Revisiting the Kinetic Solar Return

[Jim Eshelman]

I've been extremely impressed with Kinetic Lunar Returns. They are the next tool I'd add routinely if I were adding one. Bizarrely, I've been utterly disappointed with Kinetic Solar Returns. This doesn't make a lot of sense, but I've taken it for what it is.

As my Demi-KSR is today (which I really don't expect much from since even Demi-SSRs are disappointing), the whole topic came back to my mind. Some recent other work - on secondary progressions - is fresh in my mind, so it got me thinking about the possibility:

Maybe we have been calculating the KSR wrong.

I've said for a long time that we should be calculating secondary progressions at the rate of one mean solar day = one sidereal year. Solar Fire calculates it using the tropical year instead. Over time, discrepancies develop. These discrepancies would cause a larger shift in the timing of a KSR and negligible shifts in the timing of a KLR.

So... how much is the difference?

Solar Fire calculates my current KSR for December 21, 2022, 5:20:27 PM PST (MC 22°23' Aquarius). I already know that there are a couple of places for small errors. For example, SF's Sun calculations are (for modern times) slightly inferior to TMSA's, but that doesn't make a meaningful difference. Second, since SF doesn't calculate KSRs directly, I'm calculating this as transiting Sun conjunct natal Sun. This is another minor problem because SF's transit timing isn't quite as good as its return calculation. In this case, though, that's not a factor since both transiting and progressed Suns are 1°01'09" Sagittarius (I've seen them a minute or two different).

I have an Excel spreadsheet that calculates secondary progressed times based on one mean solar day = one sidereal year. What does it give for my secondary progressions December 21, 2022, 5:20:27 PM PST, the time SF calculated for the KSR? It says my secondaries should be calculated for December 17, 1954, 6:57:38 AM PST. Letting Solar Fire do the calculation, it gives Sun's longitude as 1°01'40" - or 0°00'31' later than SF's tropical year calculation.

How much does this 31" displace things? On the day of the KSR, transiting Sun moved 1°01' (61') so, approximately, it would move 31" in just over 12 minutes of time. That's 3° on the angles, on average. While it isn't a HUGE amount, it's enough to make a difference in how one felt about the chart. In this case, calculating a return for 1°01'40" Sag gives MC 25°40' Aquarius, 3°17' closer to Neptune and with transiting Venus 3° closer to Dsc. (The chart is primarily a closely angular Venus-Neptune square on the angles with Moon opposite natal Sun and square KSR Mercury.)

It's a separate question whether this newly-calculated KSR is a correct and meaningful. As a one-off, I could argue that it is - that at least I've been more lovey-dovey and romantic this calendar year - but one chart does not make a case.

The important part of this post is that - if I am correct about the proper rate for secondary progressions - the way Siderealists have always calculated Kinetic Solar Returns is guaranteed to produce progressively wrong results as one ages. My previous conclusions about them need to be revisited. If the new mode of calculation is correct, KSRs may be the way to confirm it (or, of course, deny it).

[Jim Eshelman]

This effect will not reach to a Kinetic Lunar in the same way. (The discrepancy will be small.) Let me demonstrate this:

Solar Fire calculates the next occasion transiting Moon conjoins secondary progress Moon as June 26, 2023, 7:17:13 AM PST (I'll leave it in PST for ease of calculating). For my home, this gives MC 2°23' Aries. SF gives Moon (both progressed and transiting) as 13°13'05" Virgo.

Using my spreadsheet to calculate the sidereal year based secondaries, it says that for June 26, 2023, 7:17:13 AM PST these should be calculated for December 17, 1954, 7:13:13 PM PST. This gives Moon 13°11'08" Virgo.

That's a bigger longitude difference than for Sun (because Moon moves faster). The correct progressed Moon for that moment is 0°01'57" earlier than SF calculated it. Moon on the day of the KLR will move 12°15', so it takes just under four minutes to move the 0°01'57" gap. This is just under a degree on the angles.

I suspect I would not have noticed a 1° discrepancy here and there when assessing whether KLRs looked accurate.

[SteveS]

Jim wrote:

I've said for a long time that we should be calculating secondary progressions at the rate of one mean solar day = one sidereal year.

Will Janus offer this option?

[Jim Eshelman]

Jim wrote:

I've said for a long time that we should be calculating secondary progressions at the rate of one mean solar day = one sidereal year.

Will Janus offer this option?

Good question, Steve. I just checked (not remembering how Janus calculates secondaries). Janus ()which does explicitly offer kinetic solar and lunar returns) apparently also uses the tropical year for secondary progressions but might use some other method since it giv es slightly different results.

Janus gives my last KSR as December 17, 2022, 5:24:46 PM PST. SF calculated it 5:20 PM (four minutes earlier) and the correct time seems to be eight minutes later than Janus gets. The Midheavens of the three are:

22°23' Aqu - Solar Fire
23°37' Aqu - Janus 5
25°40' Aqu - correct time