Sidereal/Tropical Astrology, Ophiuchus, and Your True Sign

Do you think you're a Leo because you were born on July 24th? You may want to rethink your answer after reading this article.

Had there been a total solar eclipse at the moment of your birth, and had it been dark enough to let the stars come out, people looking at the eclipse would have seen it in the constellation Cancer. In fact, most people aren't the "sign" they think they are, but instead were born under the previous "sign."

This “error” in astrological calculation is due to an astronomical phenomenon called "precession of the equinoxes," a phenomenon discovered in 130 BC by Greek astronomer Hipparchus and known to Claudius Ptolemy, another astronomer, who was a Roman Citizen living in Egypt. This “error” is evident when comparing birth chart calculations between the sidereal system and the tropical system of astrology.

Sidereal and tropical are the terms for two systems of ecliptic coordinates used in astrology. Both divide the ecliptic into a number of "signs" named after constellations, but while the sidereal system defines the signs based on the fixed stars, the tropical system defines it based on the position of vernal equinox (i.e. the intersection of the ecliptic with the celestial equator Because of the precession of the equinoxes, the two systems do not remain fixed relative to each other but drift apart approximately one degree every 70 to 72 years.

A tropical system was introduced by Ptolemy in the 2nd century and remains prevalent in western astrology. A sidereal system is used in Hindu astrology, and in some 20th-century systems of western astrology.

While classical tropical astrology is based on the orientation of the Earth relative to the Sun and planets of the solar system (seasons), sidereal astrology deals with the position of the Earth relative to both of these as well as the stars of the celestial sphere. The actual positions of certain fixed stars, as well as their constellations, is an additional consideration in the horoscope. (Over very long astronomical time scales, these fixed stars are of course themselves far from stationary.)

Sidereal/Tropical Beginnings

A few centuries before the Common Era, some Greek astrologers decided to fix the zodiac on the equinox points rather than on the stars. This is the beginning of the Tropical Zodiac. In his astrological pursuits during the mid-First Century, Ptolemy noticed that the spring equinox occurred at 0*0'0" sidereal Aries. Ptolemy's translators misunderstood him, making the Tropical Zodiac the preferred zodiac in the west. The equinoxes had other plans, though, and the discrepancy between "signs," and the constellations they took their names from, is approximately 24 to 25 degrees -- almost a full "sign"!In the 1940's, an astrologer named Cyril Fagan was working with charts called Solar Returns. Solar returns are charts which are cast for the moment when the Sun returns to the place where it was when a person was born, in order to determine what issues they'll be facing until their next birthday. Every astrologer knew these charts were terribly inaccurate. While trying to solve the Solar Return problem, an exasperated Fagan eventually took a cue from Vedic Astrology (aka jyotish) and tried correcting for precession. Suddenly, Solar Returns were accurate. The Sidereal Zodiac was back. Amazingly, Fagan spent about twenty-five years doing creative work in tropical or traditional Western astrology before turning his attention to the tenets of siderealism. His book, Primer of Sidereal Astrology, is a core resource in that specialized field."

Ophiuchus Emerges

In 1995, Walter Berg, a British astrologer, introduced his 13-sign zodiac, which has the additional sign of Ophiuchus. Berg's system has been well-received in Japan after his book was translated by radio host Mizui Kumi in 1996.

A small number of sidereal astrologers wish to include other constellations, such as Ophiuchus, in their zodiac and use 13 signs instead of 12. This results in a system completely unrelated to the zodiac as described by Ptolemy. While Ptolemy noted that Ophiuchus is in contact with the ecliptic, he was aware that the twelve signs were just conventional names for 30 degrees segments (especially since the Aries sign had ceased to be in contact with the Aries constellation already in his time).

For the purpose of determining the constellations in contact with the ecliptic, the constellation boundaries as defined by the International Astronomical Union (IAU) in 1930 are used. For example, the Sun enters the IAU boundary of Aries on April 19 at the lower right corner, a position that is still rather closer to the "body" of Pisces than of Aries. Needless to say, the IAU defined the constellation boundaries without consideration of astrological purposes.

The dates the Sun passes through the 13 astronomical constellations of the ecliptic are listed below, accurate to the year 2002. Again, the dates will increment by one day every 70 to 72 years, and already several have changed. The corresponding tropical, sidereal, and astronomical (Sun in Constellation) dates are given below:



The Final Outcome

Generally, when I analyze astrological charts I use both sidereal and tropical systems for an overall view of what is occurring. During my research and studies, I have seen a trend that leads me to believe that the tropical system addresses the emotions and potential future of people as well as addresses the purpose of the person’s soul in their current incarnation. Similar conclusions can be made when we look at the seasons of the Earth, which the tropical system is based on. What changes occur to the Earth can and will in many cases affect us as well.

The sidereal system has lead me to believe that it addresses what our core foundation is and what kind of energy and past issues (karma) we have come into this life with. This can be likened to fueling up your car in preparation for a long journey. You can’t have one system without the other. Both tropical and sidereal are needed to determine the potential of the individual body, mind, and soul. Ophiuchus as a 13th zodiac sign just adds a deeper and a more profound dynamic, which I feel should also be included in the overall analysis of a chart.

Ultimately, use discernment in the analysis of your life journey. No person can tell you how your life should and will be. Only you can determine your journey. Use whichever system feels right for you because it all works when intuition is applied. Your focus determines your reality. Focus on your journey and not the destination and you might find yourself realizing that your journey followed the path of your astrological chart…!

Namaste,

David-Uriel “Eagle Heart”