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Astronomy 1 Final Sample NAME:______

Part I: Multiple Choice (2 points. ea.) Choose the best answer for each question Questions 1-5 refer to the schematic model of the shown at right

___1. Globular clusters and stars in the A

___2. The Sun’s location in the galaxy

___3. The disk

A ___4. The B C

E ___5. The Galactic nucleus D

___6. Why are HII regions red in color? (A) They contain considerable quantities of dust (B) They emit emission lines (C) They are moving away from us at high speed (D) Twenty-one cm photons are red in color

___7. We cannot see the other side of the galaxy primarily because our view is blocked by (A) too many stars. (B) glowing interstellar gas. (C) planetary nebulae and supernova remnants. (D) interstellar dust.

___8. What effect do interstellar dust particles have on the appearance of a distant star? (A) They make it look bluer and brighter. (B) They make it look bluer and dimmer. (C) They make it look redder and brighter. (D) They make it look redder and dimmer.

___9.The Milky Way is (A) a gas cloud in the solar system. (B) a gas cloud in the galaxy of which the sun is a member. (C) the galaxy of which the sun is a member. (D) a nearby galaxy.

1/13 Astronomy 1 Final Sample ___10. What did Harlow Shapley discover about globular clusters that allowed him to determine the size of the galaxy and the Sun’s location within it? (A) The clusters are confined to a thin plane. (B) The clusters are all located at the same distance from the Sun. (C) The center of the distribution of clusters is far from the Sun. (D) All of the clusters are located in a region a few parsecs across.

___11. The mass of the galaxy has been found by (A) Counting the stars it contains (B) Determining its gravitational force on nearby (C) Estimating the number of interstellar clouds it contains (D) Applying Kepler's laws to the Sun's orbit about the galaxy

___12. Where are stars being formed in the galaxy? (A) In the spiral arms. (B) In globular clusters. (C) In the nucleus. (D) In the halo.

___13. Which of the following is a true statement about the spiral arms of our galaxy? (A) Spiral arms are the crests of density waves. (B) occurs in the spiral arms. (C) They contain H II powered by the ultraviolet light from hot O and B stars (D) all of the above

___14. Hubble's original classification of galaxies was based on (A) the visual appearance of the galaxies. (B) the physical shape and size of the galaxies. (C) the dominant spectral class of stars. (D) a completely random selection.

___15. Elliptical galaxies are yellowish/reddish in color because they (A) Shine due to synchrotron radiation (B) Contain relatively few young, hot stars (C) Are moving away faster than other galaxies (D) Are surrounded by intergalactic dust clouds

___16. Which of the following is not one of the main categories for the classification of galaxies? (A) irregular (B) elliptical (C) spiral (D) orthogonal

2/13 Astronomy 1 Final Sample ___17.The masses of galaxies are often determined by (A) Determining their star formation rates. (B) Counting their stars. (C) Measuring their tidal forces on the Milky Way. (D) Measuring their rotation curves.

___18. What evidence do we have that galaxies have extended haloes of dark matter? (A) Orbital speed in the rotation curve doesn’t fall off for the outer parts of galaxies. (B) The outer parts of galaxies are intense infrared sources. (C) Light from background galaxies is blocked by the dark matter. (D) The orbits of distant globular clusters are distorted by the dark matter

___19. How was Hubble able to determine the distances of nearby galaxies? (A) by observing Cepheid variables in them (B) by measuring the typical angular separations of stars in them (C) by using radar (D) by measuring trigonometric parallaxes

___20. Hubble’s relationship between the distance to a galaxy and its speed of recession is interpreted as evidence for (A) the expansion of the . (B) galaxies being outside the Milky Way. (C) the evolution of galaxies. (D) the Doppler effect.

