2. 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.

3. 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)

4. Ursa Major
Ursa Major, the Great Bear, is visible in the Northern Hemisphere all year long.

5. Ursa Major Circumpolar Constellation

6. How to find Pole Star
Distance to the pole star is five times the distance between the two pointer stars

7. 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.

8. Ursa Minor Circumpolar Constellation

9. arc to Arcturus (Bootes) and spike to Spica (Pisces)

10. Saharan Starry Night 

11. Views of Orion from Tasmania (Australia) and Iran (Asia)

12. 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.

13. Cepheus Circumpolar Constellation

14. Cassiopeia Circumpolar Constellation
This constellation is at the edge of the Milky Way galaxy and has the shape of a "W".

15. 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.

16. Circumpolar Constellations
Visible thoroughout the year.

17. Circumpolar Constellations

18. Circumpolar Constellations

19. Circumpolar Constellations

20. Circumpolar Constellations

21. Circumpolar Constellations

22. 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.

23. Orion Not a circumpolar constellation, but a seasonal constellation Betelgeuse, 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.
Belt of Orion: Alnitak, Alnilam, Mintaka

24. On the left: The Hunter - Orion In the middle: Name: The Bull - Taurus
Bellatrix, Betelgeuse, Alnitak, Alnilam,Mintaka, Saiph, Rigel
Aldebaran
Sirius/Adara
On the left: The Hunter - Orion
In the middle: Name: The Bull - Taurus
On the right: Name: The Greater Dog - Canis Major

25. On the left: The Lion - Leo In the middle: The Herdsman - Böötes
Regulus
Arcturus
Spica
At first, this constellation was recognized as the figure of a stalk of wheat, and then was introduced to the Greeks and become the figure of a virgin who holds a stalk of wheat, linking it with Greek mythology and legend.
On the left: The Lion - Leo
In the middle: The Herdsman - Böötes
On the right: The Virgin - Virgo

26. Summer On the left: The Crab - Cancer
In the middle: The Scorpion - Scorpio
On the right: The Archer - Sagittarius

27. 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

28. 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.

29. Ecliptic Constellations

30. Hindu Calendar Rashi

31. The Constellations, using H. A. Rey's Scheme
Curious George author
The Constellations, using H. A. Rey's Scheme

33. 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
88 Constellations

34. and Their Constellations
Brightest Stars
and Their Constellations

35. The Dome of the Sky: Definitions in your local sky

36. To Polaris
Angular size of moon ~ ½ o
Angular distance between the “pointer stars” ~ 5o

37. Latitude and Longitude
Latitude : Measures positions north or south of the equator. (Note: This is an angle)
0o = the equator.
90o N= the north pole.
90o S = the south pole.
Longitude : Measures positions east or west of the Prime Meridian. (This is an angle)
The Prime meridian is an imaginary line that passes through Greenwhich, England.
Beavercreek, OH
Latitude: N,
Longitude: W

38. Different sets of constellations are visible in northern and southern skies.
The Altitude of the celestial pole (Polaris) = your latitude

39. Counter-Clockwise Rotation Clockwise Rotation
Northern Hemisphere
Southern Hemisphere
The Altitude of the celestial pole (Polaris) = your latitude

40. 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.

42. Units of R.A.
360o = 24h
 15o/h

43. Azimuth and Altitude are observer centric.
Altitude is the angular distance of an object above the local horizon. It ranges from 0 degrees at the horizon to 90 degrees at the zenith, the spot directly overhead.
Azimuth is the angular distance of an object from the local North, measured along the horizon. An object which is due North has azimuth = 0 degrees; due East is azimuth = 90 degrees; due South is azimuth = 180 degrees; due West is azimuth = 270 degrees.