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6. Cepheid variable stars could be used to determine distance after Henrietta Leavitt established a
correlation between_____________________________ using a sample of these stars found in
the Magellanic Clouds.
A. luminosity and absolute magnitude
B. apparent and absolute magnitudes
C. red shift and velocity of recession
D. period of variation and luminosity
E. mass and radius
7. In order for a solar eclipse to occur the phase of the moon must be
A. new
B. crescent
C. quarter
D. gibbous
E. full
8. At night we see different constellations during different seasons. This happens because
A. the Earth rotates on its axis.
B. the Earth precesses on its axis.
C. the Earth orbits the Sun.
D. the Earth is round.
E. the stars are much more distant than the Sun.
9. Cygnus X-1 is a good black hole candidate. Astronomers know a lot about this object because
it is also
A. a neutron star.
B. a pulsar.
C. in a binary system.
D. in a star cluster.
E. in our Solar System.
10. Electron pressure balances gravity in which kind of star?
A. main sequence star
B. protostar
C. red giant
D. supergiant
E. white dwarf
11. The 65 million year old Iridium layer observed all over the world is cited as support for
A. the formation of the Moon.
B. continental drift.
C. magnetic reversal.
D. a large asteroid impact.
E. the presence of an atmosphere rich in oxygen.
17. Why is it highly likely that if life exists elsewhere in the universe that it will be based on
carbon chemistry?
A. Carbon dioxide is the main ingredient of all planetary atmospheres.
B. Carbon is versatile in forming complex, long-chain molecules.
C. No other atom can combine easily with hydrogen and helium, the most abundant
elements in the universe.
D. Most rocks on Earth’s surface are composed primarily of carbon.
E. Carbon has been detected in the atmospheres of all of the extrasolar planets.
18. When a planet is at opposition, it can
A. never be seen from the Earth.
B. only be seen briefly after sunset.
C. only be seen briefly after sunrise.
D. be seen for the entire night.
E. sometimes be seen to transit the Sun.
19. The Sun will spend the longest period of its life as a
A. Big Mac.
B. red giant.
C. protostar.
D. pulsar.
E. main sequence star.
20. When satellite telescopes discover strong X-ray sources in the sky, astronomers know that
the X-rays aren’t coming from ordinary stars because
A. stars are not hot enough to emit many X-rays.
B. stars are too hot to emit many X-rays.
C. X-rays can only be produced by explosions.
D. stars do not rotate fast enough to produce X-rays.
E. stars are not red shifted enough to produce X-rays.
21. A huge number of impact craters are observed on the Moon, but relatively few exist on Earth.
Why?
A. All meteors burn up in the Earth’s atmosphere.
B. The Moon’s gravity is too weak to deflect any meteors.
C. The Moon lacks erosion and geological activity.
D. The Earth is differentiated but the Moon isn’t.
E. The Earth has a magnetic field, which deflects the impacting bodies.
22. If Pluto were discovered today, the majority of astronomers would conclude based on its
composition and orbit that it was most like
A. a terrestrial planet.
B. a jovian planet.
C. a member of the Oort Cloud.
D. a Kuiper Belt Object.
E. an asteroid.
23. A gigantic outburst of energy and particles occurred on the Sun this morning. Mrs. Deming
was excited and told her ASTR 101 class to look for
A. a full moon tonight.
B. an eclipse.
C. a meteor shower if it is clear.
D. an aurora if it is clear.
E. dangerous cosmic rays.
24. Which of the following changes occurs immediately after the development of a hydrogen
burning shell inside a star like the Sun?
A. The star collapses to a neutron star and then it blows up.
B. The star ejects a planetary nebula and new planets form.
C. The star emits strongly in the infrared and becomes a protostar.
D. The star’s outer layers expand and cool as it becomes a red giant.
E. A black hole forms.
25. Which of the following lists is correctly arranged in order of increasing density?
A. Jupiter, the Moon, Earth, a white dwarf, a neutron star
B. the Moon, Earth, a white dwarf, Jupiter, a neutron star
C. a neutron star, the Moon, Jupiter, Earth, a white dwarf
D. the Moon, Earth, Jupiter, a neutron star, a white dwarf
E. Jupiter, a neutron star, a white dwarf, the Moon, Earth
26. Standing on the surface of Venus, you would experience
A. violent sulfuric acid rain storms.
B. darkness all of the time.
C. tremendous crushing atmospheric pressure.
D. a drastic temperature drop when night occurs.
E. all of the above.
27. Planets near the Sun are composed of mainly rock and iron. How does the Solar Nebula
theory account for this?
