(♈) The point on the celestial equator from which right ascension is measured. It is the same as the vernal equinox. This point has zero right ascension and zero declination. It is defined as the point at which the Sun passes from south to north of the celestial equator, which happens on March 20 each year. Due to precession it is not a fixed point on the star background but regresses around the ecliptic at an annual rate of approximately 50″. Consequently, despite the name, it is no longer in the constellation of Aries but currently lies in neighbouring Pisces and in the year 2597 will move into Aquarius.
Subjects: Astronomy and Astrophysics.