(≏) The point on the celestial sphere diametrically opposite the first point of Aries. It is the same as the autumnal equinox. It has right ascension 12h and declination zero. It is the point at which the Sun passes from north to south of the celestial equator, which happens on September 22 or 23 each year. Because of precession, it no longer lies in Libra but in neighbouring Virgo.
Subjects: Astronomy and Astrophysics.