Honoring Paris Pişmiş’ Legacy: Uniform Astrophysical Properties of 14 Understudied Clusters from Gaia DR3

Abstract

Open clusters are fundamental tracers of the chemical and dynamical evolution of the Galactic disc. This study presents a systematic characterisation of 14 understudied open clusters from the Pismis catalog, selected as those for which the Gaia DR3 data support a well-defined stellar sequence, and spanning a wide range of ages and distances. Utilizing high-precision Gaia DR3 data, we aim to provide a high-fidelity modernisation of these historical discoveries while testing the consistency of our analytical framework across diverse stellar populations. Membership probabilities were determined via the unsupervised UPMASK algorithm using Gaia DR3 astrometric data (positions, proper motions, and parallax). To ensure high sample purity, the member samples entering the isochrone fits were restricted to P ≥ 0.90, with all subsequent astrophysical parameters calculated through membership-weighted likelihoods. Fundamental properties-including age, distance, reddening, and metallicity-were derived using a Bayesian Nested Sampling approach to isochrone fitting, a methodology chosen for its robustness in navigating the parameter degeneracies typical of dense Galactic fields. The 14 systems exhibit a broad distribution of properties, with ages ranging approximately 11 Myr to 1.5 Gyr and distances spanning approximately 690 to 5445 pc. These refined and uniform parameters reconcile historical observations with the precision era of modern astrophysics, providing an internally homogeneous baseline for systems that large-scale automated surveys recover only partially. A direct cross-match against widely used automated catalogs shows that they typically contain only about a third of the members identified here, and substantially less in the most crowded fields, underscoring the value of cluster-specific analysis. This work contributes to a more complete census of the Galactic disc and sets out a reproducible, per-cluster reliability assessment that can be applied to the many comparable low-latitude systems that remain to be characterised.