equinox


equinox
/ee"kweuh noks', ek"weuh-/, n.
1. the time when the sun crosses the plane of the earth's equator, making night and day of approximately equal length all over the earth and occurring about March 21 (vernal equinox or spring equinox) and September 22 (autumnal equinox).
2. either of the equinoctial points.
[1350-1400; ME < ML equinoxium, for L aequinoctium the time of equal days and nights (aequi- EQUI- + noct- (s. of nox) NIGHT + -ium -IUM)]

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Either of two moments in the year when the Sun is exactly above the Equator and day and night are of equal length all over Earth; also, either of two points in the sky where the ecliptic and the celestial equator (see celestial sphere) intersect.

The vernal equinox, when spring begins in the Northern Hemisphere, occurs about March 21, when the Sun moves north across the celestial equator. The autumnal equinox falls about September 23, as the Sun crosses the celestial equator going south. See also solstice.

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      either of the two moments in the year when the Sun is exactly above the equator and day and night are of equal length; also, either of the two points in the sky where the ecliptic (the Sun's annual pathway) and the celestial equator intersect. The vernal equinox, marking the beginning of spring in the Northern Hemisphere, occurs about March 21, when the Sun moves north across the celestial equator. The autumnal equinox falls about September 23, as the Sun crosses the celestial equator going south.

      Some astronomical coordinates—e.g., right ascension and celestial longitude—are measured from the vernal equinox. It is sometimes called the first point of Aries because it was at the beginning of that constellation some 2,000 years ago. The term is still used, though precession of the equinoxes has moved the vernal equinox into Pisces.

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Universalium. 2010.

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Look at other dictionaries:

  • Equinox — E qui*nox, n. [OE. equinoxium, equenoxium, L. aequinoctium; aequus equal + nox, noctis, night: cf. F. [ e]quinoxe. See {Equal}, and {Night}.] 1. The time when the sun enters one of the equinoctial points, that is, about March 21 and September 22 …   The Collaborative International Dictionary of English

  • equinox — [ē′kwi näks΄, ek′wə näks] n. [ME < OFr equinoxe < ML aequinoxium < L aequinoctium < aequus (see EQUAL) + nox, NIGHT] 1. the time when the sun in its apparent annual movement along the ecliptic crosses the celestial equator, making… …   English World dictionary

  • Equinox TV — Equinox is a Cameroon based television station. Soon after its launch, it became one of the most vocal critics of Paul Biya s regime. The station was notorious for showing live footage of political demonstration against constitutional change in… …   Wikipedia

  • equinox — late 14c., from O.Fr. equinoce (12c.) or directly from M.L. equinoxium equality of night (and day), from L. aequinoctium the equinoxes, from aequus equal (see EQUAL (Cf. equal)) + nox (gen. noctis) night (see NIGHT (Cf. ni …   Etymology dictionary

  • equinox — ► NOUN ▪ the time or date (twice each year, about 22 September and 20 March) at which the sun crosses the celestial equator and when day and night are of equal length. ORIGIN Latin aequinoctium, from aequus equal + nox night …   English terms dictionary

  • Equinox — This article is about the astronomical event when the sun is at zenith over the Equator. For other uses, see Equinox (disambiguation). For the same event happening on other planets and setting up a celestial coordinate system, see Equinox… …   Wikipedia

  • Equinox — Das Wort Equinox (vom englischen equinox für die „Tagundnachtgleiche“) steht für: ein Album von Jean Michel Jarre aus dem Jahr 1978, siehe Equinoxe (Album) ein Film von 1992, siehe Equinox (Film) ein Konsolenspiel des Genres Rollenspiel, das 1994 …   Deutsch Wikipedia

  • equinox — i. One of the two points of intersection of the ecliptic and the celestial equators, occupied by the sun when its declination is 0°. Also called an equinoctial point. That point occupied on or about March 21, when the sun’s declination changes… …   Aviation dictionary

  • Equinox — Это  статья о музыкальном проекте Билла Либа и Криса Петерсона. Об альбоме Жана Мишеля Жарра 1978 года см. Equinoxe. Об одной из реализаций OSGi (спецификации модульной шины для создания Java приложений) см. Equinox (OSGi). О среднеразмерном …   Википедия

  • Equinox — Pour les articles homonymes, voir Equinox (homonymie). Equinox est un super vilain créé par Marvel Comics. Il est apparu pour la première fois dans Marvel Team up #23, en 1974. Origine Terrence Sorenson était le fils d un couple de chercheurs… …   Wikipédia en Français


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