Transcript 5 Introduction to Constellations

Introduction to Constellations
Backyard Astronomy
Motion of planets and stars
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http://www.lightandmatter.com/area2planet.
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Zodiacs
Aries
Aquarius
Cancer
Capricornus
Gemini
Leo
Libra
Pisces
Sagittarius
Taurus
Virgo
Scorpius
Circumpolar Constellations
1.
2.
3.
4.
5.
6.
Ursa Major
Ursa Minor
Cepheus
Andromeda
Draco
Cassiopeia
Warm Up
1.
2.
3.
4.
5.
6.
What is the name of the main character?
What is the location where the movie takes
place?
What historical event occured that changed the
lives of the main characters?
What happens to the schools science teacher?
What is the result of the national science fair?
What ultimately happens to the main
character?
Warm Up
1.
2.
3.
4.
5.
6.
According to the “Elegant Universe”, what did
Newton say about the force of gravity.
How did Newton describe gravity?
According to the “Elegant Universe”, what did
Einstein say about the force of gravity?
How did Einstein describe gravity?
What do most modern physicists believe to be
the nature of matter?
What is quantum mechanics say about
subatomic particles?
Warm Up
1.
2.
3.
4.
5.
What is a constellation?
What is a circumpolar constellation?
Around what point do all the stars rotate?
How do you locate Polaris?
Name four things that make stargazing more
comfortable?
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 portents, 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. Planets
follow this same pattern unless they are
in a retrograde period, though these
periods are not especially common.
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 getting away from the city when you
can. Crowder’s Mountain, South Mountain, The Blue
Ridge Parkway and several rural spots outside
Matthews and Huntersville are still fairly dark. I
recommend the Parkway in the Fall and Winter. The
quantity of stars you see will take your breath.
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. We will make one in here,
so you get the idea, but laminated ones
are nice and they are protected from dew
and spilled drinks when your tripping
around in the dark. Star Maps are also
called planespheres. You can find them
in hobby stores for a couple of bucks.
What You Need: Flashlight
Well, you don’t have to trip around in the dark. You
can bring a flashlight! There’s one problem here
though. It takes your eyes about 20-30 minutes to get
acclimated to the dark. Your pupils aren’t fully
dilated until then, so a regular flashlight will never
do. Your eyes will have to get acclimated every time
you turn it on. To prevent this, your flashlight should
have a red gel to protect your eyes. Red saran wrap
with a rubber band works great . It works great for
catching night crawlers too.
What You Need: Binoculars
Binoculars don’t have to be very strong to
give you a much better, brighter view of
the stars. Binoculars have the ability to
gather light even at low magnifications.
Even 4X ones will make a marked
difference in the detail you can see.
What You Need: Telescope?
No, you don’t need a telescope, though they
are fun. Telescopes require a certain amount
of sophistication to set up and operate and
they are not for everybody. There are some
nice models available at affordable costs. The
optics are available alone also if you want to
build your own.
What You Need: Warm Clothes
You’ll be happy to
know that the best
time to look at stars is
the least popular time
of year to be outside,
the winter. So, dress
warmly. Remember
that the nights are
longer in the winter.
Leonid: An Aside
I remember the 2002 Leonid meteor shower
very well. The Leonid comes in November and
that year it was really cold. I got up about 3:30
a.m. (yes, that’s right) to have a look. It was
incredible. Meteors were streaking across the
sky every few seconds. Sometimes several at
once. It was the best Leonid for over 35 years.
I even woke my wife up to join me. We sat on
the deck in sleeping bags and drank coffee. It’s
one of my happiest memories. Another Leonid
of that magnitude is not expected again until
2098 or 2131.
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.
Getting Oriented or Where the Hell is
North?
Yea, you have to find north. It’s where Polaris
(or North Star) is. You’ll need a compass or
major highway to orient yourself. I-77 is good
because it runs due north and south. You can
make a compass with a needle, magnet and a
cup of water. Just rub the needle across a
magnet (see your refrigerator) or leave it
attached overnight. Then rub the needle across
your nose and place it in the cup very gently. It
will float. It will turn north.
Figuring the Angle
Once you’ve decided where north is (right
ascension), face in that direction. Next you
have to figure declination (up and down).
Extend your arm and make a fist. Put the
bottom of your fist on the horizon. The top of
your fist is about 80 higher. Place your other
fist on top of your first. You’ve now measured
160 up from the horizon. Polaris is located
between 250 and 300 above the horizon. Polaris
is faint, so look carefully!
Another Way to Find Polaris
If all that compass making and angle
crap is just too complicated, there is
another way to find Polaris. Find the Big
Dipper (not a constellation). Most people
recognize this asterism. 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.
Now That You’re Oriented, It’s Time
to Explore.
You also have access to software that
provides you with the same information.
Circumpolar Constellations
“Circum” means around (i.e. circumcise,
circumnavigate, circumference). Polar
refers to the North Pole. Therefore,
circumpolar constellations circle Polaris.
This makes the 5 circumpolar
constellations visible throughout the
entire year. Let’s look at each!
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 asterism, 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
Cassiopeia
Cassiopeia was the wife of King Cepheus. She was very
pretty, and would often boast that she and her daughter
were more beautiful than the sea nymphs, the Nereids.
They complained to Poseidon, who unleashed a monster
onto Cepheus' land. In order to save their country, the
king and queen sacrificed their daughter, Andromeda.
Just before the monster, named Cetus, ate the princess,
Perseus saved her. All five figures are represented in the
sky as constellations.
