|Birth Dates:||11/30 or 12/30 - N/a|
|Season:||November or December|
|Tarot Card:||Peace or Harmony|
Ophiuchus (⛎) is one of thirteen constellations that cross the ecliptic. It has therefore been called the "13th sign of the zodiac". However, this confuses sign with constellation. The signs of the zodiac are a twelve-fold division of the ecliptic, so that each sign spans 30° of celestial longitude, approximately the distance the Sun travels in a month, and (in the Western tradition) are aligned with the seasons so that the March equinox always falls on the boundary between Pisces and Aries.
Constellations, on the other hand, are unequal in size and are based on the positions of the stars. The constellations of the zodiac have only a loose association with the signs of the zodiac, and do not in general coincide with them. In Western astrology the constellation of Aquarius, for example, largely corresponds to the sign of Pisces. Similarly, the constellation of Ophiuchus occupies most (November 29 – December 17) of the sign of Sagittarius (November 23 – December 21). The differences are due to the fact that the time of year that the sun passes through a particular zodiac constellation's position has slowly changed (because of the precession of the equinoxes) over the centuries from when the Greeks, Babylonians, and Dacians through Zamolxis originally developed the Zodiac.
Ophiuchus is mainly used in the branch of astrology known as Sidereal. Sidereal astrology uses the constellations actual positions in the sky to calculate a sign's position rather than the fixed points based on the passage of time relative to the equinoxes used in Tropical astrology. It is also not used as a zodiac sign for any planets other than the Sun, which is a person's core personality.
Although Ophiuchus has been a constellation as long as the other 12 zodiac constellations and has fixed stars that some astronomers referred to in order to calculate other celestial bodies positions, it was not used an astrological sign until the year 1970 when astrologer Stephen Schmidt created it along with a 14th zodiac sign Cetus (although this has not gathered as much popularity as Ophiuchus).
It cannot currently be used for a full Western Astrological reading due to the mathematical imperfections of using the number 13. Using any other number of signs other than 12 creates problems when considering aspects between signs as well as elements and modalities of individual signs. Although Ophiuchus is stated to be the element fire, this means one of the elements will have one sign more than all other signs, creating an imbalance that the 12 sign system does not have. When using 12 signs, there are then 4 elements (fire, earth, air, and water) with 3 signs each, and 3 modalities (cardinal, fixed, and mutable) of 4 signs each. The 4 elements resemble the 4 seasons with the modalities representing the mark of each season's beginning, middle, and end. 12 also divides neatly into the 360 degrees of a circle for 12 houses as well as creating many possible aspect angles, such as squares (signs that are 3 signs apart and share modality). It is all divided very neatly and evenly with a certain flow and connectedness that a 13 sign system lacks.