Investigation of open cluster NGC 7789 using GAIA EDR3 data

Abstract

We present the membership determination of the NGC 7789 open cluster located at Cassiopeia. Based on the astrometric data from Gaia Early Data Release 3 (positions, parallaxes, and proper motions) are considered to derive cluster members of the open cluster. The Hierarchical Density-Based Spatial Clustering of Applications with Noise and Gaussian Mixture Model techniques in determining the frequency and degree of a star’s membership in a cluster were being utilized in the study. We calculate the parallax and distance of the NGC 7789 cluster center to be 0.1994 ± 0.11 mas and 18637 ± 333110 pc respectively. The cluster center is calculated to be α = 359° 16' 56.44'', δ = 56° 42''38.46 ' and proper motion to be µα = −1.386 ± 0.68 mas/yr and µδ = −1.052 ± 0.37 mas/yr. We also utilized the Automated Stellar Cluster Analysis tool and obtained: log(age) = ~9.20, distance modulus (m-M)v =0.6516, reddening E(B V)=0.26±0.28, and metallicity [Fe/H] = −0.26, respectively. The stars in NGC 7789 show very little movement on proper motion and might be caused by fainter observations.