Download Name _________ Date _____________ Period ______ Skills

Name __________________________________________ Date ______________ Period ______
Skills Worksheet
Directed Reading B
Section: Stars
1. What is a star made of?
_______________________________________________________________
_______________________________________________________________
2. To learn about stars, astronomers study ______________________.
COLOR OF STARS
_____ 3. What color are the hottest stars?
a. blue
b. yellow
c. white
d. red
4. What can we conclude about stars that differ in color?
_______________________________________________________________
_______________________________________________________________
COMPOSITION OF STARS
_____ 5. The band of colors produced when white light passes through a prism is a(n)
a. color wheel.
b. emission line.
c. ultraviolet light.
d. spectrum.
_____ 6. A hot, solid object gives off a(n)
a. continuous spectrum.
b. absorption spectrum.
c. emission line.
d. partial spectrum.
_____ 7. What colors are shown in a continuous spectrum?
a. primary colors
b. cool colors
c. warm colors
d. all colors
171
Directed Reading B continued
_____ 8. The colors that appear when a chemical element emits light are called
a. continuous lines.
b. absorption lines.
c. color lines.
d. emission lines.
_____ 9. Each element in a hot gas can be identified by
a. a unique set of bright emission lines.
b. a unique set of bright absorption lines.
c. a set of emission lines shared with other elements.
d. a set of absorption lines shared with other elements.
10. Why is the spectrum of a star called an absorption spectrum?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
11. How is an absorption spectrum produced?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
12. What do the black lines of a star’s spectrum represent?
_______________________________________________________________
_______________________________________________________________
13. In what ways is the pattern of lines in a star’s absorption spectrum unique?
_______________________________________________________________
_______________________________________________________________
14. Why is it often difficult to identify a star’s elements from its absorption
spectrum?
_______________________________________________________________
_______________________________________________________________
15. What are the two main elements found in stars?
_______________________________________________________________
_______________________________________________________________
________________________________________________________________
172
Directed Reading B continued
16. What are the three most common trace elements found in stars?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
CLASSIFYING STARS
_____ 17. In the 1800s, astronomers classified stars according to
a. their elements.
b. their temperature.
c. their age.
d. their size.
_____ 18. Stars are now classified by
a. their elements.
b. their temperature.
c. their age.
d. their size.
_____ 19. Class O stars, the hottest stars, are
a. yellow.
b. orange.
c. red.
d. blue.
20. Early astronomers called the brightest stars in the sky
______________________ stars.
21. What type of numbers are used to represent the magnitudes of dim stars?
_______________________________________________________________
22. What type of numbers are used to represent the magnitudes of very bright stars?
_______________________________________________________________
HOW BRIGHT IS THAT STAR?
23. The brightness of a star as seen from Earth is its ______________________.
24. The brightness that a star would have at a distance of 32.6 light-years from
Earth is its ______________________.
173
Directed Reading B continued
25. Why is the sun the brightest object in the sky?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
DISTANCE TO THE STARS
_____ 26. What unit of measurement do astronomers use to measure the
distance from Earth to the stars?
a. a solar year
b. a parallax
c. a light-year
d. magnitude
27. The distance that light travels in one year; about 90.46 trillion kilometers, is
called a(n) ______________________.
28. An apparent shift in the position of an object when seen from different
locations is called ______________________.
MOTIONS OF STARS
29. Explain why you see different constellations in the sky at different times of the year.
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
30. What causes the stars to appear to make one complete circle around Polaris every 24 hours?
_______________________________________________________________
31. Why is the actual motion of the stars difficult to see?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
174