| Orion has to be the most famous constellation
in the sky. Situtated over the celestial equator he is easily visible
to people both north and south of the equator. The three stars of
his belt have lined up nearly perfectly in a wonderful coincidence.
For us in the southern hemisphere the return of Orion and his dog Canis
Major to the evening skies marks the start of the hot weather of summer.
He holds above his head a club and on his other arm is a shield, sometimes
drawn as a lion's skin. He is usually drawn as raising his
shield towards the oncoming horns of Taurus the Bull.
At his feet lies Lepus the Hare. Eridanus
the River begins near Rigel, his knee. Orion lies in the star clouds
of the Mikly Way but they are not as rich as those towards Scorpius as
in this direction we are looking towards the outer edge of the galaxy.
An excerpt from Johan van
Keulen's Boeck zee-kaardt, 1709.
A reversed Orion fending
off Taurus as he stands on Lepus.
The dashed line marking
the celestial equator runs though his middle.
Orion is also one of the oldest constellations.
The ancient Egyptians connected their god Osiris with the figure, the Jews
connected it with the giant Nimrod and the Babylonians connected it with
a giant figure as well. The Greeks added their own story, of course,
and theirs is the one commonly recited today in our culture.
Orion was the son of Posiedon and the nymph
Euryale. This son of a god was naturally of great beauty as well
are large in size and had great strength. He was a great hunter was
well and boasted that he feared no animal on Earth, he could take them
all on. To teach him a lesson Gaia, the goddess of the Earth, sent
a scorpion to slay him and Orion was hence struck down by a seemingly insignificant
creature. This is why, it is said, Orion sets in the west as Scorpius
rises in the east. There was also the story made to connect
the surrounding constellations to Orion - that Orion lusted after the Pleiades
but Taurus was placed in the sky to keep him away from the maidens.
The main shape of Orion
and the stars that mark the "corners."
The brightest star in Orion is Betelgeuse.
It is commonly pronounced "beetle-juice" but for those who like to be correct
the closest correct pronounciation should be "bettel-gerz". It's
current name is a corruption of an older Arabic name and is commonly described
as meaning the "armpit of the giant" although some scholars will point
out it actually means the "armpit of the sheep" (if you are confused and
want to take the middle ground you can just call it the armpit).
It is a distinctive orange-red colour to the naked eye, an indication of
it's true nature, that of a massive red giant star. It is one of
the largest stars known, so large some features can be discerned on it's
surface. One day our sun will look like this - a dying, puffed up
star, about to start throwing off shells of gas to form a planetary nebula.
Rigel, beta (b)
Orionis, on the opposite side of the belt to the south, is by contrast
a hot white star. Rigel is the "knee" of the the giant.
Bellatrix, gamma (g)
Orionis, marks the other shoulder of Orion. It is the Female Warrior,
from the latin, sometimes also called the Amazon Star.
The three stars of the belt are next in
sequence. On the western side is Mintaka, delta (d)
Orionis, "the belt". It is the first of the trio to rise. Next
is Alnilam, epsilon (e)
Orionis, "the string of pearls". Third and last to rise is Alnitak,
zeta (z)
Orionis, "the girdle." It is below this star that the famous Horsehead
Nebula can be found. The horse's head is a dark nebula, a cloud
of dust blocking off the light behind it, shillouetted against a red glowing
emission nebula. This nebula is very hard to see visually but is
spectacular in photographs.
Saiph, eta (h)
Orionis, makes the fourth corner of the larger rectangle of Orion's body.
It means "sword."
Theta (q)
Orionis is actually a group of stars that are imbedded in a much more famous
object, the Great Orion Nebula (Also known as Messier 42)
To the naked eye this star is not that bright. It is the middle of
what is commonly known as "the sword of Orion" - or sometimes "the handle
of the saucepan." If you turn binoculars this way you will be able
to discern a greenish glow surrounding these stars - this is the nebula!
A telescope reveals much more detail, including the group of four stars
known as the Trapezium. The Trapezium is designated as theta Orionis,
their combined light is the "star" we see with the unaided eye.
They are the largest stars that have been born in this star-forming region
- detailed study has revealed there are many other stars nearby and some
blobs of matter that may yet ignite into stars. The hot, young stars
of the Trapezium are blowing away the gas of the nebula that birthed them
at a tremendous rate. One day, in the distant future, the gas and
dust will have been evapourated into space and an open cluster will shine
in it's place. This nebula is one of the most studied areas
of the sky and the first photograph of it was taken in 1880 by Henry Draper.
The Orionid meteor shower is active in
October and is considered one of the major showers of the year. Meteors
seen from this shower are debri from Comet Halley - this comet also
causes the more active eta Aquarid meteor shower in early May as
well.
(Author's note: This constellation
has so much connected both with cultural mythology and scientific discoveries
with it that this article will revised and updated at some time in the
future)
This article is ©2001
Stargazers Astronomy Shop
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