dwarfs taken from the RAVE DR4 database. The sample defined by the constraints Zmax<=825 pc and ep<=0.10 consists of stars with metal…

Astrophysics of Galaxies · Physics 2015-11-18 O. Plevne , T. Ak , S. Karaali , S. Bilir , S. Ak , Z. F. Bostanci