Astronomy, ASU, Exam 1 Questions With Complete Solutions

What is the definition of the Astronomical Unit? correct answer: The average distance between the Sun and the Earth Which sequence is correct when ordered by increasing size? correct answer: Earth Solar System Milky Way Galaxy Galaxy Clusters How many stars does a typical galaxy like the Milky Way Galaxy contain? correct answer: a few hundred billion How long does it take for light to cross the diameter of the Milky Way Galaxy? correct answer: about 100,000 years Which of the following is the same as 1.573 X 10⁴? correct answer: 15730 Given only the names of the following stars, which is likely the brightest? correct answer: There's not enough information to tell! (Since the stars belong to different constellations, their names are not useful in determining their comparative brightnesses.) What do you think the second brightest star in the constellation of Delphinus would be called? correct answer: Beta Delphini Use the table to determine which star would be the brightest. Star Name Magnitude δ Dra 3.07 α Cet 2.53 ρ Per 3.98 Nim 8.07 α CMa -1.46 correct answer: α CMa The flux ratio correct answer: tells you how many times brighter one star is than another. can be used to determine the difference of the magnitudes of two stars. If star A has an apparent magnitude, mv= 1.3, and star B has an apparent magnitude, mv= -0.8, which star is brighter? correct answer: Star B is brighter If star A has an apparent magnitude, mv= 1.3, and star B has an apparent magnitude, mv= -0.8, what is the flux ratio (FA/FB) for the two stars? Report one decimal place in your answer. correct answer: 0.1 True or false: the zenith moves with you. correct answer: True How much of the celestial sphere can an observer on Earth see at one time? correct answer: exactly half An observer on Earth's equator would find... correct answer: the celestial equator passing directly overhead.