Name: 
 

AST 111 Practice Final


Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
 

 1. 
The radius of the moon's orbit is about __________ times larger than the radius of Earth.
a.
0.6
b.
6
c.
60
d.
600
e.
6000
 

 2. 
In the diagram below, what is the diameter of Mercury?

studyguide1-20_files/i0030000.jpg
a.
about 240 km
b.
about 2400 km
c.
about 24,000 km
d.
about 240,000 km
e.
about 2.4 ´ 106 km
 

 3. 
Seen from the northern latitudes, the star Polaris
a.
is never above the horizon during the day.
b.
always sets directly in the west.
c.
is always above the northern horizon.
d.
is never visible during the winter.
e.
is the brightest star in the sky.
 

 4. 
The apparent visual magnitude of a star is a measure of the star's
a.
size.
b.
intensity.
c.
distance.
d.
color.
e.
temperature.
 

 5. 
You live at a latitude of 73° N. What is the angle between the northern horizon and the north celestial pole?
a.
73°
b.
27°
c.
17°
d.
23studyguide1-20_files/i0060000.jpg°
e.
5°
 

 6. 
You live at a latitude of 16° S. What is the angle between the southern horizon and the south celestial pole?
a.
74°
b.
164°
c.
16°
d.
23studyguide1-20_files/i0070000.jpg°
e.
5°
 

 7. 
What is the approximate latitude of the observer in the diagram below?

studyguide1-20_files/i0080000.jpg
a.
90° N
b.
90° S
c.
50° N
d.
50° S
e.
0°
 

 8. 
An observer in the Northern Hemisphere takes a time exposure photograph of the night sky. If the illustration below depicts the photograph taken by the observer, which direction was the camera pointing?

studyguide1-20_files/i0090000.jpg
a.
straight north
b.
straight east
c.
straight south
d.
straight west
e.
straight up, directly overhead
 

 9. 
An observer in the Southern Hemisphere takes a time exposure photograph of the night sky. If the illustration below depicts the photograph taken by the observer, which direction was the camera pointing?

studyguide1-20_files/i0100000.jpg
a.
straight north
b.
straight east
c.
straight south
d.
straight west
e.
straight up, directly overhead
 

 10. 
An observer in the Northern Hemisphere takes a time exposure photograph of the night sky. If the illustration below depicts the photograph taken by the observer, which direction was the camera pointing?

studyguide1-20_files/i0110000.jpg
a.
straight north
b.
straight east
c.
straight south
d.
straight west
e.
straight up, directly overhead
 

 11. 
An observer in the Southern Hemisphere takes a time exposure photograph of the night sky. If the illustration below depicts the photograph taken by the observer, which direction was the camera pointing?

studyguide1-20_files/i0120000.jpg
a.
straight north
b.
straight east
c.
straight south
d.
straight west
e.
straight up, directly overhead
 

 12. 
Precession of the rotation axis of Earth is caused by
a.
the force of gravity from the sun and moon on Earth's equatorial bulge.
b.
the force of gravity from the sun and Jupiter on the Earth-moon system.
c.
the magnetic field of Earth.
d.
the formation and subsequent melting of glaciers during the ice-ages.
e.
the impact of asteroids.
 

 13. 
The __________ is 18 years and 11studyguide1-20_files/i0140000.jpg days long.
a.
sidereal period
b.
synodic period
c.
eclipse season
d.
saros cycle
e.
eclipse year
 

 14. 
Northern Hemisphere winters are colder than Northern Hemisphere summers because
a.
Earth is closer to the sun during the summer.
b.
the snow that falls in the northern latitudes cools Earth during the winter.
c.
the light from the sun shines more directly on the Northern Hemisphere during the summer.
d.
the period of sunlight is longer during the summer than during the winter.
e.
c and d
 

 15. 
The sun is on the celestial equator at the times of the
a.
vernal equinox and the summer solstice.
b.
autumnal equinox and the vernal equinox.
c.
summer solstice and the winter solstice.
d.
autumnal equinox and the winter solstice.
e.
sun is on the ecliptic and is never on the celestial equator.
 

