The word ‘antiscion’ or the plural ‘antiscia’ has a very arcane sort of ring to it. In “A Paradox for the Solstice” I discussed its character as a mirror of the axis of the solstices.
In this article I would like to acquaint you with the ‘parallel’ which essentially is the more generalised form of the antiscion and the contra-antiscion, as the opposite degree of an antiscion is sometimes called. While an antiscion is the mirror or parallel point of the longitudinal position of a planet with respect to the solstice points, the highest and lowest declination of the Sun, the parallel considers the declination of the planet itself. The declination of a planet describes its distance from the celestial equator. So two planets with the same declination on the same side of the celestial equator are parallel to each other. If they are on opposite sides of the celestial equator they are contra-parallel. Simple enough if you have an ephemeris that includes the declinations of the planets. The parallel is so to speak a conjunction by declination rather than by longitude.
What is not generally known is that each degree of declination can be projected onto the ecliptic. There is a geometrical relationship between the two. This can be most clearly seen with the equinox points at 0° Aries and Libra which have a declination of 0° and the solstice points at 0° Cancer and Capricorn where the Sun has its highest or lowest declination of 23°27.
Now the parallel aspect need not only be applied to a natal chart. It can also be considered in primary directions. It is seldom used, but you will come across it now and then in older authors.
How does one find the parallel aspect points in a chart? The easiest way is to use a set of tables. I say easy as a set of tables can give you some idea of what generally is happening. A computer programme may help to quickly calculate a value, comprehension is however reduced to a minimum. I have two sets of tables. I generally use is those of Erich Carl Kühr, “Primär-Direktions-Tabellen” along with a table of logarithms. The Kühr Tables are useful as he includes the log tan of declination for each minute of right ascension, interpolation is unnecessary. All I do is look up the log tan of a planets declination and then refer to Kühr’s tables. So if a planet has a declination of say 22°11south (this is Jupiter’s current declination), I look up the log tan, which is 9.61040, this is quickly found at 11°35 Gemini/Sagittarius and also at 18°25 Cancer/Capricorn. Did you notice something? The parallel and contra-parallel points have exactly the same character as the antiscion points! The antiscion of a planet in Gemini is always found in Cancer, just as the the antiscion of a planet in Sagittarius is always in Capricorn. This tells us something about antiscions. The antiscion of the Sun is also its parallel degree (the Sun’s declination when projected to the ecliptic will always be the same as its longitude). With the rest of the ‘planets’ we are in a sense aligning the planet with the Sun. Jupiter has at the moment a longitude of 19°30 Capricorn, so his antiscion is at 10°30 Sagittarius. This means that earlier in the month he was contra-parallel to the Sun. If you look in your ephemeris you will find that this was at the end of May.