Spectroscopic Bolometric Corrections and Empirical Zero-point Constants of Gaia Magnitudes, 𝐺, 𝐺BP, and 𝐺RP, from Gaia XP Spectra

Abstract

The International Astronomical Union 2015 Resolution B2 (IAU2015GARB2) has resolved the long-standing problem of zeropoint constants for the absolute and apparent bolometric magnitude scales and opened a new window in fundamental astrophysics. The empirical zero-point constants of the bolometric corrections, 𝐶2 (𝜉), and the absolute/apparent magnitudes, 𝐶𝜉 /𝑐 𝜉 , for the Gaia passbands were obtained from 88 Gaia XP spectra, and absolute bolometric/filtered magnitudes. The individual zero-point constants ⟨𝐶2⟩ of the bolometric corrections (𝐵𝐶𝜉 ) for each star revealed weighted averages of ⟨𝐶2 (𝐺)⟩ = 0.8677 ± 0.0109 mag, ⟨𝐶2 (𝐺BP)⟩ = 1.0449 ± 0.0116 mag, and ⟨𝐶2 (𝐺RP)⟩ = 2.0510 ± 0.0087 mag. Furthermore, 𝐶Bol = 71.197425... mag and 𝑐Bol = −18.997351...mag announced by IAU2015GARB2, and using the definition of 𝐶2 = 𝐶Bol − 𝐶𝜉 = 𝑐Bol − 𝑐 𝜉 , where the subscript 2 indicate the wavelength ranges of two in which one is for bolometric and the other for one of the three filters, the zero-point constants of magnitudes for Gaia filters as 𝐶G = 70.1525 ± 0.0109 mag and 𝑐G = −19.8651 ± 0.0105 mag, 𝐶GBP = 70.1525±0.0116 mag and 𝑐GBP = −20.0423±0.0116 mag, and𝐶GRP = 69.1464±0.0087 mag and 𝑐GRP = −21.0484±0.0087 mag, if 𝐿𝜉 and 𝑓𝜉 are in SI units, assuming no extinction. Lastly, spectroscopic 𝐵𝐶s for Gaia magnitudes of 88 stars and the spectroscopic 𝐵𝐶 − 𝑇eff relation for each Gaia filter are presented.

Keywords

• Stellar fundamental parameters
• Sun
• Bolometric magnitude
• Spectroscopy
• Photometry

References

1. Adelman S. J., Gulliver A. F., Gucella L. J., 2017, Astronomische Nachrichten, 338, 584 google scholar
2. Arentsen A., et al., 2019, A&A, 627, A138 google scholar
3. Aschenbrenner P., Przybilla N., Butler K., 2023, A&A, 671, A36 google scholar
4. Astropy Collaboration et al., 2013, A&A, 558, A33 google scholar
5. Astropy Collaboration et al., 2018, AJ, 156, 123 google scholar
6. Astropy Collaboration et al., 2022, ApJ, 935, 167 google scholar
7. Bailey J. D., Landstreet J. D., 2013, A&A, 551, A30 google scholar
8. Bakış V., Eker Z., 2022, Acta Astron., 72, 195 google scholar

