Related papers: 47 Tuc: The Spectroscopic Versus CMD Age Discrepan…

We use photometric and spectroscopic observations of the eclipsing binary V69-47 Tuc to derive the masses, radii, and luminosities of the component stars. Based on measured systemic velocity, distance, and proper motion, the system is a…

We discuss the present state of knowledge and thought concerning the spread in age found among Galactic globular clusters, with some discussion of the implications for what happened during the earliest stages of the formation of the Milky…

We extend our previous method to determine globular cluster ages using the luminosity function (Jimenez \& Padoan 1996). We show that the luminosity function depends on both age and distance modulus and that it is possible to distinguish…

We explore the reliability and robustness in measuring the age, metallicity and mass of a sample of old Milky Way globular clusters (GCs) from their integrated light, setting the stage for using GCs as cosmic clocks at high redshift. We…

In this paper we present CCD multicolor photometry for 172 globular clusters (GCs), taken from the Bologna catalog (Battistini et al. 1987), in the nearby spiral galaxy M31. The observations were carried out by using the National…

Stellar ages are key to improving our understanding of different astrophysical phenomena. However, many techniques to estimate stellar ages are highly model-dependent. The lithium depletion boundary (LDB), based on the presence or absence…

Determining reliable ages for old stellar objects at different redshifts offers a powerful means to constrain cosmology without relying on a specific cosmological model: this is known as the cosmic clocks method. Globular clusters (GCs),…

The well-known age-metallicity-attenuation degeneracy does not permit unique and good estimates of basic parameters of stars and stellar populations. The effects of dust can be avoided using spectral line indices, but current methods have…

Context: Analysis of ages and metallicities of star clusters in the Magellanic Clouds provide information for studies on the chemical evolution of the Clouds and other dwarf irregular galaxies. Aims: The aim is to derive ages and…

We report new photometry for the cluster NGC 2121 in the Large Magellanic Cloud, which shows a prominent hydrogen core exhaustion gap at the turnoff, and a descending subgiant branch remniscent of Galactic open clusters. We achieve an…

Context. Stellar ages are typically very difficult to estimate for field stars. New empirical methods, based on abundance ratios of chemical elements, are emerging and need to be calibrated. Aims. Our main aim is to contribute to revealing…

We used integrated-light medium-resolution spectra of six Galactic globular clusters and model stellar atmospheres to carry out population synthesis and to derive chemical composition and age of the clusters. We used medium-resolution…

We report the detection of intermediate-age and old stars belonging to the SMC at 6.5 kpc from the SMC center in the southern direction. We show, from the analysis of three high quality 34\arcmin $\times$ 33\arcmin CMDs, that the age…

I explore the current ability of both white dwarf cooling theory and main sequence stellar evolution theory to accurately determine stellar population ages by comparing ages derived using both techniques for open clusters ranging from 0.1…

In previous papers of the series we used a combination of optical and near-infrared colours to derive constraints on the relative age structure in globular cluster systems. Here, we present the details, strength and limitations of our…

We report the results of a study exploring the stellar populations of 13 luminous (L>L*), spectroscopically confirmed, galaxies in the redshift interval 5.5<z<6.5, all with WFC3/IR and IRAC imaging from the HST/CANDELS and Spitzer/SEDS…

HST (V,I) photometry has been obtained for the inner halo globular cluster NGC 6652. The photometry reaches approximately 4 mag below the turn-off and includes a well populated horizontal branch. This cluster is located close to the…

We present a color-magnitude diagram (CMD) of the globular cluster SKHB-312 in the Andromeda galaxy (M31), obtained with the Advanced Camera for Surveys on the Hubble Space Telescope. The cluster was included in deep observations taken to…

We present V, V-I color-magnitude diagrams (CMDs) for three old star clusters in the Large Magellanic Cloud (LMC): NGC 1466, NGC 2257 and Hodge 11. Our data extend about 3 magnitudes below the main-sequence turnoff, allowing us to determine…

This paper supplements Jiang et al. (2003), who studied 172 M31 globular clusters (GCs) and globular cluster candidates from Battistini et al. (1987) on the basis of integrated photometric measurements in the…