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

In this case, your distance North of the equator AD would be your zenith distance AB minus the sun's declination DB.

From Lectures in Navigation by Draper, Ernest Gallaudet

It is a little more accurate to find the altitude by taking the complement of the observed zenith distance, if the vertical arc has sufficient range.

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

No observations should be made near the horizon; and, when the objects examined are at any considerable zenith distance, stars differing several degrees in altitude should be avoided.

From A Plan for Securing Observations of the Variable Stars by Pickering, E. C.

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

From Lectures in Navigation by Draper, Ernest Gallaudet