___21. Which of the following is true of Seyfert galaxies? (A) They have no spiral arms (B) They have unusually bright nuclei (C) They are a form of (D) They are all found in the Local Group of galaxies

___22. For a typical luminous , the radio emission comes primarily from (A) the central few hundred parsecs of the galaxy (B) large lobes on opposite sides of the visible galaxy. (C) a large halo with a radius of about ten kiloparsecs. (D) the disk, where most of the stars are concentrated

___23. Some quasars vary in brightness in only a few days. What does this tell us about the quasars? (A) They have large magnetic fields (B) They are quite small (C) They must be highly luminous (D) They cannot emit radio waves

___24. Since quasars are thought to be at cosmological distances, we see them as they were when (A) the universe was much older than it is today (B) the universe was relatively young (C) the universe was contracting (D) the universe was much larger than it is today

3/13 Astronomy 1 Final Sample ___25. According to current theories, the energy source of radio galaxies and quasars is (A) a one thousand solar mass pulsar in each of two radio lobes. (B) a one hundred million solar mass black hole accreting matter at the center of the object. (C) the conversion of hydrogen to helium via nuclear reactions. (D) gravitational contraction of massive stars near the spiral arms.

___26. The maximum luminosity that the nucleus of a galaxy could have without pushing away surrounding matter is called the (A) spiral density wave. (B) event horizon. (C) mass-luminosity relationship. (D) Eddington luminosity.

___27. The brightest quasars are (A) about 1% as bright as the Milky Way (B) as bright as the Milky Way (C) as bright as 10,000 Milky Way galaxies (D) about as bright as the Sun

___28 Quasars all have great distances. Why are there no nearby quasars? (A) No quasars have existed in the recent past. (B) Quasars avoid spiral galaxies. (C) Quasars are found only in clusters of galaxies. (D) If quasars are too close to us, they look like pulsars.

___29. Which of the following statements best describes the distribution of galaxies in the universe? (A) the galaxies lie on sheets and chains surrounding empty regions (B) the galaxies are distributed uniformly in space (C) there are a few large clusters of galaxies with nothing in between (D) there are many clusters near us in space, but nothing beyond

___30. The Local Group is: (A) a group of about 30-50 galaxies containing the Milky Way galaxy. (B) the local group of Population II stars in the solar neighborhood. (C) a large of galaxies centered on the Milky Way. (D) all stars within 10 pc. of the sun

___31. The richness of a cluster of a galaxies is a measure of (A) how many galaxies it contains. (B) its age. (C) its distance. (D) its redshift

___32. A cluster of galaxies is consider rich if (A) it contains more helium than hydrogen (B) it has a large number of galaxies (C) a large fraction of its mass consists of hot intergalactic gas (D) it contains numerous quasars

4/13 Astronomy 1 Final Sample ___33. The model of cluster formation in which clusters form first which then fragment to form galaxies is called the (B) implosion model. (C) hierarchical clustering model. (A) pancake model. (D) top-down model.

___34. The point in space towards which nearby clusters of galaxies appear to be moving is referred to as (A) “The Great Attractor”. (B ) “The Whole Shebang”. (C) “LGM”. (D) “The Big Crunch”.

___35.In which part of the sky is the cosmic background radiation brightest? (A) equally bright in all parts of the sky. (B) toward the Virgo cluster (C) toward the center of the universe (D) toward the spot where the took place

___36. Which of the following is not true of the cosmic background radiation? (A) it is nearly equally bright in all directions (B) it came from glowing gas at the time the universe became transparent. (C) it is currently brightest in the radio (microwave) part of the spectrum (D) it is starlight

___37. Which of the following is NOT an implication of Hubble's law? (A) the universe is expanding. (B) we are in the center of the universe. (C) the universe had a beginning. (D) the universe was once denser than it now is

___38. The expansion age of the universe is about (A) 12 to 14 million years. (B) 12 to 14 billion years. (C) 120 to 140 billion years. (D) 1200 to 1400 billion years.

