CONSTELLATIONS
“No known roof is as beautiful as
the skies above”
The celestial sphere is
divided into 88
constellations
Twelve of the 88 constellations reside on or near the ecliptic,
the Sun’s path across the sky over a 365-day (one year)
period. These twelve constellations are referred to as the
Signs of the Zodiac.
SIGNS OF THE ZODIAC
Constellation
Object Represented
Dates of the Sun
Capricornus
Aquarius
Pisces
Aries
Taurus
Gemini
Cancer
Leo
Virgo
Libra
Scorpius
Sagittarius
“The Sea Goat”
“The Water Carrier”
“The Fishes”
“The Ram”
“The Bull”
“The Twins”
“The Crab”
“The Lion”
“The Virgin”
“The Scales”
“The Scorpion”
“The Archer”
Dec 22 – Jan 20
Jan 21 – Feb 19
Feb 20 – Mar 20
Mar 21 – Apr 20
Apr 21 – May 20
May 21 – Jun 21
Jun 22 – Jul 22
Jul 23 – Aug 23
Aug 24 – Sep 22
Sep 23 – Oct 23
Oct 24 – Nov 22
Nov 23 – Dec 21
Some are more
easily recognized
than others
Taurus “The Bull”
Orion “The Hunter”
Ursa Major “The Big Bear”
The Big Dipper is part
of the constellation
Ursa Major.
Tail of the Bear
It is only part of the
constellation.
Body of the Bear
The Big Dipper is an example
of what astronomers call an
asterism. An asterism is a
commonly recognized
grouping of stars but not one of
the 88 official constellations.
The Big Dipper
In a constellation the brighter stars are designated using the
lower case Greek alphabet starting with α for the brightest,
β for the second brightest, and so on.
The first five letters in the Greek alphabet are:
α
β
γ
δ
ε
alpha
beta
gamma
delta
epsilon
The Greek letter is followed by the first three
letters of the constellation’s one-word name.
If the constellation has a two-word name, use
the first letter of the first word followed by the
first two letters of the second.
One-Word Name
Two-Word Name
Orion
Taurus
Leo
Eridanus
Ursa Major
Ursa Minor
Canis Major
Canis Minor
= Ori
= Tau
= Leo
= Eri
= UMa
= UMi
= CMa
= CMi
Orion
• Orion can be easily seen
in the night sky from late
fall to winter in the
Northern Hemisphere
• Know as The Hunter
• Followed by his faithful
hunting dog Canis Major
– Contains the bright star
Sirius
– Sometimes called the
Dog Star
Orion
Son of the sea- god Neptune.
He challenged the Gods,
boasting that he could kill
every animal on Earth. As a
result of this, Earth conjured
up an enormous scorpion,
one which Orion could not
defeat. In the end, Orion was
killed by the scorpion, and
both him and the scorpion
were put up in the sky as
constellations. (the scorpion
is known as "Scorpio")
Orion’s Belt
• May be reflected in
the layout of the
three Great
Pyramids in Egypt
Betelgeuse
• Semi regular variable
star located
approximately 640 lightyears from the Earth.
• The second brightest
star in Orion and the
ninth brightest star in
the night sky.
Betelgeuse
• Betelgeuse is a red
supergiant, and one of the
largest and most luminous
stars known.
• For comparison, if the star
were at the center of our
solar system its surface
might extend out to
between the orbits of Mars
and Jupiter, wholly
engulfing Mercury, Venus,
the Earth and Mars.
Betelgeuse
• Astronomers believe Betelgeuse is only a few
million years old, but has evolved rapidly
because of its high mass.
• Some astronomers believe it may become a
supernova within a timeframe where it could
be observable by human civilization.
Orion Nebula
• A nebula is a cloud of
gas and dust in space.
• On a clear winter night,
you can see with your
naked eye the Great
Nebula of Orion as a
fuzzy wisp in Orion’s
sword.
Orion Nebula
• At the center lie four
brilliant blue-white stars
known as the
Trapezium.
