The library · The other points and bodies

The true south lunar node

the true (osculating) south lunar node, the point exactly opposite the true north node, shown beside the mean south node the corpus reads elsewhere

What the tradition reads

The true south node is not reckoned on its own. Wikipedia's orbital node page defines the line of nodes as the straight line where the two planes intersect, passing through both nodes, so the descending point stands opposite the ascending one, and its lunar node page gives the descending or south node as the crossing where the Moon enters the southern ecliptic hemisphere; Wikipedia's Ketu page holds Rahu and Ketu always 180 degrees from each other, in the sky and in the chart alike. Since the Swiss Ephemeris documentation reads the true node as the osculating node of the momentary lunar orbit, this end of the axis wobbles with the other. What the older Western tradition reads here is subtraction. Lucia Bellizia's study of the nodes quotes Abu Ma'shar, who reports the Head judged augmentative and gives the Tail a nature diminutiva, lessening both the malefics and the benefics that stand with it, and Ali al-Qabisi, who composes the Tail of Saturn and Mars and reads it as "degradation and loss and poverty". The Vedic reading is not simply unfortunate: Wikipedia's Ketu page reads the south node as karmic accumulation both good and bad, malefic and benefic at once, and a significator of wisdom, non-attachment and the turn toward liberation, and reports its exaltation disputed, Brihat Parashara Hora Shastra giving Scorpio where most modern astrologers now give Sagittarius.

The story

The tail has its own names. Wikipedia's lunar node page gives the descending node as the dragon's tail, cauda draconis in Latin, and records that medieval Arabic texts blamed eclipses on a pseudo-planet, al-Tinnin or al-Jawzahr, divided into the Head (ra's) and the Tail (dhanab) of a mythological dragon; Bellizia's study adds Catabibazon as the Arabs' name for the descending point. The same study preserves the picture those names came from. Gerolamo Vitali's Lexicon Mathematicum has the serpent wide in the body and slender at head and tail, the two thin places being the crossings themselves, while the points of greatest latitude were called its bendings. John of Eschenden, whose Summa the study quotes from a 1489 Venice printing, glossed the image plainly: from the dragon's head the Moon begins to rise, and from the tail it begins to descend along its inclined orbit, so that "each Dragon tail presages evil". The reckoning of periods kept the same asymmetry, the firdaria in Haly Abenragel's list allotting the Head three years and the Tail two. India's account gives the tail a body rather than a fault: Wikipedia's Ketu page holds him the severed trunk of the asura Svarbhanu, a torso that needs nothing and so a personification of renunciation, and reproduces a mural at the Jawahar Kala Kendra in Jaipur that depicts him as the body without a head.

Written from

Corpus key point:TrueKetu.