1. Stars

2. Star
A spherical celestial object made up of gases held together by gravity that shines.

3. The Sun as photographed with a hydrogen filter.
Solar Flare
The Sun: a medium-size, main sequence star.

4. What produces starlight?
nuclear fusion: is the process by which multiple- like charged atomic nuclei join together to form a heavier nucleus

5. Conditions for Nuclear Fusion
High temperature - The high temperature gives the hydrogen atoms enough energy to overcome the electrical repulsion between the protons.
Fusion requires temperatures about 100 million Kelvin (10-15 Million degrees F)
High pressure - Pressure squeezes the hydrogen atoms together. They must be within 1x10-15 meters of each other to fuse.

6. Stellar Evolution The Life Cycle of Stars
A star’s life is dependent upon initial mass.
Produces two main paths of stellar evolution: Massive Stars and Sun-Like Stars.

7. Group Assignment
Using the chapter provided from your text, read about the particular stage of stellar evolution.
Write down 4 VIP’s. Discuss with your group why they are important.
Determine what path and stage of stellar evolution your group is in.
Prepare to present your VIP’s to the class!

8. Stellar Evolution Research Assignment
Create a Power Point Presentation or an oral presentation with a visual aid.
Includes:
Identify path and stage of stellar evolution
Discuss the stage: characteristics of the stage (Fun Facts!)
Identify and discuss an example of the particular stage of stellar evolution: location, size, distance from Earth i.e. Ant Nebula, Betelgeuse
Use Google Sky to show us an example of your stage of stellar evolution.

9. Path of Stellar Evolution
Massive Stars
nebula protostar  main sequence super giant supernova  neutron star or black hole

10. Path of Stellar Evolution
Sun-like Star
nebula  protostar  main sequence  red giant  planetary nebula  white dwarf  black dwarf

11. How could organize this group of people?
Height
Weight
Eye color
Hair color
Ethnicity
Hair Length
Wardrobe

12. Where is classification useful?
Carl Linnaeus

13. Where is classification useful?
Use a system of classification to make your life much easier!
What a mess!

14. Classification
the allocation of items or characteristics to groups according to type
Ex. Classification of living organisms
Ex. Classification of Stars

15. Ancient White Dwarf Stars in the Milky Way

16. How do we classify stars?
Temperature
Luminosity
Luminosity: the amount of energy radiated by a star over a given period of time
Apparent Magnitude v. Luminosity
Factors that Affect Luminosity: size and temperature