Omicron-2 Orionis, an orange giant star in Orion
Omicron-2 Orionis is an orange giant star in the constellation Orion. At 186 light years away, it shines at an apparent visual magnitude of 4.06.
Omicron-2 Orionis (HIP 22957)
Omicron-2 Orionis is an orange giant star in the constellation Orion. At 186 light years away, it shines at an apparent visual magnitude of 4.06. Omicron-2 Orionis is the primary component of a multiple-star system. The iron abundance of Omicron-2 Orionis is -0.21 (61.7% of the Sun). It is moving through the Galaxy at a speed of 23.6 km/s relative to the Sun. Its projected Galactic orbit carries it between 23,800 and 36,200 light years from the center of the Galaxy.
Sky position: RA 4h 56.4m, Dec +13° 30.6'
Common designations: Omicron-2 Orionis, 9 Orionis, HIP 22957, HD 31421
Brightest stars in Orion:
(list all)
| Rank | Mag. | Star |
| 7 | 2.25 | Mintaka |
| 8 | 2.75 | Hatsya |
| 9 | 3.19 | Tabit |
| 10 | 3.35 | Eta Orionis |
| 11 | 3.39 | Heka |
| 12 | 3.59 | Tau Orionis |
| 13 | 3.68 | Pi-4 Orionis |
| 14 | 3.71 | Pi-5 Orionis |
| 15 | 3.77 | Sigma Orionis |
16
| 4.06
) Omicron-2 Orionis
| Rank | Mag. | Star |
| 17 | 4.09 | Phi-2 Orionis |
| 18 | 4.12 | Mu Orionis |
| 19 | 4.13 | 29 Orionis |
| 20 | 4.20 | A Orionis |
| 21 | 4.35 | Pi-2 Orionis |
| 22 | 4.39 | Phi-1 Orionis |
| 23 | 4.39 | Chi-1 Orionis |
Hover over other bright stars to identify or click to jump.
Galactic Orbit of Omicron-2 Orionis
(compared to the Sun)
E
ccentricity: 20.7% vs. 16.0%Angle φ : 29.0°vs. 26.0°
Semi-major axis : 9,199 pc vs. 8,686 pc
Semi-minor axis: 8,999 pc vs. 8,574 pc
Focus-to-center
: 1,906 pcvs. 1,388 pcSemilatus rectum : 8,804 pc vs. 8,464 pc
Perigalacticon: 7,293 pc vs. 7,297 pc
Apogalacticon
: 11,105 pcvs. 10,074 pcSome Tabulated XHIP Data for Omicron-2 Orionis
(see also: SIMBAD)
Astrometry
2007A&A...474..653V
| Position | Proper Motion | |
| Right Ascension: | 74.09300433° ±0.18 mas | -74.89 ±0.28 mas/yr. |
| Declination: | 13.51457808° ±0.13 mas | -44.34 ±0.19 mas/yr. |
| Galactic Longitude: | 186.62625781° | -6.42 mas/yr. |
| Galactic Latitude: | -18.05194722° | -86.80 mas/yr. |
Parallax: 17.54 ± 0.21 mas
Spectrography
Spectral Type: K1III 2008ApJS..176..216A.
Radial Velocity: 1.64 ±0.25 km/s [A rating] 2005A&A...430..165F.
Iron Abundance [Fe/H]:
-0.21 ±0.03 dex
2011A&A...525A..71W, 1998A&A...338..623M, 1990ApJS...74.1075M.
Photometry
| band | magnitude | Abs. Mag. |
| U | ||
| B | 5.22 | 1.44 |
| V | 4.06 | 0.28 |
| R | ||
| I | 3.05 | -0.73 |
| J | ||
| H | ||
| K |
B-V: +1.16 V-I: +1.01
Derivations
Heliocentric distance: 57.00 pc (1.2% margin of error)
Galactocentric distance: 7,454 pc
Transverse velocity: 23.5 km/s
3D heliocentric position and motion:
|
toward: |
Galactic center | Galactic rotation | North Galactic Pole |
| Position ( X, Y, Z) | -53.8 pc | -6.3 pc | -17.7 pc |
| Velocity (U, V, W) | 5.5 km/s | 2.4 km/s | -22.8 km/s |