In this study, we investigate the fundamental astrophysical parameters of the old open cluster NGC 188 using two complementary methods: isochron fitting and spectral energy distribution (SED) analysis. Using photometric, astrometric, and spectroscopic data from the Gaia Data Release 3 (DR3, Gaia Collaboration et al. 2023), we identified 868 most likely member stars with membership probabilities 𝑃 ≥ 0.5. The mean proper-motion components and trigonometric parallaxes of the cluster are derived as (𝜇𝛼 cos 𝛿, 𝜇𝛿) = (-2.314±0.002, -1.022±0.002) mas yr−1 and 𝜛 = 0.550±0.023 mas, respectively. From this initial selection of high probable member stars, we proceed with the determination of astrophysical parameters using the isochron-fitting method. Simultaneously estimating the colour excess, distance and age of the cluster, we employe PARSEC isochrones to observational data on Gaia based colour-magnitude diagrams. These findings were obtained as 𝐸(𝐺BP − 𝐺RP) = 0.066 ± 0.012 mag, 𝑑 = 1806 ± 21 pc, and 𝑡 = 7.65 ± 1.00 Gyr, respectively. In addition, we identified and detected 19 previously confirmed blue straggler stars within NGC 188. Subsequently, we performed SED analyses for 412 of the 868 cluster members. We obtained colour excess, distance and age of the cluster as 𝐸(𝐵 −𝑉) = 0.034±0.030 mag, 𝑑 = 1854±148 pc, and 𝑡 = 7.78±0.23 Gyr, respectively. The analysis of member stars revealed patterns of extinction in the 𝑉-band, with higher values of 𝐴V observed in the lower right quadrant of the cluster. By comparing our SED analysis results with models of stellar evolution, particularly in terms of temperature and surface gravity, we confirm agreement with theoretical predictions. This comprehensive investigation sheds light on the astrophysical properties of NGC 188, contributing to our understanding of stellar evolution within open clusters.
Galaxy: open clusters individual: NGC 188 Methods: spectral energy distribution (SED)
Birincil Dil | İngilizce |
---|---|
Konular | Klasik Fizik (Diğer) |
Bölüm | Araştırma Makalesi |
Yazarlar | |
Yayımlanma Tarihi | 11 Haziran 2024 |
Gönderilme Tarihi | 15 Mart 2024 |
Kabul Tarihi | 18 Nisan 2024 |
Yayımlandığı Sayı | Yıl 2024 |