Orion Constellation

The Orion Constellation is one of the original 48 constellations listed by Ptolemy in the 2nd century. These constellations formed the basis for the modern list agreed by the IAU. Constellations from the Southern hemisphere, unable to be seen from the Mediterranean, represent the majority of the additions.

Orion is prominent in ancient mythology, originally a significant character of Babylon. Orion’s belt, which is an easily identified asterism, is used for navigation and identifying other stars. Orion constellation highlights an interesting observation into the distance of the stars from earth. Despite having 7 of the 70 brightest stars in this constellation, none of the light originated in your lifetime. The nearest star of those 7 is 245 light years away while all others are over 600 light years away. Therefore, the light you see in each of these stars originates from before Copernicus discovered the sun to be the centre of our solar system.

Quick Facts:

Symbolism: The Hunter

Neighbouring constellations: Gemini (north west) , Taurus (north east), Lepus (south), Canis Major (south west), horizon for northern hemisphere observers

Stars brighter than 3 magnitude: 7

Primary stars: 23 + 1 (10 in the body, 4 in the club, 9 in the bow & a nebula representing his sword). The main shape of the body is made up of 8 stars – 3 for the belt, 1 for each foot, 1 for each shoulder and 1 for the head. Two lesser stars represent a knee and an elbow. Orion’s sword is represented by Orion’s Nebula (M42).

Latitude: 10 degrees south – 20 degrees north

Northern Hemisphere Season: Winter (November – March)

Canis Major

Which months can you see Orion Constellation?

Northern hemisphere winter – November to March

For observers in the northern hemisphere Orion is visible from November to March, while in the southern hemisphere it is visible from October to April. Orion lies between 10 degrees south and 20 degrees north latitude. Therefore the further south your position the higher it will appear in the night sky.

Orion is not possible to see throughout the northern hemisphere summer, as it passes in the daytime sky. It becomes visible in the southern sky during winter from November to March. At its maximum range it is possible to see at latitudes between +60 and -90. However, the lower latitudes will have visibility for longer periods of the year.

Canis Major

How to find Orion constellation?

Difficulty to locate: Very easy – Difficulty to interpret: Easy – Locating asterism: Orion’s belt

Orion constellation is visible in the southern sky during winter months for observers in the northern hemisphere. To find Orion constellation; it is most convenient to first identify the 3 close stars in a line that form his belt. These 3 stars can also be known as the 3 kings or the 3 sisters. This asterism is among the most obvious and is a starting point for finding many other constellations.

The alternate approach for locating Orion is with the winter triangle or hexagon. The winter triangle connects the constellations of Orion with Canis Major and Canis Minor. The winter hexagon connects those 3 constellations with Gemini, Auriga and Taurus. Although the same star represents the other constellations, Orion contributes different stars. Betelgeuse is part of the Winter Triangle, but is in the centre of the hexagon where Rigel forms one corner.

Betelgeuse marks the shoulder of Orion and Rigel marks a foot. With the belt clearly apparent between these stars you have a good starting point to tracing the outline of Orion.

The shape of Orion Constellation

The body of Orion

The body of Orion is the easiest to identify, with the 8 brightest stars in the constellation marking the extremities.

  • Rigel the brightest star marks Orion’s left (eastern) foot. [Orion is considered to be facing earth so his left will correspond with your right]

  • Orions belt made up of Alnitak, Alnilam & Mintaka. When identifying to overall constellation it is useful to be aware that the belt angles downward at its western end.

  • The right (western) foot is a similar distance from the belt with the legs angled outward at around a 30 degrees gradient marked by Saiph.

  • Betelguese is the other very bright star in the constellation and marks the right (western) shoulder.

  • The left (eastern) shoulder marked by Bellatrix is similarly distanced from the belt to the other feet and shoulders with only the angle of the belt preventing an appearance of symmetry.

  • Orion’s head (Meissa or Heka) is equidistant from the two shoulders at a 45 degrees angle.

Additionally there is a bright Nebula and 2 lesser stars that are part of the body of Orion.

  • The sword is  attached to the belt and is recognisable as the bright nebula located in the middle of the belt and the two feet.

  • There is another star considered to mark the left (eastern) knee around a third of the way between Rigel and the belt.

  • There is a star that marks the right (western) elbow of Orion. This star is 90 degrees from the line between Betelguese and Meissa and around half the distance.

