Download Orion – The Hunter - Guild of Students

Orion – The Hunter
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Orion Nebula
The constellation Orion became most famous for its nebula. The Messier database has
detailed information about The Large Orion Nebula M 42 and M 43, the DeMairan
nebula, which is a part of the Orion Nebula.
Mythology
Greco-Roman (Roman names are shown in parentheses)
There are many versions of the story of Orion, the two main ones being as follows:
Version one:
Orion's mother was Euryale, the Amazon queen, and his father was Poseidon
(Neptune). He was the world's greatest but biggest-headed hunter.
Variation one: He boasted that he could kill any animal, so a tiny scorpion stung and
killed him.
Variation two: He boasted that he could kill any animal, so the gods sent him an
enormous, heavily armoured scorpion for a laugh, which killed him.
Version two:
Orion had no parents and was a gift to a pious peasant from Zeus (Jupiter), Poseidon
and Hermes (Mercury). He was a great hunter, a blacksmith, and alleged to be able to
walk on water. He made the lame blacksmith god Hephaestus (Vulcan) an
underground palace beneath Mount Aetna in Sicily, and created coastal defences for
the island.
He fell in love with Merope, princess of Chios. Her father, King Oenopion wasn't
having any of it and would not allow Orion to marry his daughter, even after he killed
every wild beast on the island. Orion got drunk and tried to rape Merope, so Oenopion
blinded him and left him wandering the shoreline.
Variation one: Orion consulted an oracle who told him that the sun god Helios would
help him out.
Variation two: Orion followed the sound of a cyclops' hammer (a cyclops is a horrible
one-eyed giant) and reached Lemnos, where Hephaestus took pity on him and sent
him to see Helios with Kedalion on his shoulders as a guide.
Helios restored his sight. On his way to get revenge for his blinding, Orion met and
stayed with Artemis (Diana), the virgin goddess of hunting, who became very fond of
him and was considering marriage. Her brother Apollo was annoyed because she was
supposed to be a virgin goddess, so marrying would go against everything she stood
for.
Variation one: Thus, Apollo sent a scorpion to kill him.
Variation two: Thus, when he saw Orion wading in the sea with only his head visible
above the waves; he challenged Artemis to shoot with an arrow the distant object
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Orion Nebula
bobbing in the sea which was unidentifiable as Orion's head. Unfortunately, Artemis
took up the challenge and unwittingly killed him.
In all versions, Artemis was reputedly devastated and placed Orion, and when present,
the scorpion in the night sky as the constellations Orion and Scorpius. She placed the
scorpion opposite him, so that never are the two visible at once.
The sky shows him followed by his two fighting dogs, Canis Major and Minor, and
fighting a bull, Taurus. Oddly, the bull is completely irrelevant to the story of Orion.
The bull represents the form taken by Zeus when he wanted to seduce Europa. She
was so impressed by the bull's gentle nature and shining white coat that she climbed
on the bull's back to see if she could ride on it (no double entendre intended). The bull
ran off and swam to Crete, where Zeus revealed his true form and had his wicked
philandering way with her.
Egyptian
The ancient Egyptians are thought to have identified the constellation of Orion with
Osiris, their god of the underworld. It is believed that the three pyramids at Giza were
built to mirror the three stars of Orion's belt.
Osiris was born in Thebes in Upper Egypt, the heavenly mirror-world that the
Egyptians believed existed in the sky, to Nut and Geb. His grandfather Ra made him
heir to the throne and so when his father Geb retired he took over as the fourth divine
pharaoh and married his sister Isis. He abolished cannibalism, built temples, and
taught the people justice and agriculture. This earned him the name Onnophris ('the
good one'). He left Egypt to civilise the entire world and Isis did a very good job of
running the kingdom in his absence.
He met his end when his brother Set got jealous and built him a coffin. He then held
an enormous party to which Osiris was invited and offered the coffin to whomever
fitted in it best. Obviously, Set had built it especially for his brother and when he got
in, Set closed the lid and chucked it and Osiris in the Nile.
Isis went to look for Osiris' body and Set took the throne. She found the body far
away in Byblos, brought it back and hid it in a marsh. Set found it, tore it up and
threw it back into the river. Osiris' genitals got eaten by a fish, but Isis found the rest
and wrapped her husband up with bandages to hold him together (the first mummy),
and the late Osiris went to underworld to become king of the dead.
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Orion Nebula
Position in the Sky
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Orion Nebula
The Brighter Stars
Name
Rigel
Bayer/
Mag.
Flamsteed
Beta
R.A.
Decl.
Spectrum
0.18 5h 15m -9° -12"
B8Ia
Betelgeuse Alpha
0.45 5h 55m 7° 24"
M2Ib
Bellatrix
Gamma
1.64 5h 25m 6° 21"
B2III
Alnilam
Epsilon
1.69 5h 36m -2° -12"
B0Ia
Alnitak
Zeta
1.74 5h 41m -2° -57"
O9.5Ib SB
Saiph
Kappa
2.07 5h 48m -10° -40" B0.5Iavar
Mintaka
Delta
2.25 5h 32m -1° -18"
O9.5II
Iota
2.75 5h 35m -6° -55"
O9III
Pi
3.19 4h 50m 6° 58"
F6V
Eta
3.35 5h 24m -3° -24"
B1V + B2
Lambda
3.39 5h 35m 9° 56"
O...
