Understanding Stars: Formation, Life Cycle, and Evolution, Lecture notes of Astronomy

Download Understanding Stars: Formation, Life Cycle, and Evolution and more Lecture notes Astronomy in PDF only on Docsity! Galaxies and Stars A) hotter than Rigel B) more luminous than Rigel C) closer than Rigel D) larger than Rigel 1. To an observer on Earth, the Sun appears brighter than the star Rigel because the Sun is A) nuclear fusion B) conduction C) convection D) radioactive decay 2. Light and other forms of electromagnetic radiation are given off by stars using energy released during 3. Base your answer to the following question on The reaction below represents an energy-producing process. A) in the Sun by fusion B) when water condenses in Earth’s atmosphere C) from the movement of crustal plates D) during nuclear decay The reaction represents how energy is produced 4. The reaction below represents an energy-producing process. A) in the Sun by fusion B) when water condenses in Earth’s atmosphere C) from the movement of crustal plates D) during nuclear decay The reaction represents how energy is produced Base your answers to questions 5 and 6 on the graph below, which shows changes in the Sun’s magnetic activity and changes in the number of sunspots over a period of approximately 100 years. Sunspots are dark, cooler areas within the Sun’s photosphere that can be seen from Earth. A) B) C) D) 5. Which graph best represents the relationship between the number of sunspots and the amount of magnetic activity in the Sun? A) randomly and unpredictably B) precisely at the beginning of each decade C) in a cyclic pattern, repeating approximately every 6 years D) in a cyclic pattern, repeating approximately every 11 years 6. The graph indicates that years having the greatest number of sunspots occur A) Barnard’s Star, Polaris, Sirius, Rigel B) Aldebaran, the Sun, Rigel, Procyon B C) Rigel, Polaris, Aldebaran, Barnard’s Star D) Procyon B, Alpha Centauri, Polaris, Betelgeuse 21. Which list shows stars in order of increasing temperature? A) hotter and more luminous B) hotter and less luminous C) cooler and more luminous D) cooler and less luminous 22. Compared to the temperature and luminosity of the star Polaris, the star Sirius is A) Rigel B) Barnard’s Star C) Alpha Centauri D) Aldebaran 23. Which star has a higher luminosity and a lower temperature than the Sun? A) Sirius B) Rigel C) the Sun D) Betelgeuse 24. Which star’s surface temperature is closest to the temperature at the boundary between Earth’s mantle and core? A) Betelgeuse and Barnard's Star B) Rigel and Betelgeuse C) Alpha Centauri and the Sun D) Sirius and Procyon B 25. Which two stars have the most similar luminosity and temperature? Base your answers to questions 26 through 28 on the diagram below, which shows two possible sequences in the life cycle of stars, beginning with their formation from nebular gas clouds in space. A) explode in a supernova B) become a black hole C) change into a white dwarf D) become a neutron star 26. According to the diagram, a star like Earth’s Sun will eventually A) nebula B) supernova C) red giant D) black dwarf 27. Stars like Earth’s Sun most likely formed directly from a A) mass and size B) temperature and origin C) luminosity and color D) luminosity and structure 28. According to the diagram, the life-cycle path followed by a star is determined by the star’s initial A) blue B) white C) yellow D) red 29. Which star color indicates the hottest star surface temperature? 30. The graph below represents the brightness and temperature of stars visible from Earth. A) A B) B C) C D) D Which location on the graph best represents a star with average brightness and temperature? A) It could be a main sequence star. B) It may be quite large. C) This is a typical characteristic of stars. D) There must be an error in measurement. 31. Measurements indicate that a certain star has a very high luminosity (100,000 times that of our sun) and yet has a temperature that is cooler than the sun. What can you conclude about this observation? A) among the hottest stars B) among the smallest stars C) very unique D) about average in all respects 32. Compared to other stars, the sun is A) the sun B) a blue supergiant C) a white dwarf D) a red giant 33. Which of the following stars is least bright? A) hotter and larger B) hotter and smaller C) cooler and larger D) cooler and smaller 34. Compared to the sun a white dwarf star is A) at the upper left end of the main sequence B) at the lower right end of the main sequence C) at the upper right corner of the H-R diagram D) at the lower left corer of the H-R diagram 48. The smallest stars on a H-R diagram are found A) hotter B) farther away C) larger D) older 49. Red giant stars have greater luminosity than our sun mainly because they are A) a red giant B) a white dwarf C) the sun D) a red dwarf 50. Which of the following stars is hottest? A) White Dwarf B) Supergiant C) Red Giant D) Main Sequence 51. What type of star is Polaris? A) blue B) red C) yellow D) white 52. Small cool stars would most likely appear to be A) Sun B) Alpha Centauri C) Betelgeuse D) Procyon 53. Which star has the greatest size? A) Barnard's star B) Procyon C) Alpha Centauri D) Rigel 54. Which star has the greatest luminosity? A) The star's temperature. B) The star's size. C) The star's distance. D) The star's shape. 