No Arabic abstract
This paper presents an investigation on the four open clusters Czernik 14, Haffner 14, Haffner 17 and King 10 located near the Perseus arm of Milky Way Galaxy using Gaia DR2, 2MASS, WISE, APASS and Pan-STARRS1 data sets. We find normal interstellar extinction in twelve photometric bands for these clusters. Likely cluster members are identified as 225, 353, 350 and 395 for Czernik 14, Haffner 14, Haffner 17 and King 10, respectively by using Gaia DR2 proper motion data. Radii are determined as 3.5, 3.7, 6.2 and 5.7 arcmin for Czernik 14, Haffner 14, Haffner 17 and King 10 respectively. Mean proper motions in RA and DEC are estimated as (-0.42 pm 0.02, -0.38 pm 0.01), (-1.82 pm 0.009, 1.73 pm 0.008), (-1.17 pm 0.007, 1.88 pm 0.006) and (-2.75 pm 0.008, -2.04 pm 0.006) mas/yr for Czernik 14, Haffner 14, Haffner 17 and King 10, respectively. The comparison of observed CMDs with solar metallicity isochrones leads to an age of 570 pm 60, 320 pm 35, 90 pm 10 and 45 pm 5 Myr for these clusters. The distances 2.9 pm 0.1, 4.8 pm 0.4, 3.6 pm 0.1 and 3.8 pm 0.1 kpc determined using parallax are comparable with the values derived by the isochrone fitting method. Mass function slopes are found to be in good agreement with the Salpeter value. The total masses are derived as 348, 595, 763 and 1088 solar mass for the clusters Czernik 14, Haffner 14, Haffner 17 and King 10, respectively. Evidence for the existence of mass-segregation effect is observed in each cluster. Using the Galactic potential model, Galactic orbits are derived for the clusters. The present study indicates that all clusters under study fallow a circular path around the Galactic center.
We present BVI photometry for poorly known southern hemisphere open clusters: NGC 2425, Haffner 10 and Czernik 29. We have calculated the density profile and established the number of stars in each cluster. The colour-magnitude diagrams of the objects show a well-defined main sequence. However, the red giant clump is present only in NGC 2425 and Haffner 10. For these two clusters we estimated the age as 2.5 +/- 0.5 Gyr assuming metallicity of Z=0.008. The apparent distance moduli are in the ranges 13.2<(m-M)_V<13.6 and 14.3<(m-M)_V<14.7, while heliocentric distances are estimated to be 2.9<d<3.8 kpc and 3.1<d<4.3 kpc, respectively for NGC 2425 and Haffner 10. The angular separation of 2.4 deg (150 pc at mean distance) may indicate a common origin of the two clusters.
We present the broad band UBVI CCD photometric investigations in the region of the two open clusters Haffner 11 and Czernik 31. The radii of the clusters are determined as 3.5 arcmin and 3.0 arcmin for Haffner 11 and Czernik 31 respectively. Using two colour (U-B) versus (B-V) diagram we determine the reddening E(B-V) = 0.50+/-0.05 mag and 0.48+/-0.05 mag for the cluster Haffner 11 and Czernik 31 respectively. Using 2MASS JHKs and optical data, we determined E(J-K) = 0.27+/-0.06 mag and E(V-K) = 1.37+/-0.06 for Haffner 11 and E(J-K) = 0.26+/-0.08 mag and E(V-K) = 1.32+/-0.08 mag for Czernik 31. Our analysis indicate normal interstellar extinction law in the direction of both the clusters. Distance of the clusters is determined as 5.8+/-0.5 Kpc for Haffner 11 and 3.2+/-0.3 Kpc for Czernik 31 by comparing the ZAMS with the CM diagram of the clusters. The age of the cluster has been estimated as 800+/-100 Myr for Haffner 11 and 160+/-40 Myr for Czernik 31 using the stellar isochrones of metallicity Z = 0.019.
