1. Constellations

2. The rotation of the earth causes the apparent daily motion of stars. The rotation of the earth causes the apparent daily motion of stars. Their daily paths, diurnal circles, are centered on the celestial pole. Their daily paths, diurnal circles, are centered on the celestial pole.

3. Stars rise in the east, set in the west. Stars rise in the east, set in the west. Circumpolar stars never set. Circumpolar stars never set. They circle the pole. They circle the pole.

4. All visible stars are in our galaxy. All visible stars are in our galaxy. Only about 1 in 4 stars is single. Only about 1 in 4 stars is single.

5. Most occur in groups of 2 (binary) or more Most occur in groups of 2 (binary) or more

6. Stars are “suns” but millions of times further away. A few thousand stars are visible to the unaided eye.

7. What you see depends on the brightness of the sky and the quality of your vision http://www.inhabitat.com/2006/08/19/light-pollution-the-continuing-spread /

8. Even far from city lights our eyes see only a fraction of the 100 billion stars in our galaxy.

9. Star groups that form recognizable patterns are called constellations. Star groups that form recognizable patterns are called constellations.

10. Modern def refers to a region of the sky. The 88 official constellations cover the celestial sphere.

11. Stars in a constellation appear close together but have no relationship to each other. Stars in a constellation appear close together but have no relationship to each other.

12. Asterisms are not Constellations Some commonly recognized patterns of stars have names but are not constellations  The Big Dipper is a prime example, being just the rear end and tail of Ursa Major (the Great Bear)

13. Stars in a constellation are labeled according to brightness. Stars in a constellation are labeled according to brightness. EX: Betelgeuse the brightest star in Orion, is labeled Alpha, EX: Betelgeuse the brightest star in Orion, is labeled Alpha,

14. Every star you see has dozens of names The bright star Vega, is also The bright star Vega, is also   Lyrae, HR 7001, 3 Lyrae, 2MASS J18365633+3847012, … The brightest stars have classical names, originating largely from the Arabic language.  Rigel (  Ori) – The left leg of the giant  Sheliak (  Lyr) – The tortise  Aldebaran (  Tau) – The Follower (of the Pleiades)  Antares (  Sco) – The rival of Mars

15. As the earth orbits the sun different constellations are visible at night. As the earth orbits the sun different constellations are visible at night.

16. The stars are all moving relative to one another  These motions are perceptible to the eye only over thousands of years.  The constellations/asterisms known to us will be obsolete 100,000 years from now. Movie of the Changing Big Dipper