In astronomy, evection (Latin for "carrying away") is the largest inequality produced by the action of the Sun in the monthly revolution of the Moon around the Earth. The evection, formerly called the moon's second anomaly, was approximately known in ancient times, and its discovery is attributed to Hipparchus or Ptolemy. The current name itself dates much more recently, from the 17th century: it was coined by Bullialdus in connection with his own theory of the Moon's motion.
In astronomy, evection (Latin for "carrying away") is the largest inequality produced by the action of the Sun in the monthly revolution of the Moon around the Earth. The evection, formerly called the moon's second anomaly, was approximately known in ancient times, and its discovery is attributed to Hipparchus or Ptolemy. The current name itself dates much more recently, from the 17th century: it was coined by Bullialdus in connection with his own theory of the Moon's motion.
Evection causes the Moon's ecliptic longitude to vary by approximately ± 1.274° (degrees), with a period of about 31.8 days. The evection in longitude is given by the expression +4586.45\sin (2D-\ell), where D is the mean angular distance of the Moon from the Sun (its elongation), and \ell is the mean angular distance of the Moon from its perigee (mean anomaly'').
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).