Astrology with Donnalyn  (

OpeningArt   Welcome   Articles, Links, & Events   Services   About Donnalyn   ContactDonnalyn


Declination conversion is a method for converting a planets degree of declination to a degree of the zodiac. What we
commonly think of as a planets zodiac degree its Longitudinal positionis just one of three zodiac degrees that
correlate to the planets actual position in our sky.

Astrology derives meaning from planets positions along the ecliptic (the Suns apparent path through the zodiac). But
most of the time, except for the Sun, planets are located off the ecliptic. So we must decide which point(s) along the
ecliptic to use as a planets zodiac degree.

Astrologers almost exclusively use planet's longitude-based zodiac degree (the zodiac degree the Sun would be at if it
were at that planets degree of Longitude). However, for a planets position off the ecliptic, there are two other
meaningful zodiac degrees, known as the Declination-Equivalent and Declination-Antiscia. By taking these other
zodiac degrees into account, we can fine-tune our astrology!


A planets Declination-Equivalent and Declination-Antiscia degrees are the two zodiac degrees at which the Sun could
be if it were at that planets degree of declination (the distance north or south of the celestial equator). Except for the
solstices, for every degree of declination the Sun passes on its trek North, it passes the same degree of declination
again on its way South. So for each degree of declination there are two corresponding zodiac degrees. The position
closest to the planets regular, longitudinal zodiac degree is its Declination-Equivalent zodiac degree. The other position
is its Declination-Antiscia zodiac degree.

Many astrologers already use raw declination degrees to determine whether two planets are parallel or contra-
parallel one another. While this provides some information, it has drawbacks. Raw declination degrees do not have the
impact of zodiac degrees. Notice the differing impressions you get reading 12N43 and 26Leo25. (Or, for that matter,
the raw longitude degree of 146.42.) While each corresponds to the same point on the ecliptic, far more information
floods into your mind with the zodiac notation. More importantly, raw declinations do not show all the aspects we use,
such as squares, semi-squares and quindeciles.

Caution! Because declination-conversion increases the potential number of aspects, it is crucial to strictly limit aspect
orbs and to focus on measurements that either activate tense natal configurations or have their own clear, significant

I generally use the following orbs:
Natal aspects: no more than about 2.5 degrees.
Solar Arcs: no more than about 2/3 degree applying and 1/3 degree separating.
Outer planet transits: no more than about 1/3 degree.
Jupiter or Saturn transits: no more than about 1 degree.
Mars transits: no more than about 1.5 degrees.

Declination-conversions are easily calculated using software such as Hallorans AstrolDeluxe. I've recently learned that
SolarFire 6 also has this function. A conversion table is also available here, along with instructions for calculating by hand.


Home | Contact
© 2006 Astrology with Donnalyn | Web Site Design by Barbara