8 research outputs found
An Investigation of 11 previously unstudied open star clusters
The main astrophysical properties of 11 previously unstudied open star
clusters are probed with JHK Near-IR (2MASS) photometry of Cutri et al. [Cutri,
R., et al., 2003. The IRSA 2MASS All-sky Point Source Catalog, NASA/IPAC
Infrared Science Archive] and proper motions (NOMAD) astrometry of Zacharias et
al. [Zacharias, N., Monet, D., Levine, S., Urban, S., Gaume, R., Wycoff, G.,
2004. American Astro. Soc. Meeting 36, 1418]. The fundamental parameters have
been derived for IC (1434, 2156); King (17, 18, 20, 23, 26)}; and Dias (2, 3,
4, 7, 8)}, for which no prior parameters are available in the literature. The
clusters' centers coordinates and angular diameters are re-determined, while
ages, distances, and color excesses for these clusters are estimated here for
the first time.Comment: 9 pages, 3 figure, the first version of this article was presented as
a poster paper in the First Middle East-Africa, Regional IAU Meeting, Cairo,
Egypt, April 5-10, 200
The structure and dynamics of young star clusters: King 16, NGC 1931, NGC 637 and NGC 189
In this paper, using 2MASS photometry, we study the structural and dynamical
properties of four young star clusters viz. King 16, NGC 1931, NGC 637 and NGC
189. For the clusters King 16, NGC 1931, NGC 637 and NGC 189, we obtain the
limiting radii of 7', 12', 6' and 5' which correspond to linear radii of 3.6
pc, 8.85 pc, 3.96 pc and 2.8 pc respectively. The reddening values
obtained for the clusters are 0.85, 0.65--0.85, 0.6 and 0.53 and their true
distances are 1786 pc, 3062 pc, 2270 pc and 912 pc respectively. Ages of the
clusters are 6 Myr, 4 Myr, 4 Myr and 10 Myr respectively. We compare their
structures, luminosity functions and mass functions () to the parameter to study the star
formation process and the dynamical evolution of these clusters. We find that,
for our sample, mass seggregation is observed in clusters or their cores only
when the ages of the clusters are comparable to their relaxation times (). These results suggest mass seggregation due to dynamical effects. The
values of , which characterise the overall mass functions for the
clusters are 0.96 0.11, 1.16 0.18, 0.55 0.14 and 0.66
0.31 respectively. The change in as a function of radius is a good
indicator of the dynamical state of clusters.Comment: Accepted for publication in Astrophysics & Space Scienc
Photometric and astrometric study of open cluster FSR 814 (Koposov 36) using SDSS/2MASS/PPMXL/Gaia DR2
The astrophysical behavior of open clusters along the Milky Way Galaxy
The main aim of this paper is to study the astrophysical behaviour of open clustersâ properties along the Milky Way Galaxy. Near-IR JHKS (2MASS) photometry has been used for getting a homogeneous Catalog of 263 open clustersâ parameters, which are randomly selected and studied by the author through the last five years; most of them were studied for the first time. The correlations between the astrophysical parameters of these clusters have been achieved by morphological way and compared with the most recent works