
Concept explainers
A referent system that can be used to locate objects in the sky is the
a. celestial globe.
b. celestial coordinates.
c. celestial sphere.
d. celestial maps.

The referent system that can be used to locate the objects in the sky from the following options:
Celestial globe
Celestial coordinates
Celestial sphere
Celestial maps
Answer to Problem 1AC
Solution:
Option (c) is correct.
Explanation of Solution
Introduction:
Referent system is a system for reference that can be needed in order to locate anything, including astronomical objects or planets, in the skyappropriately. It can be established easily by first considering the sky to be an imaginary ‘celestial sphere’.
Explanation:
Reason for the correct option:
The imaginary sphere of arbitrarily larger radius, with earth located at its center is usually referred as theCelestial sphere. In astronomy, all the objects located in the observer’s sky are assumed as projected upon the inner surface of the celestial sphere. To locate the objects in the sky, an imaginary celestial sphere is thus considered as the referent system.
Hence, option (c) is correct.
Reason for the incorrect option:
Option (a) is incorrect because the celestial globe is basically referred as the representation of constellations and stars as they are located on an apparent sphere in the sky. These globes are used for some astrological or astronomical calculations, and as ornaments. So, it is a wrong answer.
Option (b) is incorrect because celestial coordinates are the set of numbers that are used for reference in order to pinpoint the position of a celestial object in the sky. In astronomy, several different coordinate systems are used to locate the position of an object in the celestial sphere in the sky. So, it is a wrong answer.
Option (d) is incorrect because celestial maps are the representations of astronomical objects located in the sky. The division of grids makes it easier for the astronomers to develop and use the celestial maps in an appropriate manner. Thus, it cannot be used as a referent system. So, it is a wrong answer.
Hence, options (a), (b) and (d) are incorrect.
Conclusion:
The referent system that can be used to locate the objects in the sky is the celestial sphere.
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Chapter 14 Solutions
Physical Science
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