Astrophysical Parameters of the Open Cluster NGC 2509

TL;DR

This paper determines the astrophysical parameters of the poorly studied open cluster NGC 2509 using Gaia DR3 data, including membership, distance, age, and reddening, through isochrone fitting.

Contribution

It provides the first detailed analysis of NGC 2509's parameters using Gaia DR3 astrometry and photometry, including membership probabilities and isochrone-based parameter estimation.

Findings

244 probable cluster members identified

Distance to NGC 2509 is approximately 2518 parsecs

Cluster age estimated at 1.5 billion years

Abstract

This study presents structural and fundamental astrophysical parameters of poorly studied open cluster NGC 2509. We used the third photometric and astrometric data release of the Gaia (Gaia DR3) to perform analyses. By taking into account the Gaia DR3 astrometric data, we calculated the membership probabilities of the stars in the region of NGC 2509. As a result of the membership analysis, 244 stars with membership probabilities $P\geq50$% were determined as the physical members of the cluster. The colour excess, distance and age were obtained simultaneously by fitting solar metallicity PARSEC isochrones to $G\times G_{\rm BP}-G_{\rm RP}$ colour-magnitude diagram. We considered the most likely cluster member stars during the fitting procedure and calculated the colour excess, distance and age of the NGC 2509 as $E(G_{\rm BP}-G_{\rm RP})=0.100\pm0.015$ mag, $d=2518\pm667$ pc and $t=1.5\pm 0.1$ Gyr, respectively.