Tau
3
3.59 5h 18m -7° -51"
B5III
4
3.68 4h 51m 5° 36"
B2III SB
5
3.71 4h 54m 2° 26"
B2III SB
3.77 5h 39m -3° -36"
O9.5V...
4.06 4h 56m 13° 31"
K2III
Phi
4.09 5h 37m 9° 17"
G8III-IV
Mu
4.12 6h 2m
Am...
29
4.13 5h 24m -8° -48"
G8III
32
4.20 5h 31m 5° 57"
B5V
Pi
Pi
Sigma
2
omicron
2
2
4.35 4h 51m 8° 54"
A1Vn
1
4.39 5h 35m 9° 29"
B0IV...
1
Chi
4.39 5h 54m 20° 17"
G0V
Nu
4.42 6h 8m
14° 46"
B3IV
Xi
4.45 6h 12m 14° 13"
B3IV
Rho
4.46 5h 13m 2° 52"
K3III...
6
Pi
4.47 4h 59m 1° 43"
K2IIvar
Omega
4.50 5h 39m 4° 7"
B3IIIe
Pi
Phi
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9° 39"
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Orion Nebula
Betelgeuse; alpha Ori
In Arabic Betelgeuse means “Armpit of the central one (or Giant)”. Betelgeus is a
variable red giant, its brightness varies from 0.4 in 1.3 in absolute magnitude, it has
no set period. It belongs to the 20 brightest stars in the sky. During its pulsations the
diameter of the star varies from 300 to 400 times the size of the sun!
Rigel; beta Ori
It is the leg of the hunter, in Arabic Rigel means “the foot”. It is a blue-white giant of
which has an absolute magnitude of 0.08. This makes Rigel the sixth brightest star in
the sky and the brightest in Orion. With medium sized telescopes it is possible to
distinguish the companion star of Rigel (it is a 7th magnitude star, caught in the glare
of Rigel)
Mintaka; delta Ori
In Arabic it is the “upper end of the girdle”. delta a blue-white star of 2.2 mag with a
7th mag companion.
Other stars of interest with binoculars and telescopes:
Iota Ori, a 3rd mag and a 7th mag star forming an unequal double; in the same field
the wider double
Struve 747 can be found - a pair of a 5th mag and a 6th mag star.
Lambda Ori, a tight pair of 4th and 6th mag stars.
Sigma Ori is a multiple star; with binoculars this a blue-white star of 4 mag and a 7th
mag companion can be resolved.
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Orion Nebula
NGC 1981, a little cluster of 10 stars including the binary Struve 750, a pair of a 6th
mag and a 8th mag star.
The multiple star theta1 Ori, the northern star of the deggar of the Hunter is also
called the Trapezium; it is located in the heart of the Orion nebula. This group of stars
has been formed from the gas of the nebula, which now glows in their light.
Zeta Ori (Alnitak), it is a tight double consisting of a 2.02 and 4th magnitude star.
Eta Ori is a difficult pair to see as therse stars are 4th and 5th magnitude.
The Nebulae
M-42 - The Great Nebula. One of the finest sights
in the sky, this nebula is easily visible to the naked
eye as the 'fuzzy' star in the middle of Orion's
sword. It appears distinctly nebulous in binoculars
or finder scopes. The brightest region surrounds the
four relatively bright stars known as the Trapezium.
The region around the Trapezium appears as a cold
steel blue colour, wile the wispy regions further
away can appear as a soft ruddy pink.
M42 is approximately 1630 light years away. The bright part of the nebula is the glow
of many luminous, newborn stars shining on the surrounding gas cloud that they
collapsed from. The most important part of the Orion
Nebula is the part that can not be seen is the opaque Orion
Molecular Cloud. This is a region of very cold gas and has
a mass of about 2000 times the mass of the Sun. This gas
slowly collapses due to gravitation to form stars. This part
of the nebula is visible whenever a new star is formed.
M42 is an open cluster.
.
M-43, de Mairan's Nebula. This is a diffuse nebula. The
dark features along its eastern border are well visible in
telescopes starting at about 8 inch. The nebula itself is a
fine view even in a 4- inch.
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Orion Nebula
M-78, diffuse nebula. This is another
fine area of nebulosity. It is somewhat
fan shaped. NGC's 2064, 2067, and
2071 lie in very close proximity to M78, and are all nebulous regions as
well.
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Orion Nebula
Contributors:
Samuel George
Alexandra Yannacopoulou
Emma Robinson
References:
www.heavens-above.com
www.nasa.gov
www.afit.edi
Starry Night Backyard Software
www.trailtopobservatory.org
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Orion Nebula