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

TL;DR

This study uses Gaia EDR3 data to analyze the old open cluster King 11, determining its membership, kinematics, age, distance, and orbital parameters, providing insights into its structure and Galactic orbit.

Contribution

It provides a comprehensive Gaia-based photometric and kinematic analysis of King 11, including membership, proper motion, orbit, and age, which was not previously detailed.

Findings

Identified 676 probable cluster members with >90% probability.

Determined the cluster's age as approximately 3.63 Gyr.

Calculated the cluster's orbit and birthplace in the Galaxy.

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 ($P_{\mu}$) $> 90\%$, we identified 676 most probable cluster members within the cluster's limiting radius. The mean proper motion (PM) for King 11 is determined as: $\mu_{x}=-3.391\pm0.006$ and $\mu_{y}=-0.660\pm0.004$ 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$\pm$0.42 Gyr and $3.33\pm0.15$ kpc, respectively. The cluster's apex coordinates ($A=267.84^{\circ} \pm 1.01^{\circ}$, $D=-27.48^{\circ} \pm 1.03^{\circ}$) are determined using the apex diagram (AD) method and verified using the ($\mu_U$,$\mu_T$) 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 $\pm$ 2.16 km s$^{-1}$. A significant oscillation along the $Z$-coordinate up to 0.556$\pm$0.022~kpc is determined.