Characterizing NGC 6383: Study of fundamental properties,pre-main sequence stars, mass segregation, and age using Gaia DR3 and 2MASS
Year: 2026
Type: article
Abstract: This study is focused on the young open cluster NGC 6383, situated in the Carina-Sagittarius arm within the Sh 2-012 star-formation region. Previous studies have provided estimates of the distance, age, and structural properties of the cluster. The presence of pre-main sequence (PMS) and low-mass stars, combined with DR3 and 2MASS data, makes NGC 6383 a compelling target for a refined characterization. Gaia We aim to identify cluster members, determine the fundamental parameters, assess the mass segregation, and derive the age and distance of NGC 6383 from DR3 and 2MASS data. Gaia We employed Bayesian analysis and machine-learning techniques, including Hierarchical Density-Based Spatial Clustering of Applications with Noise (HDBSCAN) for member identification, PyMC for the Bayesian modeling, the Sagitta neural network for the identification and age estimation of PMS stars, and ASteCA for the isochrone fitting. We identified 321 likely cluster candidates, with tilde p >0.5, and used a reference sample of 254 sources with tilde p to derive the cluster parameters. The mode cluster age is with łog( , ) = 6.55^ age yr^ -1 +0.40 _ -0.20 (with the uncertainty dominated by PMS model systematics that act toward older ages) and the distance is 1.11± 0.06 kpc. The core radius is 1.96^ +0.19 _ -0.16 , (0.63^ arcmin +0.06 _ -0.05 , ); the King outer radius, measured on the only extraction that reaches a fitted background annulus beyond the cluster (70, _ pc is 54^ +7 -11 , (17.4^ arcmin +2.3 _ -3.6 , ). This posterior is truncated from above by the adopted prior bound, so we report it as a model-dependent outer scale. Given the cluster's dynamical youth (age simeq0.14 of the half-mass relaxation time), the mass segregation of binary stars, which is conditional on the membership of the outer low-mass candidates, is consistent with a primordial or near-primordial origin. The color-magnitude diagram (CMD) shows a well-defined main sequence and a population of PMS stars, whose bulk lies between the 1.6 and 6.3 Myr isochrones, consistent with a recent, possibly extended star formation episode. The software used for this investigation has been released with the paper. pc Combining machine-learning membership with Bayesian parameter estimation, our analysis provides updated parameters for NGC 6383, an apparent age spread consistent with recent, possibly extended star formation, and a segregation pattern. This pattern, which is conditional on the membership of the outer low-mass candidates, is consistent with a primordial origin or with rapid early dynamical segregation (near-primordial).
Source: Astronomy and Astrophysics
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
OpenAlex ID: W7223137532