celestial longitude see longitude

celestial mechanics singular noun (astronomy)

The study of the motions of celestial objects in gravitational fields, esp, as by Newton, satellite and planetary motion in the solar system

celestial navigation noun

Navigation by the stars, etc (also astronavigation)

celestial poles plural noun (astronomy)

The two points at which the earth's axis, extended indefinitely, cuts the celestial sphere

celestial sphere noun (astronomy)

An imaginary sphere of infinite radius, of which the observer is the centre, onto which stars and other celestial bodies are projected

longitude /lonˈji-tūd or longˈgi-/

1. The arc of the equator between the meridian of a place and a standard meridian (usu that of Greenwich) expressed in degrees East or West
2. (also celestial longitude) the arc of the ecliptic between a star's circle of latitude and the first point of Aries or vernal equinox (21 March), measured eastwards (astronomy)
3. Length

longitūdˈinal adjective

1. Relating to longitude
2. Lengthways

longitūdˈinally adverb

longitudinal wave noun (acoustics)

A wave in which the particles are displaced in the direction of advance of the wave