1. oneone ESS-5B Objective: To identify characteristics of stars in order to explain how these characteristics affect a star’s appearance from Earth. Astronomy Note: How can you tell stars apart? Drill: 1. Take out your log book and your text. 2. Title a new page “Characteristics of Stars”. 3. Create a list of at least 6 characteristics.

2. oneone ESS-5B Think about our earlier lessons on classifying matter. Identify characteristics that can be used to tell 2 stars apart. ColorTemperatureSize BrightnessCompositionMass LocationSun or notAge

3. oneone ESS-5B Which characteristics do you think will be easiest to learn about? Why? Astronomers classify stars according to physical characteristics. Skim text page 127 to identify 5 characteristics that astronomers use to classify stars. ColorTemperatureSize BrightnessComposition

4. oneone ESS-5B Activity 2: Exploring Characteristics of Stars

5. oneone ESS-5B Objective: To identify characteristics of stars in order to explain how these characteristics affect a star’s appearance from Earth. Astronomy Note: How can you tell stars apart? Drill: 1. Take out your activity sheet and your text. 2. You have 10 minutes to complete the ditto.

6. oneone ESS-5B COLOR AND TEMPERATURE (Text Page 127) What does the color of a star indicate about the star? Temperature

7. oneone ESS-5B Identify the temperature associated with each color, and include an example of a star that would appear each color. Temperature Example Red: about 3,200° C Betelgeuse White/Yellow: about 5,500° C Our Sun Blue: over 20,200° C Rigel

8. oneone ESS-5B SIZE (Text Page 127) Stars vary greatly in their sizes. List five sizes of stars from smallest to largest and a fact related to each type of star.

9. oneone ESS-5B Star Fact a. Neutron Stars about 20 km in diameter b. White Dwarf Star about the size of Earth c. Medium Sized Star like our sun d. Large/Giant Star 10-100 times the size of our sun e. Super Giant Star from our sun to Jupiter

10. oneone ESS-5B COMPOSITION (Text Page 128) What are the two main elements found in most stars? Hydrogen 73% Helium 25% Other Gases 2% What tool do scientists use to study the composition of stars? Spectrograph

11. oneone ESS-5B Brightness of Stars (Text Page 128-129) What two factors determine how bright a star really is? 1.Temperature 2.Size What are 2 factors that determine how bright a star appears from Earth? 1.Distance From Earth 2.Absolute Brightness

12. oneone ESS-5B Hmmm… PARALLAX

13. oneone ESS-5B Hertzsprung-Russell Diagram (Text Page 132-133) On what 2 characteristics is the Hertzsprung- Russell Diagram based? 1.Absolute Brightness 2.Surface Temperature What pattern exists for main sequence stars based upon these two characteristics? For main sequence stars, as the surface temperature increases, the absolute brightness increases.

14. oneone ESS-5B HOMEWORK: Ditto – Galaxies and Stars