zenith distance

American  

noun

Astronomy.

1. the angular distance from the zenith of a point on the celestial sphere to the sphere, measured along a great circle that is perpendicular to the horizon; the complement of the altitude.

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Etymology

Origin of zenith distance

First recorded in 1695–1705

Example Sentences

Atmospheric Absorption.—The principal object of conducting the investigation during the summer solstice has been the facilities afforded for determining atmospheric absorption, the sun's zenith distance at noon being only 17° 12' at New York.

From Scientific American Supplement, No. 458, October 11, 1884 by Various

Your zenith distance is the distance in the celestial sphere you are from the sun.

From Lectures in Navigation by Draper, Ernest Gallaudet

Bradley had a zenith sector, and with this he observed with the greatest care the zenith distance of Gamma Draconis at every possible opportunity.

From Astronomy: The Science of the Heavenly Bodies by Todd, David Peck

As the distance from the horizon to the zenith is 90°, the difference, or complement of the altitude, is called the zenith distance, or co-altitude.

From Scientific American Supplement, No. 360, November 25, 1882 by Various

Your zenith distance, therefore, is the difference between the true meridian altitude of the sun, obtained by your sextant, and 90�.

From Lectures in Navigation by Draper, Ernest Gallaudet