HD 123657, or BY Boötis, is a variable star of magnitude 4.98–5.33V. This makes it a dim naked eye star. The star is located near the end of the handle of the Big Dipper, but just within the boundaries of the constellation Boötes.

The variability of the brightness of HD 123657 was announced by Joel Stebbins and Charles Morse Huffer in 1928, based on observations made at Washburn Observatory.[11] The star was given its variable star designation, BY Boötis, in 1973.[12] It is a slow irregular red giant variable star with a range of less than half a magnitude. It is over a thousand times as luminous as the sun, only 3,500 K but with a large expanded atmosphere.
References
- ^ a b c d e Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600.
- ^ a b c d Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237: 0. Bibcode:2002yCat.2237....0D.
- ^ Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
- ^ a b Alvarez, R.; Jorissen, A.; Plez, B.; Gillet, D.; Fokin, A.; Dedecker, M. (2001). "Envelope tomography of long-period variable stars". Astronomy and Astrophysics. 379: 305–322. arXiv:astro-ph/0109259. Bibcode:2001A&A...379..305A. doi:10.1051/0004-6361:20011261. S2CID 15502307.
- ^ Famaey, B.; Jorissen, A.; Luri, X.; Mayor, M.; Udry, S.; Dejonghe, H.; Turon, C. (2005). "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters". Astronomy and Astrophysics. 430: 165. arXiv:astro-ph/0409579. Bibcode:2005A&A...430..165F. doi:10.1051/0004-6361:20041272. S2CID 17804304.
- ^ Park, Sunkyung; Kang, Wonseok; Lee, Jeong-Eun; Lee, Sang-Gak (2013). "Wilson-Bappu Effect: Extended to Surface Gravity". The Astronomical Journal. 146 (4): 73. arXiv:1307.0592. Bibcode:2013AJ....146...73P. doi:10.1088/0004-6256/146/4/73. S2CID 119187733.
- ^ Pasinetti Fracassini, L. E.; Pastori, L.; Covino, S.; Pozzi, A. (2001). "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics". Astronomy and Astrophysics. 367 (2): 521. arXiv:astro-ph/0012289. Bibcode:2001A&A...367..521P. doi:10.1051/0004-6361:20000451. S2CID 425754.
- ^ a b Blum, R. D.; Ramírez, Solange V.; Sellgren, K.; Olsen, K. (2003). "Really Cool Stars and the Star Formation History at the Galactic Center". The Astrophysical Journal. 597 (1): 323–346. arXiv:astro-ph/0307291. Bibcode:2003ApJ...597..323B. doi:10.1086/378380. S2CID 5664467.
- ^ Marrese, P. M.; Boschi, F.; Munari, U. (2003). "High resolution spectroscopy over lambda lambda 8500-8750 Å for GAIA. IV. Extending the cool MK stars sample". Astronomy and Astrophysics. 406 (3): 995. Bibcode:2003A&A...406..995M. doi:10.1051/0004-6361:20030647.
- ^ "Hipparcos Tools Interactive Data Access". Hipparcos. ESA. Retrieved 8 December 2021.
- ^ 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. Retrieved 4 December 2024.
- ^ Kukarkin, B. V.; Kholopov, P. N.; Kukarkina, N. P.; Perova, N. B. (October 1973). "59th Name-List of Variable Stars" (PDF). Information Bulletin on Variable Stars. 834: 1–22. Bibcode:1973IBVS..834....1K. Retrieved 4 December 2024.