Is there really a 13th sign?
Every once in a while like a Kraken from the depths of the ocean, the 13th sign will rise up to threaten the order of astrology. Does it debunk astrology?
It’s merely a clever confusion of terminology. Let’s do a deep dive into the wonders of how we view the skies.
the equinoxes and to the twelve "Ages" which constitute twelve
sections of such a cycle.
Constellations vs. Signs
The 12 zodiac signs in astrology is different from a constellation of stars. What we call a zodiac, or star, sign is 1/12 of the ecliptic — that is, a 30-degree section of the apparent yearly path of the sun (the earth's orbit in the modern heliocentric system).
A zodiacal sign belongs to the tropical zodiac, while the twelve zodiacal constellations belong
to the sidereal zodiac.
In astrology there are separate schools of thought: one favoring the tropical
zodiac, the other the sidereal zodiac. The tropical zodiac refers to the twelve
signs of the zodiac, the sidereal zodiac to the twelve constellations. BOTH the signs and constellations bear the same name (Aries, Taurus, Gemini, etc.)
How do we calcuate the skies?
Modern astrology gets it data by calculating the positions of celestial objects by referring to two basic circles of motion:
One, apparent yearly path of the sun, called the ecliptic. In other words, how the earth goes in its yearly revolution around the sun.
Second, imagine the plane of the earth's equator is made to extend infinitely in space, becoming thus the
"celestial equator". This is the earth rotation in its equatorial plane.
The lines of intersection between the “celestial equator” and the which we call the spring and fall equinoxes. These two points are said to represent respectively longitude 0° (Aries 0°) and longitude 180° (Libra 0°).
The north pole and our north star
So the line of intersection of the ecliptic and the equatorial planes changes progressively because of a particular earth-motion — like a wobbling top.
Right now, the polar axis points to Polaris, in the constellation Ursa Minor, is our pole star. So, the earth can point to different "pole stars"; it is a cycle of a circle in space in about 25,000 years.