1st Edition

ISBN: 9781938168284

Author: Andrew Fraknoi; David Morrison; Sidney C. Wolff

Publisher: OpenStax

Concept explainers

We may see thousands of stars in the dark sky. Our universe consists of billions of stars. Stars may appear tiny to us but they are huge balls of gasses. Sun is a star of average size. Some stars are even a thousand times larger than the sun. The stars d…

Red Shift

It is an astronomical phenomenon. In this phenomenon, increase in wavelength with corresponding decrease in photon energy and frequency of radiation of light. It is the displacement of spectrum of any kind of astronomical object to the longer wavelengths…

Textbook Question

Chapter 17, Problem 37E

You have enough information from this chapter to estimate the distance to Alpha Centauri, the second nearest star, which has an apparent magnitude of 0. Since it is a G2 star, like the Sun, assume it has the same luminosity as the Sun and the difference in magnitudes is a result only of the difference in distance. Estimate how far away Alpha Centauri is. Describe the necessary steps in words and then do the calculation. (As we will learn in the Celestial Distances chapter, this method-namely, assuming that stars with identical spectral types emit the same amount of energy-is actually used to estimate distances to stars.) If you assume the distance to the Sun is in AU, your answer will come out in AU.

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Chapter 17, Problem 36E

Chapter 17, Problem 38E

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Chapter 17 Solutions

Astronomy

Ch. 17 - What two factors determine how bright a star...Ch. 17 - Explain why color is a measure of a star’s...Ch. 17 - What is the main reason that the spectra of all...Ch. 17 - What elements are stars mostly made of? How do we...Ch. 17 - What did Annie Cannon contribute to the...Ch. 17 - Name five characteristics of a star that can be...Ch. 17 - How do objects of spectral types L, T, and Y...Ch. 17 - Do stars that look brighter in the sky have larger...Ch. 17 - The star Antares has an apparent magnitude of 1.0,...Ch. 17 - Based on their colors, which of the following...

Ch. 17 - Order the seven basic spectral types from hottest...Ch. 17 - What is the defining difference between a brown...Ch. 17 - If the star Sirius emits 23 times more energy than...Ch. 17 - How would two stars of equal luminosity-one blue...Ch. 17 - Table 17.2 lists the temperature ranges that...Ch. 17 - Suppose you are given the task of measuring the...Ch. 17 - Star X has lines of ionized helium in its...Ch. 17 - The spectrum of the Sun has hundreds of strong...Ch. 17 - What are the approximate spectral classes of stars...Ch. 17 - Look at the chemical elements in Appendix K. Can...Ch. 17 - Appendix I lists some of the nearest stars. Are...Ch. 17 - Appendix J lists the stars that appear brightest...Ch. 17 - What star appears the brightest in the sky (other...Ch. 17 - Suppose hominids one million years ago had left...Ch. 17 - Why can only a lower limit to the rate of stellar...Ch. 17 - Why do you think astronomers have suggested three...Ch. 17 - Sam, a college student, just bought a new car....Ch. 17 - Would a red star have a smaller or larger...Ch. 17 - Two stars have proper motions of one arcsecond per...Ch. 17 - Suppose there are three stars in space, each...Ch. 17 - What would you say to a friend who made this...Ch. 17 - In Appendix J, how much more luminous is the most...Ch. 17 - Verify that if two stars have a difference of five...Ch. 17 - As seen from Earth, the Sun has an apparent...Ch. 17 - An astronomer is investigating a faint star that...Ch. 17 - The center of a faint but active galaxy has...Ch. 17 - You have enough information from this chapter to...Ch. 17 - Do the previous problem again, this time using the...Ch. 17 - Star A and Star B have different apparent...Ch. 17 - Star A and Star B have different apparent...Ch. 17 - The star Sirius A has an apparent magnitude of 1.5...Ch. 17 - Our Sun, a type G star, has a surface temperature...

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