The equinox that occurs on or near September 21 each year. See also equinox vernal equinox
A day of equal day and night that marks the beginning of fall and occurs when the sun passes directly over the equator.
The place in the sky where the Sun crosses the celestial equator moving southwards. The autumnal equinox marks the beginning of autumn and falls on, or near, September 21. See celestial sphere for a helpful diagram.
The time when the sun crosses the Earth's equator moving south and there is equal day and night time hours.
(see also equinoxes).
equinox occurring on September 22 or 23
The point on the Ecliptic where the Sun crosses the Celestial Equator, heading south. Also, the day when it does so. Also, the first day of autumn in the northern hemisphere.
The intersection of the ecliptic and celestial equator where the Sun crosses the equator from north to south. A time when every place on Earth has 12 hours of day-light and 12 hours of night.
Point on the Celestial equator where the sun moves from north to south declination.
date on which the Sun crosses the celestial equator moving southward, occurring on or near September 21; direct rays of sunlight would be on the equator
The moment when the Sun crosses the celestial equator travelling in a southward direction, on or about September 22. In the Northern Hemisphere, it marks the first day of fall. The term is also applied to the Sun's position in the sky at that moment. It is one of two points where the ecliptic and celestial equator intersect, the other being the vernal equinox.
When the sun passes from north to south on or near September 23rd. See equinox.
the time of year around September 23 when the sun crosses the celestial equator heading south.
The equinox at which the sun approaches the Southern Hemisphere and passes directly over the equator. Occurs around September 23.
The first day of Autumn and the position on the ecliptic occupied by the sun on September 23, when it crosses the celestial equator going from north to south.
The equinox at which the sun approaches the Southern Hemispheres, marking the start of astronomical autumn in the Northern Hemisphere. The time of this occurrence is approximately 22 September. On that day, daylight is everywhere 12 hours. Compare with vernal equinox, offset by six months.
The place where the Sun crosses the celestial equator heading south. B Canis Majoris Variable Short Period variables stars that do not lie in the instability strip
a day of the year in autumn when the night and day are of equal length.
The equinox (approximately 22 September) at which the sun crosses the celestial equator from the Northern Hemisphere to the Southern Hemisphere.
The point at which the sun passes directly over the equator on its journey south. The time of this occurrence is approximately September 22.
specific moment in the year (on September 22) when the Sun is directly on the celestial equator, moving south of the celestial equator.