As early as 5000 years ago, people began naming patterns of stars, called constellations, in the honor of mythological characters or great heroes.

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• As early as 5000 years ago, people began naming
  patterns of stars, called constellations, in the
  honor of mythological characters or great heroes.
• Today, 88 constellations are recognized.
• They divide the sky into disjoint units.
• Every star in the sky is in one of these
  constellations.

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• Astronomers label stars within a constellation
  based on their apparent brightness,
• brightest alpha a,
• second brightest beta b,
• Some of the brightest stars have actual names,
  like Rigel Betelgeuse (both in the
  constellation Orion)

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Ursa Major
Ursa Major, the Great Bear, is visible in the
Northern Hemisphere all year long.
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Ursa MajorCircumpolar Constellation
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How to find Pole Star
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Ursa Minor

• Ursa Minor, the Little Bear, is visible in the
  Northern Hemisphere all year long.
• Ursa Minor is mostly known for Polaris, the North
  Star, which may be found at the end of the
  handle.

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Ursa MinorCircumpolar Constellation
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Saharan Starry Night 
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Views of Orion from Tasmania (Australia) and
Iran (Asia)
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Cepheus

• The story behind it
• Cepheus was the King of Ethiopia. He married
  Cassiopeia and they had a daughter Andromeda.
  Cassiopeia was incredibly beautiful but immensely
  vain. She was also proud of her daughter's
  beauty. In fact she continually boasted that the
  two of them were more beautiful than any of the
  fifty sea nymphs who attended Poseidon's court.
• These nymphs (the Nereids) complained to
  Poseidon, who felt he had to defend his own
  reputation. So he sent a flood to devastate
  Cepheus' kingdom. The oracles told Cepheus that
  in order to save his people he must sacrifice his
  daughter to a great sea monster Andromeda was
  tied to a rock along the coastline, dressed only
  in her jewelry. The monster would be along in due
  time to take his prize.
• At that moment Perseus came flying by. He had
  just killed the Gorgon Medusa and was carrying
  the severed head back to Athene. To make a long
  story short, he saved her then turned everyone
  into stone by showing them the severed head.
• Poseidon then put the stone frozen Cepheus and
  Cassiopeia into the heavens, but with a twist he
  made the vain Cassiopeia spin around on her
  chair, spending half the year upside down. As for
  Cepheus, Poseidon gave him a number of medium
  sized stars that go to make his square face with
  a pointed crown.

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CepheusCircumpolar Constellation
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CassiopeiaCircumpolar Constellation
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Draco

• Draco, the Dragon, used to hold special
  significance as the location of the pole star,
  but due to the Earth's precession, the pole has
  shifted to Polaris in Ursa Minor.

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Circumpolar Constellations
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Circumpolar Constellations
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Circumpolar Constellations
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Circumpolar Constellations
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Circumpolar Constellations
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Circumpolar Constellations
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Orion

• Orion is the master of the winter skies. He lords
  over the heavens from late fall to early spring,
  with his hunting dog Sirius trailing at his feet.
  
• The story behind it (Orion holding an animal)
• Orion was known as the "dweller of the mountain",
  and was famous for his prowess both as a hunter
  and as a lover. But when he boasted that he would
  eventually rid the earth of all the wild animals,
  his doom may have been sealed. The Earth Goddess
  sent the deadly scorpion to Orion to kill him.
  Orion engaged the scorpion in battle but quickly
  realized its armour was impervious to any
  mortal's attack. Orion then jumped into the sea
  and died. In his eternal hunting, Orion is
  careful to keep well ahead of the scorpion. Orion
  disappears over the horizon by the time Scorpio
  rises in the east, as it becomes his turn to rule
  the evening sky.

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Orion Not a circumpolar constellation, but a
seasonal constellationBetelgeuse, the right arm
of Orion (or "armpit" as the name suggests),
glows with a dull red. Rigel, in the opposite
corner of the constellation, is blue and much
brighter.
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• Orion

• On the left The Hunter - Orion
• In the middle Name The Bull - Taurus
• On the right Name The Greater Dog - Canis Major
  

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• On the left The Lion - Leo
• In the middle The Herdsman - Böötes
• On the right The Virgin - Virgo

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Summer

• On the left The Crab - Cancer
• In the middle The Scorpion - Scorpio
• On the right The Archer - Sagittarius

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• On the left and in the middle Andromeda
• The Andromeda constellation is famous for
  containing the Andromeda Nebula, the closest
  galaxy to our Milky Way.
• On the right The Fishes, Pisces

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Ecliptic Constellations Zodiac Signs

• A band of 12 constellations around the sky
  entered on the ecliptic (apparent path of the sun
  on the earth as the earth revolves around it).
• Aries, Leo, Sagittarius, Taurus, Virgo,
  Capricorn, Gemini, Libra, Aquarius, Cancer,
  Scorpio, and Pisces.

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Ecliptic Constellations
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Hindu Calendar Rashi
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The Constellations, using H. A. Rey's Scheme
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Andromeda Antlia Apus Aquarius
Aquila Ara Aries Auriga
Boötes Caelum Camelopardalis Cancer
Canes Venatici Canis Major Canis Minor Capricornus
Carina Cassiopeia Centaurus Cepheus
Cetus Chamaeleon Circinus Columba
Coma Berenices Corona Australis Corona Borealis Corvus
Crater Crux Cygnus Delphinus
Dorado Draco Equuleus Eridanus
Fornax Gemini Grus Hercules
Horologium Hydra Hydrus Indus
Lacerta Leo Leo Minor Lepus
Libra Lupus Lynx Lyra
Mensa Microscopium Monoceros Musca
Norma Octans Ophiuchus Orion
Pavo Pegasus Perseus Phoenix
Pictor Pisces Piscis Austrinus Puppis
Pyxis Reticulum Sagitta Sagittarius
Scorpius Sculptor Scutum Serpens
Sextans Taurus Telescopium Triangulum
Triangulum Australe Tucana Ursa Major Ursa Minor
Vela Virgo Volans Vulpecula
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Brightest Stars and Their Constellations
http//www.enchantedlearning.com/subjects/astronom
y/stars/bright.shtml
http//www.astro.wisc.edu/dolan/constellations/ex
tra/brightest.html
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The Dome of the SkyDefinitions in your local sky
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To Polaris
Angular size of moon ½ o
Angular distance between the pointer stars 5o
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Latitude and Longitude
Beavercreek, OH Latitude 39.73 N, Longitude
84.06 W
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• Different sets of constellations are visible in
  northern and southern skies.

The Altitude of the celestial pole (Polaris)
your latitude
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Counter-Clockwise Rotation
Clockwise Rotation
Northern Hemisphere
Southern Hemisphere
The Altitude of the celestial pole (Polaris)
your latitude
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Right Ascension and Declination

• Right Ascension (RA) Analogous to longitude, but
  on the celestial sphere.
• It is the east-west angle between the vernal
  equinox and a location on the celestial sphere.
• Declination (dec) Analogous to latitude, but on
  the celestial sphere.
• It is the north-south angle between the celestial
  equator and a location on the celestial sphere.

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Units of R.A. 360o 24h ? 15o/h
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Azimuth and Altitude are observer centric.