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

See Examples For:

zenith distance

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

The difference observed was 12 minutes 55 seconds, which arose no doubt from the uncertainty of the refraction for a zenith distance, of which observations are wanting.

From Personal Narrative of Travels to the Equinoctial Regions of America, During the Year 1799-1804 — Volume 1 by Ross, Thomasina

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

Two extremely sensitive levels are attached to the telescope, which latter carries a micrometer in its eye-piece, with a screw of long range for measuring differences of zenith distance.

From Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 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.