Machine learning-enabled membership determination of open cluster AH03_J0748-26.9 using Gaia DR3 astrometry
Year: 2026
Type: article
Abstract: As populations of stars born concurrently, open clusters serve as fundamental laboratories for validating models of star formation, stellar evolution, and the dynamical processes of the Galactic disk. This paper provides a comprehensive astrometric and photometric analysis of the open cluster AH03_J0748-26.9, leveraging data from the Gaia DR3 catalog. We employ the Hierarchical Density-Based Spatial Clustering of Applications with Noise (HDBSCAN) algorithm to analyze astrometric data from Gaia Data Release 3 (DR3). Our analysis characterizes the identified clusters through several fundamental parameters, specifically the census of probable members, spatial radii, age, distance, the initial mass function (IMF), and total cluster mass.We determined a concentration parameter of [Formula: see text] for AH03_J0748-26.9. The estimated number of members for AH03_J0748-26.9 is 128 stars. A distance modulus of [Formula: see text] mag and an age of 114.815 Myr ([Formula: see text]) were derived using PARSEC isochrone fitting. Given a relaxation time of 32.125 Myr and an age of 114.815 Myr ([Formula: see text]), the cluster AH03_J0748-26.9 is found to be dynamically relaxed. We analyzed the mass function (MF) for AH03_J0748-26.9 using a Monte Carlo method coupled with synthetic cluster modeling. We characterized the MF over the range 0.102-[Formula: see text] by fitting a two-segment broken power law, deriving slopes of [Formula: see text] (for [Formula: see text]) and [Formula: see text] (for [Formula: see text]) with a characteristic break mass of [Formula: see text]. The steep slope in the higher mass regime suggests a deviation from the canonical Salpeter IMF, which is consistent with the effects of dynamical evolution and mass segregation. By integrating this best-fit MF and adopting a binary fraction of [Formula: see text]-typical for concentrated open clusters-we estimate a total cluster mass of [Formula: see text]. A sensitivity analysis indicates that varying the binary fraction between 0.5 and 0.9 alters the total mass estimate by approximately [Formula: see text], supporting the robustness of the mass scale. A sample of 128 member stars yielded a mean radial velocity of [Formula: see text]. These kinematic data, combined with proper motions, served as input for the galpy package to determine the cluster's Galactic orbit.
Source: Scientific Reports
Authors: W. A. Badawy, H. I. Abdel Rahman
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,690
OpenAlex ID: W7204202096