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.

HD 123657
(BY Boötis)
Location of BY Boö (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Boötes
Right ascension 14h 07m 55.756s[1]
Declination 43° 51′ 16.03″[1]
Apparent magnitude (V) 5.28[2] (4.98-5.33[3])
Characteristics
Spectral type M4.5III[4]
U−B color index 1.66[2]
B−V color index 1.58[2]
R−I color index 1.66[2]
Variable type LB[4]
Astrometry
Radial velocity (Rv)-36.24[5] km/s
Proper motion (μ) RA: 11.63[1] mas/yr
Dec.: -30.08[1] mas/yr
Parallax (π)6.36 ± 0.26 mas[1]
Distance510 ± 20 ly
(157 ± 6 pc)
Absolute magnitude (MV)−0.90[6]
Details
Radius70[7] R
Luminosity1,380[8] L
Temperature3,500[8] K
Metallicity [Fe/H]−0.03[9] dex
Other designations
BY Boötis, JP11 2471, AG+44° 1162, GSC 03040-00969, 2MASS J14075576+4351160, TYC 3040-969-1, BD+44° 2325, HD 123657, N30 3210, UBV M 19995, CSV 7099, HIC 69038, PLX 3214, UBV 12478, DO 34564, HIP 69038, PMC 90-93 957, FK5 1368, HR 5299, PPM Star Catalogue 53940, GC 19084, IRAS 14059+4405, RAFGL 1680, AAVSO 1403+44, GCRV 8285, IRC +40253, SAO 44901.
Database references
SIMBADdata
A light curve for BY Boötis, plotted from Hipparcos data[10]

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

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  1. ^ 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.
  2. ^ 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.
  3. ^ 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.
  4. ^ 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.
  5. ^ 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.
  6. ^ 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.
  7. ^ 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.
  8. ^ 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.
  9. ^ 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.
  10. ^ "Hipparcos Tools Interactive Data Access". Hipparcos. ESA. Retrieved 8 December 2021.