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The astrophysical parameters of the open star cluster Mayer 3 have been estimated using the Newtonian focus (f/4.84) of the 1.88 m Telescope of Kottamia Observatory in Egypt. The VRI observations have been carried out down to a limiting magnitude of V ~ 20 mag. To emphasize the main astrophysical parameters, Near-Infra Red, Two Micron All Sky Survey (2MASS-JHK) database has been used. Analyzing the color-magnitude diagrams and radial density distribution of Mayer 3, the cluster's age, reddening, distance from the Sun, the limited border, core and tidal radii are evaluated. The photometrical membership, the Galactocentric coordinates from the Galactic center and Galactic plane are estimated. Luminosity - mass functions, and the total mass of the cluster are established. Finally, the relaxation time estimation conclude that Mayer 3 is not dynamically relaxed yet., Comment: 17 pages, 8 figures, 3 tables

We present 776 truly physical galaxy pairs, 569 of them are close pairs and 208 false pairs from Karachentsev (1972) and Reduzzi & Rampazzo (1995) catalogues, which contains 1012 galaxy pairs. Also we carried out star formation activity through the far-infrared emission (FIR) in physical (truly) interacting galaxies in some galaxy pairs and compared them with projection (optical) interacting galaxy pairs. We focused on the triggering of star formation by interactions and analyzed the enhancement of star formation activity in terms of truly physical galaxy pairs. The large fraction of star formation activity is probably due to the activity in the exchange of matter between the truly companions. The star formation rate (SFR) of galaxies in truly galaxy pairs is found to be more enhanced than the apparent pairs., Comment: 9 pages, 8 figures, 1 table, International Journal of Advanced Research, 2014

The astrophysical parameters of four unstudied open star cluster candidates - Harvard 9, Ivanov 2, Ivanov 7, and Ivanov 9 - have been estimated for the first time using the PPMXL database. The stellar density distributions and color-magnitude diagrams for each cluster are used to determine the geometrical structure (cluster center, limited radius, core and tidal radii, the distances from the Sun, from the Galactic center and from the Galactic plane). Also, the main photometric parameters (age, distance modulus, color excesses, membership, total mass, relaxation time, luminosity and mass functions) are estimated., Comment: 16 pages, 6 figures

Here we have obtained the {\it BVRI CCD} photometry down to a limiting magnitude of $V \sim$ 20 for the southern poorly studied open cluster NGC 6631. It is observed from the {\it 1.88 m} Telescope of Kottamia Observatory in Egypt. About 3300 stars have been observed in an area of $\sim 10^{\prime} \times 10^{\prime}$ around the cluster center. The main photometric parameters have been estimated and compared with the results that determined for the cluster using {\it JHKs 2MASS} photometric database. The cluster's diameter is estimated to be 10 arcmin; the reddening E(B-V)= 0.68 $\pm$ 0.10 mag, E(J-H)= 0.21 $\pm$ 0.10 mag, the true modulus (m-M)$_{o}$= 12.16 $\pm$ 0.10 mag, which corresponds to a distance of 2700 $\pm$125 pc and age of 500 $\pm$ 50 Myr., Comment: 13 pages, 6 figures

We present here the fundamental parameters of ten open star clusters, nominated from Kronberger et al. (2006) who presented some new discovered stellar groups on the basis of 2MASS photometry and DSS visual images. Star counts and photometric parameters (radius, membership, distances, color excess, age, luminosity function, mass function, total mass, and the dynamical relaxation time) have been determined for these ten clusters for the first time. In order to calibrate our procedures, the main parameters (distance, age, and color excesses) have been re-estimated for another five clusters, which are studied by Kronberger et al. (2006) as well., Comment: 10 pages, 5 figures, 2 tables; accepted in "Research in Astronomy and Astrophysics Journal"

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 selected from Kronberger et al. (2006) who presented some new discovered stellar groups on the basis of 2MASS photometry and the DSS visual images. The astrometry and photometric parameters are determined using the stellar density distributions and color-magnitude diagrams fittings. Center, radius, membership, distances, reddening, age, luminosity function, mass function, total mass, and the dynamical relaxation time have been estimated for the first time. This paper is a part of Reda's PhD project., Comment: 14 pages, 9 figures, 1st Arab Conference on Astronomy and Geophysics, Egypt 2008