Foundations of Astronomy (MindTap Course List)
14th Edition
ISBN: 9781337399920
Author: Michael A. Seeds, Dana Backman
Publisher: Cengage Learning
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Chapter 17, Problem 2LTL
To determine
The reason for background
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The Andromeda Galaxy, M31, is the closest large spiral galaxy to our Milky Way. When we look at its chemical spectrum, we see that its hydrogen alpha emission line (Hα) has an observed wavelength of λobs = 655 nm.-Calculate z, being careful with the sign.-How fast is it moving in km/s?-Is it redshifted or blueshifted? Is it moving towards or away from us?
answer to three significant figures.
Imagine that you are observing the light from a distant star that is located in a galaxy 100 million lightyears
away from you. By analysis of the starlight received, you are able to tell that the image we see is of a 10-
million-year-old star. You are also able to predict that the star will have a total lifetime of 50 million years, at
which point it will end in a catastrophic supernova.
a) How old does the star appear to be to us here on Earth now?
b) How long will it be before we receive the light from the supernova event?
c) Has the supernova already occurred? If so, when did it occur?
Assuming stars to behave as black bodies stefan-boltzmann law to show that the luminosity of a star is related to its surface temperature and size in the following way:
L = 4(3.14)R^2oT^4
where o= 5.67 ×10^-8 Wm^-2 K-4 is the stefan- boltzmann constant. Then use this expression together with the knowledge that the sun has a surface temperature of 5700k and radius 695 500km to calculate the luminosity of the Sun in units of Watts
Chapter 17 Solutions
Foundations of Astronomy (MindTap Course List)
Ch. 17 - Is cosmology the study of the Universe, the...Ch. 17 - Is a cosmologist an astronomer? Is an astronomer a...Ch. 17 - How does the darkness of the night sky tell you...Ch. 17 - Explain the differences among the observable...Ch. 17 - Prob. 5RQCh. 17 - Prob. 6RQCh. 17 - Prob. 7RQCh. 17 - Prob. 8RQCh. 17 - Prob. 9RQCh. 17 - Prob. 10RQ
Ch. 17 - Prob. 11RQCh. 17 - If you accept the cosmological principle, how can...Ch. 17 - Why cant an open universe have a center? How can a...Ch. 17 - In which type of model universe is space-time...Ch. 17 - In which type of model universe is space-time...Ch. 17 - What is the fate of a closed universe? In what...Ch. 17 - In which model universe does the average density...Ch. 17 - Prob. 18RQCh. 17 - What evidence shows that the Universe is...Ch. 17 - Why couldnt atomic nuclei exist when the Universe...Ch. 17 - Why are measurements of the current density of the...Ch. 17 - What percentage of matter is ordinary matter? What...Ch. 17 - How does the inflationary universe hypothesis...Ch. 17 - Prob. 24RQCh. 17 - What is the evidence that the Universe was...Ch. 17 - Prob. 26RQCh. 17 - If the Universe is negatively curved, and dark...Ch. 17 - What is the difference between hot dark matter and...Ch. 17 - Prob. 29RQCh. 17 - What evidence can you cite that the Universe's...Ch. 17 - Prob. 31RQCh. 17 - Reasoning by analogy often helps make complicated...Ch. 17 - Prob. 33RQCh. 17 - In science, wishing something to be true does not...Ch. 17 - Prob. 1PCh. 17 - Prob. 2PCh. 17 - Prob. 3PCh. 17 - Measure the lengths of the two arrows in the left...Ch. 17 - Prob. 5PCh. 17 - Prob. 6PCh. 17 - Find the wavelength of maximum intensity of the...Ch. 17 - Prob. 8PCh. 17 - Prob. 9PCh. 17 - Prob. 10PCh. 17 - Prob. 11PCh. 17 - Prob. 12PCh. 17 - Prob. 1SOPCh. 17 - Prob. 2SOPCh. 17 - Prob. 1LTLCh. 17 - Prob. 2LTLCh. 17 - Prob. 3LTLCh. 17 - Prob. 4LTLCh. 17 - Prob. 5LTLCh. 17 - Prob. 6LTL
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