A. The Sun’s magnetic field attracted all of the iron in the nebula into the inner Solar
System.
B. The forming Sun’s heat prevented substances such as ices from condensing in the
inner Solar System.
C. The planets that today are far from the Sun were captured.
D. The planets that today are near the Sun were captured.
E. As the planets were captured, denser ones were pulled closer to the Sun by gravity.
28. A comet’s gas tail results when
A. part of the comet drifts in the direction opposite to the comet’s motion.
B. the solar wind pushes some of the coma in the direction away from the Sun.
C. gravitational forces pull loosely held material from the Sun toward the comet.
D. tidal forces tear apart the comet.
E. the comet nears aphelion.
29. Which type of binary star is useful in finding the radii of stars?
A. visual binaries
B. spectroscopic binaries
C. eclipsing binaries
D. composite spectrum binaries
E. optical binaries
30. A study of the spectrum provides information on a star’s
A. radial motion.
B. composition.
C. temperature.
D. all of the above.
E. only answers A and B
31. In order to use Hubble’s Law to determine the distance to a galaxy, which observation and
analysis are required?
A. take photographs separated by 6 months & measure the angular shift
B. take photographs & measure the galaxy’s apparent brightness
C. take the spectrum & measure the galaxy’s average temperature
D. take the spectrum & measure the redshift to determine the galaxy’s velocity of
recession
E. take the spectrum & measure the widths of the hydrogen lines to determine the
galaxy’s size
32. A spiral galaxy is identified. Its angular diameter is only 1/10 that of the Andromeda Galaxy.
If the distance to the Andromeda Galaxy is 2 million light years and assuming that the identified
spiral is approximately the same physical size as the Andromeda Galaxy, estimate the spiral
galaxy’s distance.
A. 0.2 million light years
B. 2 million light years
C. 4 million light years
D. 20 million light years
E. 40 million light years
33. Edwin Hubble classified galaxies based on
A. their distances.
B. their ages.
C. their visible appearance.
D. their masses.
E. their temperatures.
34. The latest observations made by astronomers suggest
A. that the Universe is beginning to contract.
B. that the expansion of the Universe is accelerating.
C. that the Universe’s expansion has stopped.
D. that time is slowing down.
E. that time is speeding up.
40. Based on observations of other spiral galaxies like our Milky Way Galaxy, astronomers
estimate that supernovae occur once or twice a century. The last supernova in our galaxy
occurred in 1604. What’s the problem?
A. Our galaxy does not have star formation taking place today, so there are no young
stars blowing up.
B. Our galaxy has a high abundance of heavy elements already.
C. We cannot see the entire galaxy due to the presence of interstellar dust.
D. They go off when we’re not watching so we miss them.
E. No stars are older than the Sun in our galaxy, but other galaxies are older so there are
more supernovae.
41. The neutrons and protons in an atom are held together by
A. gravity.
B. the strong nuclear force.
C. the weak nuclear force.
D. their attractive electromagnetic force.
E. their repulsive electromagnetic force.
42. Synchrotron radiation is produced by
A. only objects with temperatures below 1,000 Kelvin.
B. high velocity electrons moving in a strong magnetic field.
C. cold hydrogen atoms in space.
D. the collapsing cores of massive stars.
E. the helium flash.
43. In the last lab (it was a computer lab) dealing with the expansion of the universe, you
estimated the age of the universe using
A. Hubble's constant.
B. the Gravitational constant.
C. Cepheid variables.
D. an HR Diagram.
E. the Doppler ball.
44. Many clusters of galaxies contain a few gigantic elliptical galaxies among the thousands of
smaller ones. A current theory proposes that these gigantic galaxies are the result of
