Heliocentric Declination

Heliocentric declination – astrology without astronomy

Sergey Tarasov

Very often I receive the question “How to calculate HELIOCENTRIC DECLINATION for some planets?”. And I always have to provide the same answer: “My friends, there is no such a thing in Nature as Venus heliocentric declination (as an example)”.
This misunderstanding came from George Bayer’s book “Stock & Commodity Trader’s Hand-Book of Trend Determination”. Please check any of his rules where “heliocentric declination” is used. Let us look together at the Rule N30 and check it using the ephemeris. You will see easily that Bayer speaks about regular declination in geocentric coordinates.
Declination is the latitude of the planet in Equator coordinates (accordingly, Right Ascension is the longitude). Usually it changes between 23-rd South and 23-rd North degrees; sometimes the planets exceed these borders (especially Pluto though it is not a planet any more).
I put here declination diagrams for the Sun (yellow) and Venus (lime):

I know the only way to calculate “heliocentric declination”. You may follow these steps:
a) calculate heliocentric longitude for any planet;
b) find what declination of the Sun corresponds to this longitude (now we assume geocentric longitude).
You can easily calculate this declination as Sinus of heliocentric longitude:

But you always should remember that:
1) this “declination” has not any connection with the astronomical reality;
2) George Bayer did not use it.
The important points of this “declination” Zodiac correspond to Venus’s ingress to cardinal signs in heliocentric coordinates (Aries changes the semisphere from South to North, Cancer – max north declination, etc):

I believe this is a simple mistyping in a book that continues to live.
Somehow this situation reminds me one ancient Hindu legend: “One old master of yoga used to tie his cat to the nearest tree when he did a prayer. It was his favourite cat, and it bothered him constantly, so the master had no other choice. Times came by, the master passed away, and his followers continued the work of their teacher. Before starting a prayer, they looked for a cat, and it became a mandatory part of the praying ritual. They would not pray until some cat was found and tied to the same tree.”
I understand the respect that we all have to the great masters of the past. However, in my opinion, they would be more pleased if we understood what they actually were doing…