Related papers: Binary stars in globular clusters: detection of a …

By far, the color-magnitude diagrams (CMDs) of Galactic open clusters have been considered proto-types of single stellar populations. By using photometry in ultraviolet and optical bands we discovered that the nearby young cluster NGC6705…

The possible association of Galactic globular clusters with the Sgr Stream is shortly reviewed at the light of the most recent observations of the Stream. >= 20 % of the Galactic globular clusters with R_{GC}>= 10 Kpc are found to lie…

The Main Sequence Luminosity Function (LF) of the Galactic globular cluster NGC 288 has been obtained using deep WFPC2 photometry. We have employed a new method to correct for completeness and fully account for bin-to-bin migration due to…

We have carried out high-precision photometry on a large number of archival HST images of the Galactic globular cluster NGC 6752, to search for signs of multiple stellar populations. We find a broadened main sequence, and demonstrate that…

We report the discovery of the only very nitrogen-enhanced metal-poor star known in a Galactic globular cluster. This star, in the very metal-poor cluster ESO280-SC06, has [N/Fe]$>+2.5$, while the other stars in the cluster show no obvious…

We investigate the binary content of the two stellar populations that coexist in the globular cluster NGC 3201. Previous studies of binary stars in globular clusters have reported higher binary fractions in their first populations (P1,…

Our 5 ks Chandra ACIS-S observation of the globular cluster NGC 6652 detected 7 X-ray sources, 3 of which are previously unidentified. This cluster hosts a well-known bright low-mass X-ray binary, source A (or XB 1832-330). Source B shows…

We present extensive new photometry in (g',i') of the large globular cluster (GC) system around NGC 3311, the central cD galaxy in the Hydra cluster. Our GMOS data cover a 5.5' field of view and reach a limiting magnitude i' = 26, about 0.5…

We report on the discovery and analysis of 14 short-period variable stars in the field of the southern globular cluster NGC 3201, located within roughly two magnitudes on either side of the main-sequence turnoff. 11 of these variable stars…

We present the abundance analysis of stars from the tip of the red giant branch (RGB) to below the RGB-bump in the globular cluster NGC 2808, based on high resolution echelle spectra. We derived abundances of Al, alpha-process elements (Si…

This Letter presents the color distributions of the globular cluster (GC) systems of 12 Virgo elliptical galaxies, measured using data from the Hubble Space Telescope. Bright galaxies with large numbers of detected GC's show two distinct…

The fraction of binary stars is an important ingredient to interpret globular cluster dynamical evolution and their stellar population. We investigate the properties of main-sequence binaries measured in a uniform photometric sample of 59…

Globular clusters have been recognized to host multiple stellar populations. A spectacular example of this is the massive cluster NGC2808, where multiple populations have been found along the horizontal branch (HB) and the main sequence…

We have carried out a new photometric study of the remote Galactic globular cluster NGC 2419, using proprietary and archive B,V,I time-series CCD photometry of the cluster, that allowed us to discover a large number of new variable stars…

We present the first CCD photometric observations of the northern open cluster NGC 2126. Data were taken on eight nights in February and December 2002 with a total time span of ~57 hours. Almost 1000 individual V-band frames were examined…

The binary fractions of open and globular clusters yield powerful constraints on their dynamical state and evolutionary history. We apply publicly available Bayesian analysis code to a $UBVRIJHK_{S}$ photometric catalog of the old open…

We present results of a search for objects with H-alpha excess, such as cataclysmic variables (CVs) and chromospherically active binaries (ABs), as counterparts to X-ray sources detected with Chandra satellite observatory in six Galactic…

We exploit multi-band Hubble Space Telescope photometry to investigate multiple populations (MPs) along the red horizontal branches (HBs) and red clumps of fourteen metal-rich Globular Clusters (GCs), including twelve Milky Way GCs and the…

NGC 2808 is a unique globular cluster with not only a bimodal-horizontal branch (HB) but also with gaps on the blue horizontal branch. Adequate interpretation of the nature of the detected peculiarities in "bimodal" and "gap" clusters is of…

In addition to the extended main-sequence turnoffs widely found in young and intermediate-age (~ 600 Myr-2 Gyr-old) star clusters, some younger clusters even exhibit split main sequences (MSs). Different stellar rotation rates are proposed…