Orion Constellation

                        Orion Constellation: Facts About the Hunter

Locating Orion the Hunter:

Orion is clearly visible in the night sky from November to February. Orion is in the southwest sky if you are in the Northern Hemisphere or the northwestern sky if you are in the Southern Hemisphere. It is best seen between latitudes 85 and -75 degrees. Its right ascension is 5 hours, and its declination is 5 degrees.

Alnilam, Mintaka and Alnitak, which form Orion’s belt, are the most prominent stars in the Orion constellation. Betelgeuse, the second brightest star in Orion, establishes the right shoulder of the hunter. Bellatrix serves as Orion's left shoulder.

The Orion Nebula—a formation of dust, hydrogen, helium and other ionized gases rather than a star—is the middle "star" in Orion’s sword, which hangs off of Orion's Belt.

Meissa, forms Orion's head. Saiph serves as Orion's right knee. Rigel forms the hunter's left knee. With one exception, all of the main stars in Orion are bright young blue giants or supergiants, ranging in distance from Bellatrix (243 light-years) to Alnilam (1,359 light-years). The Orion Nebula is farther away than any of the naked eye stars at a distance of about 1,600 light-years. One light-year is the distance light travels in a single year, about 6 trillion miles (10 trillion kilometers).

The exception is the star Betelgeuse, which is a red giant and one of the largest stars known. It is also the only star in the sky large enough and close enough to have been imaged as a disk in the Hubble Space Telescope. Observers with a keen eye should be able to see the difference in color between Betelgeuse and all the other stars in Orion. 

Orion Constellation Facts

Ø  Orion is visible in both the Northern and Southern hemispheres.

Ø  In the Northern hemisphere the constellation can be seen from late autumn to early spring.

Ø  In the Southern hemisphere Orion can be seen in the summer months, note that it will appear upside down.

Ø  The constellation mainly consists of bright blue supergiant stars, the most notable exception being the red supergiant Betelgeuse which lies on Orion's shoulder.

Ø  Betelgeuse is also the largest star in the constellation, it has 1,000 times the radius of the sun.

Ø  The brightest star in the constellation is Rigel, which is 40,000 times brighter than the sun and emits 100,000 times the energy.

Ø  The three stars which form a line through the middle of the constellation are known as Orion's Belt.

Ø  If you follow an imaginary line down through Orion's Belt it will take you to the brightest star in the night sky, Sirius, follow the line up in the southern hemisphere.

Main Stars in the Orion Constellation

Ø  Betelgeuse
A red supergiant star around 640 light years from Earth, Betelgeuse, also known as Alpha Orionis, has a radius 1,000 times larger than the sun and is expected to explode as a supernova in the next million years.

Ø  Meissa
A blue giant star with surface temperatures around 5 times hotter than our sun, Meissa is actually a pair of binary stars, its companion is similar in size and mass to the sun.

Ø  Bellatrix
A blue giant star around 250 light years from Earth, Bellatrix is 6 times larger than our sun and 8 times more massive, the star is also known as Gamma Orionis.

Ø  Alnitak
Alnitak is a triple star system around 736 light years from Earth, the primary star is a blue supergiant star with a radius around 20 times larger than the sun, Alnitak is also known as Zeta Orionis.

Ø  Alnilam
A blue supergiant star around 1,400 light years from Earth, Alnilam is 24 times larger than the sun and more than 250,000 times as luminous, the star is also known as Epsilon Orionis.

Ø  Mintaka
Also known as Delta Orionis, Mintaka is actually a pair of blue giant stars with the largest having 16 times the radius of the sun, both stars are around 100,000 times more luminous than the sun.

Ø  Saiph
A blue supergiant star around 650 light years from Earth, Saiph is 16 times more massive and around 22 times larger in diameter than the sun.

Ø  Rigel
Also known as Beta Orionis, Rigel is around 800 light years from Earth and is the brightest star in the constellation, once again like most of the others it is a blue supergiant around 75 times larger in diameter than the sun and around 40,000 times brighter.

Ø  M42
Perhaps the most interesting component of the Orion constellation, M42 is not a star but is in fact the Orion nebula, a vast star forming region some 1,500 light years from Earth, the nebula makes up the sword of Orion along with two other stars. The Orion nebula has an apparent magnitude of 4.0, making it easily visible with the naked eye apart from those living in an around the center of large cities.

MYTH

Ø  In Greek mythology, the hunter Orion was the most handsome of men. He was the son of the sea god Poseidon and Euryale, the daughter of King Minos of Crete. In Homer’s Odyssey, Orion is described as exceptionally tall and armed with an unbreakable bronze club.

Ø  In one myth, Orion fell in love with the Pleiades, the seven sisters, daughters of Atlas and Pleione. He started pursuing them and Zeus scooped them up and placed them in the sky. The Pleiades are represented by the famous star cluster of the same name, located in the constellation Taurus. Orion can still be seen chasing the sisters across the sky at night.

Ø  In another story, Orion fell in love with Merope, the beautiful daughter of King Oenopion who didn’t return his affections. One night, he had too much to drink and tried to force himself on her. The king, enraged, put out Orion’s eyes and banished him from his land, the island of Chios. Hephaestus felt sorry for the blind, wandering Orion and offered one of his assistants to guide the hunter and act as his eyes. Orion eventually encountered an oracle that told him if he went east toward the sunrise, his sight would be restored. Orion did so and his eyes were miraculously healed.

Ø  The constellation Orion has its origins in Sumerian mythology, specifically in the myth of Gilgamesh. Sumerians associated it with the story of their hero fighting the bull of heaven, represented by Taurus. They called Orion URU AN-NA, which means “the light of heaven.” Their name for the constellation Taurus was GUD AN-NA, or “the bull of heaven.”

Ø  Orion is often shown as facing the attack of a bull, yet there are no myths in Greek mythology telling any such tale. When describing the constellation, the Greek astronomer Ptolemy describes the hero with a club and lion’s pelt, both of which are usually associated with Heracles, but there is no evidence in mythology books of a direct relation between the constellation and Heracles. However, since Heracles, the most famous of Greek heros, is represented by the much less conspicuous constellation Hercules, and since one of his tasks was to catch the Cretan bull, there are at least hints of a possible connection between the two.

Ø  Most myths about Orion’s death involve a scorpion, but the stories differ from one mythographer to another. In one tale, Orion boasted to the goddess Artemis and her mother Leto that he could kill any beast on earth. The Earth Goddess heard him and sent a scorpion, which stung the giant to death. In another story, he tried to force himself on Artemis and she was the one who sent the scorpion. In yet another account of his death, Orion was stung while trying to save Leto from the scorpion. All myths of Orion’s death share the same outcome: Orion and the scorpion were placed on opposite sides of the sky, so that when the constellation Scorpius rises in the sky, Orion sets below the horizon in the west, fleeing from the scorpion.

                                                               K.BALAKRISHNAN MSc.,MEd.,

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