In this paper, we present astrophysical parameters of the open cluster King 13 based on the VI CCD and 2MASS JHKs photometric data. This is a poorly studied cluster, for which new results have been found in the present work. To identify probable members, we use proper motion data from Gaia DR2 catalogue. The mean proper motion of the cluster is determined as -2.8 pm 0.2 and -0.88 pm 0.14 mas yr{-1} and cluster extent is derived as 3.2. Using color-magnitude diagrams, we estimate the age and distance of the cluster as 510 pm 60 Myr and 3.84 pm 0.15 kpc respectively. Interstellar reddening E(B-V) in the direction of the cluster is determined as 0.80 pm 0.2 mag using color-color diagram. Mass function slope of the cluster is found to be comparable with the Salpeter value. The total mass of this cluster is derived as 270 M_{odot}. The present analysis shows that King 13 is a dynamically relaxed cluster.
We present reddening, photometric metallicity, age and distance estimates for the Frolov 1 and NGC 7510 open clusters based on CCD UBV photometric and Gaia data. Photometric observations were collected using the 1-m telescope of the TUB.ITAK National Observatory. Gaia DR2 proper motion data in the direction of two groupings were used to identify cluster membership. We determined mean proper motion values ($ mu_{alpha}cosdelta, mu_{delta}$) = ($-3.02pm 0.10$, $-1.75 pm 0.08$) and ($-3.66 pm 0.07$, $-2.17 pm 0.06$) mas yr$^{-1}$ for Frolov 1 and NGC 7510, respectively. We used two-colour diagrams to obtain $E(B-V)$ colour excesses for Frolov 1 and NGC 7510 as $0.65pm0.06$ and $1.05pm0.05$ mag, respectively. We derived the photometric metallicity of Frolov 1 as [Fe/H] = 0.03$pm$0.03 dex and adopted a solar metallicity for NGC 7510. Based on these reddening and metallicities we determined the distance moduli and ages of the clusters via fitting PARSEC isochrones to the cluster colour-magnitude diagrams. Isochrone fitting distances for Frolov 1 and NGC 7510 are $2864 pm 254$ and $2818 pm 247$ pc, respectively, which correspond to the ages $35pm 10$ Myr and $18pm 6$ Myr. We also calculated mean Gaia distances and compared them with those given in the literature and in this study, concluding that our results are in good agreement with previous work. Finally, we calculated the mass function slopes as being $X=-1.21pm0.18$ for Frolov 1 and $X=-1.42pm0.27$ for NGC 7510.
The open cluster IC 4996 in Cygnus and its vicinity are investigated by applying a two-dimensional photometric classification of stars measured in the Vilnius seven-color photometric system. Cluster members are identified by applying distances based on the Gaia DR2 parallaxes and the point vector diagram of the Gaia DR2 proper motions. For some B-type stars, spectroscopic MK types are also obtained from the Asiago spectra and collected from the literature. New parameters of the cluster are derived. The interstellar extinction $A_V$ covers a wide range of values, from 1.3 to 2.4 mag; the mean value in the central part of the cluster is 1.8 mag. The cluster distance is 1915 $pm$ 110 pc, and its age is within 8-10 Myr. The cluster exhibits a long sequence from early-B to G stars, where stars cooler than B8 are in the pre-main-sequence stage. The plot of extinction versus distance shows a steep rise of $A_V$ up to 1.6 mag at 700-800 pc, which is probably related to dust clouds at the edge of the Great Cygnus Rift. The next increase in extinction by an additional 0.8 mag at $d$ $geq$ 1.7 kpc is probably related to the associations Cyg OB1 and Cyg OB3. The cluster IC 4996 does not belong to the Cyg OB1 association, which is located closer to the Sun, at 1682 $pm$ 116 pc. It seems likely that the cluster and the surrounding O-B stars have a common origin with the nearby association Cyg OB3 since Gaia data show that these stellar groups are located at a similar distance.