Related papers: Low mass variable stars in the globular cluster NG…

We present the results of a search for variable stars in the central part of the globular cluster NGC 6752. The monitored sample included 160 BHB and 107 EHB stars, respectively. A total of 17 variables were detected of which 14 are new…

In this paper we have examined the internal dynamics of the globular cluster NGC 362. A V band surface brightness profile (SBP) was constructed from CCD images, and, after it was determined that the cluster is not post core-collapse, fit…

We present new time-series CCD \emph{VR} photometry of the globular cluster NGC 5634. We aim to use the known RR Lyrae stars, members of the cluster, as indicators of mean metallicity and distance. Accurate coordinates, periods and an…

In this paper we present a new, accurate determination of the three components of the absolute space velocity of the Galactic globular cluster NGC6397 (l 338d, b -12d). We used three HST/WFPC2 fields with multi-epoch observations to obtain…

We describe a variability study of the moderately old open cluster NGC 6819. We have detected 4 new detached eclipsing binaries near the cluster turnoff (one of which may be in a triple system). Several of these systems should be able to…

We have undertaken a search for variable stars in the metal-rich globular cluster NGC 6441 using time-series BV photometry. The total number of variables found near NGC 6441 has been increased to ~104, with 48 new variables being found in…

We report the discovery of a variable blue straggler in the core of the globular cluster M5, based on a 12-hour long series of images obtained with the Planetary Camera aboard the Hubble Space Telescope. In addition, we present the light…

We have applied the image subtraction method to images of the peculiar, bimodal-horizontal branch globular cluster NGC 2808, taken over a total of six nights over a range of five months. As a result, we have found, for the first time, a…

We observed a large sample of B & Be stars in the Magellanic Clouds, respectively 176 and 344 stars, with the multi-object spectrograph GIRAFFE at ESO/VLT. We obtained spectra at different settings at various epochs. It allowed us to…

We report the discovery of a sizeable, previously unknown variable star population in the Sagittarius dwarf spheroidal globular clusters NGC 5634, Arp 2 and Terzan 8. Location, preliminary pulsation periods and B-band light curves in…

We have undertaken a study of the globular cluster (GC) systems of a large sample of elliptical and spiral galaxies in order to test predictions of galaxy formation models. Here we present results for the giant Virgo elliptical NGC 4472…

We present the results of a photometric and spectroscopic survey of the globular cluster system of NGC 5128 (Centaurus A), a galaxy whose proximity makes it an important target for early-type galaxy studies. We imaged three fields in UBVRI…

We present (V,V-I) VLT-FORS1 observations of the Galactic Globular Cluster NGC 6397. We derive accurate color--magnitude diagrams and luminosity functions (LFs) of the cluster Main Sequence (MS) for two fields extending from a region near…

The total-to-selective extinction RV in the direction of a cluster is found to be 3.12 +/- 0.2 (close to its normal value). We derive the luminosity and mass functions for the cluster main sequence stars. The mass function slope is found to…

Cataclysmic variables (CVs) are tracers of dynamical evolution in globular clusters. A significant sample has been found by the relatively shallow \Halpha surveys conducted with HST thus far in just three globulars: NGC 6397 (3), NGC 6752…

Evolutionary trends in the surface abundances of heavier elements have recently been identified in the globular cluster NGC 6397 ([Fe/H]=-2), indicating the operation of atomic diffusion in these stars. Such trends constitute important…

NGC 6357 is an active star-forming region located in the Sagittarius arm displaying several star clusters, which makes it a very interesting target to investigate star formation and early cluster evolution. We explore NGC 6357 with the…

We present optical lightcurves of variable stars consistent with the positions of X-ray sources identified with the Chandra X-ray Observatory for the Chandra Galactic Bulge Survey. Using data from the Mosaic-II instrument on the Blanco 4m…

We present a far-ultraviolet (FUV) study of the globular cluster M30 (NGC 7099). The images were obtained using the Advanced Camera for Surveys (ACS/SBC, F150LP, FUV) and the Wide Field Planetary Camera 2 (WFPC2, F300W, UV) on board the…

Variable stars have been identified for the first time in Fornax 4, the globular cluster located near the center of the Fornax dwarf spheroidal galaxy. By applying the image subtraction technique to B,V time series photometry obtained with…