Quindecile (165°). Does it have any importance.

[Soft Alpaca]

I've been reading more on qundeciles. I believe Noel tyl found them important in some of his work many people sites and articles say it is a compulsive aspect (meaning a hard aspect?)

Janis Joplin has Moon-Mars with this aspect

David bowie would have a Moon-Sun

Kim Kardashian a Moon-Venus

Joan jett Moon-Uranus and Moon-Venus (both loose at 3 degrees)

Just curious if this aspect holds any potency.

[Jim Eshelman]

The 15° series of aspects has been found useful for some specialized micro-analytical purposes such as the timing of solar flares and very targeted use of solar directions of midpoint structures.

In a natal chart, the series is worthless. As a 24th harmonic, it's far past the threshold of workable aspects (by this point, you'd have nearly the whole 360° saturated with aspectivity - it would be impossible for two planets not to be in aspect.

[Jim Eshelman]

Here is a repost of the "Specific Harmonics" section of my paper as Astrological Structures:

The astrological value (meaning) of an aspect expresses an interaction of the nature of the two planets, regardless of which aspect they form. This interaction of the two planets can be viewed in different ways, e.g., a co-existence and interrelationship of the needs corresponding to each planet, a "firing off" of the two circuits simultaneously, each planet modifying or conditioning the expression of the other, etc. Ultimately, these are all variants on the same idea, and likely will be valid approaches as long as they boil down to the co-expression or interaction of the two planetary ideas.

Nonetheless, once we understand the primary meaning of an aspect to be the co-expression of the two planets, we also find distinctions between different aspect types (different angular separations). The most obvious distinctions appear to group in families of aspects. The aspect families are based on the division of the whole circle by a prime number, and then the successive halving of that value one or more times, each halving representing a degradation of strength and simplicity of the aspect's expression.

We need to keep the greatest interpretive attention on the natures of the planets involved, not on the type of aspect. Were it the other way around, we could argue that all planet pairs are in some sort of aspect at any time, and our job is to identify which aspect they might have - and interpret it accordingly. This doesn't match astrological experience with the aspects with which we are most familiar, and so likely doesn't match how other aspect types work.

This being so, the primary distinction is whether two planets are in aspect. (They have gradients of strength for those in aspect; but still, in practice, more like a light-switch that you punch to turn on-off, and turn to adjust intensity. Even though there is no absolute "off" setting, there do appear to be thresholds beyond which the drop-off is acute. In my model, this is the 50% threshold, where the strength of an aspect expresses the odds that it will manifest, so dropping from 51% to 49% strength means crossing a line between still more likely to manifest than not to not likely to manifest.)

While some meaningful connection theoretically could exist with any prime division of the circle, there comes a point where the practicality of a further "family" of aspects collapses because we start to lose distinction between whether a planet pair is "in aspect" or not. For example, 1/7 of the circle is 51.4°, not all that close to any other aspect; but 1/11 is 32.7°, and 1/13 is 27.7°, not only close to each other but close to the 30° aspect (semi-sextile) that may be of some importance. It would be absurd if aspects of 27.7°, 30°, and 32.7° all existed, even if they had only a 1° orb. This simply points out to us that there has to come a point where we stop defining further aspects!

Here are known aspect families, and what I believe are the distinctive characteristics of each. The divisors are all prime numbers.

Division by 1: 360°/1 = 360° = 0°. Theoretically this includes the CONJUNCTION (0°). I actually wonder if there is a "1 series," though, because aspects are measured by the angular separation between two great circles. The great circle (say, the circle of celestial longitude at right angles to the ecliptic) passing through a given planet wraps around the whole 360° of the celestial sphere and includes the opposition point on the opposite side. That is, if we measure the angular separation between two great circles, the conjunction and opposition appear to be the same aspect. (This doesn't mean we can't distinguish between one and the other half of the same great circle, but it does solve a few small technical problems.) Consider the conjunction as included in the next paragraph along with the opposition. [NOTE: In practice, conjunctions do seem to have more of a sense of identification, while oppositions often have more sense of one planet working on the other.]

Division by 2: 360°/2 = 180°. This is the OPPOSITION Family. This aspect set is also called hard aspects or dynamic aspects. They share the characteristics of dynamic action, incentive, and movement. The word "dynamic" broadly implies activity, force, energy, and change. These aspects seem more instinctual, direct, and impulse-driven. The CONJUNCTION (0°) and OPPOSITION (180°) are the first tier members of this family. The first degradation (first halving) produces the SQUARE (90°), which is nearly as strong and of similar character. A second degradation (second halving) produces the SEMI-SQUARE (45°) and SESQUI-SQUARE (135°) which are weaker, but still quite important, and of a similar nature (but perhaps having a more discernible friction, or drag against resistance, than the square). Some astrologers, especially of German schools, apply a third degradation to the 22.5° series: I have seen this operative in Solar Arc directions with very tiny orbs, but firmly dismiss them in natal charts: The second degradation appears to be the effective drop-off point in natal astrology.

NOTE: While another name for the semi-square is the octile (one-eighth), and for the sesqui-square the tri-octile (three times one-eighth), I question the need to distinguish between their names at all. There is no interpretive value to be gained, and the problem becomes much more complicated as we move through later aspect families. I propose calling both of these aspects "octile," which we understand to be short for "a member of the octile family." (This solves several linguistic awkwardnesses.)

