SED Analysis of the Old Open Cluster NGC 188

Abstract

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.

Keywords

• Galaxy: open clusters
• individual: NGC 188
• Methods: spectral energy distribution (SED)

References

1. Adams F. C., Lada C. J., Shu F. H., 1987, ApJ, 312, 788 google scholar
2. Aizenman M. L., Demarque P., Miller R. H., 1969, ApJ, 155, 973 google scholar
3. Ak T., Bilir S., Özdönmez A., Soydugan F., Soydugan E., Püsküllü Ç., google scholar
4. Ak S., Eker Z., 2015, Ap&SS, 357, 72 google scholar
5. Allard F., Homeier D., Freytag B., 2012, Philosophical Transactions of the Royal Society of London Series A, 370, 2765 google scholar
6. Belloni T., Verbunt F., Mathieu R. D., 1998, A&A, 339, 431 google scholar
7. Bossini D., et al., 2019, A&A, 623, A108 google scholar
8. Bovy J., 2015, ApJS, 216, 29 google scholar

9. Bovy J., Tremaine S., 2012, ApJ, 756, 89 google scholar
10. Bressan A., Marigo P., Girardi L., Salasnich B., Dal Cero C., Rubele google scholar
11. S., Nanni A., 2012, MNRAS, 427, 127 google scholar
12. Bukowiecki L., Maciejewski G., Konorski P., Strobel A., 2011, Acta google scholar
13. Astron., 61, 231 google scholar
14. Cantat-Gaudin T., Anders F., 2020, A&A, 633, A99 google scholar
15. Cantat-Gaudin T., et al., 2018, A&A, 618, A93 google scholar
16. Caputo F., Chieffi A., Castellani V., Collados M., Martinez Roger C., google scholar
17. Paez E., 1990, AJ, 99, 261 google scholar
18. Cardelli J. A., Clayton G. C., Mathis J. S., 1989, ApJ, 345, 245 google scholar
19. Carraro G., Chiosi C., 1994, A&A, 287, 761 google scholar
20. Carraro G., Costa E., 2007, A&A, 464, 573 google scholar
21. Carraro G., Lia C., Chiosi C., 1998, MNRAS, 297, 1021 google scholar
22. Carraro G., Sales Silva J. V., Moni Bidin C., Vazquez R. A., 2017, AJ, 153, 99 google scholar
23. Carrera R., et al., 2022a, A&A, 658, A14 google scholar
24. Carrera R., et al., 2022b, A&A, 663, A148 google scholar
25. Casamiquela L., et al., 2021, A&A, 652, A25 google scholar
26. Castelli F., Kurucz R. L., 2003, in Modelling of Stellar Atmospheres. p. A20, doi:10.48550/arXiv.astro-ph/0405087 google scholar
27. Chen L., Hou J. L., Wang J. J., 2003, AJ, 125, 1397 google scholar
28. Coşkunoglu B., et al., 2011, MNRAS, 412, 1237 google scholar
29. De Meulenaer P., Narbutis D., Mineikis T., Vansevicius V., 2013, A&A, 550, A20 google scholar
30. Demarque P. R., Larson R. B., 1964, ApJ, 140, 544 google scholar
31. Demarque P., Green E. M., Guenther D. B., 1992, AJ, 103, 151 google scholar
32. Dias W. S., Monteiro H., Caetano T. C., Lepine J. R. D., Assafin M., Oliveira A. F., 2014, A&A, 564, A79 google scholar
33. Dias W. S., Monteiro H., Moitinho A., Lepine J. R. D., Carraro G., Paunzen E., Alessi B., Villela L., 2021, MNRAS, 504, 356 google scholar
34. Donor J., et al., 2018, AJ, 156, 142 google scholar
35. Dotter A., 2016, ApJS, 222, 8 google scholar
36. Elsanhoury W. H., Haroon A. A., Chupina N. V., Vereshchagin S. V., Sariya D. P., Yadav R. K. S., Jiang I.-G., 2016, New Astron., 49, 32 google scholar
37. Fitton S., Tofflemire B. M., Kraus A. L., 2022, RNAAS, 6, 18 google scholar
38. Fornal B., Tucker D. L., Smith J. A., Allam S. S., Rider C. J., Sung H., 2007, AJ, 133, 1409 google scholar
39. Friel E. D., 1995, ARA&A, 33, 381 google scholar
40. Gaia Collaboration et al., 2016, A&A, 595, A1 google scholar
41. Gaia Collaboration et al., 2018, A&A, 616, A1 google scholar
42. Gaia Collaboration et al., 2021, A&A, 649, A1 google scholar
43. Gaia Collaboration et al., 2023, A&A, 674, A1 google scholar
44. Gao X., Fang D., 2022, Ap&SS, 367, 87 google scholar
45. Glebbeek E., Pols O. R., 2008, A&A, 488, 1017 google scholar
46. Greenstein J. L., Keenan P. C., 1964, ApJ, 140, 673 google scholar
47. Harris W. E., Pudritz R. E., 1994, ApJ, 429, 177 google scholar
48. Hills J. G., Day C. A., 1976, Astrophys. Lett., 17, 87 google scholar
