Alkaphrah, an orange giant star in Ursa Major
Alkaphrah is an orange giant star in the constellation Ursa Major. At 184 light years away, it is the 357th brightest star in the Earth's sky, where it shines at an apparent visual magnitude of 3.69.
Alkaphrah (HIP 57399)
Alkaphrah is an orange giant star in the constellation Ursa Major. At 184 light years away, it is the 357th brightest star in the Earth's sky, where it shines at an apparent visual magnitude of 3.69. The iron abundance of Alkaphrah is -0.36 (43.7% of the Sun). It is moving through the Galaxy at a speed of 38.8 km/s relative to the Sun. Its projected Galactic orbit carries it between 23,000 and 28,100 light years from the center of the Galaxy.
Sky position: RA 11h 46.1m, Dec +47° 46.8'
Common designations: Alkaphrah, Chi Ursae Majoris, 63 Ursae Majoris, HIP 57399, HD 102224
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Brightest stars in Ursa Major:
(list all)
| Rank | Mag. | Star |
| 8 | 3.06 | Tania Australis |
| 9 | 3.12 | Talitha |
| 10 | 3.17 | Theta Ursae Majoris |
| 11 | 3.32 | Megrez |
| 12 | 3.35 | Muscida |
| 13 | 3.45 | Tania Borealis |
| 14 | 3.49 | Alula Borealis |
| 15 | 3.57 | Kappa Ursae Majoris |
| 16 | 3.65 | 23 Ursae Majoris |
17
| 3.69
) Alkaphrah
| Rank | Mag. | Star |
| 18 | 3.78 | Upsilon Ursae Majoris |
| 19 | 3.99 | Alcor |
| 20 | 4.46 | 15 Ursae Majoris |
| 21 | 4.47 | 26 Ursae Majoris |
| 22 | 4.54 | 24 Ursae Majoris |
| 23 | 4.55 | Phi Ursae Majoris |
| 24 | 4.59 | Muscida |
Hover over other bright stars to identify or click to jump.
Galactic Orbit of Alkaphrah
(compared to the Sun)
E
ccentricity: 9.9% vs. 16.0%Angle φ : -62.2°vs. 26.0°
Semi-major axis : 7,839 pc vs. 8,686 pc
Semi-minor axis: 7,801 pc vs. 8,574 pc
Focus-to-center
: 776 pcvs. 1,388 pcSemilatus rectum : 7,762 pc vs. 8,464 pc
Perigalacticon: 7,063 pc vs. 7,297 pc
Apogalacticon
: 8,615 pcvs. 10,074 pcSome Tabulated XHIP Data for Alkaphrah
(see also: SIMBAD)
Astrometry
2007A&A...474..653V
| Position | Proper Motion | |
| Right Ascension: | 176.51305883° ±0.14 mas | -138.31 ±0.14 mas/yr. |
| Declination: | 47.77933685° ±0.10 mas | 28.57 ±0.11 mas/yr. |
| Galactic Longitude: | 150.31915362° | 92.28 mas/yr. |
| Galactic Latitude: | 65.72327579° | -106.92 mas/yr. |
Parallax: 17.76 ± 0.16 mas
Spectrography
Spectral Type: K0.5IIIb: 1989ApJS...71..245K.
Radial Velocity: -9.06 ±0.20 km/s [A rating] 2005A&A...430..165F.
Iron Abundance [Fe/H]:
-0.36 dex
2011A&A...525A..71W, 2008A&A...480...91S, 2007A&A...475.1003H, 1995AJ....110.2968L, 1990ApJS...74.1075M.
Photometry
| band | magnitude | Abs. Mag. |
| U | ||
| B | 4.87 | 1.12 |
| V | 3.69 | -0.06 |
| R | ||
| I | 2.68 | -1.07 |
| J | 1.68 | -2.07 |
| H | 1.03 | -2.73 |
| K | 0.99 | -2.76 |
B-V: +1.18 V-I: +1.01
Derivations
Heliocentric distance: 56.30 pc (0.9% margin of error)
Galactocentric distance: 7,420 pc
Transverse velocity: 37.7 km/s
3D heliocentric position and motion:
|
toward: |
Galactic center | Galactic rotation | North Galactic Pole |
| Position ( X, Y, Z) | -20.1 pc | 11.5 pc | 51.3 pc |
| Velocity (U, V, W) | -31.6 km/s | -10.4 km/s | -20.0 km/s |