A. mergers of smaller galaxies.
B. gas and dust from the Big Bang coming to rest in these galaxies.
C. the evolutionary expansion of galaxies in a cluster.
D. the expansion of the universe.
E. magnification by gravitational lenses.
45. Which of the following correctly lists objects in terms of increasing distance from Earth?
A. Pluto, Sun, Andromeda galaxy, Orion Nebula
B. Sun, Orion Nebula, Pluto, Andromeda galaxy
C. Orion Nebula, Sun, Pluto, Andromeda galaxy
D. Sun, Pluto, Orion Nebula, Andromeda galaxy
E. Sun, Orion Nebula, Andromeda galaxy, Pluto
46. The rotation curves for the Milky Way and other spiral galaxies are unusual.
observations are interpreted as support for
A. the presence of dark mater in the halo of these galaxies.
B. the presence of a supermassive black hole at the center of these galaxies.
C. the dominance of matter over antimatter in these galaxies.
D. the dominance of antimatter over matter in these galaxies.
E. a universe that is 13.7 billion years old.
These
47. If there are five objects of the same size that have different temperatures, the hottest object
would be the one emitting the greatest number of
A. radio photons.
B. red photons.
C. blue photons.
D. ultraviolet photons.
E. X-ray photons.
48. Your latitude on Earth is also the altitude of
A. the zenith.
B. the nadir.
C. the celestial pole.
D. the celestial equator.
E. the ecliptic.
49. The Earth's Moon is said to be in synchronous rotation. Which of the following is a
consequence of this property?
A. The same side of the Moon always faces Earth.
B. The Moon orbits the Earth once every 24 hours.
C. The motion of the Moon is synchronized with the motions of the moons of the
other planets.
D. The phases of the Moon are synchronized with Earth's year.
E. The far side of the Moon is always dark.
50. According to Einstein’s theory of general relativity, the gravitational force results from
A. pressure exerted by radiation.
B. interatomic forces between masses.
C. curvature of space by mass.
D. the expansion of the universe.
E. the relative weights of the objects involved.
SHORT ANSWER QUESTIONS (50 pts.)
Please answer each of the following questions as completely as you can using what you have
learned in ASTR 101. After you have finished a part, please go back and re-read the question, to
make sure you have answered what was asked.
51. Two types of black holes were discussed in this class.
a) A black hole in a binary star system has a mass of 10 solar masses. What is the radius of its
event horizon? GIVE THE EQUATION AND SHOW YOUR WORK. (4 pts.)
b) The model developed in class of active galaxies used a supermassive black hole in
explaining how X-rays are produced. Describe this model and include a labeled sketch. (6 pts.)
c) The brilliant planet visible during the early evening is ________________________.
In which direction do you need to look to see this planet in the early evening? (2 pts.)
52. a) Explain why it is warmer now in College Park than it was in January when the semester
began. (4 pts.)
b) What do astronomers mean when they say “the universe is expanding?” Explain. (4 pts.)
EXTRA CREDIT (2 pts.)
You look at a Hubble Space Telescope photo. In the center of the photo you see a cluster of
galaxies. Describe the appearance of any foreground stars.
53. a) Explain why astronomers in the eighteenth and nineteenth centuries had difficulty in
determining the position of our Solar System in the collection of stars today known as the Milky
Way Galaxy. (4 pts.)
b) Radio astronomers have mapped the galaxy using 21 cm radiation. What produces 21 cm
radiation? Describe carefully how this radiation is produced. (6 pts.)
EXTRA CREDIT (2 pts.)
Who was Charles Messier and what was his main contribution to astronomy?
54. a) How did Hubble determine the distance to the Andromeda galaxy? Describe his method
and observations. (5 pts.)
b) How did Hubble determine the relation known as Hubble’s Law? Describe his observations
and the results. (5 pts.)
55. a) Explain why the discovery of the Cosmic Background Radiation supports the Big Bang
Theory. (4 pts.)
b) Where in our Solar System besides Earth is the most likely place to search for life (current or
past life)? Choose 1 place and support your choice. (6 pts.)
Extra Credit (4 pts.) Today is new moon. When would be the next opportunity to easily see the
moon? Where would you look? (Give a direction and time—“In the sky at night” isn’t good
enough!)