Orion
the hunter is one of the best-known constellations. Its astronomy and
mythology make it even more interesting to watch as it stalks across
the winter sky.
Rising
early in the evening, Orion is a superb winter constellation. South
of the ecliptic along the stream of the Milky Way, he hunts on the fringes
of the zodiac, facing Taurus the bull. A large rectangle defines the
torso of the hunter, and a short, easy-to-spot line of three stars marks
his signature belt. Orion reaches one arm over his head, wielding a
club, and the other arm holds a shield. With more bright stars than
any other constellation, this figure has been an outstanding character
from ancient times, even among the other great "gods" in the
heavens.
Stars
of Orion
Betelgeuse
(pronounced like petal-juice) takes the prize for the largest star in
the heavens. Located in one shoulder, its odd and catchy name comes
from the Middle East, and means armpit! Its orange color identifies
it as a red super giant star. This star is so big that if you imagine
the Earth as a period at the end of a sentence, Betelgeuse would be
a twenty-two-story building in comparison.
Like other
red stars, Betelgeuse is pumping away so hard to fuel itself that it
periodically puffs up and gets larger. Plus, it is surrounded by a potassium
gas field that is three hundred times larger than our solar system out
to Pluto. According to modern astronomical measurement, Betelgeuse is
about five hundred light years away, meaning it takes the light that
long to get to us. The other shoulder star is Bellatrix, in any other
constellation a more outstanding beauty itself.
At the
opposite end of the rectangle of Orion’s body is Rigel (rye-gell), a
brilliant blue-white star sixty thousand times as luminous as our Sun,
marking one of his feet, or knees. Even at nine hundred light years
away, it is one of the brightest stars in the sky.
The three
belt stars, Alnitak, Alnilam and Mintaka, are even farther. They are
around one thousand five to six hundred light years distant—an exercise
in time travel.
Myths
About Orion’s Stars
For some
cultures, the belt stars make an image of their own, sometimes associated
with animals—three stags in Siberia and Mongolia, or mountain sheep,
antelope and deer for Californian Indians. In one story from India,
they form an arrow that is fired at the creator god, Prajapati, their
name for Orion, who lusted after his daughter Dawn, represented by nearby
Aldebaran. For northern Australian Aborigines, the three stars were
three fishermen in a celestial canoe, an image shared by the Wasco Indians
in Oregon.
A canoe
also figures in Mayan cosmology. The three stars outline the turtle
that cracks his shell to rebirth the maize god. The god then traveled
in a canoe, paddled by a stingray and a jaguar, to the Orion sector
of the sky, carrying a sack of seeds (the Pleiades). They planted the
first three stars in the sky in a triangle made of Alnitak, Rigel and
Saiph, the other foot of Orion. When you trace this large triangle in
the sky, you will find something special right in the middle—the Orion
Nebula. This is where the first hearth was kindled, according to the
Maya.
The
Orion Nebula
The Great
Orion Nebula is a huge cloud of gas and dust where stars are being born.
It looks like smoke, or a hazy star. Here is the usual way to find it.
Hanging from the belt stars is a smaller line of stars, pictured as
Orion’s sword. At the bottom of the sword is the brightest star, actually
a double star. Once you find that, go back up one star toward the belt,
and you will see the Orion Nebula. Though visible with the naked eye,
binoculars give a better view of the wispy cloud.
The opening
show at the new Rose Center for Earth and Space in New York takes viewers
on a deep space voyage right through the Orion Nebula and beyond. A
favorite subject for astrophotographers, this Nebula is a stunning visual
treat. No wonder the Nebula and its host are at the center of many cosmological
myths. In Egyptian mythology, Orion was the great god Osiris, followed
by his beloved Isis, the star Sirius. In Mesopotamia, too, he was an
eternally dying and reborn god, Tammuz. For the Sumerians, he was the
true shepherd in the sky.
But it
is Orion the Greek hunter that we are most familiar with, a guy so big
he could walk through the ocean and still have his head above the water.
Unfortunately, his ego was big, too, and when he boasted he could hunt
and kill any creature, Mother Earth had heard enough. She sent a scorpion
to kill him. This story is told each year, for when Scorpio the scorpion
rises in the east, Orion sets in the west, dead and gone for the season.
Orion has
just started to rise for the season, and is visible for about three
quarters of the year. For North America, it's visible in the early evening
starting in December and remains in the night sky through April. In
May, it starts setting with the Sun. The earlier in the season, the
later it rises. In September, for instance, Orion rises later in the
night, depending on your longitude. The more west you are, the later
it rises.
So catch
him while you can. And if it’s a little too cold to stay out long, read
about Orion in these recommended books: Secrets of the Night Sky
by Bob Berman; Beyond the Blue Horizon: Myth and Legends of the
Sun, Moon, Stars and Planets by Dr. E.C. Krupp; and Orion’s
Legacy: A Cultural History of Man as Hunter by Charles Bergman.
Notes
See ScienceNet
for a more detailed map
of Orion or a great image
of the Orion Nebula taken by the Hubble telescope.
