Theta-1 Orionis, a blue giant star in Orion
Theta-1 Orionis is a blue giant star in the constellation Orion. At 2,027 light years away, it shines at an apparent visual magnitude of 4.98.
Theta-1 Orionis (HIP 26220)
Theta-1 Orionis is a blue giant star in the constellation Orion. At 2,027 light years away, it shines at an apparent visual magnitude of 4.98. Theta-1 Orionis is a component of a multiple-star system. It is moving through the Galaxy at a speed of 28.4 km/s relative to the Sun and is part of the NGC 1980 moving group.
Sky position: RA 5h 35.3m, Dec -5° 23.4'
Common designations: Theta-1 Orionis, 41 Orionis, HIP 26220, HD 37020
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Brightest stars in Orion:
(list all)
| Rank | Mag. | Star |
| 39 | 4.76 | 56 Orionis |
| 40 | 4.77 | 49 Orionis |
| 41 | 4.78 | HR 1887 |
| 42 | 4.81 | 15 Orionis |
| 43 | 4.89 | 25 Orionis |
| 44 | 4.90 | 51 Orionis |
| 45 | 4.91 | Lalande 12104 |
| 46 | 4.95 | HR 1952 |
| 47 | 4.95 | 69 Orionis |
48
| 4.98
) Theta-1 Orionis
| Rank | Mag. | Star |
| 49 | 4.98 | Theta-2 Orionis |
| 50 | 4.99 | 23 Orionis |
| 51 | 5.04 | 74 Orionis |
| 52 | 5.07 | 27 Orionis |
| 53 | 5.13 | Theta-1 Orionis C |
| 54 | 5.14 | 64 Orionis |
| 55 | 5.18 | 6 Orionis |
Hover over other bright stars to identify or click to jump.
Galactic Orbit of Theta-1 Orionis
(compared to the Sun)
E
ccentricity: 10.7% vs. 16.0%Angle φ : -5.8°vs. 26.0°
Semi-major axis : 8,867 pc vs. 8,686 pc
Semi-minor axis: 8,816 pc vs. 8,574 pc
Focus-to-center
: 950 pcvs. 1,388 pcSemilatus rectum : 8,765 pc vs. 8,464 pc
Perigalacticon: 7,917 pc vs. 7,297 pc
Apogalacticon
: 9,817 pcvs. 10,074 pcSome Tabulated XHIP Data for Theta-1 Orionis
(see also: SIMBAD)
Astrometry
2007A&A...474..653V
| Position | Proper Motion | |
| Right Ascension: | 83.81592896° ±23.22 mas | -0.92 ±2.06 mas/yr. |
| Declination: | -5.38731536° ±17.40 mas | 0.13 ±1.34 mas/yr. |
| Galactic Longitude: | 209.00721369° | -0.53 mas/yr. |
| Galactic Latitude: | -19.38535104° | -0.76 mas/yr. |
Parallax: -1.85 ± 2.12 mas
Spectrography
Spectral Type: B3III-IV 1988IBVS.3246....1B.
Radial Velocity:
28.30 ±1.00 km/s [A rating]
2004A&A...424..727P.
This star is a spectroscopic binary with a solved orbit.
Iron Abundance [Fe/H]:
n/a
Photometry
band
magnitude
Abs. Mag.
U
5.85
-3.12
B
V
4.98
-3.99
R
I
J
H
K
Derivations
Heliocentric distance: 621.91 pc (fitted to cluster)
Galactocentric distance: 7,920 pc
Transverse velocity: 2.7 km/s
3D heliocentric position and motion:
|
toward: |
Galactic center | Galactic rotation | North Galactic Pole |
| Position ( X, Y, Z) | -513.1 pc | -284.5 pc | -206.4 pc |
| Velocity (U, V, W) | -23.5 km/s | -11.2 km/s | -11.5 km/s |