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NAME_______________________________________ DATE_________________ PERIOD______
Star Distance, Brightness, and Surface Temperature
____
1. A parsec is a greater distance than a light year.
TRUE
FALSE
____
2. The shaded area of the graph correctly represents the percentage of stars that are in the main sequence of an HR diagram.
TRUE FALSE
____
3. Stars more massive than the Sun use up their fuel at a slower rate. TRUE
____
4. The greatest proportion of elements in the universe are those with the smallest masses. TRUE
FALSE
FALSE
For questions 5 - 10, Indicate whether the statement is true or false. If false, change the identified word or phrase to make the
statement true.
____
5. In the modern classification of apparent magnitude, a difference of 5 magnitudes corresponds to a factor of 100 in
brightness. _________________________
____
6. Astronomers can sometimes identify binary stars even if only one star is visible. _________________________
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7. Absolute magnitude takes distance into account when indicating the surface temperature of a star.
_________________________
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8. Using the parallax technique, astronomers can accurately measure the distance of stars up to 300 pc away.
_________________________
____
9. The Hertzsprung-Russell diagram (H-R) diagram, first plotted in the nineteenth century, demonstrates the relationship of
luminosity and temperature. _________________________
____ 10. Stars are assigned a spectral type, with M being the hottest stars. _________________________
____ 11. A scientist comparing the properties of a large number of different stars could expect to find the most variation in the
data describing the stars’________.
A) luminosity
C) composition
B) diameter
B) temperature
____ 12. Use the table to calculate which of the following units represents the greatest distance.
A) meter
B) parsec
C) light year
D) kilometer
____13.If the following line represents unshifted light from a star, which of these shows how the light waves would change if the
star started moving away from the observer?
A)
C)
B)
D)
____ 14. A scientist using parallax to determine the distance to a star will notice the greatest shift in a star’s apparent position
when measured________.
A) at 6-month intervals
C) at the midpoint of the star’s rotation
B) during Earth’s coldest weather
D) at the peak of the star’s blueshift
____ 15. What causes the dark bands observed in a solar spectrum?
A) the emission of specific elements
B) different chemical elements which absorb light at specific wavelengths
C) highly compressed, glowing gas
D) warmer gas in front of a source that emits a continuous spectrum
____ 16. The apparent shift in a star’s position caused by the motion of the observer is called ____.
A) luminosity
C) absolute magnitude
B) apparent magnitude
D) parallax
____ 17. A star that is gravitationally bound to another star can either be part of a star cluster or a ____ star.
a. constellation
c. binary
b. white dwarf
d. red giant
____ 18. The ____ of a star determines its temperature, luminosity, and diameter.
A) mass
C) energy output
B) composition
D) density
____19. The total amount of energy that a star puts out as light each second and in every direction is the star's
A) flux
B) luminosity
C) apparent magnitude
D) absolute magnitude
E) both B and D
____20. Brighter objects have lower magnitudes.
TRUE
FALSE
____21. The FLUX of a star is determined by the distance to the star, the size of the star, and the sensitivity of our light detector.
TRUE FALSE
____22. The parallax angle used to calculate the distance to a nearby star is always measured in
A) inches B) arcminutes C) degrees D) arcseconds
____23. an O1 is hotter than
A) B3
B) A7
C) G2
D)M5
E) all of these
____24. An A1III star is about _____ times more luminous than our sun.
A)
B)
C)
D)
10
100
1000
10,000
____25. Every star emits every wavelength of the electromagnetic spectrum all at once.
____26. By definition, it is impossible to DIRECTLY measure the luminosity of a star.
TRUE
TRUE
FALSE
FALSE
____27. A Cepheid Variable star is a STANDARD CANDLE. It has a known luminosity because
A) all Cepheid variables are the same size.
B) it pulsates, and the rate of pulsation is directly related to its size, therefore its brightness.
C) all Cepheid variables are the same exact distance away
____28. On the visible-light portion of the electromagnetic spectrum, blue represents the ______ wavelength while red represents
the _______ wavelength.
A) shortest, longest
B) longest, shortest
____29. Visible light takes up a very large portion of the entire electromagnetic spectrum.
____30. There are 3600 arcseconds in one degree of angular measurment.
TRUE
TRUE
FALSE
FALSE
____31. Apparently, there are locations on the H-R diagrams where stars can not exist.
TRUE
FALSE
____32. A star classified as K2III has which of the following properties
A) 30,000K surface temp, blue giant, ABSOLUTE MAGNITUDE -15
B) 10,000 surface temp, red giant, ABSOLUTE MAGNITUDE -5
C) 5000K surface temp, orange giant, ABSOLUTE MAGNITUDE 0
____33. A Type 1a supernova always explodes with the same luminosity.
TRUE
FALSE
____34. A Type 1a Supernova is very bright, therefore can be seen from many millions of light years away.
TRUE
FALSE
____35. The H-R diagram was first calibrated using
A) magic
B) the parallax method
C) standard candles D) the flux capacitor
____36. The flux of a star diminishes by an amount proportional to the inverse of the square of the distance from that star.
TRUE
FALSE
____37. The ABSOLUTE MAGNITUDE of an object is equal to what the Apparent Magnitude of that object would be if it were at
a distance of 10 parsecs. TRUE FALSE
____38. Every data point on the H-R diagram represents an individual star.
TRUE
FALSE
____39. A cepheid variable star has the same luminosity every time we see one. Its luminosity has nothing to do with its size and
the rate of its pulsation. TRUE FALSE
____40. A star with spectral type O is a
A) yellow star B) hot star C)
D) cold star E) red star F)
____41. A star's color is an indicator of its
A) surface temperature
B) size
C) age
____42. The light from a star diminishes with distance.
TRUE
FALSE
____43. The brighter the object, the lower its apparent magnitude. In other words, Venus (-4.4) is brighter than Sirius (-1.4).
TRUE FALSE
____44. Our sun is a
A)
B)
C)
D)
____45. ONE Parsec is equal to
A) 93 million miles
____46. The correct sequence of spectral types is
B) 3.26 light years
A) OBAFGKM
O5Ia
K3V
G2V
F5III
C) 1.69 AU
B) FAGMOBK
C) FGAKMOB
____47. The TREND LINES on the H-R diagram represent
A) the average of the patterns of all the data points
B) where each data point SHOULD have been after taking human error into account
____48. One of the main purposes of the Parallax Method of calculating distances to stars is to
A) calculate the distance to stars too far for any other method
B) calibrate other techniques for measuring distances to stars
C) calculate the distance to every object in the universe
____49. A "Standard Candle" is an object in the universe with a known luminosity.
____50. Apparent Magnitude and Flux are the same thing.
TRUE
FALSE
TRUE
FALSE
Star Distance, Brightness, and Surface Temperature
Answer Section
TRUE/FALSE
1. ANS:
2. ANS:
3. ANS:
4. ANS:
T
T
F
T
MODIFIED TRUE/FALSE
5. ANS: T
6. ANS: T
7. ANS: F, brightness
8. ANS: F, 500 pc
9. ANS: F, twentieth century
10. ANS: F, coolest
MULTIPLE CHOICE
11. ANS: A
12. ANS: B
13. ANS: A
14. ANS: A
15. ANS: B
16. ANS: D
17. ANS: C
18. ANS: A
19. E
20. T
21. T
22. D
23. E
24. B
25. T
26. T
27. B
28. A
29. F
30. T
31. T
32. C
33. T
34. T
35. B
36. T
37. T
38. T
39. F
40. B
41. A
42. T
43. T
44. C
45. B
46. A
47. A
48. B
49. T
50.F