# celestial longitude

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**celestial longitude**— n. Astron. the arc of the ecliptic measured eastward from the vernal equinox to the point where the ecliptic is intersected by the great circle through the star, planet, etc. and the poles of the ecliptic …2

**celestial longitude**— The celestial longitude of a body is the arc of the ecliptic contained between the first point of Aries and the secondary ecliptic through that body measured eastward from Aries. It is the angular distance along the ecliptic from the vernal… …3

**celestial longitude**— noun (astronomy) the equatorial coordinate specifying the angle, measured eastward along the celestial equator, from the vernal equinox to the intersection of the hour circle that passes through an object in the sky; usually expressed in hours… …4

**celestial longitude**— Astron. the angular distance of a point on the celestial sphere from the great circle that is perpendicular to the ecliptic at the point of the vernal equinox, measured through 360° eastward parallel to the ecliptic. * * * …5

**celestial longitude**— /səˌlɛstiəl ˈlɒŋgətjud/ (say suh.lesteeuhl longguhtyoohd) noun → longitude (def. 2a) …6

**celestial longitude**— noun Astronomy the angular distance of a point east of the First Point of Aries, measured along the ecliptic …7

**Celestial meridiator**— is a vertical imaginary line that goes over the celestial poles and crosses (perpendicular to) the celestial equator. There are two celestial meridiators on the celestial sphere: Equinox meridiator and Solstice meridiator.NameThe meridiators are… …8

**Longitude by chronometer**— Longitude by Chronometer, known by mariners as Long by Chron , is an astronomical navigation method of calculating an observer s position on earth. The method gives the observer a position line on which the observer is situated. Usually the… …9

**longitude**— [län′jə to͞od΄, län′jətyo͞od΄; lôn′jə to͞od΄, lôn′jə tyo͞od΄] n. [ME < L longitudo < longus, LONG1] 1. length 2. distance east or west on the earth s surface, measured as an arc of the equator (in degrees up to 180° or by the difference in… …10

**Longitude**— For Dava Sobel s book about John Harrison, see Longitude (book). For the adaptation of Sobel s book, see Longitude (TV series). Map of Earth Longitude (λ) Lines of longitude appear vertical with varying curvature in this projection, but are… …11

**longitude**— Synonyms and related words: Antarctic Zone, Arctic Circle, Arctic Zone, Cartesian coordinates, Frigid Zones, Lambert conformal projection, Mercator projection, Miller projection, Torrid Zone, Tropic of Cancer, Tropic of Capricorn, Variable Zones …12

**longitude**— /ˈlɒŋgətjud / (say longguhtyoohd), /ˈlɒŋətjud/ (say longuhtyoohd), / tʃud/ (say choohd) noun 1. Geography angular distance east or west on the earth s surface, measured along the equator by the angle contained between the meridian of a particular …13

**longitude**— (Roget s IV) n. Syn. longitude in arc, longitude in time, celestial longitude; see distance 3 , measure 1 …14

**longitude**— /lon ji toohd , tyoohd /, n. 1. Geog. angular distance east or west on the earth s surface, measured by the angle contained between the meridian of a particular place and some prime meridian, as that of Greenwich, England, and expressed either in …15

**Celestial navigation**— Celestial navigation, also known as astronavigation, is a position fixing technique that was devised to help sailors cross the featureless oceans without having to rely on dead reckoning to enable them to strike land. Celestial navigation uses… …16

**celestial mechanics**— the branch of astronomy that deals with the application of the laws of dynamics and Newton s law of gravitation to the motions of heavenly bodies. [1815 25] * * * Branch of astronomy that deals with the mathematical theory of the motions of… …17

**Celestial coordinate system**— For other uses of Celestial , see Celestial (disambiguation). Orientation of Astronomical Coordinates Orientation of the galactic, ecliptic and equatorial coordinate systems, projected on the celestial sphere, showing the galactic equator (black) …18

**Longitude of the ascending node**— The longitude of the ascending node (☊ or Ω) is one of the orbital elements used to specify the orbit of an object in space. It is the angle from a reference direction, called the origin of longitude , to the direction of the ascending node,… …19

**celestial navigation**— navigation by means of observations made of the apparent position of heavenly bodies. Also called astronavigation, celo navigation. [1935 40] * * * use of the observed positions of celestial bodies to determine a navigator s position. At… …20

**celestial coordinates**— Set of numbers used to pinpoint the position in the sky (see celestial sphere) of a celestial object. Coordinate systems used include the horizon system (altitude and azimuth), galactic coordinates, the ecliptic system (measured relative to the… …