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Orion

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List of stars in Orion
Abbreviation:	Ori
Genitive:	Orionis
Symbology:	Orion
Right ascension:	5 h
Declination:	+5°
Area:	594 sq. deg. (26th)
Main stars:	7
Bayer/Flamsteed stars:	73
Stars known to have planets:	2
Bright stars:	8
Nearby stars:	2
Brightest star:	Rigel (β Orionis) (0.12m)
Nearest star:	π3 Ori (26.3 ly)
Messier objects:	3
Meteor showers:	Orionids Chi Orionids
Bordering constellations:	Gemini Taurus Eridanus Lepus Monoceros
Visible at latitudes between +85° and −75° Best visible at 21:00 (9 p.m.) during the month of January
Credit: Mouser Williams

Orion (pronounced /ɒˈraɪən/), a constellation often referred to as The Hunter, is a prominent constellation, one of the largest and perhaps the best-known and most conspicuous in the sky^[1]. Its brilliant stars are found on the celestial equator and are visible throughout the world. Its three prominent "belt" stars - three stars of medium brightness in the mid-section of this constellation - make this constellation easy to spot and globally recognized. From mid-northern latitudes, Orion is visible in the evening from November to early May and in the morning from late July to November.^[2][3]

According to the most common contemporary imagery: Orion is standing next to the river Eridanus with his two hunting dogs Canis Major and Canis Minor, fighting Taurus the bull. Other prey of his, such as Lepus the hare, can be found nearby.

There are other contemporary names for Orion. In Australia, the belt and sword of Orion are sometimes called the Saucepan, because the stars of Orion's belt and sword resemble this kitchen utensil as seen from the Southern Hemisphere. Orion's Belt is called Drie Konings (Three Kings) by Afrikaans speakers in South Africa ^[4], and French les Trois Rois (the Three Kings) in Daudet's Lettres de Mon Moulin (1866). The appellation Driekoningen (the Three Kings) is also often found in 17th- and 18th-century Dutch star charts and seaman's guides.

The constellation is also known as an "Amber" in other Commonwealth countries such as the United Kingdom. Historically it has had other names, perhaps the earliest known is the Babylonian "Shepherd of Anu", corresponding to an apparent representation of the constellation Auriga or an element of it, as a shepherd's crook.

Contents 1 Stars in the Constellation 2 Locating other stars 3 Notable deep sky objects 4 Orion in Islamic astronomy 5 History 6 Mythology 7 In other cultures 8 References 9 See also 10 External links

The constellation is extremely rich in bright stars and in deep-sky objects. Here are some of its stars. ^[5]

Star	Magnitude	Open Clusters	Nebulae
Rigel	0.12	NGC 1981	NGC 1976
Betelgeuse	0.5	NGC 2175	NGC 1982
Bellatrix	1.64	Nil	NGC 2068
Alnilam	1.70	Nil	IC 434
Alnitak	1.77	Nil	Nil

• λ Ori (Meissa) is Orion's head.
• α Ori (Betelgeuse), at its right shoulder, is a red star with a diameter larger than the orbit of Mars. Although it is the α-star, it is somewhat fainter than Rigel.
• γ Ori (Bellatrix), is at Orion's left shoulder.
• ζ Ori (Alnitak), ε Ori (Alnilam) and δ Ori (Mintaka) make up the asterism known as Orion's Belt: three bright stars in a row; from these alone one can recognize Orion.
• η Ori (Eta Orionis), between Delta Orionis and Rigel.
• κ Ori (Saiph) is at Orion's right knee.
• β Ori (Rigel), at the constellation's left knee, is a large blue-white star, among the brightest in the sky. It has three companions, invisible to the naked eye.
• ι Ori (Hatsya) is at the tip of Orion's sword.

Orion is very useful in locating other stars. By extending the line of the Belt southeastward, Sirius (α CMa) can be found; northwestward, Aldebaran (α Tau). A line eastward across the two shoulders indicates the direction of Procyon (α CMi). A line from Rigel through Betelgeuse points to Castor and Pollux (α Gem and β Gem). Additionally, Rigel is part of the Winter Circle. Sirius and Procyon, which may be located from Orion by tracing lines, also are points in both the Winter Triangle and the Circle.^[6]

See also the list of stars in Orion.

Hanging from Orion's belt is his sword, consisting of the multiple stars θ1 and θ2 Orionis, called Trapezium and the Orion Nebula (M42). This is a spectacular object which can be clearly identified with the naked eye as something other than a star; using binoculars, its swirling clouds of nascent stars, luminous gas, and dust can be observed.

Another famous nebula is IC 434, the Horsehead Nebula, near ζ Orionis. It contains a dark dust cloud whose shape gives the nebula its name.

Besides these nebulae, surveying Orion with a small telescope will reveal a wealth of interesting deep sky objects, including Barnard's Loop, M43, M78 and the Flame Nebula (NGC 2024).

All of these nebulae are part of the larger Orion Molecular Cloud Complex which is located approximately 1,500 light-years away and is hundreds of light-years across. It is one of the most intense regions of stellar formation visible in our galaxy.

