2. Novas  Occurs in binary star system  It is a star that suddenly increases in brightness and slowly becomes dimmer  Gases from one of the stars occasionally strike the surface of the companion star and the result is nuclear explosion  Tremendous amount of heat, light and gases busts into space

3. Nova in a binary star system

4. Constellations  Star patterns shaped like people and animals  Unlike other star groups, they have stars that are usually not close together  Their stars appear close as viewed from the earth but they may actually be far apart  Rigel and Betelgeuse can be found in the Orion constellation yet they are separated by a huge distance of 600 light years

5. Constellations  They are important because they help form map of the sky  Any location in the sky can be described in relation to a constellation  Stars are also named according to the constellation in which they are located

6. Constellations  88 known constelations

7. Aquarius (the water bearer)

9. Aries (the Ram)

11. Cancer (the crab)

12. Gemini (the Twins)

20. Ursa Major

22. Orion (the Hunter)

24. Pegasus (the winged horse)

25. Cygnus