 16. 
At what two celestial locations do the celestial equator and ecliptic coincide?
a.
winter solstice and summer solstice
b.
vernal equinox and autumnal equinox
c.
they coincide at all points because they are the same.
d.
north celestial pole and south celestial pole
e.
zenith and east point
 

 17. 
A(n) __________ is a set of beliefs that appears to be based on scientific ideas, but which fails to obey the most basic rules of science.
a.
theory
b.
hypothesis
c.
pseudo science
d.
allegory
e.
scientific model
 

 18. 
__________ occur when the moon is first or third quarter.
a.
Neap tides
b.
Spring tides
c.
Total solar eclipses
d.
Annular eclipses
e.
A coppery red moon will
 

 19. 
A solar eclipse that occurs when the moon's umbra does not reach Earth's surface is called
a.
a total solar eclipse.
b.
a partial solar eclipse.
c.
an annular solar eclipse.
d.
a penumbral solar eclipse.
e.
an umbral solar eclipse.
 

 20. 
The __________ moon is visible above the western horizon a couple of hours before sunrise.
a.
waning gibbous
b.
waxing gibbous
c.
waxing crescent
d.
waning crescent
e.
new moon
 

 21. 
A total solar eclipse occurred in Wolf Point, Montana on Feb. 26, 1979. When was (will) this eclipse again (be) visible in Montana?
a.
August of 1979
b.
March of 2033
c.
March of 1997
d.
March of 1979
e.
Jan. of 2000
 

 22. 
A dime is 1.8 cm in diameter. At what distance from your eye would you have to hold a dime so that it has the same angular diameter as the full moon.
a.
2 m
b.
2 cm
c.
2 km
d.
2 inches
e.
2 ft
 

 23. 
What is the wavelength of the longest wavelength light that can be seen with the human eye?
a.
400 nm
b.
4000 nm
c.
7000 nm
d.
700 nm
e.
3 ´ 108 m
 

 24. 
__________ has (have) wavelengths that are longer than visible light.
a.
Gamma-rays
b.
Ultraviolet light
c.
Infrared radiation
d.
X-rays
e.
a, b, and d above
 

 25. 
Astronomers build telescopes on tops of mountains because
a.
there is less air to dim the light.
b.
the seeing is better.
c.
CCDs work better when there is less oxygen in the air.
d.
all of the above
e.
a and b
 

 26. 
A __________ is a piece of glass with many small parallel lines etched on its surface to produce a spectrum.
a.
grating
b.
spectrograph
c.
photometer
d.
charge-coupled device
e.
prism
 

 27. 
Interferometry
a.
is used to improve the resolving power.
b.
decreases the chromatic aberration of a telescope.
c.
works only for large x-ray and ultraviolet telescopes.
d.
requires that radio telescopes be within a few hundred feet of each other.
e.
none of the above
 

 28. 
Long wavelength visible light
a.
will have a greater energy than short wavelength visible light.
b.
will have a speed that is faster than short wavelength light.
c.
has a higher frequency than short wavelength visible light.
d.
will appear blue in color to the average human eye.
e.
will appear red in color to the average human eye.
 

 29. 
Which of the following types of electromagnetic radiation has the greatest energy?
a.
x-rays
b.
visible light
c.
radio
d.
gamma-rays
e.
infrared radiation
 

 30. 
Which of the following types of electromagnetic radiation has the lowest energy?
a.
x-rays
b.
visible light
c.
ultraviolet
d.
gamma-rays
e.
infrared radiation
 

 31. 
What is the ratio of the light gathering power of a 10 m telescope to that of a 1 m telescope?
a.
10 to 1
b.
1 to 10
c.
100 to 1
d.
1 to 100
e.
3.2 to 1
 

 32. 
The resolving power of an optical telescope with a diameter of 232 cm is
a.
0.05 arc seconds.
b.
232 arc seconds.
c.
2.32 arc seconds.
d.
5 arc seconds.
e.
11.6 arc seconds.
 

