1. STARS  Stars are the pieces of our universe.  Each star is fixed in a certain spot in its Galaxy.  Planets and other things orbit in a solar system around a star.

2. Our Star “the Sun”  It is a Medium size, yellow in color, star.  It is 5 billion years old which is half of its life

3. How big is the Sun to us?

4. How big is a medium size star?

5. Birth of Stars  Stars are born in nurseries called “Nebulas”  They are formed by swirling masses of gases.

6. Colors of stars  The color of a star is how it appears in the sky and indicates its temperature.  Red Stars are the coolest stars, then yellow stars and the hottest are White or Blue stars.

7. Star sizes  There are many stars smaller than the sun. These are White Dwarf stars (about the size of our earth) and even small neutron stars.  Stars larger than our medium size Sun are Giant and Super Giant Stars.

8. Star brightness  Apparent Brightness is the star’s brightness as see from earth.  Absolute Brightness is a star’s brightness if all stars were at the same distance from earth.

9. Hertzsprung-Russell H-R Diagram  This diagram compares the Surface temperature of a star to its absolute brightness.  Our sun is in the middle of the diagram.