HD 123657

HD 123657
(BY Boötis)
	Location of BY Boö (circled)
Observation data; Epoch J2000 Equinox J2000
Constellation	Boötes
Right ascension	14h 07m 55.756s
Declination	43° 51′ 16.03″
Apparent magnitude (V)	5.28 (4.98-5.33)
Characteristics
Spectral type	M4.5III
U−B color index	1.66
B−V color index	1.58
R−I color index	1.66
Variable type	LB
Astrometry
Radial velocity (Rv)	-36.24 km/s
Proper motion (μ)	RA: 11.63 mas/yr ; Dec.: -30.08 mas/yr
Parallax (π)	6.36 ± 0.26 mas
Distance	510 ± 20 ly ; (157 ± 6 pc)
Absolute magnitude (MV)	−0.90
Details
Radius	70 R☉
Luminosity	1,380 L☉
Temperature	3,500 K
Metallicity [Fe/H]	−0.03 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
SIMBAD	data

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.

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

^ ^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.

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[hipparcos-1] 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.

[ducati-2] 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.

[gcvs-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.

[alvarez-4] 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.

[park-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.

[cadars-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.

[blum-8] 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-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.

[HipDataAccess-10] "Hipparcos Tools Interactive Data Access". Hipparcos. ESA. Retrieved 8 December 2021.

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Observation data Epoch J2000 Equinox J2000
Location of BY Boö (circled)
Constellation	Boötes
Right ascension	14^h 07^m 55.756^s^[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 (R_v)	-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]
Distance	510 ± 20 ly (157 ± 6 pc)
Absolute magnitude (M_V)	−0.90^[6]

Details

Radius	70^[7] `R`_☉
Luminosity	1,380^[8] `L`_☉
Temperature	3,500^[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
SIMBAD	data