The name, the story, the myth
Orion, giant, beautiful and strong, is the son of the sea god Poseidon (he also gave him the gift of walking on water) and is known for his character as a skilled hunter, to the point that he himself declared himself capable of killing any animal. Just to escape his attentions, the Pleiades (daughters of Atlas) asked and obtained from the gods to be transformed into stars.
Gaea (in some versions Artemis), alarmed by his pride and bravado, made him meet with the scorpion, who managed to kill him by pricking him in the heel. It was the gods, moved to compassion, who transformed Orion and Scorpio into two constellations, and placed the hunter right next to the Pleiades.
The myth lives in the sky: in fact, when the stars of the Scorpio rise in the East, Orion defeated sets in the West; the cycle is completed when the scorpion, setting in the West, is crushed by the Ophiuchus, Aesculapius, who thus resurrects the hunter, who is reborn in the East, renewed.
According to a version with more captivating nuances, Orion landed on the island of Crete to dabble in hunting animals that he heard about and that lived only on the island. Having come across Artemis, who knew the fame of this hunter well, she was not indifferent to his charm and since they shared the same passion, she invited him to go hunting together. Apollo, brother of the goddess, showed that he was jealous of her, and wanted to protect her, fearing for his virtue and judging him a profiteer. He told Artemis' mother, Gaea, that Orion boasted of his hunting skills, and how he had claimed to be able to exterminate all the beasts that lived on earth. Enraged, Gaea brought out of the earth a gigantic and monstrous scorpion that she ordered to kill the hunter with her poison.
The clash came to pass. Orion tried to kill the beast, shooting arrows, but these did not scratch the scorpion. Then he took up his sword, but he was in vain, and cornered, and threw himself into the sea to escape him, and reached the island of Delos. But sighted in the distance from Apollo, he convinced Artemis that he was a scoundrel, and made his sister believe it was a certain Candaone who had seduced one of his priestesses, Opis, and immediately invited her to punish him, piercing him with one of the arrows in his quiver. The goddess, without knowing that in reality Candaone was the nickname with which he was called Orion in Boeotia (his native land), took aim and pierced him. But realizing the mistake, he threw himself into the sea, reached the body and dragged it ashore. Desperate, she begged for the intervention of Aesculapius' doctor, expressing the wish that he would bring him back to life thanks to his well-known medical arts. But as he was preparing to fulfill the will of Artemis, Zeus struck the healer to death. For Orion, there was nothing to be done. When Artemis was released, he decided to transport the image of the hunter to the stars.
This theme of death and rebirth would recall a more ancient conception. Five pyramids of the Fourth Dynasty in the Plain of Giza in Egypt seem to be arranged in such a way as to represent a part of the constellation Orion, with the river Nile as the Milky Way. The southern air duct of the great pyramid is aligned with the stars of Orion's belt, in particular Ori zeta, in the position of 2700- 2600 BC.
At that time the constellation represented the Egyptian god of death and first pharaoh of Egypt, Osiris. It is said that after his death, Pharaoh mystically inseminated these stars so that, through Osiris, the Sun-god Horus could be reborn as his successor.
The Sumerians in asterism celebrated one of their heroes, Gilgamesh.
When and where can one observe?
Orion is a typical winter constellation, observable, albeit at inconvenient times, even in the autumn months. However, the best observable period is between November and March. Already around 10 pm, between the end of October and the beginning of November, it is possible to see it rising towards East.
In the following months it anticipates more and more its rise until it is (in mid-January and always around 10 p.m.) at its climax, that is, at its highest on the horizon. This condition guarantees the best visibility.
At the end of March, before midnight, Orion has already made his way through the sky, and is about to set sail southwest for good. In the months to follow, it will be invisible as it will only be above the horizon during the day.
What's better than a video to understand this progression? We show you Orion's position on the first of each month at 10pm, from November to April.
Returning to the representation of the constellation and that is to the figure of Orion, we have the possibility to see two wonderful drawings taken from the first one from the Uranometria of J.Bayer (of the beginning of the seventeenth century) and the second from the Firmamentum Sobiescianum of Hevelius (posterior of almost a century): in both drawings Orion is represented in the act of fighting with his club against the Taurus, defending himself in the first case with a lion skin and in the second case much more wisely with a shield.
In the table of the Uranometria, the figure of the giant faithfully respects the position of the stars in the sky, but Orion is strangely depicted looking away from where the Taurus is, which is placed at the top right. Another objection of people interested in the work, is that the image of the hunter turns his back to the observer while in general other characters have been depicted in front of him: we will verify it time by time for each constellation we will analyze and which concerns a male or female figure. Finally we notice that in this work only the figure of Orion appears, while of his enemy, the Taurus, Aldebaran and some stars of the Hyades are represented.
Instead, in Hevelius' work, the combat scene is represented in a specular way, because we know that the constellations of Monoceros (the Unicorn) and Eridanus are actually in the sky from opposite sides to Orion: to have the correct representation, it is therefore necessary to alter the image specularly, obtaining as counterpart the various writings completely illegible! Only in this way, however, we obtain that the star Rigel is again the right foot of the giant. Apart from this apparent strangeness, due to a precise choice of the author, the representation of Hevelius is richer in details and the figure of Orion appears surrounded by animals (real or mythological) and other entities, such as Eridanus, which is none other than the river Po.
And our trusty Stellarium, as Orion represents? Soon said!
Main Stars and Belt
The main stars that outline Orion are:
and the three stars Alnitak, Alnilam and Mintaka which draw the asterism of the famous Belt
Other names of stars
In the star map that you see when you launch the applet, I've entered some new names compared to the ones we already knew. Let's see what they mean:
- Meissa (λ Ori): it would derive from a term whose meaning is the shining
- Tabit (π3 Ori): name attributed to it by the astronomer Piazzi, it is not well known why
- Trapeze (θ1 Ori): is the name assigned to an asterism of 4 stars, arranged just like a trapeze, whose main star is θ1. It is a beautiful little group of stars immersed in the well known Orion nebula M42