1. Stars

2. A star is a large ball of gas, held together by gravity.
What is a star?
A star is a large ball of gas, held together by gravity.

3. Extreme amounts of heat & pressure are needed.
Stars produce large amounts of energy by the process of Nuclear Fusion.
Extreme amounts of heat & pressure are needed.
Our Sun converts hydrogen into helium through the process of Nuclear Fusion.

4. Stars Cont.
STARS ARE SELF-LUMINOUS – they light themselves. The moon and planets reflect light from the Sun (star).

5. Brain Pop: Our Sun

6. Our Sun is an average sized star
Our Sun is an average sized star. Compared to other stars it is not too bright and not too hot. It’s just perfect!
Low Mass High Mass

7. Characteristics of 4 stars Any other star from the HR diagram
Brighter or dimmer than the sun?
Color of the star
Surface temperature of the star
Does the star have a high, medium or low mass?
1. Sun 2. 3. 4.
Sun
Any other star from the HR diagram

8. Exit Ticket: This is an individual task
Please complete the graph and write one sentence explaining the relationship.
As the mass of a main sequence star increases….
Main Sequence Stars
Luminosity
Mass

9. Stars are classified based on luminosity and temperature.
Luminosity is how bright a star is compared to the Sun if they were the same distance away.
Stars are classified based on luminosity and temperature.
Temperature affects the color of stars.
Red = cool Blue = hot

10. Which object forms by the contraction of a large sphere of gases causing nuclear fusion of lighter elements into heavier elements?
(1) comet
(2) planet
(3) star
(4) moon

11. Which process produces the energy that allows the stars of the universe to radiate visible light?
convection
nuclear fusion
insolation
radioactive decay

13. Exit Ticket: Numbered Heads Together
Groups of 4 people. Each student number off from one to four
Discussion Question: How do stars relate to everyday life?
Make sure each member of the group can answer the question if called upon.

14. Exit Ticket: Quiz your friend