 33. 
The process of removing an electron from a stable nucleus is known as
a.
ionization.
b.
Doppler broadening.
c.
collisional broadening.
d.
a red shift.
e.
quantum mechanics.
 
 
Figure 6-1

studyguide1-20_files/i0350000.jpg
 

 34. 
A plot of the continuous spectra of five different stars is shown in Figure 6-1 above. Based on these spectra, which of the stars has the lowest temperature?
a.
Star A
b.
Star B
c.
Star C
d.
Star D
e.
Star E
 
 
Figure 6-2

studyguide1-20_files/i0370000.jpg
 

 35. 
In the diagram in Figure 6-2 above, which of the transitions would absorb a photon with the greatest energy.
a.
Transition 1
b.
Transition 2
c.
Transition 3
d.
Transition 4
e.
Transition 5
 

 36. 
You are standing near a railroad track and a train is moving toward you at 60 mph and blowing its horn. What will you notice as the train moves past you?
a.
As the train approaches, the horn will sound lower in pitch than when the train is moving away.
b.
As the train approaches, the horn will sound higher in pitch than when the train is moving away.
c.
There will be no change in the pitch of the horn as it moves by.
d.
The horn will get louder as the train moves away from you.
e.
The horn will get quieter as the train moves toward you.
 

 37. 
Why don't we see hydrogen Balmer lines in the spectra of stars with temperatures of 45,000 K?
a.
There is no hydrogen in stars this hot.
b.
The stars are hot enough that most of the hydrogen is ionized and the atoms can not absorb energy.
c.
These stars are so cool that nearly all of the electrons in the hydrogen atom are in the ground state.
d.
Stars of this temperature are too cool to produce an absorption spectrum.
e.
Stars of this temperature are too hot to produce an absorption spectrum.
 
 
Table 6-1

Star Name
Spectral Type
a For
F8
o Cet
M7
35 Ari
B3
g Tri
A0
x Per
O7
 

 38. 
Table 6-1 above lists the spectral types for each of five stars. Which star in this table would have the greatest surface temperature?
a.
a For
b.
o Cet
c.
35 Ari
d.
g Tri
e.
x Per
 

 39. 
At what wavelength would a star radiate the greatest amount of energy if the star has a surface temperature of 60,000 K?
a.
50 nm
b.
500 nm
c.
300 nm
d.
1.8 ´ 1011 nm
e.
180 nm
 

 40. 
The sun has a surface temperature of approximately 5800 K. At what wavelength does the maximum energy radiated by the sun occur?
a.
5800 nm
b.
300 nm
c.
174 nm
d.
520 nm
e.
3000 nm
 

 41. 
One star has a temperature of 30,000 K and another star has a temperature of 6,000 K. Compared to the cooler star, how much more energy per second will the hotter star radiate from each square meter of its surface?
a.
5 times
b.
25 times
c.
8.1 ´ 1017 times
d.
625 times
e.
1.3 ´ 1015 times
 

 42. 
The Hg line has a wavelength of 434.0 nm when observed in the laboratory. If the Hg line appears in a stars spectrum at 434.5 nm, what is the radial velocity of the star?
a.
346 km/sec away from the observer.
b.
346 km/sec toward the observer.
c.
1.3 ´ 108 m/sec away from the observer.
d.
1.3 ´ 108 m/sec toward the observer.
e.
The radial velocity of the star can not be determined from this information.
 

 43. 
A filtergram is a photograph of the sun's surface made
a.
in a band of wavelengths in the infrared.
b.
in a band of wavelengths in the ultraviolet.
c.
using the Zeeman effect.
d.
with only those photons emitted in a specific spectral line.
e.
none of the above
 

 44. 
Which of the following is evidence that convection occurs in the layers just below the sun's photosphere?
a.
Sunspots appear to be cooler than their surroundings.
b.
Solar prominences lift large loops of gas into the chromosphere and corona.
c.
The solar wind emits large numbers of charged particles.
d.
The sun rotates differentially.
e.
The centers of granules are hot and moving away from the center of the sun.
 
