vernal point

plural vernal points

1. The point on the ecliptic where the sun crosses from the southern celestial hemisphere to the northern, which occurs at the (northern) vernal equinox; less commonly, either this point or the opposite point of crossing from north to south.

   In principle, the function is symmetrical with respect to the vernal points, the axes λ_H = 0° and λ_H = 180°.

   1970, M. A. Hoskin, editor, Journal for the History of Astronomy, volumes 1-2, page 24

   3 more examples

   Hipparchus found that the ecliptic coordinates of fixed stars (i.e. the longitudes counted from the vernal point and the latitudes) behave in the same way as the ecliptic coordinates of the sun: the longitudes are always increasing, the latitudes remain constant.

   1975, Otto Neugebauer, A History of Ancient Mathematical Astronomy, Springer, page 1083

   By following the retrograde movement of the vernal point (the zodiacal location of the Sun on March 21) through the constellations/signs of the zodiac, it is possible to date the Age of Aquarius quite precisely. The present location of the vernal point is slightly more than 5 degrees in the sign of Pisces, which means that we are still in the Age of Pisces.

   2000, Robert Powell, The Most Holy Trinosophia and the New Revelation of the Divine Feminine, page 85

   The Babylonian coordinate system, fixed in relation to individual stars rather than the vernal point, was for this reason not ideal, although it was easy to understand — since the stars can be seen and the vernal point cannot.

   2008, John North, Cosmos: An Illustrated History of Astronomy and Cosmology, page 52