Related papers: New analysis in the field of open cluster Collinde…
We present here the fundamental properties of some newly discovered open star clusters (Teutsch 144, Alessi 53, Riddle 4 and Juchrt 12) using the JHK Near-IR photometry (2MASS survey) of Cutri et al. (2003). These clusters have been…
Stromgren indices v and b are combined with broad-band index I, and a new index p, the short wavelength half of the v band, to estimate CN 4215A molecular absorption in a sample of stars in M22. The results have been used to estimate carbon…
The physical nature of a series of 20 new open clusters is confirmed employing existing data on putative star members, mainly from second Gaia Data Release (DR2). The clusters were discovered as overdensities of stars by visual inspection…
The astro-photometric parameters of the open star cluster Dolidze 41, which located in the constellation of Cygnus, have been investigated using the Gaia-ESO DR2 large Survey merging with the near Infrared Two Micron All Sky Survey 2MASS…
In this study, we have used the {\it Gaia} Third Data Release (Gaia DR3) to investigate an intermediate-age open cluster Collinder 74. Taking into account the stars with membership probabilities over 0.5 and inside the limiting radius of…
Open clusters have long been used to gain insights into the structure, composition, and evolution of the Galaxy. With the large amount of stellar data available for many clusters in the Gaia era, new techniques must be developed for…
We present new BVRI broad-band photometry for the old open cluster NGC188 based upon analysis of 299 CCD images either obtained by us, donated by colleagues, or retrieved from public archives. We compare our results on a star-by-star basis…
Current catalogues of open clusters are rather heterogeneous and incomplete lists of clusters than true catalogues. Before there has been no attempts of automatic search for open clusters in huge photometric catalogues using homogeneous…
We present a spectroscopic survey of the rich, X-ray selected, galaxy cluster CL 1358+6245 at z=0.328. When our 173 new multi-slit spectra of cluster galaxies are combined with data from the literature, we produce a catalog of 232 cluster…
We have used a star-count algorithm based the Panoramic Survey Telescope And Rapid Response System 3$\pi$ survey data aim to identify and characterize uncharted open clusters (OCs). With limiting magnitudes of about 22 mag in \gps, \rps,…
There is a growing interest in the automated characterization of open clusters using data from the Gaia mission. This work evidences the importance of choosing an appropriate sampling radius (the radius of the circular region around the…
A new CCD photometry survey of the open cluster NGC7788 in U, B, V, R and I colors to magnitude V=20 is present. Extensive comparison of our photometry with other published dataset shows excellent agreement, indicating that CCD photometry…
The estimation of the main parameters of star clusters is a very important target in astrophysical studies. Many of the open clusters listed in known catalogs have insuffcient astrometric parameters. Improving the observations and analysis…
The distribution of young stars found in the Chandra Carina Complex Project (CCCP) is examined for clustering structure. X-ray surveys are advantageous for identifying young stellar populations compared to optical and infrared surveys in…
We aim at a direct measurement of the compactness of three galaxy-scale lenses in massive clusters, testing the accuracy of the scaling laws that describe the members in strong lensing (SL) models of galaxy clusters. We selected the…
The estimation of the main parameters of star clusters is significant in astrophysical studies. The most important aspect of using the Gaia DR2 survey lies in the positions, parallax, and proper motions of cluster stars with homogeneous…
A photometric and astrometric study of the two open star clusters Gulliver 18 and Gulliver 58 was carried out for the first time using the early third data release of the Gaia space observatory (Gaia-EDR3). By studying the proper motions,…
The search for chemically peculiar (CP) stars in open clusters using photoelectric photometry sampling the presence of the characteristic flux depression feature at 5200A via the Delta a-system (Maitzen 1976) has so far delivered data for…
The galaxy cluster SRGe CL2305.2$-$2248 (SPT-CL J2305$-$2248, ACT-CL J2305.1$-$2248) is one of the most massive clusters at high redshifts ($z \simeq 0.76$) and is of great interest for cosmology. For an optical identification of this…
In gaussian theories of structure formation, the galaxy cluster abundance is an extremely sensitive probe of the density fluctuation power spectrum and of the density parameter, $\Omega$. We develop this theme by deriving and studying in…