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49 Cards in this Set
- Front
- Back
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Based on the galaxies found in the Local Group of galaxies, the most common type of galaxy in the universe is
expected to be a. the spiral galaxies. b. the barred spiral galaxies. c. the dwarf elliptical galaxies. d. the irregular galaxies. e. the giant elliptical galaxies. |
c. the dwarf elliptical galaxies.
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A megaparsec is equivalent to
a. 3.26 light-years. b. 206,265 light years. c. 206,265 AU. d. 3,260,000 light-years. e. the diameter of the Milky Way galaxy. |
d. 3,260,000 light-years.
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The most massive galaxies are
a. spiral galaxies. b. giant elliptical galaxies. c. dwarf elliptical galaxies. |
b. giant elliptical galaxies
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The most luminous galaxies are
a. giant elliptical galaxies. b. spiral galaxies. c. dwarf elliptical galaxies. |
b. spiral galaxies
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Most of the mass of a galaxy is
a. contained in the massive O and B stars in the galaxy. b. contained in the H I regions of the galaxy. c. contained in the H II regions of the galaxy. d. contained in the dark matter of the galaxy. e. contained in the disk of the galaxy. |
d. contained in the dark matter of the galaxy.
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Super massive black holes in galaxies
a. are found in their centers b. have masses proportional to the galaxy’s bulge mass. c. cause stars near them to move at high speeds. d. all of the above |
d. all of the above
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The look-back time is
a. how long the light from an object takes to reach Earth. b. numerically equal to the distance in light-years. c. smaller for more distant objects. d. all of the above e. a and b above |
e. a and b above
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____________ is an irregular galaxy that is believed to have collided with the Milky Way and is expected to
merge with the Milky Way in the future. a. The Andromeda galaxy b. The Small Magellanic Cloud c. M87 d. The Virgo cluster e. The Whirlpool |
b. The Small Magellanic Cloud
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The Milky Way galaxy is part of
a. the Virgo cluster. b. the Large Magellanic Cloud. c. the Small Magellanic cloud. d. the Local Group. e. a rich cluster. |
d. the Local Group
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What type of galaxies do astronomers believe to be the most common?
a. Elliptical b. Spiral c. Irregular d. Astronomy have no idea which type of galaxy is more common. |
a. Elliptical
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We suspect that quasars are the active centers of galaxies because
a. quasar fuzz produces stellar spectra. b. a few quasars have large red shifts. c. some quasars fluctuate rapidly. d. all of the above e. none of the above |
a. quasar fuzz produces stellar spectra.
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When we observe quasars to have large red shifts, we are seeing them as they
a. are now b. will be in the future c. were in the past |
c. were in the past
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What is the major observational difference between a Seyfert galaxy and a normal spiral galaxy?
a. Normal spiral galaxies usually have shorter spiral arms. b. Normal spiral galaxies never contain a supermassive black hole at their center. c. The central region of a Seyfert galaxy is much brighter. d. Seyfert galaxies don’t contain any star formation. |
c. The central region of a Seyfert galaxy is much brighter.
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Voids are
a. regions in an elliptical galaxy where few clouds of gas and dust are found. b. regions in the Local Group where light from distant galaxies is blocked by gas and dust. c. regions in a cluster of galaxies where no spiral galaxies are found d. regions in the universe that separate the filaments of superclusters. e. regions swept clean by the hot intergalactic medium |
d. regions in the universe that separate the filaments of superclusters.
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The assumption of isotropy states that
a. the universe looks the same at all epochs. b. the universe looks the same in all locations. c. the universe looks the same in all directions. d. all of the above e. none of the above |
c. the universe looks the same in all directions.
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The ______________ proposes that matter was created continuously so that the density of the universe never
changes as the universe expands. a. open big bang theory b. flat big bang theory c. closed big bang theory d. steady state theory e. inflationary universe theory |
d. steady state theory
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The age of the universe can be determined if
a. the universe is flat. b. the amount of dark matter in the universe can be accurately determined. c. the rate of recession of the galaxies in the Local Group can be accurately determined. d. the temperature of the cosmic background radiation can be accurately determined. e. the Hubble constant and density of the universe can be accurately determined |
e. the Hubble constant and density of the universe can be accurately determined.
