Rho Orionis, an orange giant star in Orion
Rho Orionis is an orange giant star in the constellation Orion. At 340 light years away, it shines at an apparent visual magnitude of 4.46.
Rho Orionis (HIP 24331)
Rho Orionis is an orange giant star in the constellation Orion. At 340 light years away, it shines at an apparent visual magnitude of 4.46. Rho Orionis is a multiple-star system. The iron abundance of Rho Orionis is +0.15 (141.3% of the Sun). It is moving through the Galaxy at a speed of 40.5 km/s relative to the Sun. Its projected Galactic orbit carries it between 22,700 and 28,400 light years from the center of the Galaxy. It came closest to the Sun 2.5 million years ago when it had brightened to magnitude -3.10 from a distance of 10.5 light years.
Sky position: RA 5h 13.3m, Dec +2° 51.6'
Common designations: Rho Orionis, 17 Orionis, HIP 24331, HD 33856
Brightest stars in Orion:
(list all)
| 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 |
| 24 | 4.42 | Nu Orionis |
| 25 | 4.45 | Xi Orionis |
26
| 4.46
) Rho Orionis
| Rank | Mag. | Star |
| 27 | 4.47 | Pi-6 Orionis |
| 28 | 4.50 | Omega Orionis |
| 29 | 4.53 | HR 2113 |
| 30 | 4.58 | 42 Orionis |
| 31 | 4.59 | Psi Orionis |
| 32 | 4.62 | Thabit |
| 33 | 4.64 | Pi-1 Orionis |
Hover over other bright stars to identify or click to jump.
Galactic Orbit of Rho Orionis
(compared to the Sun)
E
ccentricity: 11.1% vs. 16.0%Angle φ : -72.2°vs. 26.0°
Semi-major axis : 7,843 pc vs. 8,686 pc
Semi-minor axis: 7,795 pc vs. 8,574 pc
Focus-to-center
: 869 pcvs. 1,388 pcSemilatus rectum : 7,747 pc vs. 8,464 pc
Perigalacticon: 6,975 pc vs. 7,297 pc
Apogalacticon
: 8,712 pcvs. 10,074 pcSome Tabulated XHIP Data for Rho Orionis
(see also: SIMBAD)
Astrometry
2007A&A...474..653V
| Position | Proper Motion | |
| Right Ascension: | 78.32283171° ±0.87 mas | 2.40 ±1.00 mas/yr. |
| Declination: | 2.86125346° ±0.69 mas | 0.80 ±1.00 mas/yr. |
| Galactic Longitude: | 198.51596549° | 0.52 mas/yr. |
| Galactic Latitude: | -20.26530397° | 2.48 mas/yr. |
Parallax: 9.49 ± 0.82 mas
Spectrography
Spectral Type: K0 III 1999MSS...C05....0H.
Radial Velocity:
40.50 ±0.30 km/s [A rating]
2005A&A...430..165F.
This star is a spectroscopic binary with a solved orbit.
Iron Abundance [Fe/H]:
0.15 dex
1990ApJS...74.1075M.
Photometry
| band | magnitude | Abs. Mag. |
| U | ||
| B | 5.63 | 0.54 |
| V | 4.46 | -0.63 |
| R | ||
| I | 3.50 | -1.59 |
| J | ||
| H | ||
| K |
B-V: +1.17 V-I: +0.96
Derivations
Heliocentric distance: 104.44 pc (8.6% margin of error)
Galactocentric distance: 7,493 pc
Transverse velocity: 1.3 km/s
3D heliocentric position and motion:
|
toward: |
Galactic center | Galactic rotation | North Galactic Pole |
| Position ( X, Y, Z) | -92.9 pc | -31.1 pc | -36.2 pc |
| Velocity (U, V, W) | -36.3 km/s | -12.4 km/s | -12.9 km/s |