Related papers: Impact of distance determinations on Galactic stru…
We have investigated the results for [Fe/H] and distance for a group of 24 globular clusters in the Galactic bulge, employing recent calibrations of RR Lyrae light curves Fourier decomposition and period-absolute magnitude-metallicity (PMZ)…
We have used RR Lyrae and Blue HB stars as tracers of the old Galactic halo, in order to study the halo structure and the galactic rotation as a function of height above the plane. Our sample includes 40 RR Lyrae and 80 BHB stars that are…
The MACHO Project has catalogued $\sim 8000$ RR Lyrae stars in the Large Magellanic Cloud, $\sim 1800$ in the Galactic bulge, and $\sim$ 50 in the Sgr dwarf galaxy. These variables are excellent distance indicators, and are used as tools to…
We discuss the impact of Population II and Globular Cluster (GCs) stars on the derivation of the age of the Universe, and on the study of the formation and early evolution of galaxies, our own in particular. The long-standing problem of the…
Our Milky Way Galaxy is a typical large spiral galaxy, representative of the most common morphological type in the local Universe. We can determine the properties of individual stars in unusual detail, and use the characteristics of the…
Almost 80 years have passed since Trumpler's analysis of the Galactic open cluster system laid one of the main foundations for understanding the nature and structure of the Milky Way. Since then, the open cluster system has been recognised…
Their ubiquity and extreme densities make star clusters probes of prime importance of galaxy evolution. Old globular clusters keep imprints of the physical conditions of their assembly in the early Universe, and younger stellar objects,…
Gaia DR2 provides unprecedented precision in measurements of the distance and kinematics of stars in the solar neighborhood. Through applying unsupervised machine learning on DR2's 5-dimensional dataset (3d position + 2d velocity), we…
Type II Cepheids are both useful distance indicators and tracers of old age stellar populations in their host galaxy. We summarize near-infrared observations of type II Cepheids in the Large Magellanic Cloud and discuss the absolute…
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,…
We analyze the structure and chemo-dynamical properties of the Galactic bulge using ab-type RR Lyrae stars (RRabs) from OGLE-IV and giant stars from APOGEE and Gaia. Orbital integration of 1,879 RRab variables reveals three populations:…
From the archaeological point of view, the local dwarf galaxies are unique objects in which the imprint of the conditions that shaped the early structure formation can be studied today at high resolution. Over the last decade, this new…
The number of known globular clusters in the Galactic bulge has been increasing steadily thanks to different new surveys. The aim of this study is to provide a census of the newly revealed globular clusters in the Galactic bulge, and…
Recent surveys have detected RR Lyrae stars in M33, the Triangulum Galaxy. These variable stars are excellent tracers of ancient stellar populations. The RR Lyrae stars have been used to estimate metallicities at various locations within…
The age and chemical characteristics of the Galactic bulge link to the formation and evolutionary history of the Galaxy. Data-driven methods and large surveys enable stellar ages and precision chemical abundances to be determined for vast…
Quantification of the Galaxy's star formation history involves both the duration and the rate of formation, with these parameters being known with different precision for different populations. The early rate of star formation is knowable…
The last decade has seen apparent dramatic progress in large spectroscopic datasets aimed at the study of the Galactic bulge. We consider remaining problems that appear to be intractable with the existing data, including important issues…
Accurate astronomical distance determination is crucial for all fields in astrophysics, from Galactic to cosmological scales. Despite, or perhaps because of, significant efforts to determine accurate distances, using a wide range of…
The large astrometric and photometric survey performed by the Gaia mission allows for a panoptic view of the Galactic disc and in its stellar cluster population. Hundreds of clusters were only discovered after the latest G data release…
In order to understand the Galactic structure, we perform a statistical analysis of the distribution of various cluster parameters based on an almost complete sample of Galactic open clusters yet available. The geometrical and physical…