UBV RICCD photometric study of the open clusters Basel 4 and NGC 7067

Abstract

In this paper we present UBV RI CCD photometry in the region of two young open star clusters Basel 4 and NGC 7067 for the first time. Our sample consists of ∼4000 stars down to V∼ 21 mag. Stellar surface density profile indicates that radii of Basel 4 and NGC 7067 are about 1.8 and 3.0 arcmin respectively. The (U−B) versus (B−V) diagrams indicate that the metallicity of NGC 7067 is solar while that of Basel 4 is Z∼ 0.008. We estimate the mean value of E(B−V) = 0.45 ± 0.05 and 0.75 ± 0.05 mag for Basel 4 and NGC 7067, respectively. The analysis of 2MASS JHK data in combination with the optical data in both the clusters yields E(J−K) = 0.30 ± 0.20 mag and E(V−K) = 1.60 ± 0.20 mag for Basel 4 while E(J−K) = 0.40 ± 0.20 mag and E(V−K) = 2.10 ± 0.20 mag for NGC 7067. Furthermore, colour excess diagrams show a normal interstellar extinction law towards both the clusters. Using the intrinsic colour–magnitude diagrams of the cluster members, we estimated the distances of the clusters as 3.0 ± 0.2 and 3.6 ± 0.2 kpc for Basel 4 and NGC 7067, respectively. By fitting the proper metallicity isochrones to the bright cluster members we estimated the age of the clusters as 200 ± 50 and 100 ± 25 Myr for Basel 4 and NGC 7067, respectively. The mass function slopes that are derived by applying the corrections of field star contamination and data incompleteness are 1.55 ± 0.25 and 1.68 ± 0.47 for Basel 4 and NGC 7067, respectively. The values of the mass function slope are thus not very different from Salpeter's value. Mass segregation is observed in both the clusters, which may be caused by the dynamical evolution or the imprint of star formation processes or both.

Towards a census of the Galactic anticentre star clusters: colour–magnitude diagram and structural analyses of a sample of 50 objects

“…We derive parameters for the previously catalogued OCs Cz 22 and NGC 2234. Yadav & Sagar (2004) derived for Cz 22 a radius of 1.8 , metallicity of 0.08, E(B − V) = 0.45 ± 0.05, age of the 200 ± 50 Myr and d = 3.0 ± 0.2 kpc. NGC2234 does not have parameters derived so far.…”

The Young Open Cluster Berkeley 55

“…• 2) has distance estimates of 3.6 kpc (Yadav & Sagar 2004) and 4.4 kpc (Hassan 1973). NGC 7128 ( = 97.…”

An investigation of open cluster Melotte 72 using Gaia DR2

“…Color magnitude diagram (CMD) of the cluster is used to derive the luminosity function and mass function. Considerable work has been accomplished by many researchers (Elmegreen 2000; Phelps & Janes 1993; Piskunov et al 2004; Scalo 1986; Yadav & Sagar 2002, 2004). In this paper, one of our main aims is to determine the mass function of Melotte 72 and re‐estimated its main astrophysical properties using the database of GAIA mission.…”