Membership and age determination of M67 open cluster using GAIA EDR3 data

Abstract

Abstract We present our study on the membership and age determination of M67 (NGC 2682), one of the oldest open clusters known to date. Proper motions and parallax of stars collected in the Gaia Early Data Release 3 are used to derive the cluster members by employing the Hierarchical Density-Based Spatial Clustering of Applications with Noise algorithm, which is further improved upon using a Gaussian Mixture Model. We calculate the position of the cluster centre and the parallax to be α = 08h51m24s±1m33s, δ = 11°49’12"±0°22’48" and 1.1497±0.06 mas respectively. The proper motion of the cluster is obtained to be μa = −10.96 ± 0.20 mas/yr and μs = −2.90 ± 0.19 mas/yr. Subsequently, we perform an isochrone fitting to the Color-Magnitude Diagram (CMD) of M67 source members by using the Automated Stellar Cluster Analysis tool (ASteCA). Our findings estimate the log age, metallicity (z), reddening (EB–V ), and distance modulus (m – M)0 to be 9.630 ± 0.033 log-years, 0.01865 ± 0.001, 0.037 ± 0.008, and 9.409 ± 0.031 respectively.