The Hertsprung-Russell Diagram

Name ______The Hertsprung-Russell Diagram s s e n t h g i r B

The Hertsprung-Russell is a graph that shows the relationship between the temperatures of stars and their absolute magnitude (the brightness of a star). This diagram also measures luminosity or how much energy leaves a star. Luminosity of a star is affected by both temperature and size. The most luminous stars are large and hot the least luminous stars would be small and cool. The color of stars is determined by its surface temperature, which is illustrated on the diagram.

Materials: Colored pencils

Procedure: 1. Color the columns in the H-R diagram according to the colors listed on the columns 2. Answer the following analysis questions about the diagram Analysis:

1. What does the left hand side of the graph measure?

2. What does the bottom of the graph measure? 3. What is the range in surface temperatures on the H-R diagram?

4. What is the approximate surface temperature of the sun?

5. Would the surface temperature of stars classified as white dwarfs generally be lower or higher that the surface temperature of the Sun?

6. What is the color of the stars on the diagram that have the highest surface temperature?

7. What is the color of the stars on the diagram that have the lowest surface temperature?

8. List the color of the stars from the hightest to the lowest temperatures

9. What is the hottest star?

10. What is the coolest Star?

11. What is the largest star?

12. What is the smallest star?

13. Name three average stars on the H-R diagram

14. Most of the stars on the diagram are classified as what type of stars? 15. Our Sun is classified as what type of star?

16. Plot the following stars on the HR diagram. a. Star A 4,000 C and low to medium brightness b. Star B 6,000 C high brightness c. Star C 20,000 C and lost to medium brightness d. Star D 6,000 C and medium brightness

Identify the type and color for each star STAR COLOR TYPE Star A

Star B

Star C

Star D

17. How is it possible for white dwarfs to have a lower LUNIMOSITY than the Sun even though the Sun is cooler than the white dwarfs?

18 Describe the characteristic of stars in the Main sequence. What do the stars in the main sequence have in common?