Related papers: Does the mixing length parameter depend on metalli…
Atmospheric parameters (effective temperature Teff, surface gravity log g), masses and helium abundances are derived for 42 hot horizontal branch (HB) stars in the globular cluster NGC 6752. For 19 stars we derive magnesium and iron…
We present newly-calibrated period-$\phi_{31}$-[Fe/H] relations for fundamental mode RR Lyrae stars in the optical and, for the first time, mid-infrared. This work's calibration dataset provides the largest and most comprehensive span of…
The recently published spectroscopic metallicities of RR Lyrae stars in M3 (Sandstrom, K., Pilachowski, C. A., and Saha, A. 2001, AJ 122, 3212) though show a relatively wide range of the [Fe/H] values, the conclusion that no metallicity…
We present new accurate measurements of the physical properties of a statistically significant sample of 103 galaxies at z~2 using near-infrared spectroscopy taken as part of the 3D-HST survey. We derive redshifts, metallicities and star…
The recently-discovered Fundamental Metallicity Relation (FMR), which is the tight dependence of metallicity on both mass and SFR, proves to be a very useful tool to study the metallicity properties of various classes of galaxies. We have…
We conduct a series of comparisons between spectroscopic and photometric observations of globular clusters and stellar models to examine their predictive power. Data from medium-to-high resolution spectroscopic surveys of lithium allow us…
We present abundances of globular clusters in the Milky Way and Fornax from integrated light spectra. Our goal is to evaluate the consistency of the integrated light analysis relative to standard abundance analysis for individual stars in…
Observed metallicities of globular clusters reflect physical conditions in the interstellar medium of their high-redshift host galaxies. Globular cluster systems in most large galaxies display bimodal color and metallicity distributions,…
We present the detailed spectroscopic analysis of 72 evolved stars, including the [Fe/H] determination for the whole sample. These metallicities, together with the Teff values and the absolute V magnitude derived from Hipparcos parallaxes,…
A curious rotation period distribution in the Color-Magnitude-Period Diagram (CMPD) of the Kepler field was recently revealed, thanks to data from Gaia and Kepler spacecraft. It was found that redder and brighter stars are spinning slower…
We review the observational evidence for extra mixing in stars on the red giant branch (RGB) and discuss why thermohaline mixing is a strong candidate mechanism. We recall the simple phenomenological description of thermohaline mixing, and…
The metallicity dependence of the wide binary fraction (WBF) is critical for studying the formation of wide binaries. While controversial results have been found in recent years. Here we combine the wide binary catalog recognized from Gaia…
We derive ages, metallicities and [alpha/Fe] ratios from the integrated spectra of 23 globular clusters in M31, by employing multivariate fits to two stellar population models. In parallel we analyze spectra of 21 Galactic globular clusters…
The metal content of planet hosting stars is an important ingredient which may affect the formation and evolution of planetary systems. Accurate stellar abundances require the determinations of reliable physical parameters, namely the…
Host star metallicities have been used to infer observational constraints on planet formation throughout the history of the exoplanet field. The giant planet metallicity correlation has now been widely accepted, but questions remain as to…
Aims. J, H, and K' images obtained from the near-infrared imager CFHTIR on the Canada-France-Hawaii Telescope are used to derive the morphological parameters of the red giant branch (RGB) in the near-infrared color-magnitude diagrams for 12…
This study is an attempt to determine the metallicities of WUMa-type binary stars using spectroscopy. ~4,500 spectra collected at the David Dunlap Observatory were subject to the same Broadening Function processing to determine the combined…
A catalog including a set of the most recent Color Magnitude Diagrams (CMDs) is presented for a sample of 61 Galactic Globular Clusters (GGCs). We used this data-base to perform an homogeneous systematic analysis of the evolved sequences…
A modification to the absolute magnitude calibration for W~UMa-type systems, taking into account differences in metal abundances, is derived on the basis of contact binary systems recently discovered in metal-poor clusters. A preliminary…
One of the desired outcomes of studying exoplanetary atmospheres is to set decisive constraints on exoplanet formation theories. Astronomers often speak of the "metallicity" in broad terms. When modeling the bulk metallicity, workers refer…