astronomy chapter 13 – Flashcards
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Which of the following stars is the hottest? a. l star b. b star c. g star d. f star
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b. b star
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Which of the following is a main- sequence star hotter than the Sun? a. A k- type star b. An f-type star c. a c red giant d. a white dwarf
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b. an f type
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In what part of the H-R diagram do white dwarfs lie? a. lower right b. just above the sun on the main sequence c. upper right d. lower center e. upper left
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d. lower center
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if two stars have the same luminosity, but one appears only 1/64 as bright as the other, you can conclude that the dimmer star is ___ times father away. a. 64 b. 512 c. 16 d. 128 e. 8
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e. 8
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What is a parallax?
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The apparent shift in position of an object caused by a change in the observer's position.
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Star A and star B have the same size, but star A is more luminous than star B. Based on this information, which of the following must be the case? a. star A is cooler then star B b. star A is hotter than star B c. star A and star B have same temperature d. star A is more massive than star B
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b. star A is hotter than star B
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The H-R diagram is a diagram plotting the stars according to their? a. apparent brightness and temperature b. spectral and temperature c. brightness and luminosity d. Luminosity and temperature e. mass and diameter
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d. Luminosity and temperature
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The study of eclipsing binary stars is very important because it allows astronomers to determine? a.the distance between two stars b. the speed of the stars from the doppler shift of their spectral lines. c. the diameter of the stars d. the luminosity of each star e. the brightness of each star
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c. the diameter of star
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which of the following is not true for a pulsating star? a. the surface temperature of a pulsating star changes periodically b. the outer layers of a pulsating star expand and contract periodically c. the luminosity changes periodically d. they show periodic shifts in their spectral lines.
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d they are usually members of an eclipsing binary star system.
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Analysis of stellar spectra shows that most stars consist of 71 %___ 27%___ and a 2% mix of the other elements. a. hydrogen, oxygen b. hydrogen, helium c. helium, hydrogen d oxygen, nitrogen
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b. hydrogen, helium
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The hottest (O and B type) stars are usually binary stars, while the coolest (M type) stars are usually single stars. true or false
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true
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Luminosity (absolute brightness of a star depends on its ___. a. temperature b. radius c. distance from us d. both A and B e. Both A and C
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Both A and B temperature and radius
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If the distance between the Earth and a star is measured using parallax measurements, how far apart in time should the two measurement be made to make the parallax measurement as accurate as possible? a. instantaneously b. a day c. six months d. a year
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six months
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What kind of information can astronomers obtain from the spectrum of a star? more than one answer may be correct. a. the rotation of the star b. the temperature of the star's atmosphere c. the composition of the star's atmosphere d. the star's luminosity
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all of them a. the rotation of the star b. the temperature of the star's atmosphere c. the composition of the star's atmosphere d. the star's luminosity
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In a sample of nearby stars, about what percentage will lie on the main sequence? a.50% b. 99% c.35% d. 95 e. 90%
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90%
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In what part of the H-R diagram do white dwarfs lie? a. upper left b. lower center c. just above the sun on the main sequence d. upper right e. lower right
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lower center
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a star is at a distance of 10.0 parsecs form the sun. what is the distance of this star in light years? a. 3.10 light years b.0.100 light years c.10.0 light years d. 32.6 light years
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32.6 light years
