In-depth analysis of photometric and kinematic characteristics of SAI 16, SAI 81 and SAI 86 open clusters utilizing Gaia DR3

Abstract

This study comprehensively analyses three open star clusters: SAI 16, SAI 81 and SAI 86 using Gaia DR3 data. Based on the ASteCA code, we determined the most probable star candidates (\(P\ge 50\)%) and estimated the number of star members of each cluster as 125, 158 and 138, respectively. We estimated the internal structural parameters by fitting the King model to the observed radial density profiles, including the core, limited and tidal radii. Isochrone fitting to the colour–magnitude diagram provided \(\log \) age of \(9.13 \pm 0.04\), \(8.10 \pm 0.04\) and \(8.65 \pm 0.04\) and distances (d) of \(3790 \pm 94\), \(3900 \pm 200\) and \(3120 \pm 30\) pc for SAI 16, SAI 81 and SAI 86, respectively. Moreover, we have calculated their projected distances from the galactic plane (\(X_{\odot }\), \( Y_{\odot })\) as well as their projected distance from the galactic plane \((Z_{\odot })\), distance from the galactic centre (\(R_{gc}\)) and total mass (\(M_{C}\)) in solar units are about \(142\pm 12\), \(302\pm 17\) and \(192\pm 14\) for SAI 16, SAI 81 and SAI 86, respectively. Examining the dynamical relaxation state indicates that all three clusters are dynamically relaxed. By undertaking a kinematic analysis of the cluster data, space velocity was determined. We calculated the coordinates of the apex point (\(A_o,D_o\)) using the AD diagram method along with the derivation of solar elements (\(S_{\odot }\), \(l_A\), \(b_A\)). Through our detailed dynamic orbit analysis, we determined that the three SAI clusters belong to the young stellar disc, confirming their membership within this component of the galactic structure.