Related papers: Comparison between predicted and empirical DV(Bump…
We present new empirical estimates of the Delta V_HB_bump parameter for 15 Galactic globular clusters (GGCs) using accurate and homogeneous ground-based optical data. Together with similar evaluations available in the literature, we ended…
We present observational estimates of the magnitude difference between the luminosity function RGB bump and the HB (Delta(bump-zahb)), and of star counts in the bump region (R_bump), for a sample of 54 Galactic globular clusters (GCs)…
We present wide field JHKs photometry of 16 Galactic globular clusters located towards the Galactic bulge, calibrated on the 2MASS photometric system. Differential reddening corrections and statistical field star decontamination are…
We have developed an homogeneous evolutionary scenario for H- and He-burning low-mass stars by computing updated stellar models for a wide metallicity and age range (0.0002$\le Z \le$0.004 and 9$\le t(Gyr) \le$15, respectively) suitable to…
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…
V-band luminosity functions have been obtained for the upper main-sequence, sub-giant branch and red giant branch of 18 galactic globular clusters from HST data. A comparison with four sets of theoretical models has been performed. In…
We present high quality near infrared Color Magnitude Diagrams of 10 Galactic Globular Clusters (GCs) spanning a wide metallicity range (-2.15<[Fe/H]<-0.2). This homogeneous data-base has been used to perform a detailed analysis of the Red…
New theoretical evaluations of the RGB luminosity function 'bump' and the ZAHB luminosity covering the range of metallicities typical of galactic globular cluster are presented. The variation of the theoretical RGB bump and ZAHB levels due…
Using photometric data from the 2MASS second incremental release point source catalog we constructed Ks vs. (J-Ks) color-magnitude diagrams (CMDs) of Galactic globular clusters (GGCs) for which the JKs photometric data have been made…
The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters is providing a major breakthrough in our knowledge of Globular Clusters (GCs) and their stellar populations. Among the main results, we discovered that all the…
We present the broadest and most precise empirical investigation of red giant branch bump (RGBB) brightness and number counts ever conducted. We implement a new method and use data from two \textit{Hubble Space Telescope (HST)} globular…
Color-magnitude diagrams of globular clusters often exhibit a prominent horizontal branch (HB) and may also show features such as the red giant branch (RGB) bump and the asymptotic giant branch (AGB) bump. Stellar evolution theory predicts…
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 estimate the empirical R parameter in 26 Galactic Globular Clusters covering a wide metallicity range, imaged by WFPC2 on board the HST. The improved spatial resolution permits a large fraction of the evolved stars to be measured and…
We use the Stetson, HST, and Gaia DR3 data sets for 22 Galactic globular clusters to select their members and fit their CMDs with isochrones from DSED and BaSTI for $[\alpha/$Fe$]=+0.4$ and an adopted helium mass fraction $Y$. As a result,…
Hubble Space Telescope imaging for 26 giant early-type galaxies, all drawn from the MAST archive, is used to carry out photometry of their surrounding globular cluster (GC) systems. Most of these targets are Brightest Cluster Galaxies…
In the present work we analyzed seven globular clusters selected from their location in the Galactic bulge and with metallicity values in the range $-1.30\lesssim\rm{[Fe/H]}\lesssim-0.50$. The aim of this work is first to derive cluster…
We estimate the initial He content in about 30% of the Galactic globular clusters (GGCs) from new star counts we have performed on the recently published HST snapshot database of Colour Magnitude Diagrams (Piotto et al. 2002). More in…
Stars in massive star clusters exhibit intrinsic variations in some light elements (MPs) that are difficult to explain in a coherent formation scenario. In recent years, HST photometry has led to the characterisation of the global…
We present a measurement of metallicity in the Galactic center Quintuplet Cluster made using quantitative spectral analysis of two Luminous Blue Variables (LBVs). The analysis employs line-blanketed NLTE wind/atmosphere models fit to…