A Gaia-based Photometric and Kinematic Analysis of the Old Open Cluster King 11

This paper presents an investigation of an old age open cluster King 11 using Gaia’s Early Data Release 3 data. Considering the stars with membership probability ( P μ ) > 90%, we identified 676 most probable cluster members within the cluster’s limiting radius. The mean proper motion for King 11 is determined as: μ x = − 3.391 ± 0.006 and μ y = − 0.660 ± 0.004 mas yr −1 . The blue straggler stars of King 11 show a centrally concentrated radial distribution. The values of limiting radius, age, and distance are determined as 18.′51, 3.63 ± 0.42 Gyr, and 3.33 ± 0.15 kpc, respectively. The cluster’s apex coordinates ( A = 267.°84 ± 1.°01, D = − 27.°48 ± 1.°03) are determined using the apex diagram method and verified using the ( μ U , μ T ) diagram. We also obtained the orbit that the cluster follows in the Galaxy and estimated its tentative birthplace in the disk. The resulting spatial velocity of King 11 is 60.2 ± 2.16 km s −1 . A significant oscillation along the Z coordinate up to 0.556 ± 0.022 kpc is determined.