oneESS-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.

Classifying Stars

oneESS-5B

Think about our earlier lessons on classifying matter. 

Identify characteristics that can be used to tell 2 stars apart.

Color Temperature SizeBrightness Composition MassLocation Sun or not Age

Classifying Stars

oneESS-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.

Color Temperature SizeBrightness Composition

Classifying Stars

oneESS-5B

Activity 2: Exploring Characteristics of

Stars

Classifying Stars

oneESS-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.

Classifying StarsDay 2

oneESS-5B

COLOR AND TEMPERATURE (Text Page 127) 

What does the color of a star indicate about the star?

Temperature 

Classifying Stars

oneESS-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

Classifying Stars

oneESS-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. 

Classifying Stars

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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

Classifying Stars

oneESS-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

Classifying Stars

oneESS-5B

Brightness of Stars (Text Page 128-129) 

What two factors determine how bright a star really is?

1. Temperature2. Size

What are 2 factors that determine how bright a star appears from Earth?

3. Distance From Earth4. Absolute Brightness

Classifying Stars

oneESS-5B

Hmmm…PARALLAX

Classifying Stars

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Hertzsprung-Russell Diagram (Text Page 132-133) 

On what 2 characteristics is the Hertzsprung-Russell Diagram based?

1. Absolute Brightness2. 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.

Classifying Stars

oneESS-5B

HOMEWORK: Ditto – Galaxies and Stars

Classifying Stars