Progressions and Directions – some notes

 

AC = AstroConnexions. SA = Solar Arc, RA = Right Ascension, Long = Longitude, MC = Midheaven, Asc = Ascendant

Secondary Progressions

RA, Long – Naibod

Tropical and sidereal are calculated by AC in the same way Solar Fire, Astro Gold iOS, and astro.com calculate these progressions. Note that astro.com does not calculate sec. prog. in long.

MC by Solar arc – this is similar to the setting in astro,com (which is used with sec prog. in RA):

MC from Solar Arc

MC from Solar Arc

Solar Arc directions

Long 

AC calculates the difference between the natal Sun in long and the progressed Sun in long which gives the Solar Arc. This arc is added to the ramc of the natal MC to give the progressed MC in RA. Then the ecliptic longitude of the progressed MC and corresponding Asc is derived.

astro,com gets the same results as AC. Astro gold iOS calculates the Asc differently. It adds the SA arc to the natal Asc. This gives a different Asc directed degree from AC and astro.com

The SA arc is added to the natal planetary positions to get the SA progressed planetary positions. Parts, eg Part of fortune are calculated from the new progressed positions.

RA

AC calculates the difference between the natal Sun in RA and the progressed Sun in RA – Solar Arc. This arc is added to the ramc of the natal MC to give the progressed MC in RA. Then the ecliptic longitude of the progressed MC and corresponding Asc is derived.

Astro.com does not include SA by RA. Note that Astro Gold iOS calculates the Asc and MC differently than AC.

The Solar Arc in RA is added to the natal planetary positions to get the SA progressed planetary positions for AC. Astro Gold iOS does not do this.

Parts, eg Part of fortune, are calculated from the new progressed positions.

Tropical and sidereal:

AC recommends using Solar Arc in Long, Secondary Progressions in RA.