Pi-5 Orionis, a blue subgiant star in Orion
Pi-5 Orionis is a blue subgiant star in the constellation Orion. At 1,301 light years away, it is the 362nd brightest star in the Earth's sky, where it shines at an apparent visual magnitude of 3.71.
Pi-5 Orionis (HIP 22797)
Pi-5 Orionis is a blue subgiant star in the constellation Orion. At 1,301 light years away, it is the 362nd brightest star in the Earth's sky, where it shines at an apparent visual magnitude of 3.71. It an intrinsic variable star that varies between magntitudes 3.62 and 3.67 over a period of 3.7 days. The iron abundance of Pi-5 Orionis is -0.28 (52.5% of the Sun). It is moving through the Galaxy at a speed of 24.2 km/s relative to the Sun. Its projected Galactic orbit carries it between 25,200 and 33,300 light years from the center of the Galaxy.
Sky position: RA 4h 54.3m, Dec +2° 26.4'
Common designations: Pi-5 Orionis, 8 Orionis, HIP 22797, HD 31237
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Brightest stars in Orion:
(list all)
| Rank | Mag. | Star |
| 5 | 1.74 | Alnitak |
| 6 | 2.07 | Saiph |
| 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
| Rank | Mag. | Star |
| 15 | 3.77 | Sigma Orionis |
| 16 | 4.06 | Omicron-2 Orionis |
| 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 |
Hover over other bright stars to identify or click to jump.
Galactic Orbit of Pi-5 Orionis
(compared to the Sun)
E
ccentricity: 13.8% vs. 16.0%Angle φ : -11.3°vs. 26.0°
Semi-major axis : 8,972 pc vs. 8,686 pc
Semi-minor axis: 8,886 pc vs. 8,574 pc
Focus-to-center
: 1,239 pcvs. 1,388 pcSemilatus rectum : 8,801 pc vs. 8,464 pc
Perigalacticon: 7,733 pc vs. 7,297 pc
Apogalacticon
: 10,211 pcvs. 10,074 pcSome Tabulated XHIP Data for Pi-5 Orionis
(see also: SIMBAD)
Astrometry
2007A&A...474..653V
| Position | Proper Motion | |
| Right Ascension: | 73.56289884° ±0.33 mas | 0.55 ±0.41 mas/yr. |
| Declination: | 2.44067160° ±0.19 mas | 0.61 ±0.22 mas/yr. |
| Galactic Longitude: | 196.26693982° | -0.23 mas/yr. |
| Galactic Latitude: | -24.56247214° | 0.79 mas/yr. |
Parallax: 2.43 ± 0.39 mas
Spectrography
Spectral Type: B1.5IV 1977PASP...89..797A.
Radial Velocity:
24.20 ±0.70 km/s [A rating]
2004A&A...424..727P.
This star is a spectroscopic binary with a solved orbit.
Iron Abundance [Fe/H]:
-0.28 dex
1992ApJ...387..673G.
Photometry
| band | magnitude | Abs. Mag. |
| U | 2.72 | -5.29 |
| B | 3.53 | -4.47 |
| V | 3.71 | -4.30 |
| R | ||
| I | 3.85 | -4.15 |
| J | 4.19 | -3.82 |
| H | 4.35 | -3.65 |
| K | 4.27 | -3.73 |
B-V: -0.18 V-I: -0.14
Derivations
Heliocentric distance: 399.18 pc (16.0% margin of error)
Galactocentric distance: 7,751 pc
Transverse velocity: 1.6 km/s
3D heliocentric position and motion:
|
toward: |
Galactic center | Galactic rotation | North Galactic Pole |
| Position ( X, Y, Z) | -348.5 pc | -101.7 pc | -165.9 pc |
| Velocity (U, V, W) | -21.8 km/s | -5.9 km/s | -8.7 km/s |