Progression Types & Settings Explained

iPhemeris currently offers the most common Progression styles.

Changing the default Progression settings does not change the progression style used on progressed charts previously created and already in your chart database.

Progression settings for individual charts are stored with each chart in the database allowing you to experiment with different progression styles. To change the progression settings of an existing chart, edit the chart individually using the chart editor.

TERMS EXPLAINED (Sort of)

We say “sort of” because there is a lot of loose usage and conflation relative to Progression terminology. iPhemeris uses them in the following manner:

• Progression – Moves the planets, bodies and angles in time based on the actual planetary motion for the elapsed time between the date/time of the Natal or Radix chart, and the date/time of the Progressed chart. Progressions typically produce positions as they are found in an Ephemeris. Progressions techniques produce charts where the angular relationships are constantly changing over time just as they do in the sky.
• Direction – Moves all planets and points by the same amount or arc, either degrees longitude or Right Ascension (RA), depending per the selected type. Direction is typically based on the Sun’s arc in Longitude or RA, but directions can also be based on the movements of other bodies. Currently iPhemeris offers directions based on the Sun. Direction techniques keep all the angles between the directed elements the same.

PROGRESSION STYLES – PLANETS

• Secondary Progressed – Planets & other bodies are moved 1 day for each year and fraction thereof between the date of the natal or radix chart, and the date of the Progressed Chart. They are all shown in their position on the implied Secondary progressed date and time. iPhemeris calculates the exact time (to the second) between the two dates given, and uses the interpolated ephemeris positions for that time. For example, in a Secondary Progressed birth chart for a person 30 years and 6 months old, you would see that the positions shown on the progressed chart are between the Ephemeris values at the 30th and 31st rows (days) after the birth date.
• Solar Arc in Longitude – All planets are moved the same number of degrees (in longitude) which the Sun moved as calculated by the Secondary Progressed technique described above. Using this style of progression, planets will be in positions they never actually occupied (as a group) in time and space. For example, inner planets move faster than 1 degree per year and some of the outer planets move less than 1 degree per year and so moving them all together at the rate of the sun’s movement creates a configuration that never actually existed.

PROGRESSION STYLES – CUSPS

• Solar Arc in Longitude – The MC is progressed by the Sun’s Solar Arc in Longitude from the natal or radix date to the progressed date. The Ascendant and cusps are calculated from the progressed MC’s implied Right Ascension. Solar Arc in Longitude uses the distance the Sun travels along the plane of the Ecliptic.
• Solar Arc in RA – The MC is progressed by the Sun’s Solar Arc in Right Ascension from the natal or radix date to the progressed date.  The Arc of RA is applied to the natal RAMC and then used to derive all the other cusp and sensitive points. Solar Arc in RA uses the distance the Sun travels along the Equator.
• Naibod in Longitude – The average daily motion of the Sun in longitude (360°/365.24219879) between natal date and date progressed to is added to the MC and which is then used to derive the other sensitive points.
• Naibod in RA – The average daily motion of the Sun in longitude (0° 59′ 8.33″) between natal date and date progressed to is added to the MC and which is then used to derive the other sensitive points.
• Quotidian – Calculates the cusps using the actual date/time of interpolated progressed date. This is useful for progressing and doing Horary analysis because the progressed cusps change throughout the year according to the fractional portion of the year of the radix. If you don’t understand this explanation then use Solar Arc in Longitude.
• Solar Solar Arc Directed – MC, ASC and cusps are moved the same number of degrees in longitude the Sun moved, using the Secondary Progression technique.