Cassiopeia has a very distinct shape. She looks like a "W"
or "M" in the sky, depending on where she is. Some
legends say that Cassiopeia was chained into the sky and
sometimes hangs upside-down to remind others not to be
so boastful.
Cassiopeia
Cepheus
Cepheus is one of the oldest constellations in the
night sky. This house-shaped constellation is named
after an ancient king of a land called Ethiopia
(different from the current country, Ethiopia). He was
married to the beautiful Cassiopeia and had a
daughter, Andromeda.
In Greek mythology, Cassiopeia boasted that she and
her daughter were more beautiful than the Nereids.
They complained to the sea god Poseidon, who sent a
monster to destroy Cepheus' land. The king and
queen offered their daughter to the monster, but she
was saved by Perseus.
Cepheus
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
Signs of the Zodiac
Common Constellations
Aquarius: The Water Bearer
In Greek mythology Aquarius was Ganymede, "cup-bearer
to the gods". Alpha Aquarii ("Sadalmelik") and beta
Aquarii ("Sadalsuud") are twin supergiants with nearly
identical names. The names mean, respectively, "The
Lucky One of the King" and "The Luckiest of the Lucky".
Gamma Aquarii shares in the good fortune: "Sadachbia":
"The Lucky Star of Hidden Things" Incidentally, if the
"Age of Aquarius" was celebrated in the 1960s, the real
event is still some 600 years off: at that time Aquarius will
contain the vernal equinox, marking the return of the Sun
into the northern celestial hemisphere.
Aquarius: The Water Bearer
Aries: the Ram
Aries, "The Ram", is an ancient constellation which was of
considerable importance since the sun passed through it at
the vernal equinox.
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This point has now moved into Pisces, but the vernal equinox
is still known as the First Point of Aries. In another six
hundred years the point will have moved into Aquarius.
The Ram in question may have been the one whose golden
fleece was the object of Jason's quest.
There is some reason to believe that the Greeks just took
over a much older horned animal at this time of the year;
the horn being a symbol for fecundity, renewal, and so on.
As the Sun came into this constellation, at the vernal
equinox, the year itself was being renewed.
Aries: the Ram
Cancer The Crab
The name comes from the Latin; cancer
means crab. The crab in question is the
one sent by Hydra to attack Heracles. It
was only a bit part, but one which
secured its immortality.
Cancer
Gemini The Twins
Gemini, the Twins, are really only halfbrothers. They share the same mother (Leda)
but have different fathers. Castor's father was a
king of Sparta, Tyndareus - who would be
chased from his throne but later rescued by
Heracles (who nevertheless wound up killing
him). The father of Pollux was none other than
Zeus, or Jupiter. Zeus visited Leda on her
wedding night in the guise of a swan. Thus the
twins would be born. (In fact two twins came
from this double union, but let's not complicate
the matter even more...)
Gemini
Leo: The Lion
The first on the list of Heracles' labors was the
task of killing the Nemean Lion, a giant beast
that roamed the hills and the streets of the
Peloponnesian villages, devouring whomever it
met. The animal's skin was impervious to iron,
bronze, and stone. Heracles' arrows harmlessly
bounced off the lion; his sword bent in two; his
wooden club smashed to pieces. So Heracles
wrestled with the beast, finally choking it to
death. He then wrapped the lion's pelt about
him; it would protect him from the next labor:
killing the poisonous Hydra.
Leo
Libra: The Scales
Libra means "The Scales" or "Balance", so named because
when the zodiac was still in its infancy, some four
thousand years ago, the sun passed through this
constellation at the autumnal equinox (21 September). At
the two equinoxes (Spring and Autumn) the hours of
daylight and darkness are equal. As a symbol for equality,
the constellation came to represent Justice in several
middle Eastern cultures. However, the Greeks had a
different perspective; at one time Scorpius, which lies just
to the east, was much larger, and the stars that make up
Libra were then known as the Claws of the Scorpion.
Libra
Pisces: The Fish
Pisces is an ancient constellation derived, some say,
from the story of the terrible Greek god Typhon.
(This is not the Chinese word for "big wind", which in English - is of course spelled "typhoon". The
French, however, spell this word "typhon", which
adds to the confusion. It is possible that the
Chinese borrowed the word from the Greek. The
modern Greek equivalent is spelled "tau upsilon
phi omega nu" and means "cyclone".)
Pisces
Sagittarius
It was the Romans who named the constellation
Sagittarius ("sagitta" is Latin for `arrow'),
although several stars carry Arabic names
which identify just which portion of the
constellation they represent. Sagittarius has a
muddled history. In ancient times the asterism
of three bright stars in a curved line was seen
as a bow to some, leading both Greek and
Roman writers to confuse the constellation with
Centaurus.
Sagittarius
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
Taurus: The Bull
Is Taurus attacking Orion, the Hunter, or
are the Horns of the Bull the real story?
The horn was a symbol of fertility and
bountiful riches in many cultures for
thousands of years, and it is probably the
case here, for the constellation would
have announced the Vernal Equinox at
around 4000 BC.
Taurus
Virgo: The Virgin
Virgo is the second largest constellation (after
Hydra). As a member of the Zodiac, Virgo has a
number of ancient myths and tales. The Sun
passes through Virgo in mid-September, and is
therefore the constellation that announces the
harvest. Virgo is often represented as a
"maiden" (as its name indicates). In antiquity,
she may have been Isis, the Egyptian
protectress of the living and the dead and the
principal mother goddess.
Virgo