# CCD UBV and Gaia DR3 based analysis of NGC 189, NGC 1758 and NGC 7762 open clusters

**Authors:** T. Yontan, S. Bilir, H. Cakmak, M. Raul, T. Banks, E. Soydugan, R. Canbay, S. Tasdemir  
**arXiv:** [2304.04294](https://arxiv.org/abs/2304.04294)  
**Date:** 2023-04-09  
**Summary page:** https://www.summarizepaper.com/en/paper/2304.04294v1/

## Key points

- The paper analyzes three open clusters: NGC 189, NGC 1758, and NGC 7762.
- CCD UBV photometric and Gaia Data Release 3 (DR3) data were used to identify member stars in each cluster based on membership analyses.
- Color excesses $E(B-V)$ and photometric metallicities [Fe/H] were determined separately using UBV two-color diagrams.
- Distance moduli and ages of the clusters were obtained by comparing PARSEC isochrones with color-magnitude diagrams constructed from UBV and Gaia photometric data while keeping constant color excesses and metallicities for each cluster during this process.
- The estimated isochrone distance is $1201 \pm 53$ pc for NGC 189, $902 \pm33$ pc for NGC 1758, and $911\pm31$ pc for NGC7762 which are compatible with values obtained from trigonometric parallax measurements.
- The ages of the clusters are 500 Myr $\pm50$, 650 Myr $\pm50$,and 2000 Myr $\pm200$, respectively for
- NGC189 ,NGC1758 ,andNGC7762.
- Galactic orbit integration of the clusters was conducted to find that while both
- NGC189 andNGC7762 enter the solar circle during their orbits;
- NGC1758 completely orbits outside it.

## Summary

This paper presents a comprehensive analysis of three open clusters, NGC 189, NGC 1758 and NGC 7762. The authors used CCD UBV photometric and Gaia Data Release 3 (DR3) data to identify the most probable member stars in each cluster based on membership analyses. They determined their color excesses $E(B-V)$ and photometric metallicities [Fe/H] separately using UBV two-color diagrams. The results showed that $E(B-V)$ is $0.590 \pm 0.023$ mag for NGC 189, $0.310 \pm 0.022$ mag for NGC 1758 and $0.640 \pm 0.017$ mag for NGC 7762; while the photometric metallicity [Fe/H] is $-0.08 \pm 0.03$ dex for both NGC 189 and NGC 1758, and $-0.12 \pm 0.02$ dex for NGC 7762 respectively. The authors also obtained distance moduli and ages of the clusters by comparing PARSEC isochrones with the color-magnitude diagrams constructed from UBV and Gaia photometric data while keeping constant color excesses and metallicities for each cluster during this process. They found that the estimated isochrone distance is $1201 \pm 53$ pc for NGC 189, $902 \pm33$ pc for NGC 1758, and $911\pm31$ pc for NGC7762 which are compatible with values obtained from trigonometric parallax measurements; furthermore they determined that the ages of the clusters are 500 Myr $\pm50$, 650 Myr $\pm50$,and 2000 Myr $\pm200$, respectively for 
NGC189 ,NGC1758 ,andNGC7762 . Additionally, they conducted galactic orbit integration of the clusters to find that while both 
NGC189 andNGC7762 enter the solar circle during their orbits; 
NGC1758 completely orbits outside it . Overall, this study provides valuable insights into the properties and characteristics of these open clusters as well as contributes to our understanding of stellar system formation and evolution processes .