Pi-1 Orionis, a white main-sequence star in Orion
Pi-1 Orionis is a white main-sequence star in the constellation Orion. At 116 light years away, it shines at an apparent visual magnitude of 4.64.
Pi-1 Orionis (HIP 22845)
Pi-1 Orionis is a white main-sequence star in the constellation Orion. At 116 light years away, it shines at an apparent visual magnitude of 4.64. Pi-1 Orionis is the primary component of a multiple-star system. The iron abundance of Pi-1 Orionis is -0.82 (15.1% of the Sun). It is moving through the Galaxy at a speed of 25.4 km/s relative to the Sun. Its projected Galactic orbit carries it between 20,600 and 24,500 light years from the center of the Galaxy.
Sky position: RA 4h 54.9m, Dec +10° 9'
Common designations: Pi-1 Orionis, 7 Orionis, HIP 22845, HD 31295
Brightest stars in Orion:
(list all)
| Rank | Mag. | Star |
| 24 | 4.42 | Nu Orionis |
| 25 | 4.45 | Xi Orionis |
| 26 | 4.46 | Rho Orionis |
| 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
| Rank | Mag. | Star |
| 34 | 4.64 | Chi-2 Orionis |
| 35 | 4.65 | 11 Orionis |
| 36 | 4.71 | Omicron-1 Orionis |
| 37 | 4.71 | 31 Orionis |
| 38 | 4.72 | 22 Orionis |
| 39 | 4.76 | 56 Orionis |
| 40 | 4.77 | 49 Orionis |
Hover over other bright stars to identify or click to jump.
Galactic Orbit of Pi-1 Orionis
(compared to the Sun)
E
ccentricity: 8.6% vs. 16.0%Angle φ : 150.0°vs. 26.0°
Semi-major axis : 6,929 pc vs. 8,686 pc
Semi-minor axis: 6,903 pc vs. 8,574 pc
Focus-to-center
: 598 pcvs. 1,388 pcSemilatus rectum : 6,877 pc vs. 8,464 pc
Perigalacticon: 6,331 pc vs. 7,297 pc
Apogalacticon
: 7,527 pcvs. 10,074 pcSome Tabulated XHIP Data for Pi-1 Orionis
(see also: SIMBAD)
Astrometry
2007A&A...474..653V
| Position | Proper Motion | |
| Right Ascension: | 73.72376741° ±0.20 mas | 41.42 ±0.25 mas/yr. |
| Declination: | 10.15114489° ±0.13 mas | -128.74 ±0.16 mas/yr. |
| Galactic Longitude: | 189.34563913° | 129.86 mas/yr. |
| Galactic Latitude: | -20.25318461° | -37.75 mas/yr. |
Parallax: 28.04 ± 0.25 mas
Spectrography
Spectral Type: A3VakB9.5mB9.5 lambda Boo 2003AJ....126.2048G.
Radial Velocity: 11.10 ±1.20 km/s [A rating] 2006AstL...32..759G.
Iron Abundance [Fe/H]:
-0.82 dex
2011A&A...525A..71W.
Photometry
| band | magnitude | Abs. Mag. |
| U | ||
| B | 4.73 | 1.96 |
| V | 4.64 | 1.88 |
| R | ||
| I | 4.56 | 1.79 |
| J | 4.85 | 2.09 |
| H | 4.52 | 1.76 |
| K | 4.42 | 1.66 |
B-V: +0.09 V-I: +0.08
Derivations
Heliocentric distance: 35.66 pc (0.9% margin of error)
Galactocentric distance: 7,433 pc
Transverse velocity: 22.9 km/s
3D heliocentric position and motion:
|
toward: |
Galactic center | Galactic rotation | North Galactic Pole |
| Position ( X, Y, Z) | -33.0 pc | -5.4 pc | -12.3 pc |
| Velocity (U, V, W) | -4.5 km/s | -23.0 km/s | -9.8 km/s |