___39. What was the universe made of one hour after it began to expand? (A) hydrogen and helium (B) and (C) iron and nickel (D) potassium and carbon

5/13 Astronomy 1 Final Sample ___40. The conversion of hydrogen into helium began about 2 minutes after the beginning of the expansion of the universe. Why was there no helium in the universe during the first 2 minutes? (A) There was no matter in the universe during the first 2 minutes. (B) Collisions were too violent for helium to be stable during that time. (C) No collisions occurred during the first two minutes. (D) Neutrino disruption dominated during the first two minutes.

___41. What evidence do we have for the existence of “dark energy”? (A) It blocks our view of distant parts of the universe. (B) The universe contains more light than has ever been emitted by stars. (C) Expansion seems to be accelerating. (D) We see the cosmic background radiation in all directions.

___42. Where in the universe did the Big Bang occur? (A) very close to the Milky Way galaxy (B) at the center (C) near the Virgo cluster. (D) everywhere.

___43. Imagine that a year from now you read that astronomers have discovered a group of 50 billion-year-old stars. What would you conclude from such a discovery? (A) They must be spectral class O and B stars (B) They must be in a late stage of stellar evolution (C) We would have to revise our theories of stellar energy sources (D) Our present ideas on evolution of the universe are seriously in error

___44. Why have few planets with conditions considered habitable have been found so far? (A) Habitable planets are thought to be highly improbable. (B) Terrestrial planets at 1 AU distance are hard to detect with current technologies. (C) Giant planets usually create conditions that are unfavorable for terrestrial planets. (D) Very few solar systems are thought to have had suitable angular momentum to create terrestrial planets.

___45. The oldest fossils date from about how long after Earth formed? (A) 10 million years (B) 100 million years (C) 1 billion years (D) 10 billion years

___46. A “habitable zone” (A) is a region around a star where an earth sized planet could have liquid on its surface. (B) is a region on a particular planet where might exist comfortably. (C) is a region in the galaxy where alien civilizations have been detected by their radio emissions. (D) is the region in a supercluster where galaxy formation is currently taking place.

6/13 Astronomy 1 Final Sample ___47. Billions of years from now, the habitable zone of the solar system will not include the Earth but will include (A) Mars. (B) Mercury. (C) Venus. (D) the Moon.

___48. As with life on earth, we expect that life on other planets would most likely be chemically based upon (A) carbon and . (B) carbon and . (C) silicon and carbon. (D) carbon and water.

___49. The is (A) a relation between the distance of a galaxy and the red shift in its spectrum. (B) a description of the expansion of the universe. (C) a relationship between the size of a neutron star and its radius. (D) an attempt to estimate the probability of finding .

___50. SETI stands for (A) Signal Enhancement Through Interferometry. (B) Search for Extraterrestrial Intelligence. (C) Satellite Examination of Technological Images. (D) Studies of Europa’s Tidal Icefields.

______(you’re half-way done!)______

___51.The point directly over an observer's head is that observer's (A) horizon. (B) zenith. (C) equator. (D) azimuth.

___52. During a night in Schuylkill Haven, the stars generally move (A) southward. (B) eastward. (C) westward. (D) the actual direction depends upon the season.

___53. The sun moves eastward among the stars at the rate of about one degree per (A) day. (B) week. (C) month. (D) year.

7/13 Astronomy 1 Final Sample ___54. The Sun's annual path on the celestial sphere is the ______which takes it through the ______. (A) Zenith, Planets. (B) Equator, Tropics. (C) Meridian, Celestial Poles. (D) Ecliptic, Zodiac.

___55. When does the most northernly sunrise occur? (A) autumnal equinox (B) vernal equinox (C) summer solstice (D) winter solstice

___56. A planet's temporary “backward” motion relative to the stars, illustrated at right, is called (A) retrograde motion. (B) the big crunch (C) closed geometry. (D) elliptical motion.

___57. Why did Tycho Brahe reject Copernicus's model of the solar system? (A) He could not detect stellar parallax (B) He could not detect retrograde motion for Mars (C) The ellipse had not been discovered yet (D) Tycho found mistakes in Copernicus's calculations

___58. Ptolemy used epicycles (illustrated at right) to explain (A) retrograde motion. (B) the equation of time. (C) circumpolar motion. (D) eclipses.

