Zodiac is a circular band extending approximately 9° on either side of the
ecliptic , so a band of 18°. The word derives from the Greek zoon, meaning
animal. In ancient times the zodiac was known as the "circle of animals" in
reference to the names of animals that designate constellations.
The Sidereal Zodiac puts the starting point (0° Aries) fixed with respect to the background stars.
The Tropical Zodiac puts the starting point (0° Aries) at the
Vernal Equinox , which due to the
precession of the equinoxes is moving 1° every 72 years against the background of stars.
The exact number of degrees of
between the Tropical and Sidereal
Zodiac (called Ayanamsha) is different depending on the school of Sidereal
From approximately, a planet located at 0° Aries for school Fagan
Bradley appears on 1° Aries in schools Lahiri and Krishnamurti, and on 5° Aries
in Sassanian and Hipparchos.
Currently displacement between Tropical and Sidereal
Zodiac Fagan Bradley is about 24° (and increased by 1° every 72 years.)
The only difference you will see in your reports with Sidereal Zodiac is that
most of the planets are in the zodiacal sign before the Tropical zodiac sign.
Aspects between planets and the positions of planets in the houses do not vary.
Currently tropical zodiac signs do not match the fixed star constellations
bearing the same name. Furthermore there is an important difference: the signs
are geometric sections of equal size, each comprising 30° in correspondence
with a period of approximately one month, the constellations have more irregular
shapes and sometimes overlap.
If we go to a astronomical observatory
one March 21 and ask astronomers where the Sun is, undoubtedly they will said it's in the fixed stars constellation of Pisces,
although in the Tropical zodiac will appear in the sign of Aries.
To the ancient civilizations that used astrology over 3000 years ago, the
beginning of spring (vernal equinox) marked the beginning of the year, as it was
the moment that life was returning to sprout in the ground, so the beginning or
Zodiac zero-point on the ecliptic was established using the vernal equinox , a
day during which the day and night are of equal length worldwide. (The word
"equinox" comes from Latin Aequinoctium, which means 'equal night' and vernal
From that point on the ecliptic Vernal divided into segments of
30° to delimit the 12 signs of the Zodiac. This way of defining the zodiac is
called Tropical Zodiac, also called "seasonal" because it is based on the
beginning of the seasons.
Puts the 0° Aries at the vernal equinox, is seasonal.
Puts the 0 ° Aries is fixed relative to the background stars.
It moves about 1° every 72 years over the background of stars.
Fixed on the background of stars. There are several schools to define the point 0º Aries
(Ayanamsha): Bradley Fagan, Lahiri, Sassanian, Krishnamurti, etc..
Used in almost all western Astrology.
Used in oriental Astrology (Hindu or Vedic) and in some schools Hipparchos.
We do not claim that the Sidereal Zodiac is better or worse than the Tropical.
Some astrologers believe that young people tend to identify more with the
Tropical and going "maturing" (acquiring higher level of consciousness, it has
not to do with age) is best suited for the Sidereal. Decide yourself which one suits you
best, in the current era of your life based on your own experience.
And if in
doubt, do not use any Zodiac at all: while reading your reports use only information on
aspects between planets and planets in houses as that information does not
change when using a zodiac or another.
The great astrologer Johannes Kepler abandoned the use of the zodiac and
based its astrological system only in the aspects between planets. Dane Rudhyar
wrote that the zodiac is a product of the capacity of the human psyche to
create myths and a remnant of the ancient civilizations that used it to determine
and mentally calculate the positions and aspects of planets.