104 Herculis is a solitary[1] variable star[2] located around 560[3] light years away from the Sun in the northern constellation of Hercules.[4] It has the variable star designation V669 Herculis and the Bayer designation A Herculis, while 104 Herculis is the Flamsteed designation. This object is visible to the naked eye as a dim, red-hued point of light with a baseline apparent visual magnitude of 4.96.[5] It is moving closer to the Earth with a heliocentric radial velocity of −1.2 km/s.[5]

The variability of the brightness of 104 Herculis was announced by Joel Stebbins and Charles Morse Huffer in 1928, based on observations made at Washburn Observatory.[6] It was given its variable star designation in 1977.[7]

This is an aging red giant star on the asymptotic giant branch[8] with a stellar classification of M3 III.[9] It is a semiregular variable[10] with an amplitude of 0.14 in the B-band[11] and pulsation periods of 22.9 and 24.0 days.[12] Having exhausted the hydrogen at its core, the star has expanded to 86 times the Sun's radius.[3] It is radiating 1,202 times the Sun's luminosity[3] from its swollen photosphere at an effective temperature of 3,535 K.[13]

References

  1. ^ Eggleton, P. P. & Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879, arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID 14878976
  2. ^ Adelman, Saul J. & Harrell, William L. (2006), "BVRI Photometry of nz Gem, HD 73017, HD 77247, RT Vir and 104 Her", Baltic Astronomy. 15: 363–381, Bibcode:2006BaltA..15..363A
  3. ^
  4. ^ "104 Her". Retrieved 2019-06-17.
  5. ^ Anderson, E. & Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters. 38 (5): 331, arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644
  6. ^ Stebbins, Joel & Huffer, C. M. (1928). "The Constancy of the Light of Red Stars". Publications of the Washburn Observatory. 15: 137–174. Bibcode:1928PWasO..15..137S
  7. ^ Kukarkin, B. V.; Kholopov, P. N.; Fedorovich, V. P.; Kireyeva, N. N.; Kukarkina, N. P.; Medvedeva, G. I.; Perova, N. B. (March 1977). "62nd Name-List of Variable Stars". Information Bulletin on Variable Stars. 1248: 1–25. Bibcode:1977IBVS.1248....1K. Retrieved 8 December 2024.
  8. ^ Eggen, Olin J. (July 1992), "Asymptotic giant branch stars near the sun", Astronomical Journal. 104 (1): 275–313, Bibcode:1992AJ....104..275E. doi:10.1086/116239
  9. ^ Keenan, Philip C. & McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series. 71: 245, Bibcode:1989ApJS...71..245K. doi:10.1086/191373. S2CID 123149047
  10. ^ Glass, I. S. & Van Leeuwen, F. (2007), "Semiregular variables in the solar neighbourhood", Monthly Notices of the Royal Astronomical Society. 378 (4): 1543–1549, arXiv:0704.3150. Bibcode:2007MNRAS.378.1543G. doi:10.1111/j.1365-2966.2007.11903.x. S2CID 14332208
  11. ^ Samus, N. N. et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports. 61 (1): 80–88, 5.1, Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. S2CID 125853869
  12. ^ Tabur, V. et al. (December 2009), "Long-term photometry and periods for 261 nearby pulsating M giants", Monthly Notices of the Royal Astronomical Society. 400 (4): 1945–1961, arXiv:0908.3228. Bibcode:2009MNRAS.400.1945T. doi:10.1111/j.1365-2966.2009.15588.x. S2CID 15358380
  13. ^ Prugniel, Ph. et al. (July 2011), "The atmospheric parameters and spectral interpolator for the MILES stars", Astronomy & Astrophysics. 531: A165, arXiv:1104.4952. Bibcode:2011A&A...531A.165P. doi:10.1051/0004-6361/201116769. S2CID 54940439