Astronomy a beginners guide to the universe 8th CHaisson mcmillan chapter 10 clicker questions

Astronomy A BEGINNER’S GUIDE TO THE UNIVERSE EIGHTH EDITION CHAPTER 10 Measuring the Stars Clickers © 2017 Pearson Education, Inc Question Stellar parallax is used to measure the a) b) c) d) e) © 2017 Pearson Education, Inc sizes of stars distances of stars temperatures of stars radial velocity of stars brightness of stars Question Stellar parallax is used to measure the a) b) c) d) e) sizes of stars distances of stars temperatures of stars radial velocity of stars brightness of stars Explanation: Parallax can be used to measure distances to stars accurately to about 200 parsecs (650 light-years) © 2017 Pearson Education, Inc Question The angle of stellar parallax for a star gets larger as the a) b) c) d) e) © 2017 Pearson Education, Inc distance to the star increases size of the star increases size of the telescope increases length of the baseline increases wavelength of light increases Question The angle of stellar parallax for a star gets larger as the a) b) c) d) e) distance to the star increases size of the star increases size of the telescope increases length of the baseline increases wavelength of light increases Explanation: Astronomers typically make observations of nearby stars months apart, making the baseline distance equal to AU (astronomical units) © 2017 Pearson Education, Inc Question You can best model the size and distance relationship of our Sun and the next nearest star using a) b) c) d) e) © 2017 Pearson Education, Inc one tennis ball here and one on the Moon two beach balls separated by 100 city blocks two grains of sand 100 light-years apart two golf balls 100 km apart two baseballs 100 yards apart Question You can best model the size and distance relationship of our Sun and the next nearest star using a) one tennis ball here and one on the Moon b) two beach balls separated by 100 city blocks c) two grains of sand 100 light-years apart d) e) two golf balls 100 km apart two baseballs 100 yards apart Explanation: The Sun is about million miles in diameter The next nearest star is about 25 million times farther away © 2017 Pearson Education, Inc Question A star’s proper motion is its a) b) true motion in space apparent shift as we view from opposite sides of Earth’s orbit every months c) annual apparent motion across the sky d) motion toward or away from us, revealed by Doppler shifts e) © 2017 Pearson Education, Inc orbital motion around the Galaxy Question A star’s proper motion is its a) b) true motion in space apparent shift as we view from opposite sides of Earth’s orbit every months c) annual apparent motion across the sky d) motion toward or away from us, revealed by Doppler shifts e) orbital motion around the Galaxy Explanation: A star’s “real space motion” combines its apparent proper motion with its radial motion toward or away from Earth © 2017 Pearson Education, Inc Question In the stellar magnitude system invented by Hipparchus, a smaller magnitude indicates a _ star a) b) c) d) e) © 2017 Pearson Education, Inc brighter hotter cooler fainter more distant Question What are the two most important intrinsic properties for classifying stars? a) Distance and surface temperature b) Luminosity and surface temperature c) d) e) Distance and luminosity Mass and age Distance and color Explanation: The H–R diagram plots stars based on their luminosities and surface temperatures © 2017 Pearson Education, Inc Question 10 Wien’s law tells us that the hotter an object, the _ the peak wavelength of its emitted light a) b) c) d) e) © 2017 Pearson Education, Inc longer more green heavier shorter more constant Question 10 Wien’s law tells us that the hotter an object, the _ the peak wavelength of its emitted light a) b) c) d) e) longer more green heavier shorter more constant Explanation: Wien’s law states that hotter stars appear more blue in color, and cooler stars appear more red in color © 2017 Pearson Education, Inc Question 11 We estimate the surface temperature of a star by using a) b) its color the pattern of absorption lines in its spectrum c) d) Wien’s law differences in brightness as measured through red and blue filters e) © 2017 Pearson Education, Inc All of the above are used Question 11 We estimate the surface temperature of a star by using a) b) its color the pattern of absorption lines in its spectrum c) d) Wien’s law differences in brightness as measured through red and blue filters e) © 2017 Pearson Education, Inc All of the above are used Question 12 Which spectral classification type corresponds to a star like the Sun? a) b) c) d) e) © 2017 Pearson Education, Inc O A F G M Question 12 Which spectral classification type corresponds to a star like the Sun? a) b) c) d) e) O A F G M Explanation: The OBAFGKM classification scheme is based on absorption lines © 2017 Pearson Education, Inc Question 13 The key difference between the spectra of B stars and G stars is a) b) c) d) e) © 2017 Pearson Education, Inc B stars show strong hydrogen lines; G stars show weaker hydrogen lines B stars show few metal lines; G stars show many B stars have no metal atoms G stars have no hydrogen atoms Both a and b are true Question 13 The key difference between the spectra of B stars and G stars is a) b) c) B stars show strong hydrogen lines; G stars show weaker hydrogen lines B stars show few metal lines; G stars show many B stars have no metal atoms d) G stars have no hydrogen atoms e) Both a and b are true Explanation: The original OBAFGKM sequence was arranged alphabetically by the strength of hydrogen absorption lines B stars had strong hydrogen lines; G stars had weak lines © 2017 Pearson Education, Inc Question 14 Astronomers can estimate the size of a star using a) b) c) d) e) © 2017 Pearson Education, Inc apparent brightness direct observation of diameter temperature distance to the star a, b, and c are all true Question 14 Astronomers can estimate the size of a star using a) b) apparent brightness direct observation of diameter c) d) e) temperature distance to the star a, b, and c are all true Explanation: Brightness and temperature are used to plot the star on an H–R diagram and indicate its approximate size Some stars are large enough to measure directly © 2017 Pearson Education, Inc Question 15 Eclipsing binary stars are very useful for determining the a) b) c) d) e) © 2017 Pearson Education, Inc ages of stars absolute luminosities of stars masses of stars distances to stars rotation rates of stars Question 15 Eclipsing binary stars are very useful for determining the a) b) ages of stars absolute luminosities of stars c) d) e) masses of stars distances to stars rotation rates of stars Explanation: Analysis of the light curve of an eclipsing binary star system can reveal the masses of the stars © 2017 Pearson Education, Inc Question 16 What is the single most important characteristic in determining the course of a star’s evolution? a) b) c) d) e) © 2017 Pearson Education, Inc Density Absolute brightness Distance Surface temperature Mass Question 16 What is the single most important characteristic in determining the course of a star’s evolution? a) b) c) d) e) Density Absolute brightness Distance Surface temperature Mass Explanation: A star’s mass determines how fast it forms, its luminosity on the main sequence, how long it will shine, and its ultimate fate © 2017 Pearson Education, Inc ... metal lines; G stars show many B stars have no metal atoms d) G stars have no hydrogen atoms e) Both a and b are true Explanation: The original OBAFGKM sequence was arranged alphabetically by the. .. Stellar parallax is used to measure the a) b) c) d) e) sizes of stars distances of stars temperatures of stars radial velocity of stars brightness of stars Explanation: Parallax can be used to measure... stellar parallax for a star gets larger as the a) b) c) d) e) distance to the star increases size of the star increases size of the telescope increases length of the baseline increases wavelength