Without doubt the brightest and grandest constellation in the sky.
In one Greek story Orion was boasting to a large crowd of
people of all the animals he had killed, however he did not see a scorpion
creeping up behind him. The scorpion stung him on the ankle and killed him. The
gods were so impressed with his boasting that he was placed in the sky forever.
So was the clever scorpion. To make sure they could never meet again Orion was
placed in the winter sky while the scorpion was placed in the summer sky.
In Egypt Orion was seen as Horus in a boat surrounded by
stars while the Arabs saw Orion as Al Jabbar the Giant or Al Babadur the Strong
One.
In Hindu astronomy Orion was seen as Praja-pati seen chasing
his daughter across the sky, the daughter being Aldebaran the brightest star in
Taurus. In China Orion was the White Tiger.
The Anglo Saxons called it Ebuorung referring to the Milky
Way, while the Vikings called the constellation Goddess Frigg or Mother Earth.
Alpha Orion of Betelgeuse which means The Armpit of the Central One. Most other astronomers from various civilisations refer to Betelgeuse as an Arm. Betelgeuse is the star that some people like to refer to as Beetlejuice.
Betelgeuse is the 9th brightest star in the sky. It varies
in brightness between 0.4-1.3 these variations were first reported in 1836 by
John Herschel, the son of William Herschel who discovered the planet Uranus in
1781. When at its faintest it is
decidedly fainter than Rigel. During the winter of 2019-2020 Betelgeuse became
very faint causing astronomers to wonder if it was in the process of going
supernova. It wasn’t, Betelgeuse produced a massive flare that blocked some of
the light from the star. The star has in
fact been as faint as this before in 1927. It is a red supergiant star entering
its final phase and will probably go supernova within the next 1 million
years. It is 642 light years away and
is a M class supergiant with a temperature of around 3,300’ C.
Beta or Rigel is usually referred to as The Left Foot of the
Giant, however the Arab astronomer Al Sufi in his star catalogue called it Rai
al Jauzah or The Herdsman of the Camels. Rigel is the 7th brightest star in the
sky at mag 0.1. It is 863 light years away and is a B class supergiant star
with a temperature of around 12,000’ C and like Betelgeuse will end up going
supernova.
Gamma or Bellatrix which means the conqueror or Amazon star
is the 3rd brightest star in Orion. Al Sufi referred to the star as Al Ruzam or
the Lion. It has a magnitude of 1.6 and
lies at 250 light years. It is a B class giant with a temperature of 21,500’ C.
There is a Harry potter connection with Bellatrix because
one of the characters form the Harry potter stories is Bellatrix Lestrange. I
think she was one of the baddies.
Orion’s Belt is formed of three stars and from left to right
they are;
Zeta or Alnitak which means the Girdle is the left-hand star
of the belt. Alnitak has a magnitude of 2.0 and is 1200 light years distant. It
is one of the rare O class supergiant stars with a temperature of 29,000’C.
Alnitak will become a supernova in the future
Epsilon or Alnilam which means String of Pearls at magnitude
1.6 is the 4th brightest star in Orion. Alnilam is the middle star of the belt.
Its distance is about 2,000 light years, and is a B class supergiant with a
temperature of 27,000’C. It will also go supernova in the future.
Delta or Mintaka the right-hand star of the belt its name
means the Belt, its magnitude is 2.2 and also lies 1200 light years away,
another of the rare O class stars with a temperature of 29,000’C, and as with
Alnitak, Mintaka will become a supernova.
Kappa or Saiph which means The Right Leg of the Giant is of
magnitude 2.1 and lies 650 light years away, it is a B class star with a
temperature of 26,000’C.
Iota or Na’ir al Saif, which means "the Bright One of
the Sword is the brightest star in the asterism known as the sword of Orion, magnitude
2.8 and lying at a distance of 2,300 light years. Like many of the stars in
Orion it is one of the rare O class giant stars with a temperature of 32,000’C.
As with the O class stars in Orion, it will become a supernova in the future.
Messier 42/43
Below the stars that form Orion’s Belt is the Orion Nebula,
an area of the galaxy where stars are being formed.
One of the great mysteries in visual astronomy is that
Galileo apparently never noticed the great nebula in Orion. There also appears
to be no record of it in medieval records either. Yet here is one of the
grandest naked eye nebulae in the heavens just below the famous Orion belt
stars. It could not possibly have been missed by Galileo and is especially
puzzling. It is also interesting that the Arab astronomers including Al Sufi
had recorded the much fainter nebula in Andromeda M31 but not the Orion nebula.
What could have been going on? The first mention in western records is around
1615.
There are hundreds of stars being formed here today. The
Orion nebula is an enormous cloud of gas about 40 light years in diameter. The
cloud is illuminated by a group of four stars known as the Trapezium, these
four jewels are between magnitude 5 to 8, all the stars which are very young
being about 1 million years old and there are thousands of unseen stars between
300,000 to 1 million years old. The nebula is about 1600 light years away.
M43 is a separate nebula often overlooked because of its close proximity to the Great Orion Nebula, it is separated from M42 by a dark lane of gas known as the Fish Mouth. M43 surrounds a 7th magnitude star known as Bond’s star. To see M43 you have to block the light from M42.
M78
A diffuse nebula with a magnitude 8.3 and lying at a
distance of 1,300 light years, above and to the right of the star Alnitak. You
would need a pair of binoculars just to glimpse it.
Surrounding Orion is the Barnard Loop, this is the remains
of a supernova that exploded about 2 million years ago. It was first
photographed by Edward Barnard in 1883; it can be seen with the eye under the
best of conditions. There are suggestions that it was seen by the Vikings over
1,000 years ago.
www.theramblingastronomer.co.uk
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