autumnal equinox


Also found in: Thesaurus, Legal, Encyclopedia.

autumnal equinox

n.
1. One of two points at which the ecliptic intersects the celestial equator. At the autumnal equinox, the sun is moving along the ecliptic in a southeasterly direction.
2. The moment at which the sun passes through this point on or about September 23, marking the beginning of autumn in the Northern Hemisphere and spring in the Southern Hemisphere.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

autumnal equinox

n
1. (Physical Geography) the time at which the sun crosses the plane of the equator away from the relevant hemisphere, making day and night of equal length. It occurs about Sept 23 in the N hemisphere (March 21 in the S hemisphere)
2. (Astronomy) the time at which the sun crosses the plane of the equator away from the relevant hemisphere, making day and night of equal length. It occurs about Sept 23 in the N hemisphere (March 21 in the S hemisphere)
3. (Astronomy) astronomy
a. the point, lying in the constellation Virgo, at which the sun's ecliptic intersects the celestial equator
b. the time at which this occurs as the sun travels north to south (23 September)
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014

autum′nal e′quinox


n.
1. See under equinox (def. 1).
2. Also called autum′nal point′. the position of the sun at the time of the autumnal equinox.
[1670–80]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.

au·tum·nal equinox

(ô-tŭm′nəl)
The moment of the year when the sun crosses the celestial equator while moving from north to south. It occurs on September 22 or 23, marking the beginning of autumn in the Northern Hemisphere. Compare vernal equinox.
The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.autumnal equinox - September 22autumnal equinox - September 22        
Sep, Sept, September - the month following August and preceding October
equinox - either of two times of the year when the sun crosses the plane of the earth's equator and day and night are of equal length
autumn, fall - the season when the leaves fall from the trees; "in the fall of 1973"
2.autumnal equinox - (astronomy) the equinoctial point that lies in the constellation of Virgo
astronomy, uranology - the branch of physics that studies celestial bodies and the universe as a whole
equinoctial point, equinox - (astronomy) either of the two celestial points at which the celestial equator intersects the ecliptic
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
References in classic literature ?
It was by my account the 30th of September, when, in the manner as above said, I first set foot upon this horrid island; when the sun, being to us in its autumnal equinox, was almost over my head; for I reckoned myself, by observation, to be in the latitude of nine degrees twenty-two minutes north of the line.
It ends with the autumnal equinox around 23 September in the Northern Hemisphere and around 22 March in the Southern Hemisphere.
Every year, equal lengths of day and night happen twice a year during the vernal and autumnal equinox, on March and September, respectively.
SEPTEMBER SEPTEMBER 14 - HARVEST MOON THE Harvest Moon is the full moon closest to the autumnal equinox, and is characterised by its orange color.
I remembered that the rising sun's position was N90E two weeks ago on the Autumnal Equinox Day (September 22).
Around the time of the autumnal equinox, there does seem in most years, to be a period of very unsettled weather, thus we often experience storms.
Europe is 0.2-0.6% lower on the majors, while Asia was mostly closed for autumnal equinox, though the HK Hang Seng slumped 1.6% as a proxy for the rest of Sino-related exchanges.
September 22, 2018, was the day of the autumnal equinox this year.
As we reach the autumnal equinox, take heart that a pub in North Warwickshire has a warm welcome and coal in the hearth ready for your arrival.
THE sun will be exactly vertical over the earth's equator with the length of day and night approximately equal as the Autumnal Equinox phenomenon will occur at 4:54am Doha local time on September 23, 2018, according to Qatar Calendar House (QCH).
The season of fall begins with the autumnal equinox each year in the northern hemisphere.
Ebrahim Al Jarwan, General Supervisor at Sharjah Planetarium, said that according to astronomical calculations, the autumnal equinox will fall on Sunday, September 23 -- it always takes place from September 22 to September 24.