Transcript Introduction to Constellations

Introduction to Constellations
Backyard Astronomy
The Night Sky
People have watched the night skies for
millions of years. Some just out of
curiosity. Some out of boredom. Some
looking for omens, either good or bad.
However, the one thing that they all saw
was that there was a pattern in the way the
stars revolved around the heavens.
The Night Sky
You need only to look up for a few hours to
begin to see these same patterns yourself.
Like the Sun, stars rise in the east and
set later in the west.
What You Need for Stargazing
You don’t really need anything, but some
things are handy, like…
Complete darkness-Don’t laugh, it’s not
that easy to find. Rural area are slowly
being urbanized, bringing their lights with
them. Light pollution is a real problem.
What You Need: Darkness
Darkness means keeping up with the
phases of the moon, too. When the moon
is waxing past half full, it’s quite hard to
see.
What You Need: Star Map/ Planesphere
It is handy to have a star map to help get
you oriented.
Star Maps are also called planespheres.
You can find them in hobby stores for a
couple of bucks.
Finding Polaris and Why
Polaris (or the North Star) is where you
want to start. Because Polaris is aligned
with the Earth’s axis of rotation, it
remains fixed, with all the other planets
and stars appearing to move around it. It is
the one star that remains fixed at all times.
A Way to Find Polaris
Find the Big Dipper. Most people
recognize this constellation. The two stars
that form the front of the cup of the dipper
define a line pointing to Polaris.
The Big Dipper
The Stars Circling Polaris
Now That You’re Oriented, It’s Time
to Explore.
You’re pointed in the right direction, but what now.
Stars and constellations move constantly and
seasonally. What am I looking for? What you need is a
star map.
A Few Constellations...
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Ursa Minor
Once you’ve located Polaris, you’re ready
to identify your first constellation. Polaris
is the last star located in the handle of the
Little Dipper. The name of the
constellation that contains the Little
Dipper is Ursa Minor or Little Bear.
Ursa Minor
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Ursa Minor, also called the Little Dipper, is a
circumpolar constellation. This means it never
sets in the northern sky. The true figure
represented by the stars is the Little Bear.
There are several mythological stories behind
these famous constellations. In Greek myth, Zeus
was having an affair with the lovely Callisto.
When his wife, Hera, found out she changed
Callisto into a bear. Zeus put the bear in the sky
along with the Little Bear, which is Callisto's son,
Arcas.
Ursa Minor
Ursa Major
Ursa Major is probably the most famous constellation, with
the exception of Orion. Also known as the Great Bear, it has
a companion called Ursa Minor, or Little Bear. Everyone
living in the Northern Hemisphere has probably spotted the
easily recognized portion of this huge constellation. The body
and tail of the bear make up what is known as the Big
Dipper.
Several different cultures saw a big bear in the sky. The
ancient Greeks had a few different stories to explain how the
animal ended up there. In one story, Hera discovered Zeus
was having an affair with Callisto and turned her into a bear.
Zeus put her in the sky along with her son, Arcas, who
became the Little Bear.
Ursa Major
Draco
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Draco the dragon, is only present in the Northern
Hemisphere, so those living in the Southern Hemisphere will
never see this long constellation.
The easiest way to spot Draco is by finding his head. It
consists of four stars in a trapezoid, burning brightly just
north of Hercules. From there, the tail slithers through the
sky, eventually ending between the Big and Little Dippers. It
can be difficult to trace Draco in the night sky. From the
head, follow the body north towards Cepheus. It suddenly
shifts south and west, ending up between the two dippers.
The end of the constellation is held by Thuban, which was
the pole star over 4,000 years ago.
Draco
Orion’s Belt
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Cassiopeia
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Cassiopeia was the beautiful wife of Cepheus, king of
Ethiopia, and the mother of Andromeda. She is most famous
in connection with the myth of her daughter, Andromeda. The
queen made the mistake of bragging she was more lovely
than the Nereids, or even than Juno herself. The goddesses
were, needless to say, rather insulted, and went to Neptune,
god of the sea, to complain. Neptune promptly sent a sea
monster (possibly Cetus?) to ravage the coast. The king and
queen were ordered to sacrifice their daughter to appease
Neptune's wrath, and would have done so had Perseus not
arrived to kill the monster in the nick of time. As a reward, the
hero was wedded to the lovely Andromeda.
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Cassiopeia
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Cygnus
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Cygnus is a constellation in the northern sky. Its name means
“the swan” in Latin, and it is most frequently associated with
the myth of Zeus and Leda. The Swan constellation is easy
to find in the sky as it features a well-known asterism known
as the Northern Cross.
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Cygnus constellation is associated with several myths, most
frequently the one of the Spartan Queen Leda, who gave
birth to two sets of twins, the immortal Pollux and Helen and
mortal Castor and Clytemnestra, after being seduced by the
god Zeus, who had transformed himself into a swan. The
immortal children were fathered by the god and the mortal
ones by Leda’s husband, King Tyndareus. Castor and Pollux
are represented by the zodiac constellation Gemini.
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Cygnus
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Scorpius: The Scorpion
As mentioned regarding Orion, Gaia may have
sent the scorpion to kill the mighty hunter, as he
had vowed to rid the earth of all wild animals. Or
Apollo might have told Gaia of Orion's boast,
fearful that Orion had designs on Apollo's sister
Artemis. In any case it was Gaia who sent the
scorpion to kill Orion. Later the animal would
chase Orion across the heavens, but it could
never catch him, for the scorpion was so placed
that it would rise in the east only after Orion had
safely disappeared over the western horizon.
Scorpius