Related papers: Classical Cepheids as Age Indicators
Classical Cepheid variable stars are both sensitive astrophysical laboratories and accurate cosmic distance tracers. We have recently investigated how the evolutionary effects of rotation impact the properties of these important stars and…
Classical Cepheid stars have been considered since more than a century as reliable tools to estimate distances in the universe thanks to their Period-Luminosity (P-L) relationship. Moreover, they are also powerful astrophysical…
To study the evolution of binary star clusters we have imaged 7 systems in the Small Magellanic Cloud with SOAR 4-m telescope using B and V filters. The sample contains pairs with well-separated components (d < 30 pc) as well as systems…
The Magellanic Clouds (MCs) present a rich system of stellar clusters that can be used to probe the dynamical and chemical evolution of these neighboring and interacting irregular galaxies. In particular, these stellar clusters (SCs)…
We present homogeneous age determinations for a large sample of 55 Galactic globular clusters, which constitute about 30% of the total Galactic population. A study of their age distribution reveals that all clusters from the most metal poor…
The metal-poor, fundamental-mode (P0) and first-overtone (P1) Cepheids in the dwarf galaxies IC 1613, WLM, Pegasus, Sextans A, Sextans B, and Leo A are compared with the about equally metal-poor Cepheids of the Small Magellanic Cloud (SMC).…
We present Period-Luminosity-Color and Period-Luminosity relations of classical Cepheids constructed for about 1280 Cepheids from the LMC and 2140 from the SMC. High quality BVI observations (120-360 epochs in the I-band and 15-40 in the…
The popularity of pulsating stars resides in their capacity of determining several crucial and relevant parameters such as heliocentric distances, ages, metallicity gradients and reddening. RR Lyrae stars are old stellar tracers and have…
The determination of stellar populations of galaxies are important for studying the formation and evolution of galaxies, because all galaxies contain many stars and they evolve with galaxies. Spectra data are usually used to determine the…
In this work we study 35 stellar clusters in the Small Magellanic Cloud (SMC) in order to provide their mean metallicities and ages. We also provide mean metallicities of the fields surrounding the clusters. We used Str\"omgren photometry…
Chemical clocks offer a powerful tool for estimating stellar ages from spectroscopic surveys. We present a new detailed spectroscopic analysis of 68 Kepler red giant stars to provide a suite of high-precision abundances along with…
We show that the UV flux of old stellar systems can tell us about their ages. Two independent populations synthesis groups that have had wildly different views have here worked together and generated two solutions that can be easily tested…
We study 147 star clusters in the Large Magellanic Cloud (LMC) in order to determine their mean metallicities and ages, as well as the mean metallicities of 80 surrounding fields. We construct an age-metallicity relation (AMR) for the…
Recent analyses of solar spectroscopic data (see Asplund, Grevesse & Sauval 2004 and references therein) suggest a significative variation of the heavy elements abundance. The change of heavy mixture might affect the determination of the…
The age-metallicity relation is fundamental to study the formation and evolution of the disk. Observations have shown that this relation has a large scatter which can not be explained by observational errors only. That scatter is hence…
Globular cluster ages are more than just lower limits to the age of the universe; the distribution of ages constraints the timescales for galaxy formation and chemical evolution. Globular cluster populations with different metallicities…
Observations of rich LMC and SMC clusters reveal an increasing spread in core radius with age. This trend likely represents real physical evolution in these systems. Old Magellanic Cloud clusters appear either extended or compact. Similar…
We discuss recent developments on the age and metallicity distribution for early type galaxies in different environments.
The Small Magellanic Cloud (SMC) is the only dwarf galaxy in the Local Group known to have formed and preserved populous star clusters continuously over the past 12 Gyr. These clusters provide a unique, closely spaced set of single-age,…
In the age of high-resolution spectroscopic stellar surveys of the Milky Way, the number of stars with detailed abundances of multiple elements is rapidly increasing. These elemental abundances are directly influenced by the evolutionary…