1. Stars
Diamonds of the sky

2. Stars are __________?
“Fireflies… fireflies that got stuck up in that big bluish- black thing.”
“Kings from the past looking down on us.”
“Balls of gas, burning billions of miles away.”

3. Stars
Spheres of gas that produce energy by fusion

4. Nuclear fusion
Nuclear fusion is a nuclear reaction in which two or more nuclei collide at a very high speed and join to form a new type of atomic nucleus.

5. Nuclear fusion Helium is the fuel for stars. Examples
Hydrogen + Hydrogen = Helium
Hydrogen + Helium = Lithium
Helium + Helium = Beryllium
Helium is the fuel for stars.

6. Classification of Stars
Based on:
Mass (small  large)
Age (young  old)
Composition (amount and kind of material)
Temperature (hot  cool)

7. Temperature (hot  cool)
Purple 35,000oC
Blue
Green
Lt. Yellow
Dk. Yellow
Orange
Red 3,000oC

8. White light A combination of all colors of light
“Rainbow” – white light separated into colors

9. Black line spectrum
When an object is heated and glows, its spectrum shows a specific pattern of black lines.
Can be used to identify substances
Emission Spectrum
Absorption Spectrum or Black Line Spectrum

10. A star is born
Life and death of a star

11. Stellar Nursery Stars are born from a nebula (plural = nebulae)
A nebula is a cloud of gas and dust (solids)

12. Mature star Light and heat given off (think of our sun)
Longest stage of a star’s life
3 sizes:
Average (our sun), huge, or giant

13. Red giant For small/medium stars (up to 1.5 times our sun):
1st stage in death of a star
Star swells to gigantic size (200x its normal size)
After a while, the hydrogen will run out and fusion will stop…

14. Collapse! Planetary nebula 2nd stage in death of a star
Light and heat greatly decreased
Pressures of gravity become imbalanced

15. White dwarf Black dwarf Final stage in death of star
3rd stage in death of a star Star shrinks to small, hot star Size of small planet
Black dwarf
Final stage in death of star
No light or heat given off

16. Massive Stars
Bigger than average….

17. Red supergiant
For giant and supergiant stars (over 1.5 times our sun):
1st stage in death of a star
Star swells to gigantic size (even more than the red giant)
After a while, the hydrogen will run out and fusion will stop…

18. Collapse!
Supernova
2nd stage in death of a star
Star explodes

19. Neutron Star
Giant stars (1.5 to 3 times the size of our sun): Form a neutron star – a star where the protons (positive charge) and electrons (negative charge) have fused to become neutrons (no charge)

20. Black Hole
Supergiant stars (over 3 times the size of our sun): Form a black hole – a place where the gravitational force is so great that not even light can escape.