• Like a great
thundercloud
illuminated from within,
the churning currents of
gas and dust suggest
immense power.
Orion Nebula
• A deeper significance
lies hidden behind the
visible nebula.
• Radio and infrared
astronomers have
discovered a vast dark
cloud just beyond the
visible nebula in which
stars are now being
created.
Cassiopeia
• Symbolism: the Seated
Queen
• Right ascension: 1h
• Declination: +60°
• Main stars: 5
Cassiopeia
• After promising her daughter in
marriage to Perseus, Cassiopeia
had second thoughts.
• She convinced one of Poseidon's
sons, Agenor, to disrupt the
ceremony by claiming
Andromeda for himself. Agenor
arrived with an entire army, and a
fierce struggle ensued.
• In the battle Cassiopeia is said to
have cried "Perseus must die". At
any rate it was Perseus who was
victorious, with the help of the
Gorgon's head.
Cassiopeia
• Perseus had recently slain
Medusa, the Gorgon, and had put
its head in a bed of coral. He
retrieved the head and waved it
in midst of the warring wedding
party, instantly turning them all
to stone. In the group was both
Cepheus and Cassiopeia.
• A contrite Poseidon put both
father and mother in the
heavens. But because of
Cassiopeia's vanity, he placed her
in a chair which revolves around
the Pole Star, so half the time
she's obliged to sit upside down.
Ursa Major – The Great Bear
• Right Ascension: 11
hours
• Declination: 50 degrees
• Visible between
latitudes 90 and -30
degrees
• Best seen in April (at
9:00 PM)
Ursa Major – The Great Bear
• According to some Native
American legends, the bowl
of the Big Dipper is a giant
bear and the stars of the
handle are three warriors
chasing it.
• The constellation is low in
the sky in autumn evening
sky, so it was said that the
hunters had injured the
bear and its blood caused
the trees to change color to
red.
Ursa Major – The Great Bear
•
•
•
One day Callisto, who was turned into
a bear previously by Hera, found
herself face-to-face with a young and
handsome hunter and suddenly
recognized him as her son, Arcas.
She raised up on her hind legs to
embrace her son. Thinking that the
bear was about to attack him, Arcas
raised his spear and was about to
hurl it and kill his mother.
Zeus happened to be looking down
on the scene from his position on Mt.
Olympus and instantly turned Arcas
into a bear also. Zeus then grasped
each bear by its tail and tugged and
tugged until he had managed to lift
both high into the sky, Callisto as Ursa
Major and her son Arcas as Ursa
Minor.
Ursa Major – The Great Bear
• This tugging of tails over
such a long journey through
the sky, stretched both tails
and explains why our
celestial bears, unlike
earthly ones, have long
tails.
• The tail of Arcas became
even longer since he was
continuously swung around
the sky by the end-star in
his tail, Polaris.
Ursa Major – The Great Bear
•
•
•
On discovering that her husband had
given Callisto and Arcas honored places in
heaven, Hera was furious. She went down
to Earth to visit her friend the ocean god,
Oceanus. She asked that he forever keep
the two penned so that they may never
wander far.
Oceanus was sympathetic and promised
that he would grant Hera her wish. He
would see to it that "the couple never
would be permitted to enter our water in
their wandering," in other words, that the
bears forever would be forbidden to set
below the horizon of the sea as other
constellations do.
To this day both the Lesser Bear and the
Greater Bear are held high in the sky near
the Pole Star, never permitted to sink
beneath the sea horizon.
Ursa Minor – The Little Bear
•
•
•
•
•
•
Often called the Little Dipper
Constellation in the northern sky.
Its name is Latin for 'little bear',
contrasting with Ursa Major, the
Great Bear.
Like the big dipper, the handle of the
little dipper is the tail of the "little
bear".
It was one of the 48 constellations
listed by the 2nd century astronomer
Ptolemy, and remains one of the 88
modern constellations.
Notable as the location of the north
celestial pole, although this will
change after some centuries due to
the precession of the equinoxes.