Alnitak ζ Ori is a star in the constellation Orion. It is the lowest of the prominent three stars [Other two:ε Ori (Alnilam), δ Ori (Mintaka)], which form a straight line, commonly known as the Orion Belt. The names Alnitak, Mintaka and Alnilam originate from Arabic.

The configurations of the constellation Orion roughly formed about 1.5 million years ago, because of relative slow movements of stars within the constellation from earth's perspective (especially the belt of Orion). Orion will remain visible in the night sky for the next 1 to 2 million years, making it one of the longest observable constellations, parallel to the rise of human civilization.

Being so bright and distinctive, the pattern of stars that forms Orion was recognized as a coherent constellation by many ancient civilizations, though with different representations and mythologies.

The ancient Sumerians saw this star pattern as forming part of an image of a shepherd (sometimes in a chariot) with his sheep and in some versions a shepherd's crook, while in China, Orion was one of the 28 lunar mansions Sieu (Xiu) （宿）. Known as Shen （參）, literally meaning "three", it is believed to be named so for the three stars located in Orion's belt. (See Chinese constellation)

The stars were associated with Osiris, the god of death and underworld, by the ancient Egyptians. The Giza pyramid complex, which consists of the Great Pyramid of Giza, the Pyramid of Khafre and the Pyramid of Menkaure, is said to be a sky-map of the Belt of Orion, that is, of Osiris.

References in ancient Middle Eastern and Mediterranean literature to the "belt and sword" imagery of Orion are those most often echoed in modern western literature and for this reason this imagery has found its way into popular western culture, for example in the form of the shoulder insignia of the 27th Infantry Division of the United States Army during both World Wars, probably owing to a pun on the name of the division's first commander, Major General John F. O'Ryan.

Around October 21 each year the famous Orionid meteor shower reaches its peak. Coming from the border to the constellation Gemini as much as 20 meteors per hour can be seen.

Main article: Orion (mythology)

Greek mythology has several versions of the history of Orion, the gigantic hunter of primordial times^[7]. These end in different versions of his death: He challenged the gods, either by attempting to rape Artemis or by claiming that he could kill every wild animal on Earth. Some versions then say Artemis shot him with her arrows; but others say that Artemis or Earth produced a great Scorpion whom he could not defeat and which killed him. The gods raised him and the Scorpion to the skies, as Scorpio/Scorpius. Yet other stories say Orion was chasing the Pleiades.^[8]

The nearby constellations of Canis Major and Canis Minor are visualized in some myths as Orion's hunting dogs.

It may be that the naming of the constellation precedes the mythology in this case. It has been suggested that Orion is named from the Akkadian Uru-anna, the light of heaven, the name then passing into Greek mythology. As such, the myth surrounding Orion may derive simply from the relative positions of the constellations around it in the sky.

In some depictions, Orion appears to be composed of three bodies, having three arms [5], two divergent legs, and a small central one, as well as the three bodies being bound at the waist. As such, together with other features of the area in the Zodiac sign of Gemini (i.e. the Milky Way, the deserted area now considered as the constellations Camelopardalis and Lynx, and the constellations Gemini, Auriga, and Canis Major), this may be the origin of the myth of the cattle of Geryon, which forms one of The Twelve Labours of Herakles.

In pre-Christian Scandinavia, the "Orion's belt" portion of the constellation was known as Frigg's Distaff (Friggerock) or Freyja's distaff^[9].

In Finnish mythology the constellation of Orion is called the scythe of Väinämöinen. The term most likely comes from the fact it can be seen in the sky in early autumn in the Northern Hemisphere, the time of haymaking.

In ancient Aram, the constellation was known as Nephila, Orion's descendants were known as Nephilim^[10].

The constellation is mentioned in Horace's Odes, Homer's Odyssey and Iliad, and Virgil's Aeneid.

The Bible mentions Orion 3 times: Job 9:9, Job 38:31 , and Amos 5:8.

The Seri people of northwestern Mexico call the three stars in the belt of this constellation Hapj (a name denoting a hunter) which consists of three stars: Hap (mule deer), Haamoja (pronghorn), and Mojet (bighorn sheep). Hap is in the middle and has been shot by the hunter; its blood has dripped onto Tiburón Island.^[11]

Orion is also important in Australian Aboriginal Astronomy. For example, the Yolngu people of Arnhem Land say that the constellation of Orion, which they call Julpan, is a canoe. They tell the story of two brothers who went fishing, and caught and ate a fish that was forbidden under their law. Seeing this, the Sun sent a waterspout that carried the two brothers and their canoe up into the sky where they became the Orion constellation.

In Indian Mythology, the constellation is known as 'Vyadh', which also means The Hunter.

• Ian Ridpath and Wil Tirion (2007). Collins Stars and Planets Guide, HarperCollins, London. ISBN 978-0007251209.

• Orvandil

• Map of Orion
• The Deep Photographic Guide to the Constellations: Orion
• Anne Wright's page on Orion Note: Astrological perspective
• Melbourne Planetarium: Orion Sky Tour
• The clickable Orion
• Star Tales – Orion