___59. Newton's great breakthrough in how he viewed the cosmos was that he (A) viewed gravity as a mysterious force between masses. (B) thought that natural motion was distinct from forced motion. (C) determined that the universe as infinite in extent. (D) applied the same physical laws in the sky and on Earth.

(for 60-63) Match the element of the Copernican model below with its observation consequence: A. Earth's motion around object. B. Motion of object around earth. C. Object overtakes Earth. D. Earth rotates.

60. The moon's monthly motion

61. Venus undergoing retrograde motion

62. The sun moves west to east along the ecliptic

63. The sun moves east to west daily

8/13 Astronomy 1 Final Sample ___64. If the distance between two objects is increased, the force of gravity they exert on each other will (A) remain the same (B) increase (C) decrease (D) vanish

___65. Which of the following principles from Optics are relevant to telescopes? (A) Refraction (light rays bend at interfaces). (B) Reflection (light rays bounce at surfaces). (C) Diffraction (light waves bend around corners). (D) all of the above

___66. Newton's theory of Universal Gravitation, combined with mechanics (A) was important because it described both earthly and cosmic phenomena using the same principles. (B) explained falling objects and projectile motion. (C) explained Kepler's Laws. (D) all of the above.

___67.The Doppler Effect is ______. (A) the speed of light divided by the frequency of the wave (B) the change in the wavelength divided by the change in the frequency (C) the change in frequency and wavelength of a wave due to motion between the source and observer (D) the decrease in wave intensity with increasing distance from the source

___68. The same telescope is used to obtain an image using light of the following wavelengths. Which of the images will have the poorest angular resolution? (A) Blue (shortest wavelengths) (B) Yellow (medium wavelengths) (C) Red (longer wavelengths) (D) Infrared (longest wavelengths)

___69. The age of the earth is estimated at roughly: (A) 4.6 trillion years. (B) 4.6 billion years. (C) 4.6 million years. (D) less than 6 thousand years.

___70. What is the origin of the Earth's magnetic field? (A) pockets of solar magnetism captured from the solar wind. (B) permanent magnetism left over from the formation of the Earth. (C) the flow of ionized gases in the Earth's upper atmosphere. (D) convection currents in the Earth's molten iron core which create an electric dynamo.

___71. The process by which gravitational forces separate material of different densities within the planetary interior is called (A) Subduction. (B) Homogenization. (C) Differentiation. (D) Transvection.

9/13 Astronomy 1 Final Sample ___72. How can craters tell us about the ages of surface regions of planets? (A) Impacts produce carbon 14, which can be dated by radioactive methods. (B) Material blasted from the craters sometimes reaches Earth and can be dated. (C) Craters shrink in size at a predictable rate (D) Crater density increases with time, so older surfaces have more craters.

___73. Both the moon and Mercury have very large temperature variations between day and night. The main reason for this large variation is: (A) lack of atmosphere. (B) rocky composition. (C) distance from the sun. (D) small mass.

___74. Why are there more craters on Mercury, than on Venus, Earth, and Mars? (A) more large scale surface activity enhance the cratering effect on Mercury. (B) Less large scale surface activity preserve the existing craters on Mercury. (C) More collisions with Meteors have occurred on Mercury's surface, compared with Venus, Earth, and Mars. (D) Larger volcanic eruptions have occurred on Mercury's surface, compared with Venus, Earth, and Mars

___75. Why does the thick atmosphere of Venus lead to a high temperature at its surface? (A) The atmosphere reflects most sunlight back into space. (B) High winds in the thick atmosphere generate frictional heating. (C) The atmosphere blocks the escape of infrared radiation from Venus. (D) There are heat-producing chemical reactions in Venus’s.

