celestial horizon

celestial horizon

n.

A great circle on the celestial sphere having a plane that passes through the center of the earth and is parallel to an observer's horizon. Also called rational horizon.

---

celestial horizon

n

(Astronomy) See horizon [2b]

---

celestial horizon

A great circle on the celestial sphere having a plane that passes through the center of the Earth at a right angle to the line formed by an observer's zenith and nadir. The celestial horizon divides the celestial sphere into two equal hemispheres based on the observer's location, with one hemisphere representing the half of the sky visible to the observer at that location and the other representing the half that is hidden from the observer below the Earth's horizon. The celestial horizon is used as the reference point in determining a celestial body's altitude. Also called rational horizon. Compare sensible horizon.

Thesaurus

Noun

1.

celestial horizon - the great circle on the celestial sphere whose plane passes through the sensible horizon and the center of the Earth horizon great circle - a circular line on the surface of a sphere formed by intersecting it with a plane passing through the center