1. Attach Your Completed H-R Diagram…Along with Procedure Steps 2 & 3

Lab: Classifying Stars Name: ______Earth Science Date: ______Hr: ____ Introduction: Astronomers use two basic properties of stars to classify them. These two properties are luminosity, or brightness, and surface temperature. Astronomers will often use a star’s color to measure it’s temperature. Stars with low temperature produce a reddish light, while stars with high temperature shine with a brilliant blue white light. Surface temperatures of stars range from 2,000 Kelvin to 50,000 Kelvin. When these surface temperatures are plotted on a graph against luminosity, the stars fall into 3 groups: Main Sequence, Giants, and White Dwarfs.

Question: When plotting stars using brightness and temperature, what group do most stars belong to?

Hypothesis:

Procedure: 1. Plot the stars listed below on the graph provided. 2. Circle around/label each group of stars (Main Sequence, Giants/Supergiants, White Dwarfs). 3. Find the Sun and make its DOT darker.

OBSERVATIONS: Table #1: Star Brightness and Surface Temperature Star Brightness (x Sun) Surface Temperature ( x 1000 K) Rigel 10,000 11 Polaris 2,500 6 Antares 65,000 3 Van Maanen 2 0.001 6.2 Spica 12,000 22 Vega 40 10 Procyon A 7 6.5 Regulus 150 10.3 Lacaille 0.02 3.6 Sirius B 0.01 10 Betelgeuse 100,000 3 Achernar 3,100 15 Aldebaran 500 4 Tau Ceti 0.5 5.3 Sirius A 25 10 Sun 1 5.7 Procyon B 0.004 8 Altair 10.8 8 Alpha Centauri A 1.6 5.7 Eridani B 0.08 16

------EVERYTHING MUST BE HAND-WRITTEN FROM THIS POINT ON------Analysis: 1. ATTACH YOUR COMPLETED H-R DIAGRAM…ALONG WITH PROCEDURE STEPS 2 & 3.

2. Check your H-R Diagram with the H-R Diagram class website link. How accurate were you? Explain.

3. How many different types of stars are shown on the H-R Diagram? ______

4. How does the temperature and luminosity of the Sun compare to that of the stars on the Main Sequence?

5. Which is the hottest star plotted? ______the brightest? ______

Multiple Choice: write out the question + correct complete answer 6. According to your H-R diagram, the Sun is classified as a - blue supergiant star with a temperature of 20,000K and a brightness of 700,000 - main sequence star with a temperature of 5,700K and a brightness 1 - main sequence star with a temperature of 4,000K and a brightness of 100 - white dwarf star with a temperature of 10,000K and a brightness of 0.01

7. Which star is cooler and many times brighter than Earth's Sun? - Rigel - Betelgeuse - Barnard's Star - Sirius

8. Stars undergo changes over millions of years. Based on your Stellar Evolution Concept Map, the Sun will become: - hotter and brighter, then cooler and dimmer. - cooler and dimmer, then hotter and brighter. - cooler and brighter, then hotter and dimmer. - hotter and dimmer, then cooler and brighter.

Multiple Choice: write out the complete question + the correct answer:  Hot & Bright  Hot & Dim  Cool & Bright  Cool & Dim  Medium Temperature & Medium Brightness

9. Red Giant stars are classified as: ______10. White Dwarf stars are classified as: ______11. Main Sequence stars are classified as: ______, ______, and ______.

Conclusion: Restate hypothesis + if it was accepted or rejected.

Classifying Stars Lab Rubric: Lab Component Pts /Pts Possible Front part (Title  Observations) attached BEFORE ? / 1 BACKGROUND Hypothesis was testable / 1 OBSERVATIONS (all observations were given to you for this lab) ANALYSIS

Completely hand-written? / 1 #1 – H-R Diagram - All stars correctly plotted? - Star groupings accurate? / 6 - Sun’s location is clearly marked darker than other stars? (H-R diagram Title = +1) (H-R Diagram not in correct part of lab = -1) #2 – H-R Diagram Comparison (1 pt for accuracy, 1 pt for explanation) / 2 #3, #4, #5- Correctly answered questions / 3 #6-11 – Complete sentence answers (followed multiple choice instructions) / 4 CONCLUSION Restated hypothesis, stated if it was accepted or rejected. / 2 TOTAL POINTS / 20