The Progressed Sidereal Solar Return (PSSR)

A reader recently sent this request in Spanish; here is the English translation:

“Anthony, good day. In the future could you explain Cyril Fagan’s method of progressing the sidereal solar return , from his book Primer of Sidereal Astrology (Chapter XII, page 49): the Progressed Sidereal Solar Return (P.S.S.R.)? Alexander Marr mentions that the P.S.S.R. is useful for rectifying natal charts with a 10 minute margin of error.”

Although I’m familiar with Cyril Fagan’s work, I am not a sidereal astrologer and have no special expertise in the subject. On the other hand, Fagan’s method of progressing the sidereal solar return is not unlike the way tropical astrologers might progress a return, so I decided to honor the reader’s request to the best of my ability. Comments and corrections are welcome from astrologers better versed in sidereal techniques than I am.

In his case example, Fagan starts with a well-timed birth chart, that of Susan Walker, and consideres the progressed solar return for a timed-event at age 10, her fall from a horse with a subsequent skull fracture and period of unconsciousness. Fortunately, she received treatment and recovered from the accident. Fagan calculated her chart in the sidereal zodiac with the ayanamsa that bears his name.

The accident occurred around Noon on 27 March 1960 in Blewbury, UK, 001W17, 51N35. Fagan used Campanus Houses. Susan was born in Kensington, London, UK, 000:09:26 W, 51:29:20 N at 2:33 AM GMT. Her birth was carefully timed and is accurate to the nearest minute. Here are the natal chart and the accident chart in the sidereal zodiac with Campanus houses. The solar returns are calculated for the birthplace, using Solar Fire software.

Next we need to consider that Sidereal Solar Returns preceding and following the date of the accident of 07 March 1960. They are as follows:

Some technical information:

A sidereal year is the time it takes for the Earth to complete one orbit around the Sun relative to distant stars, that is, a full revolution against the background of the fixed stars. 

The sidereal year is 20 minutes 24.5 seconds longer than the mean tropical year at J2000.0 is 365.242190402 ephemeris days long.

While the length of a sidereal year is generally considered constant at around 365.256363 days, it can vary a tiny amount from year to year due to gravitational perturbations from other planets, causing very slight fluctuations in Earth’s orbital path.

The length of a sidereal year at the epoch J2000.0 is 365.256363004 ephemeris days, or 365 days, 6 hours, 9 minutes, and 9.76 seconds. Fagan, however, used a mean length of 365.253842 days for the sidereal year in his Primer of Sidereal Astrology.

The Equation of Time shows the difference between “clock time” (what we see on our watches and phones) and “sun time” (when the Sun is actually highest in the sky) on any given day of the year. This happens because the Earth’s orbit is an ellipse and the Earth’s axis is tilted.
Our clocks assume the Sun moves perfectly regularly across the sky, but in reality the Sun is more like a train that sometimes runs a bit fast and sometimes a bit slow, depending on the season. The Equation of Time tells us exactly how “early” or “late” the Sun is running compared to our clocks. This difference can be up to about 16 minutes early or 14 minutes late, depending on the day of the year. Cyril Fagan took into account the Equation of Time when he progressed the sidereal solar return.

Cyril Fagan’s Method of Progressing the Solar Return

Fagan’s idea was to progress the MC of the Solar Return (and then calculate Asc, Dsc, and intermediate cusps) by calculating the difference in the sidereal times of two consequitive solar returns, adding 24 hours (the length of a day), and dividing the sum by the length of the sidereal year.

One could use the mean length of the sidereal year to get a mean rate at which to progress the Solar Return MC, or use the actual length of the sidereal year from a given solar return to the next, to calculate a precise rate at which to progress the MC of the solar return.

In either case, the result of this calculation gives the daily increase in sidereal time to be added to that of the initial solar return. The sidereal time of a given solar return progresses at this rate during the year, at the end of which it gives the precise sidereal time of the next solar return. Fagan writes (page 51), “Thus, there is a continuous progression of the angles of the return from birth to death at an approximate rate of 5 minutes [on the clock] a day.”

The astute reader will realize that Fagan’s method of progressing the solar return strongly resembles that of the tropical astrologer Wynn (Sidney K. Bennett) in the late 1920s.

Returning to our example, Susan Walker celebrated her 1959 sidereal solar return at her birthplace on the 8th of October at 3:58:02 UT. Solar Fire in its Chart Analysis Report indicates that the Local Sidereal Time of the solar return was 17:03:32 LST, equivalent to a RA MC of 255:53 degrees.

Her 1960 sidereal solar return occurred at her birthplace on the 7th of October at 22:14:43 UT, which Solar Fire shows as a local sideral time of 23:20:18 LST, equivalent to a RA MC of 350:04 degrees.

Following Fagan’s instructions, we find the difference in LSTs between the two returns, and then add 24 hours:
23:20:18 LST – 17:03:32 LST = 6:16:46 hours, to which we add 24 hours, giving the result 30:14:46 hours of sidereal time between the two solar returns.

Next, we must divide the difference in local sidereal times between the two solar returns by the mean number of days in a sidereal year, which is currently 365.256363004 ephemeris days:

30:14:46 hours divided by 365.256363004 days = 0.082807896 hours = 4 minutes and 58.11 seconds per ephemeris day as the rate at which to progress the 1959 solar return.

To find the progressed return for the date of the accident (27 March 1960) we must calculate the sidereal time that has elapsed between the 08 Oct 1959 solar reaturn and the 27 March 1960 accident. To do this, I like the calculator at the site https://www.timeanddate.com/date/duration.html, which gives the result that 171 days have passed between the two events. Because the 1959 solar return occurred at 3:58 AM UT and the accident at 12 Noon (a difference of about 8 hours), there is an interval of 171 days and 8 hours, or about 171.33 days between the events.

At a rate of 4 minutes 58 seconds per day, 171.33 days x 4m 51.11s = 14.1875 hours which is the amount of time to add to the time of the 1959 solar return to progress it to 27 March 1960 around Noon without taking into account the Equation of Time. Here is the progressed sidereal solar return (without the Equation of Time correction) generated with Solar Fire’s Animate feature:

1959 Sidereal Solar Return progressed to Noon on March 27, 1960 without correcting for the Equation of Time.

To correct for the Equation of time we must add an additional 18 clock-minutes to the amount of time by which we progressed the 1959 sidereal solar return. This is so because the Equation of Time for Oct 8th is + 13 minutes, and for March 27 is + 5 minutes. The sum is an additional 18 minutes by which the 1959 sidereal return must be progressed. Here is the final result, showing the 1959 sidereal solar return progressed to the date and time of the accident, corrected with the Equation of time of the dates of each chart.

1959 Sidereal Solar Rturn progressed to 27 March 1960 at Noon, with the Equation of Time correction.

Note that his progressed chart is essentially identical to the result obtained by Cyril Fagan on page 55 of his book. The tiny difference is due to Fagan’s use of a slightly different value for the length of the mean sidereal year and, perhaps, his calulating the Equation of Time a bit more precisely than I did in this demonstration.

Here is a comparison of the PSSR 1959 return with the birth chart at the time of the accident.

Natal planets in the outside wheel; PSSR on inner wheel with the natal South Lunar Node exactly on the PSSR Ascendant.