___76. In which of the following forms can water NOT exist on Mars today? (A) lakes (B) atmospheric ice crystals (C) underground ice deposits (D) atmospheric gas

___77. The Jovian planets (A) all have orbits larger than the orbit of Mars. (B) are the Jupiter-like planets. (C) have atmospheres containing mostly hydrogen and helium. (D) all of the above.

___78. The variation between pole and equatorial rotation rates for a Jovian planet (A) is called differential rotation. (B) is evidence that the planet is fluid. (C) has never actually been observed. (D) both (A) and (B) above.

10/13 Astronomy 1 Final Sample ___79. The chemical composition of Jupiter is closest to that of (A) The Earth (B) The Sun (C) Mars (D) The Moon

___80. The distance from a planet within which tides would tear a satellite apart is called the (A) Chandrasekhar limit. (B) Schwarzschild radius. (C) Roche limit. (D) Coriolis distance.

___81. Why are the inner Galilean satellites denser than the outer ones? (A) the outer ones contain more icy material. (B) the inner ones contain more iron. (C) the inner ones are larger. (D) the outer ones are made mainly of gas.

___82. Most of the asteroids have orbits that lie between the orbits of (A) Mars and Jupiter (B) Venus and the Earth (C) the Earth and Mars (D) Jupiter and Saturn

___83. Impact craters (A) appear to have never been produced on the Earth. (B) are observed only on the Moon (C) appear to be a widespread solar system phenomenon. (D) were caused by volcanic caldera.

___84. Stellar parallax tells us about that star's (A) luminosity. (B) temperature. (C) spectral class. (D) distance.

11/13 Astronomy 1 Final Sample Questions 85-89 refer to the figure below which is a graphical representation of a group of stars. Identify each type of star by its A labeled location on the diagram.

___85. White Dwarf stars. L u B m ___86. Main Sequence stars. i n C o s ___87. Giants stars. i t y D ___88. Supergiants (Asymptotic Giant Branch) stars.

Hot Cold Temperature ___89. Most of the stars in a typical H-R diagram fall on the (A) white dwarf region (B) giant region (C) supergiant region (or asymptotic giant branch). (D) main sequence

___90. Which are the two most abundant elements in the sun? (A) hydrogen and helium. (B) helium and uranium. (C) hydrogen and sodium. (D) hydrogen and iron

___91. The main sequence lifetime of a hot massive O star compared with an cooler, less massive M star is (A) Much longer because there is more fuel available (B) Much shorter because the O star burns fuel at a much faster rate. (C) About the same because all stars live about 10 billion years. (D) Much shorter because there is much less hydrogen in O stars

___92.What marks the transition from protostar to star? (A) the star begins to rotate (B) hydrogen fusion begins (C) the star first becomes luminous (D) the star becomes hot enough to ionize hydrogen

___93. According to nebular theories, the planets formed from material that was (A) part of the collapsing cloud which formed the Sun (B) captured by the Sun from interstellar space (C) pulled from the Sun during a collision with another star (D) ejected from the Sun by an explosion

12/13 Astronomy 1 Final Sample For Questions 94-97: Match the type of star with the type of pressure which supports it: ___94. neutron degeneracy pressure (A) Neutron Star

___95. normal gas pressure (B) Main Sequence Star

___96. electron degeneracy pressure (C) White Dwarf

___97. none: object has collapsed gravitationally (D) Black Hole

___98. The Algol “Paradox” is (A) a close binary star system consisting of a red giant and a less massive main sequence star (B) a close binary star system consisting of a red giant and a more massive main sequence star (C) the mysterious radio navigation beacons called pulsars (D) the event horizon of a black hole

___99. The Roche lobe is (A) the region around one of the stars in a binary system where the gravity of that star dominates (B) the type of star formed when a black hole becomes to massive to support itself (C) a cluster of stars which all have the same mass (D) the source of radio emissions in a pulsar

___100. The Schwarzschild radius describes the size of a (A) black hole. (B) neutron star. (C) accretion disk. (D) white dwarf.

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