CCD UBV photometric study of five open clusters - Dolidze 36, NGC 6728, NGC 6800, NGC 7209 and Platais 1

TL;DR

This study provides detailed CCD UBV photometry and astrophysical parameters for five poorly studied open clusters, including their distances, ages, metallicities, and mass functions, using observations from the TUBITAK National Observatory.

Contribution

It offers new photometric data and derived parameters for five open clusters, expanding knowledge of their properties and stellar populations.

Findings

Distances range from 1050 to 1710 pc.

Ages range from 175 to 750 Myr.

Mass function slopes agree with Salpeter's IMF.

Abstract

In this study, we present CCD UBV photometry of poorly studied open star clusters, Dolidze 36, NGC 6728, NGC 6800, NGC 7209, and Platais 1, located in the first and second Galactic quadrants. Observations were obtained with T100, the 1-m telescope of the TUBITAK National Observatory. Using photometric data, we determined several astrophysical parameters such as reddening, distance, metallicity and ages and from them, initial mass functions, integrated magnitudes and colours. We took into account the proper motions of the observed stars to calculate the membership probabilities. The colour excesses and metallicities were determined independently using two-colour diagrams. After obtaining the colour excesses of the clusters Dolidze 36, NGC 6728, NGC 6800, NGC 7209, and Platais 1 as $0.19\pm0.06$, $0.15\pm0.05$, $0.32\pm0.05$, $0.12\pm0.04$, and $0.43\pm0.06$ mag, respectively, the metallicities are found to be $0.00\pm0.09$, $0.02\pm0.11$, $0.03\pm0.07$, $0.01\pm0.08$, and $0.01\pm0.08$ dex, respectively. Furthermore, using these parameters, distance moduli and age of the clusters were also calculated from colour-magnitude diagrams simultaneously using PARSEC theoretical models. The distances to the clusters Dolidze 36, NGC 6728, NGC 6800, NGC 7209, and Platais 1 are $1050\pm90$, $1610\pm190$, $1210\pm150$, $1060\pm 90$, and $1710\pm250$ pc, respectively, while corresponding ages are $400\pm100$, $750\pm150$, $400\pm100$, $600\pm100$, and $175\pm50$ Myr, respectively. Our results are compatible with those found in previous studies. The mass function of each cluster is derived. The slopes of the mass functions of the open clusters range from 1.31 to 1.58, which are in agreement with Salpeter's initial mass function. We also found integrated absolute magnitudes varying from -4.08 to -3.40 for the clusters.