4 articles for "Nadir"

**Nadir**[Astro*Index]

The lower intersection of the prime vertical and the meridian, or the point on the celestial sphere directly beneath the observer, opposite the zenith. The line between the observer and the nadir is the direction of local gravity (not gravitational force) and does not pass through the center of the Earth. The nadir is in the horizonal coordinate system what the Imum coeli or lower midheaven is to the ecliptic coordinate system; the two cannot be used interchangeably.

See also:

♦ Prime Vertical ♦ Imum Coeli ♦ Meridian ♦ Celestial Sphere ♦ Zenith ♦ Gravity

**Nadir**[Prima]

The point below the horizon that is directly opposite the zenith; not to be confused with the Imum Coeli.

See also:

♦ Prime Vertical ♦ Imum Coeli ♦ Meridian ♦ Celestial Sphere ♦ Zenith ♦ Gravity

**Nadir**[Munkasey M.]

The equivalent South Pole of the Horizon. That point which is directly under where you are in the Horizon system of co-ordinates.

See also:

♦ Prime Vertical ♦ Imum Coeli ♦ Meridian ♦ Celestial Sphere ♦ Zenith ♦ Gravity

**Nadir**[DeVore]

The lowest point below the Earth, or opposite point to the Zenith. It should not be confused with the Imum Coeli. *v. Celestial Sphere.*

See also:

♦ Celestial Sphere

Astro*Index Copyright © 1997 Michael Erlewine