49. Hills S., von Hippel T., Courteau S., Geller A. M., 2015, AJ, 149, 94 google scholar
50. Huang Y., Yuan H., Beers T. C., Zhang H., 2021, ApJ, 910, L5 google scholar
51. Hunt E. L., Reffert S., 2023, A&A, 673, A114 google scholar
52. Husser T. O., Wende-von Berg S., Dreizler S., Homeier D., Reiners A., Barman T., Hauschildt P. H., 2013, A&A, 553, A6 google scholar
53. Jacobson H. R., Pilachowski C. A., Friel E. D., 2011, AJ, 142, 59 google scholar
54. Janes K., Demarque P., 1983, ApJ, 264, 206 google scholar
55. Janes K., Barnes S. A., Meibom S., Hoq S., 2014, AJ, 147, 139 google scholar
56. Joshi Y. C., 2005, MNRAS, 362, 1259 google scholar
57. Joshi Y. C., Dambis A. K., Pandey A. K., Joshi S., 2016, A&A, 593, A116 google scholar
58. Juric M., et al., 2008, ApJ, 673, 864 google scholar
59. King I., 1962, AJ, 67, 471 google scholar
60. King I. R., Bedin L. R., Piotto G., Cassisi S., Anderson J., 2005, AJ,130, 626 google scholar
61. Lada C. J., Lada E. A., 2003, ARA&A, 41, 57 google scholar
62. Leonard P. J. T., 1989, AJ, 98, 217 google scholar
63. Leonard P. J. T., Linnell A. P., 1992, AJ, 103, 1928 google scholar
64. Lindegren L., et al., 2021, A&A, 649, A4 google scholar
65. Lorenzo-Oliveira D., Porto de Mello G. F., Schiavon R. P., 2016, A&A, 594, L3 google scholar
66. McClure R. D., Twarog B. A., 1977, ApJ, 214, 111 google scholar
67. McCrea W. H., 1964, MNRAS, 128, 147 google scholar
68. Netopil M., Oralhan İ. A., Çakmak H., Michel R., Karataş Y., 2022, MNRAS, 509, 421 google scholar
69. Oke J. B., 1974, ApJS, 27, 21 google scholar
70. Patenaude M., 1978, A&A, 66, 225 google scholar
71. Piskunov A. E., Kharchenko N. V., Röser S., Schilbach E., Scholz google scholar
72. R. D., 2006, A&A, 445, 545 google scholar
73. Rain M. J., Ahumada J. A., Carraro G., 2021, A&A, 650, A67 google scholar
74. Riess A. G., Casertano S., Yuan W., Bowers J. B., Macri L., Zinn J. C., Scolnic D., 2021, ApJ, 908, L6 google scholar
75. Robitaille T. P., Whitney B. A., Indebetouw R., Wood K., Denzmore P., 2006, ApJS, 167, 256 google scholar
76. Sandage A., 1962, ApJ, 135, 333 google scholar
77. Sarajedini A., von Hippel T., Kozhurina-Platais V., Demarque P., 1999, AJ, 118, 2894 google scholar
78. Song F.-F., Niu H.-B., Esamdin A., Zhang Y., Zeng X.-Y., 2023, Re-search in Astronomy and Astrophysics, 23, 095015 google scholar
79. Soubiran C., et al., 2018, A&A, 619, A155 google scholar
80. Spina L., et al., 2021, MNRAS, 503, 3279 google scholar
81. Spinrad H., Greenstein J. L., Taylor B. J., King I. R., 1970, ApJ, 162, 891 google scholar
82. Sun M., Jiang B., Yuan H., Li J., 2021, ApJS, 254, 38 google scholar
83. Taşdemir S., Yontan T., 2023, Physics and Astronomy Reports, 1, 1 google scholar
84. Tarricq Y., et al., 2021, A&A, 647, A19 google scholar
85. Twarog B. A., Anthony-Twarog B. J., 1989, AJ, 97, 759 google scholar
86. Upgren A. R., Mesrobian W. S., Kerridge S. J., 1972, AJ, 77, 74 google scholar
87. VandenBerg D. A., 1983, ApJS, 51, 29 google scholar
88. VandenBerg D. A., Stetson P. B., 2004, PASP, 116, 997 google scholar
89. Vines J. I., Jenkins J. S., 2022, MNRAS, 513, 2719 google scholar
90. Wang J., Ma J., Wu Z., Wang S., Zhou X., 2015, AJ, 150, 61 google scholar
91. Webbink R. F., 1976, ApJ, 209, 829 google scholar
92. Worthey G., Jowett K. J., 2003, PASP, 115, 96 google scholar
93. Yadav R. K. S., Dattatrey A. K., Rangwal G., Subramaniam A., Bisht D., Sagar R., 2024, ApJ, 961, 251 google scholar
94. Yontan T., 2023, AJ, 165, 79 google scholar
95. Yontan T., Canbay R., 2023, Physics and Astronomy Reports, 1, 65 google scholar
96. Yontan T., et al., 2015, Ap&SS, 355, 267 google scholar
97. Yontan T., et al., 2019, Ap&SS, 364, 152 google scholar
98. Zheng Z., et al., 1999, AJ, 117, 2757 google scholar
99. Zinn J. C., 2021, AJ, 161, 214 google scholar
100. Zinn R., Dahn C. C., 1976, AJ, 81, 527 google scholar