Division by 3: 360°/3 = 120°. This is the TRINE Family. This aspect set is also called soft aspects or static aspects. They share the characteristics of placidity, quietness, stillness, and a lack of visible change. For example, in natal astrology they portray a status quo in the personality where a person naturally is disinclined to change or move. These aspect manifestations seem more structure-bound within the personality and often intellectual, so they may be specifically structures within the rational-cognitive part of the psyche which is more complexly architected and less instinctual. The TRINE (120°) is the first tier member of this family. The first degradation (first halving) produces the SEXTILE (60°), which is nearly as strong and of similar character. A second degradation (second halving) produces a 30° series which, aside from other aspects already identified, adds the third tier SEMI-SEXTILE (30°) and QUINCUNX (150°). These already seem extremely weak and of questionable value: Since third tier aspects in other families seem strong, the likely explanation of the weakness in this case is that the static, unmoving quality of this family has become so frozen and entrenched at this level as to be effectively immobile. Understandably, ancient astrologers termed these two aspects inconjunct or no aspect. Occasionally they seem more like anti-aspects, their presence showing disjunction between two planets, even a sense of alienation of one from the other.

Division by 5: 360°/5 = 72°. This is the QUINTILE Family. Members of this aspect set represent functions of the psyche that unfold as self-actualization (in the Maslow sense) and deeper spiritual unfolding/disclosure occurs, or genius unfurls, and, therefore, are of no interest or value in the vast majority of horoscopes. The QUINTILE (72°) and BIQUINTILE (144°) are the first tier members of this family. (I don't know that they need separate names: "quintile" serves them both.) The first degradation (first halving) produces the DECILE (36°), which is nearly as strong and of similar character. A second degradation to the 18° series appears to be valid for the highly specialized purposes of this aspect family. (The best way to observe these is a 5th harmonic chart, in which conjunctions, oppositions, and squares represent the three tiers, and orbs are instinctual.) A more thorough study of this series is here: http://solunars.com/viewtopic.php?f=16&t=301#p1981

Division by 7: 360°/7 = 51°26.7'. This is the SEPTILE Family. I have not been able to discern a distinctive characteristic of this family, even though I have theories, and even though I have motivation since my own Sun and Moon are in triseptile aspect. (It arguably would be a defining theme in my life.) My theories center around one-seventh being the basis of a series of irrational numbers, but I have no evidence that this is relevant, or what it would mean in practice. (Some astrologers credit these aspects with an inspirational or other-worldly character, which I find nearly as obscure. John Addey, from his Harmonics research, characterized it as having a "repressive and disturbing" character, but with more concrete details that don't hold up. Dane Rudhyar theorized that it gives an "anti-social predisposition" that "tends to escape from collective constraints." I have insufficient evidence to substantiate either of these.) The SEPTILE (51.4°), BISEPTILE (102.9°), and TRISEPTILE (154.3°) are the first tier members of this family. (The best way to observe these is a 7th harmonic chart.)

Beyond this point, there seems no reason to explore further families. The Septile family seems not understood at all. Division of the circle by 11 and 13 produce aspects of 32.7° and 27.7°, respectively, which are so close to a semi-sextile that they provide little or no opportunity for two planets to be out of aspect. We seem to have hit our practical limitation. Most of the time, we will only find practical value in the Opposition and Trine series.

On the other hand, there are highly specialized situations where micro-aspects have proven useful. John Nelson's work comes immediately to mind, in which we descended to at least the 22.5° and 15° multiples and maybe further to refine his techniques of sunspot and solar flare formation. Obviously, the orbs in such instances are negligible, and a raw geometric mechanics of the universe is evidently in play with little or no planet-distinctive characterization.

NOTE: There is a kind of exception, outside framework of the above. Siderealists have widely embraced the validity of either the Novien or Navamsa sub-chart, a form of 9th harmonic. Hard aspects in these are often given considerable importance. To get all conjunctions, oppositions, and squares in the Novien or Navamsa, one can simply look at all 10°-multiples. The orbs for these, however, are quite small, one-ninth the orbs in a nativity; generally under 0°40'. I suspect that most impressive examples of semi-sextiles and quincunxes are actually simply 10° multiples.

Summary
The astrological value of an aspect primarily expresses interaction of the natures of the two planets, e.g., a co-existence or mingling of the needs corresponding to each planet, a "firing off" of two circuits simultaneously, each modifying or conditioning the expression of the other. Secondarily, we find distinctions between different aspect types. Aspect families are based on dividing the whole circle by a prime number, and then successive halving of that value one or more times, each halving representing a degradation of strength and simplicity of the aspect's expression. The OPPOSITION Family (division by 2) aka hard aspects or dynamic aspects, share characteristics of dynamic action, incentive, and movement, or activity, force, energy, and change. These are instinctual, direct, impulse-driven. The TRINE Family (division by 3) aka soft aspects or static aspects, share characteristics of placidity, quietness, stillness, a status quo or lack of visible change. They are less instinctual: more complexly architected rational structures. The QUINTILE Family (division by 5) represent psychic functions that appear as self-actualization and deeper spiritual unfolding (or biological unlocking of genius) occurs. The SEPTILE Family is division by 7. Additionally, all 10°-multiples appear to be valid aspects within tiny orbs.

[Soft Alpaca]

The 15° series of aspects has been found useful for some specialized micro-analytical purposes such as the timing of solar flares and very targeted use of solar directions of midpoint structures.

In a natal chart, the series is worthless. As a 24th harmonic, it's far past the threshold of workable aspects (by this point, you'd have nearly the whole 360° saturated with aspectivity - it would be impossible for two planets not to be in aspect.

Ok thanks Jim.