9. Bessell M. S., 1990, PASP, 102, 1181 google scholar
10. Borisov S. B., et al., 2023, ApJS, 266, 11 google scholar
11. Bressan A., Marigo P., Girardi L., Salasnich B., Dal Cero C., Rubele google scholar
12. S., Nanni A., 2012, MNRAS, 427, 127 google scholar
13. Catanzaro G., 1997, Ap&SS, 257, 161 google scholar
14. Cenarro A. J., et al., 2007, MNRAS, 374, 664 google scholar
15. Cunha K., Lambert D. L., 1994, ApJ, 426, 170 google scholar
16. Daflon S., Cunha K., Smith V. V., Butler K., 2003, A&A, 399, 525 google scholar
17. Daflon S., Cunha K., de Araújo F. X., Wolff S., Przybilla N., 2007,AJ, 134, 1570 google scholar
18. De Angeli F., et al., 2023, A&A, 674, A2 google scholar
19. Eddington A. S., 1926, The Internal Constitution of the Stars google scholar
20. Eker Z., Bakış V., 2023, MNRAS, 523, 2440 google scholar
21. Eker Z., Bakış V., 2025, Physics and Astronomy Reports, 3, 43 google scholar
22. Eker Z., Bakış V., Soydugan F., Bilir S., 2021a, MNRAS, 503, 4231 google scholar
23. Eker Z., Soydugan F., Bilir S., Bakış V., 2021b, MNRAS, 507, 3583 google scholar
24. Eker Z., Soydugan F., Bakış V., Bilir S., Steer I., 2022, AJ, 164, 189 google scholar
25. Fossati L., Ryabchikova T., Shulyak D. V., Haswell C. A., Elmasli A., google scholar
26. Pandey C. P., Barnes T. G., Zwintz K., 2011, MNRAS, 417, 495 google scholar
27. Fraser M., Dufton P. L., Hunter I., Ryans R. S. I., 2010, MNRAS, 404,1306 google scholar
28. Gaia Collaboration et al., 2023, A&A, 674, A1 google scholar
29. Gebran M., Farah W., Paletou F., Monier R., Watson V., 2016, A&A,589, A83 google scholar
30. Gordon K. D., Gies D. R., Schaefer G. H., Huber D., Ireland M., 2019,ApJ, 873, 91 google scholar
31. Griffin R. F., 2000, Ap&SS, 271, 205 google scholar
32. Griffin R., Griffin R., 1973, MNRAS, 162, 255 google scholar
33. Hertzsprung E., 1923, Bull. Astron. Inst. Netherlands, 2, 15 google scholar
34. Hill G. M., 1995, A&A, 294, 536 google scholar
35. Hillen M., Verhoelst T., Degroote P., Acke B., van Winckel H., 2012,A&A, 538, L6 google scholar
36. Holgado G., Simón-Díaz S., Herrero A., Barbá R. H., 2022, A&A,665, A150 google scholar
37. Hourihane A., et al., 2023, A&A, 676, A129 google scholar
38. Huang W., Gies D. R., McSwain M. V., 2010, ApJ, 722, 605 google scholar
39. Huang B., et al., 2024, ApJS, 271, 13 google scholar
40. Koleva M., Vazdekis A., 2012, A&A, 538, A143 google scholar
41. Kuiper G. P., 1938, ApJ, 88, 429 google scholar
42. Landolt A. U., 1992, AJ, 104, 372 google scholar
43. Lefever K., Puls J., Aerts C., 2007, A&A, 463, 1093 google scholar
44. Levenhagen R. S., Leister N. V., 2006, MNRAS, 371, 252 google scholar
45. Lindegren L., et al., 2021, A&A, 649, A2 google scholar
46. Mamajek E. E., et al., 2015, arXiv e-prints, p. arXiv:1510.06262 google scholar
47. Martin A. J., et al., 2018, MNRAS, 475, 1521 google scholar
48. Meléndez J., et al., 2012, A&A, 543, A29 google scholar
49. Monier R., et al., 2023, AJ, 166, 54 google scholar
50. Montegriffo P., et al., 2023, A&A, 674, A3 google scholar
51. Mugnes J. M., Robert C., 2015, MNRAS, 454, 28 google scholar
52. Niemczura E., Walczak P., Mikołajczyk P., Schöller M., Hummel,C. A., Hubrig S., Różański T., 2022, MNRAS, 514, 5640 google scholar
53. Nieva M. F., Simón-Díaz S., 2011, A&A, 532, A2 google scholar
54. Okuyan O., Bakıs, V., Eker Z., 2026, Advances in Space Research, 77,9868 google scholar
55. Paunzen E., Schnell A., Maitzen H. M., 2005, A&A, 444, 941 google scholar
56. Paunzen E., Schnell A., Maitzen H. M., 2006, A&A, 458, 293 google scholar
57. Prugniel P., Vauglin I., Koleva M., 2011, A&A, 531, A165 google scholar
58. Riello M., et al., 2021, A&A, 649, A3 google scholar
59. Romanovskaya A. M., Shulyak D. V., Ryabchikova T. A., Sitnova, T. M., 2021, A&A, 655, A106 google scholar
60. Royer F., et al., 2014, A&A, 562, A84 google scholar
61. Russell H. N., Adams W. S., Joy A. H., 1923, PASP, 35, 189 google scholar
62. Simón-Díaz S., Godart M., Castro N., Herrero A., Aerts C., Puls J.,Telting J., Grassitelli L., 2017, A&A, 597, A22 google scholar
63. Soubiran C., Brouillet N., Casamiquela L., 2022, A&A, 663, A4 google scholar
64. Soubiran C., et al., 2024, A&A, 682, A145 google scholar
65. Tabernero H. M., Marfil E., Montes D., González Hernández J. I.,2022, A&A, 657, A66 google scholar
66. Takeda Y., Kambe E., Sadakane K., Masada S., 2010, PASJ, 62, 1239 google scholar
67. Torres G., 2010, AJ, 140, 1158 google scholar
68. Virtanen P., et al., 2020, Nature Methods, 17, 261 google scholar
69. Wu Y., Singh H. P., Prugniel P., Gupta R., Koleva M., 2011, A&A, 525, A71 google scholar
70. Yücel G., Bilir S., Bakıs, V., Eker Z., 2026, AJ, 171, 49 google scholar
71. Zorec J., Royer F., 2012, A&A, 537, A120 google scholar
72. Zorec J., Cidale L., Arias M. L., Frémat Y., Muratore M. F., Torres google scholar
73. A. F., Martayan C., 2009, A&A, 501, 297 google scholar
74. da Silva R., Milone A. d. C., Rocha-Pinto H. J., 2015, A&A, 580, A24 google scholar