⭐ Part 1: Star Classification Knowledge Check

1. What does the HR Diagram plot on its two axes?

Temperature vs. Size

Luminosity vs. Temperature

Mass vs. Age

Brightness vs. Distance

2. Which spectral classes represent the hottest stars?

O and B

G and K

M and L

A and F

3. The difference between brightness and luminosity is:

🔄 Part 2: Card Sorting Activity Record

4. Record your group's sorting strategy. How did you initially group the star cards?

5. List three stars from your cards that belong to the Main Sequence and their key properties:

Star 1: _________________ Temperature: _______ K Luminosity: _______ solar units

Star 2: _________________ Temperature: _______ K Luminosity: _______ solar units

Star 3: _________________ Temperature: _______ K Luminosity: _______ solar units

6. Which region of the HR Diagram did your group find most challenging to identify? Explain why.

📊 Part 3: Data Interpretation

7. Match each star type with its typical characteristics:

1. White Dwarf

2. Red Giant

3. Main Sequence Star

4. Supergiant

A. Very hot, low luminosity, small size

B. Extremely large, high luminosity, cool surface

C. Stable hydrogen fusion, moderate size

D. Large, moderate temperature, high luminosity

8. A star has a surface temperature of 3,000 K and luminosity 100 times that of the Sun. Where would this star be located on the HR Diagram?

Main Sequence

White Dwarf region

Red Giant region

Blue Supergiant region

🎯 Part 4: Stellar Evolution Understanding

9. Fill in the blanks about stellar evolution:

A star like our Sun will spend most of its life on the _____________ sequence. As it ages, it will expand to become a _____________ giant before eventually becoming a _____________ dwarf. The path a star takes depends primarily on its initial _____________.

10. Explain why more massive stars have shorter lifespans, using your understanding of the HR Diagram:

11. Draw a simple HR Diagram below and label the main regions (Main Sequence, Giants, White Dwarfs). Include temperature and luminosity axes.

🤔 Part 5: Reflection and Analysis

12. What was the most surprising discovery your group made during the card sorting activity?

13. How does the HR Diagram help astronomers understand stellar evolution? Give two specific examples.

14. Challenge Question: If you could only observe a star's colour (temperature), what could you predict about its other properties using the HR Diagram?