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Alkor
	Lega Alkorja (Mizar je obkrožen, Alkor je v tem merilu neviden)
Opazovalni podatki; Epoha J2000.0 Enakonočje J2000.0
Ozvezdje	Veliki medved
Rektascenzija	13h 25m 13,53783s
Deklinacija	+54° 59′ 16,6548″
Navidezni sij (V)	+3,99
Značilnosti
Spektralni razred	A5Vn / M3-4
Astrometrija
Radialna hitrost (Rv)	−9,6 km/s
Paralaksa (π)	39,91 ± 0.13 mas
Oddaljenost	pribl. 80 sv. l. ; (pribl. 25 pc)
Absolutni izsev (MV)	+2,00
Podrobnosti
Alcor A
Masa	1,84 M☉
Polmer	1,846 R☉
Izsev	14,03 L☉
Površinska težnost (log g)	4,25 cgs
Temperatura	8.221 K
Tirna hitrost(v sin i)	228 km/s
Alcor B
Masa	0,25 M☉
Starost	0,5 ± 0,1 Ga
Druge oznake
	g Ursae Majoris, 80 Ursae Majoris, BD+55 1603, CCDM J13240+5456D, GC 18155, HD 116842, HIP 65477, HR 5062, PPM 34021, SAO 28751, WDS J13239+5456C
Sklici na podatkovne baze
SIMBAD	podatki

Alkor (Alcor, Saidak) je zvezda v bližini Mizarja. Imenujemo jo tudi Jahač in 80 Velikega medveda (80 UMa, 80 Ursae Majoris).

Ima navidezni sij 4,02^m in sodi v spektralni razred A5 V. Spada me najbolj znane navidezne dvojne zvezde, čeprav še ni natančno znano ali res ne tvori pravega dvozvezdja z Mizarjem.

Sklici

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↑ Gray, R. O; Garrison, R. F (1989). »The late A-type stars - Refined MK classification, confrontation with Stromgren photometry, and the effects of rotation«. Astrophysical Journal Supplement Series. 70: 623. Bibcode:1989ApJS...70..623G. doi:10.1086/191349.
↑ ^4,0 ^4,1 Zimmerman, Neil; Oppenheimer, Ben R; Hinkley, Sasha; Brenner, Douglas; Parry, Ian R; Sivaramakrishnan, Anand; Hillenbrand, Lynne; Beichman, Charles; Crepp, Justin R; Vasisht, Gautam; Roberts, Lewis C; Burruss, Rick; King, David L; Soummer, Rémi; Dekany, Richard; Shao, Michael; Bouchez, Antonin; Roberts, Jennifer E; Hunt, Stephanie (2010). »Parallactic Motion for Companion Discovery: An M-Dwarf Orbiting Alcor«. The Astrophysical Journal. 709 (2): 733–740. arXiv:0912.1597. Bibcode:2010ApJ...709..733Z. doi:10.1088/0004-637X/709/2/733.
↑ Kidger, Mark R; Martín-Luis, Fabiola (2003). »High-Precision Near-Infrared Photometry of a Large Sample of Bright Stars Visible from the Northern Hemisphere«. The Astronomical Journal. 125 (6): 3311. Bibcode:2003AJ....125.3311K. doi:10.1086/374996.
↑ ^6,0 ^6,1 ^6,2 Zorec, J; Royer, F (2012). »Rotational velocities of A-type stars. IV. Evolution of rotational velocities«. Astronomy & Astrophysics. 537: A120. arXiv:1201.2052. Bibcode:2012A&A...537A.120Z. doi:10.1051/0004-6361/201117691.
↑ Jones, Jeremy; White, R. J; Boyajian, T; Schaefer, G; Baines, E; Ireland, M; Patience, J; Ten Brummelaar, T; McAlister, H; Ridgway, S. T; Sturmann, J; Sturmann, L; Turner, N; Farrington, C; Goldfinger, P. J (2015). »The Ages of A-Stars. I. Interferometric Observations and Age Estimates for Stars in the Ursa Major Moving Group«. The Astrophysical Journal. 813: 58. arXiv:1508.05643. Bibcode:2015ApJ...813...58J. doi:10.1088/0004-637X/813/1/58.
↑ ^8,0 ^8,1 David, Trevor J; Hillenbrand, Lynne A (2015). »The Ages of Early-type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets«. The Astrophysical Journal. 804 (2): 146. arXiv:1501.03154. Bibcode:2015ApJ...804..146D. doi:10.1088/0004-637X/804/2/146.