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The universe is said to be closed if
I. gravity is strong enough to stop the expansion in a finite time. II. the density of the universe is less than the critical density. III. the universe is finite. a. I & II b. I & III c. II & III d. I, II, & III e. none of the above |
b. I & III
I. gravity is strong enough to stop the expansion in a finite time. III. the universe is finite. |
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The best scientific data and models suggest that the universe is
a. open, expanding, and accelerating. b. open, expanding, but decelerating. c. closed, expanding, and accelerating. d. closed, expanding, but decelerating. e. flat, expanding, and accelerating. |
e. flat, expanding, and accelerating.
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What evidence supports an acceleration in the expansion rate of the universe?
a. the discovery of super massive black holes at the center of quasars b. the discovery that type Ia supernova in distant galaxies are 25 percent fainter than expected. c. the discovery of MACHOs d. the discovery of the grand unified theory e. none of the above |
b. the discovery that type Ia supernova in distant galaxies are 25 percent fainter than expected.
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What observational evidence supports the fact that our universe is expanding?
a. Detection of the cosmic microwave background (CMB) b. Discovery of quasars c. Redshift of galaxies d. Evolution of galaxies with distance |
c. Redshift of galaxies (all of the galaxies were observed to exhibit red shifts, meaning they are moving away).
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Which of the following is not an assumption of cosmology?
a. Isotropy b. Universality c. Congruency d. Homogeneity |
c. Congruency
three basic assumptions in cosmology: I. Homogeneity- the assumption that matter is uniformly spread throughout space II. Isotropy- the assumption that the universe looks the same in every direction III. Universality - the assumption that the physical laws we know on Earth apply everywhere. |
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Homogeneity is the assumption that the universe looks the same in all directions.
True or False |
b. False - that is Isotropy
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The cosmological principle states that any observer, in any galaxy, will see the same general features of the
universe. True or False |
True
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Most of the elements heavier than helium were made during the first few minutes after the big bang.
True or False |
False
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If the average density of the universe is less than the critical density, the universe is open.
True or False |
True
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The rate of expansion of the universe is currently increasing.
True or False |
True
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A light-year is the distance light travels in one year.
True or False |
True
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Hipparchus devised the magnitude system in the late 1700’s.
True or False |
False
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The moon and visible planets are always within a few degrees of the ecliptic.
True or False |
True
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The force due to gravity has the mathematical form: F=-GMm/r^2
True or False |
True
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Light can behave as a particle or as a wave.
True or False |
True
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The largest optical telescope ever constructed was a refracting telescope.
True or False |
False
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The light-gathering power of a telescope increases as the size of the objective increases.
True or False |
True
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Granulation on the Sun is caused by rising currents of hot gas below the photosphere.
True or False |
True
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Sunspots are hotter than the photosphere.
True or False |
False
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Solar flares have no known effect on the Earth.
True or False |
False
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Solar prominences have twisted and looped shapes because of the solar magnetic field.
True or False |
True
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The energy emitted by the sun comes from chemical rather than nuclear reactions.
True or False |
False
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The element most abundant in the Sun is oxygen.
True or False |
False
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With the exception of the solar wind, the corona is the outermost region of the Sun’s atmosphere.
True or False |
True
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The sun will eventually become a supernova.
True or False |
False
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A nova destroys the star and leaves behind a white dwarf.
True or False |
False
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Because massive stars have more gravitational energy than the sun, they can fuse heavier nuclear fuels.
True or False |
True
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The average size of a white dwarf is about the same size as the Earth.
True or False |
True
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We expect neutron stars to spin rapidly because they conserve angular momentum.
True or False |
True
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Pulsars could not be pulsating stars because the pulses are too short.
True or False |
True
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Rotating black holes are called Kerr black holes.
True or False |
True
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When a star, of mass comparable to the Sun, dies it become a black hole.
True or False |
False
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