A Gaia based photometric and kinematic analysis of the old open cluster King 11

Abstract

This paper presents an investigation of an old age open cluster King 11 using Gaia's Early Data Release 3 (EDR3) 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 (PM) 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 (BSS) of King 11 show a centrally concentrated radial distribution. The values of limiting radius, age, and distance are determined as 18.51 arcmin, 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 (AD) 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.