Physica Scripta, cilt.100, sa.5, 2025 (SCI-Expanded)
In this study, we utilize photometric and kinematic data from Gaia DR3 and the ASteCA package to analyze the sparsely studied open clusters, King 2 and King 5. For King 2, we identify 340 probable members with membership probabilities exceeding 50%. Its mean proper motion components are determined as ( μ α cos δ , μ δ ) = ( − 1.407 ± 0.008 , − 0.863 ± 0.012 ) mas yr−1, and its limiting radius is derived as 6.94 − 1.06 + 0.22 arcminutes based on radial density profiles. The cluster has an estimated age of 4.80 ± 0.30 Gyr, a distance of 6586 ± 164 pc, and a metallicity of [Fe/H] = −0.25 dex (z = 0.0088). We detect 17 blue straggler stars (BSSs) concentrated in its core, and its total mass is estimated to be 356 ± 19M⊙. The computed apex motion is ( A o , D o ) = ( − 14 2 . ∘ 61 ± 0 . ∘ 08 , − 6 3 . ∘ 58 ± 0 . ∘ 13 ) . Similarly, King 5 consists of 403 probable members with a mean proper motion components ( μ α cos δ , μ δ ) = ( − 0.291 ± 0.005 , − 1.256 ± 0.005 ) mas yr−1 and a limiting radius of 11.33 − 2.16 + 5.45 arcminutes. The cluster’s age is determined as 1.45 ± 0.10 Gyr, with a distance of 2220 ± 40 pc and a metallicity of [Fe/H] = −0.15 dex (z = 0.0109). We identify 4 centrally concentrated BSSs, and the total mass is estimated as 484 ± 22M⊙. The apex motion is calculated as ( A o , D o ) = ( − 11 5 . ∘ 10 ± 0 . ∘ 09 , − 7 3 . ∘ 16 ± 0 . ∘ 12 ) . The orbital analysis of King 2 and King 5 indicates nearly circular orbits, characterized by low eccentricities and minimal variation in their apogalactic and perigalactic distances. King 2 and King 5 reach maximum heights of 499 ± 25 pc and 177 ± 2 pc from the Galactic plane, respectively, confirming their classification as young stellar disc population.