 
Figure 7-1

studyguide1-20_files/i0490000.jpg
 

 45. 
The diagram in Figure 7-1 above shows a plot of the temperature of the sun as a function of distance above the bottom of the photosphere. At what distance above the bottom of the photosphere does the temperature of the sun change the most rapidly with distance?
a.
1,000 km
b.
2,300 km
c.
2,500 km to 4,000 km
d.
400 km
e.
a and c
 

 46. 
The diagram in Figure 7-1 above shows a plot of the temperature of the sun as a function of distance above the bottom of the photosphere. What is the temperature of the sun at a distance of 2,000 km?
a.
500 K
b.
900 K
c.
5,000 K
d.
9,000 K
e.
100,000 K
 

 47. 
Sunspots
a.
are cooler than their surroundings.
b.
are regions where material is rising from below the photosphere.
c.
are the result of convection.
d.
produce spicules.
e.
are generally found near the poles of the sun during sunspot maximum.
 

 48. 
The __________ is (are) the hot gases that are the moving extension of the sun's corona.
a.
spicules
b.
prominences
c.
flares
d.
supergranules
e.
solar wind
 

 49. 
The corona of the sun can be observed
a.
during a lunar eclipse.
b.
with a coronagraph.
c.
using filtergrams.
d.
a and b above
e.
with none of the above
 

 50. 
In the proton-proton chain
a.
no neutrinos are produced.
b.
energy is released because a helium nucleus has a greater mass than a hydrogen nucleus.
c.
no photons are produced.
d.
carbon serves as a catalyst for the nuclear reaction.
e.
energy is produced in the form of gamma rays and the velocity of the created nuclei.
 

 51. 
If a sunspot has a temperature of 4,500 K and the surrounding solar surface has a temperature of 5,800 K, how many times brighter is the surface compared to the sunspot?
a.
0.28
b.
0.36
c.
2.8
d.
3.6
e.
36
 

 52. 
If the spectrum of a sunspot shows that it has a maximum intensity at 650 nm, what is the temperature of the sunspot?
a.
650 K
b.
5000 K
c.
1950 K
d.
4600 K
e.
10,000 K
 

 53. 
Sheat is an M2 II star. Based on this information which of the following are true?

I.
Sheat has a surface temperature less than the sun.
II.
Sheat has a diameter that is greater than that of the sun.
III.
Sheat is more luminous than the sun.
IV.
Sheat is located near the upper left hand corner in the HR diagram.
a.
I & II
b.
II & IV
c.
II, III, & IV
d.
I, II, & III
e.
I, II, III, & IV
 
 
Figure 8-1

studyguide1-20_files/i0590000.jpg
 

 54. 
Which star in Figure 8-1 above has the greatest surface temperature?
a.
Alnilam
b.
Antares
c.
Arcturus
d.
HR 5337
e.
Sirius B
 

 55. 
An eclipsing binary will
a.
be more luminous than a visual binary.
b.
always be a spectroscopic binary.
c.
give off most of its light in the infrared.
d.
show a constant Doppler shift in its spectral lines.
e.
show two stars with variable proper motion.
 

 56. 
The diagram below illustrates two stars in a visual binary system and the center of mass of this system. Based on this diagram, what is the ratio of the mass of star A to the mass of star B?

studyguide1-20_files/i0620000.jpg
a.
2 to 1
b.
1 to 2
c.
2 to 3
d.
3 to 2
e.
1 to 3
 

 57. 
An eclipsing binary has been analyzed and it has been determined that the ratio of the mass of star A to the mass of star B is 6 and the total mass of the two stars is 26 solar masses. What are the masses of star A and star B.
a.
Star A has a mass of 1 solar mass and star B has a mass of 6 solar masses.
b.
Star A has a mass of 20 solar mass and star B has a mass of 6 solar masses.
c.
Star A has a mass of 31.2 solar mass and star B has a mass of 5.2 solar masses.
d.
Star A has a mass of 22.3 solar mass and star B has a mass of 3.7 solar masses.
e.
The masses of star A and star B cannot be determined from the information given.
 

