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Orion (abbr. Ori, gen. Orionis)





The Hunter; a spectacular northern constellation, located southeast of Taurus in the equatorial region of the sky. Below Orion's Belt is one of the most famous deep-sky objects, the Orion Nebula. See below for details of the constellation's brightest stars and interesting deep sky objects.

Orion constellation
Orion. © 2003 Torsten Bronger.
Copied here under the terms of the GNU Free Documentation License



Stars brighter than magnitude 4.0
Star Visual
mag.
Abs.
mag.
Spectral
type
Distance
(lt-yr)
R.A. (h m s) Dec. ( ° ' '' )
Beta (Rigel) 0.12v -6.69 B8Iae 773 05 14 32 -08 12 06
Alpha (Betelgeuse) 0.5v -5.14v M2Iab 427 05 55 10 +07 24 26
Gamma (Bellatrix) 1.64 -2.73 B2III 243 05 25 08 +06 20 59
Epsilon (Alnilam) 1.69 -6.39 B0Iae 1,340 05 36 13 -01 12 07
Zeta (Alnitak) 1.74 -5.26 O9.5Ibe 817 05 40 46 -01 56 34
Kappa (Saiph) 2.07 -4.66 B0.5Iav 721 05 47 45 -09 40 11
Delta (Mintaka) 2.25 -4.99 B0II+O9V 916 05 32 00 -00 17 57
Iota (Nai'ir al Saif) 2.75 -5.30 O9III 1,330 05 35 26 -05 54 36
Pi-3 3.19 3.66 F6V 26 04 49 50 +06 57 41
Eta (Algjebbah) 3.35v -3.86 B1V+B2e 901 05 24 29 -02 23 50
Lambda (Meissa) 3.39 -4.16 O8e+B0.5v 1,060 05 35 08 +09 56 02
Tau 3.59 -2.56 B5III 555 05 17 36 -06 50 40
Pi-4 3.68 -4.25 B2III+B2IV 1,260 04 51 12 +05 36 18
Pi-5 3.71v -4.37 B3III+B0V 1,340 04 54 15 +02 26 26
Sigma 3.7 -3.96 O9.5V 1,150 05 38 45 -02 36 00


Other objects of interest
Name Type of Object Notes
Trapezium open cluster Theta-1 Orionis. See separate entry
NGC 1981 open cluster 10 stars, including the binary Struve 750, with 6th and 8th mag components. Magnitude 4.6; diameter 25'; R.A. 05h 35.2m, Dec. -04° 26'
Orion Nebula emission nebula M42. See separate entry
De Mairan Nebula emission nebula M43. Part of the Orion Nebula
Horsehead Nebula dark nebula B33. See separate entry


Orion, photographed from Dundee, Scotland, by David Cleave
Photograph of Orion taken in Dundee, Scotland, on Jan. 19, 2014. © David Cleave

The nebulae of Orion and environs

nebulae of Orion
The nebulae in and around Orion.
Image credit: Jerry Lodriguss ©, Catching the Light

The orange-red supergiant Betelgeuse appears yellow in the upper center of this photo, while Rigel shines blue-white at bottom center. Midway between these two great luminaries of Orion are the three distinctive, bright stars that define Orion's Belt.

Below and to the left of the Belt is a large stellar nursery containing M42, the Orion Nebula, surrounding the center star in Orion's Sword, which is seen overexposed in this image. Just above M42 is the nebulous complex containing the Horsehead Nebula, (B33) and the Flame Nebula (NGC 2024).

The largest emission nebula in the photo is Barnard's Loop, seen as a semicircle around the Orion's Belt and Sword. The next largest nebula is Sh2-264 surrounding Meissa (Lambda Orionis).

M78 (NGC 2068), a small but bright 8 × 7 arc-minute reflection nebula is above the three bright stars of Orion's belt.

A large but extremely faint reflection nebula, the Witch Head Nebula (IC 2118), lies just to the west of Rigel in the constellation Eridanus.

The small bright red emission nebula at the upper left of the photo is the Rosette Nebula, and above it, the faint complex of nebulosity containing the Cone Nebula. Both these objects lie in the neighboring constellation Monoceros .


Related categories

   • NOTABLE STARS
   • NEBULAE AND STAR CLUSTERS
   • GALAXIES

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