55. Which factor does not affect a stars absolute magnitude (Luminosity)? A) 5,000ºC B) 10,000ºC C) 20,000ºC D) 30,000ºC 56. A Red giant star would most likely have a temperature of A) white B) red C) yellow D) blue 57. The coolest stars appear A) size B) shape C) color D) brightness 58. An astronomer can estimate the temperature of a star by observing its A) main sequence star with a temperature of approximately 4,000ºC and a luminosity of 100 B) main sequence star with a temperature of approximately 6,000ºC and a luminosity of 1 C) white dwarf star with a temperature of approximately 10,000ºC and a luminosity of 0.01 D) blue supergiant star with a temperature of approximately 20,000ºC and a luminosity of 700,000 59. According to the graph, the Sun is classified as a Base your answers to questions 60 through 62 on the diagram below. The diagram represents the inferred stages in the formation of our solar system. Stage 1 shows a contracting gas cloud. The remaining stages show the gas cloud flattening into a spinning disk as planets formed around our Sun. A) larger diameters B) higher densities C) shorter periods of revolution D) longer periods of rotation 60. Compared to the terrestrial planets, the Jovian planets in stage 5 have A) 1 billion years B) 5 billion years C) 20 billion years D) 100 billion years 61. Approximately how long ago did stage 4 end and stage 5 begin? A) hotter and less luminous B) cooler and more luminous C) the same temperature and larger D) hotter and larger 70. Compared to the sun, Polaris is A) the late phase for small mass star B) the remains of a larger star's explosion C) in the main sequence phase D) early phases, soon after a star's formation 71. At which phase of its evolutionary life is a white dwarf star? A) to expand as a red giant, undergo a nova outburst and end as a white dwarf B) to shrink to a white dwarf then eventually expand to a red giant C) become hotter and expand into a blue supergiant D) to become a black hole 72. The probable fate of our sun is A) mass B) percentage of helium C) percentage of carbon D) apparent brightness 73. What factor from the choices below determines whether a star will evolve into a white dwarf, a neutron star, or a black hole? A) white dwarf B) nova C) supernova D) black hole 74. When a star less massive than our sun consumes all of its nuclear fuel it will then become a A) a white dwarf B) a black hole C) a supernova D) a red giant 75. According to our present theories of stellar evolution, our sun will change next into A) carbon and hydrogen B) hydrogen and helium C) helium and carbon D) carbon and heavy metals 76. What are the two most abundant elements in a main sequence star? A) Supergiant B) White dwarf C) Blue star D) Red Dwarfs 77. Which stars are the youngest? A) nova B) pulsar C) supernova D) nebula 78. The explosion of a massive star near the end of its life is known as a A) measure the size of a star B) measure the altitude of a star C) identify elements in the atmosphere of a star D) measure the diameter of a star 79. By using a spectroscope an astronomer can 80. Stars are believed to undergo evolutionary changes over millions of years. The flowchart below shows stages of predicted changes in the Sun. A) hotter and brighter in stage 2, then cooler and dimmer in stage 3 B) cooler and dimmer in stage 2, then hotter and brighter in stage 3 C) hotter and dimmer in stage 2, then cooler and brighter in stage 3 D) cooler and brighter in stage 2, then hotter and dimmer in stage 3 According to this flowchart, the Sun will become 81. The diagram below represents the shape of the Milky Way Galaxy. A) elliptical B) irregular C) circular D) spiral The Milky Way Galaxy is best described as A) a type of solar system B) a constellation visible to everyone on Earth C) a region in space between the orbits of Mars and Jupiter D) a spiral-shaped formation composed of billions of stars 82. The Milky Way galaxy is best described as A) the Moon B) Jupiter C) the Sun D) the Milky Way 83. Which celestial feature is largest in actual size? 84. The diagram below represents a side view of the Milky Way Galaxy. A) A B) B C) C D) D At approximately which position is Earth’s solar system located?