 58. 
What is the total mass of a binary star system with P = 20 yr and a = 10 AU?
a.
2 solar masses
b.
2.5 solar masses
c.
0.5 solar mass
d.
80 solar masses
e.
0.4 solar mass
 

 59. 
The diagram below shows the radial velocity curve of a double-line spectroscopic binary. Based on this radial velocity curve, which of the following statements is correct?

studyguide1-20_files/i0650000.jpg
a.
Star A is twice the mass of star B.
b.
Star B is twice the mass of star A.
c.
Star A is ten times the mass of star B.
d.
Star B is ten times the mass of star A.
e.
Star A and Star B have the same mass.
 
 
Table 8-1


Star

mv

Mv

d (pc)
Parallax
(sec of arc)
Spectral
Type
65 Tau
4.2
  
0.025
A7 IV
HR 4621
2.6
-0.3
  
B2 IV
a Pic
 
1.8
20
 
A7 V
58 Ori
 
-6.0
 
0.005
M2 I
HR 2491
-1.5
 
2.5
 
A1 V
 

 60. 
Which star in Table 8-1 above has the greatest luminosity?
a.
65 Tau
b.
HR 4621
c.
a Pic
d.
58 Ori
e.
HR 2491
 

 61. 
Which star in Table 8-1 above has the greatest diameter?
a.
65 Tau
b.
HR 4621
c.
a Pic
d.
58 Ori
e.
HR 2491
 
 
Table 8-2


Star

d (pc)
Parallax
(sec of arc)
Spectral
Type
d Cen
 
0.026
B2 IV
HR 4607
 
0.039
G8 III
HR 4758
20
 
G0 V
HD 39801
 
0.005
M2 I
9 CMa
2.5
 
A1 V
 

 62. 
Which star in Table 8-2 above is the closest to Earth?
a.
d Cen
b.
HR 4607
c.
HR 4758
d.
HD 39801
e.
9 CMa
 

 63. 
Protostars are difficult to observe because
a.
the protostar stage is very short.
b.
they are surrounded by cocoons of gas and dust.
c.
they radiate mainly in the infrared.
d.
all of the above
e.
they are all so far away that the light hasn't reached us yet.
 

 64. 
__________ are small luminous nebulae excited by nearby young stars.
a.
T Tauri stars
b.
Herbig-Haro objects
c.
O associations
d.
Bok Globule
e.
Giant molecular clouds
 

 65. 
__________ is the thermonuclear fusion of hydrogen to form helium operating in the cores of massive stars on the main sequence.
a.
The CNO cycle
b.
The proton-proton chain
c.
Hydrostatic equilibrium
d.
The neutrino process
e.
none of the above
 

 66. 
The diagram below is an HR diagram. The line indicates the location of the main sequence. Which of the five labeled locations on the HR diagram indicates a luminosity and temperature similar to that of a T Tauri star?

studyguide1-20_files/i0740000.jpg
a.
1
b.
2
c.
3
d.
4
e.
5
 

 67. 
The carbon-nitrogen-oxygen cycle
a.
operates at a slightly lower temperature than the proton-proton chain.
b.
is most efficient in star less massive than the sun.
c.
occurs when carbon and oxygen combine to form nitrogen, which produces energy.
d.
produces the energy responsible for bipolar flows.
e.
combines four hydrogen nuclei to form one helium nucleus, which produces energy.
 

 68. 
The free-fall contraction of a molecular cloud
a.
can be initiated by shock waves from supernovae.
b.
can be initiated by nearby spectral type G stars.
c.
can be initiated by the rotation of the cloud.
d.
causes the cloud to become transparent to ultraviolet radiation.
e.
causes the particles in the cloud to decrease the speed with which they move.
 

 69. 
__________ occurs when most of the material collapsing to form a protostar has fallen into a disk around the star and a strong wind from the warm protostar ejects material from its poles.
a.
An emission nebula
b.
Hydrostatic equilibrium
c.
The proton-proton chain