SCIENCE
ETO
SUCCESS ACADEMY
DATE:____________
Preparing ___________________________ to be a Sensational Scientist.
(Name)
Topic: Stars
Pre-assessment
1. Uri looks through a telescope for two stars. He knows that both stars have the same absolute brightness
and that the second star is twice as far from Earth as the first star. How bright will the second star appear
compared to the first star?
a. It will appear brighter than the first star.
c. It will appear as bright as the first star.
b. It will appear dimmer than the first star.
d. It will appear redder than the first star.
2. Chaya analyzes the data for two stars. Both stars are the same color, but the first star has an absolute
brightness greater than the second star. What should Chaya conclude about the stars?
a. The first star is larger than the second star.
c. The first star is hotter than the second star.
b. The first star is smaller than the second star.
d. The first star is cooler than the second star.
3. Stars can be many different colors. Which star in the chart has the highest surface temperature?
a. Star A
c. Star C
b. Star B
d. Star D
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What is an H-R Diagram and how astronomers use it?
1. Using the H-R Diagram above, describe the characteristics of a Class “O” Main sequence star.
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2. Class “K” stars can be separated into three groups. They all share a similar temperature, but have
different absolute magnitudes (brightness). How can astronomers distinguish these stars from one
another?
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3. Explain how a star with a low absolute brightness can have a higher apparent brightness than a star
with a high absolute brightness.
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ASSESSMENT
1. The H-R diagram compares the surface temperature and color of stars.
What would be the color of a star that has a surface temperature of 15,000 K?
A.
B.
C.
D.
Blue
Blue-white
White
Red
2. Eduardo looks at stars through his telescope. He says that the star Sirius is brighter than the star Rigel.
In reality, Rigel has a greater absolute brightness than Sirius. What can explain Eduardo’s observation?
A. Sirius is much closer to Earth than Rigel.
B. Rigel is much closer to Earth than Sirius.
C. Sirius is a hotter star than Rigel.
D. Rigel is a hotter star than Sirius.
3. If an astronomer discovered a new star, what would be the best way to characterize the star?
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