The Club of Orion

The club is held in Orion’s right (western) hand and is marked by 4 stars:

  • The star marking the handle end of the club is a direct continuation from the elbow around 3 times the distance from Betelguese.
  • A second star at the handle end is slightly to the east
  • The club is approximately the same length as the arm of Orion and is at a 45 degree angle to the arm over his head. Two stars mark the club end that are slightly further apart than the handle end.

The Bow of Orion

Orion’s bow is held in his left (eastern) hand and is marked by 9 stars curved in the shape of the bow. The bow is parallel to his body and is slightly further from Orion than the width of his shoulders. The midpoint of the bow is shoulder height and the bow spans from his hip height to slightly above his head.

Canis Major

Orion in the Ancient World

Greek mythology of Orion

There are a variety of stories related to Orion from Greek mythology. Legends related to Orion were shared by spoken stories, with the earliest written record referencing Orion is in Homer’s Odyssey. It is thought that the poem was passed on for several centuries through oral tradition before it was first written in the 6th century BC.

Although there area a variety of conflicting stories attributed to Orion, the central aspect is that he was a great hunter. He was said to carry a solid bronze club and be capable of hunting any wild animal. Orion was a prominent figure of Greek legends similar to Hercules and many stories came to reference him as the archetype of the great huntsmen.

Orion Constellation family

Several constellations adjacent to Orion have come to incorporate a narrative that ties these constellations together. Both Canis Minor and Canis Major are said to be Orion’s hunting companions. The hare is said to be pursued by his dogs on a hunt. The bull of Taurus is said to be in battle with Orion. Orion is said to have been killed by the sting of a giant scorpion, and Scorpio is the stellar representative of this scorpion.

Canis Major

Major stars

Rigel (0.18m, 772ly, #7)

Rigel from Arabic word for ‘left foot’ is the 7th brightest star visible from earth with an apparent magnitude of +0.18. The star is 772 light years from earth. Rigel forms part of the winter hexagon asterism. Rigel marks Orion’s left foot.

Betelguese (0.42m,624ly, #10)

Betelguese from Arabic for ‘armpit of Jauzah’ is the 10th brightest star visible from earth with an apparent magnitude of +0.42. Betelguese is 624 light years from earth. The name Jauzah was the Arabic name for the hunter Orion. Betelguese forms part of the winter triangle. Betelguese marks the right shoulder of Orion.

Bellatrix (1.64m, 245ly, #26)

Bellatrix from Latin for ‘female warrior’ is the 26th brightest star visible from earth with an apparent magnitude of +1.64. The star is 245 light years from earth. Bellatrix marks the left shoulder of Orion.

Alnilam (1.69m,1342ly, #29)

Alnilam from Arabic for ‘string of” is the 29th brightest star visible from earth with an apparent magnitude of +1.69. The star is 1342 light years from earth. Alnilam marks the central belt buckle of Orion.

Alnitak (1.88m, 800ly, #33)

Alnitak from the Arabic for ‘girdle’ is the 33rd brightest star visible from earth with an apparent magnitude of +1.88. The star is 800 light years from earth. Alnitak marks the western end of Orion’s belt and his right hip.

Saiph (2.07m, 650ly, #59)

Saiph from the Arabic for ‘sword’ is the 59th brightest star visible from earth with an apparent magnitude of +2.07. The star is 650 light years from earth. Saiph marks the right foot of Orion.

Mintaka (2.20m, 916ly, #67)

Mintaka from the Arabic for ‘belt’ is the 67th brightest star visible from earth with an apparent magnitude of +2.2. The star is 916 light years from earth. Mintaka marks the eastern end of Orion’s belt and his left hip

Meissa or Heka (3.47m 1042ly)

Meissa from Arabic for ‘shining one’ is also known as Heka also from Arabic for ‘white spot’. The star has an apparent magnitude of +3.47 and is 1042 light years from earth. Meissa marks the head of Orion.

Deep sky objects

Orion’s Nebula – Potentially the best known Nebula which is clearly not a single point of light, visible with the naked eye. Obvious that it is not a star without aides it has an apparent magnitude of +4 at a distance of 1344 light years

Orion Molecular Cloud Complex – Although not visible to the naked eye the cloud complex has a variety of observable objects with even a small telescope.