Vic DiCara has actively participated in Vedic culture since 1991. He began practicing Jyotisha professionally in April of 2008. He received mantra-diksha into the Rupa Goswami sampradaya of Gaudiya Vaishnavism and has translated and taught courses on many subjects of Vedic Philosophy and Rasa Theology. Additionally, Vic is a professional musician who has toured the world and published records extensively since 1988. His ability to bridge the conceptual gaps between East and West and to simplify complexities without losing subtlety has gained him renown already in Astrology and in all his pursuits. He currently offers private readings and personal instructions and can be reached via his website: www.VicDiCara.com or email: email@example.com
The universe is, in an obvious and literal sense, our mother. We exist in her womb and are made from her substances. The stars and planets of the heavens are part of our mother’s visible body. The way the planets and stars move is her “body language” revealing how the universe will move to care for the upbringing of us, her children. She communicates to us in this way to help us navigate and understand the destinies we have created for ourselves over countless lifetimes on a great journey towards self-realization.
In any language it is important to grasp the fundamental grammar. Astrological grammar has three primary parts:
- The planets
- The space through which they roam – the “zodiac”
- The way this space relates to a given time and place on earth – the “houses”
This paper will address our understanding of the second part of basic astrological grammar: the zodiac. Being a basic topic does not make it less important. On the contrary that which is fundamental is essential. This fundamental topic is in dire need of address because the international community of serious astrologers has not yet agreed upon how to even define it!
What’s the Problem?
Stated basically, there are two opposing ways to define the zodiac:
- In reference to the stars
- In reference to the Sun’s relationship to the earth.
The first is what we call a “sidereal zodiac” and the later a “tropical zodiac.” Most astrologers pick one side of the debate and denounce the other. In this paper, however, I will explore reconciliation between the two.
Sidereal Twelvefold Zodiac – A Zodiac of Stars?
My background and roots are in Indian astrology (“Vedic astrology”). Naturally, I will explore this topic from that vantage point, but I am confident that what I discover will be of significant value to the entire international astrological community regardless of school or denomination.
If you know anything about Indian astrology, the first thing you probably know is that we use a sidereal twelvefold zodiac. That’s my starting point. At first, I figured the tropical zodiac was some kind of mistake; or perhaps at best a theoretical system. After all, I could look down at my sidereal calculations telling me the Moon was in Taurus tonight, and then look up in the sky and see with my own eyes that the Moon really was in Taurus. So, the sidereal zodiac initially struck me as the obvious, real and accurate one.
But sometimes I would look down at my sidereal calculation telling me Jupiter was in Aries, for example, and then look up to see it playing with one of the fish of Pisces. The real constellations themselves, I figured out, are all sorts of different sizes. Some take up a lot more space in the zodiac than others. But the sidereal zodiac in my astrological calculations has all the twelve signs fixed at perfectly equal size: 30° each.
So, the twelve sidereal signs are really not identical to the twelve constellations.
Now that we are asking questions, if it really is a zodiac of stars, why are there twelve? According to traditional definitions of the night sky, there are thirteen constellations in the zodiac belt. You see twelve, someone else sees thirteen, I might see five symbols up there. Who defines which is correct, and based on what logic?
These are rhetorical questions, mind you, which I will soon answer. But for now what I want to know is, if the sidereal signs are not literally a zodiac of the stars, what are they?
What is the Twelvefold Sidereal Zodiac?
The question was: Why does the twelvefold sidereal zodiac have twelve equal divisions in spite of there being thirteen unequally sized zodiac constellations? The answer is: Because each division does not represent a constellation! Each division represents the amount of space traversed by the Sun in the amount of time it takes the Moon to make a complete revolution through the zodiac.
The Sun and the rest of the planets roam through a relatively narrow band of space. One complete lap of the Sun through the whole thing is the essential definition of a “year.” During each year, the Moon makes twelve complete laps through the zodiac, each the same length. Each lap is the fundamental idea of a “month” and a “sign.” This 12:1 relationship between the motions of the Moon and Sun is precisely why we have twelve signs in the zodiac, and is why each sign is the same length.
We designed our clocks to reflect this. Each of the twelve numbers on a clock face marks the distance traveled by the hour hand during a complete revolution of the minute hand. Similarly, each border of the twelve zodiac divisions marks the distance traveled by the Sun during a complete revolution of the Moon. The beautiful clockwork of Mother Nature creates the twelve signs of the zodiac, not some fanciful connect-the-dots game played in the sky.
Both systems, tropical and sidereal, use these mathematical ratios representing the Sun and Moon to define their twelve divisions. Neither uses the stars themselves. Our language reflects this. We call the divisions “signs,” not “constellations.” OK, sure, English is a sloppy language, but even in Sanskrit – which is anything but a sloppy language – we call them rāśi, not nakṣatra. The word nakṣatra directly refers to heavenly bodies: stars and planets. The word rāśi on the other hand is an abstract word that has nothing specifically to do with stars, and instead is a mathematical term referring to degrees collected in an angle of arc.
Despite advertising to the contrary, the sidereal twelvefold zodiac is not the stars themselves. What then is the difference between tropical and sidereal signs?
The Real Difference between the Sidereal and Tropical Conceptions
The only real difference between the sidereal and tropical conceptions of the twelve signs is where they choose to start from. Both of them are equal divisions of space based on the twelve months of the year (a.k.a. the twelve lunar cycles in a solar cycle). The only difference is what point in space they pick to start marking the division from.
The tropical zodiac starts relative to the Sun crossing the equator heading northward (the “vernal equinox”). The sidereal zodiac is supposed to start at the beginning of the constellation we call Aries. But, where is that? Remember, the sidereal zodiac is not exactly the stars themselves, so it’s not that the first star in Aries is the beginning of its sidereal sign, and the last star is its end. There are many opinions about where sidereal Aries begins, and thus many different versions of the sidereal signs. They all are in the same ballpark, setting the start of Aries somewhere about 40° west of the star named Aldebaran.
Which One is Better?
To my sensibilities, the “better” zodiac would be the one that makes more sense and is somehow more “original” and “authentic.”
Trying to figure out which one is more original leads us to discuss the “precession of the equinoxes.” It takes a certain amount of time to get from one vernal equinox to the next: A year. And it also takes a certain amount of time for the Sun to move from one star, around the whole plethora, and back to the same star. How much time? Also a year. They both take “a year” but they are not the same amount of time. They are slightly different. Twenty minutes different. So they phase slightly out of sync as centuries pass.
The point of the vernal equinox therefore very slowly drifts (“precesses”) in relation to the stars. About 2,000 years ago it was aligned with what we now consider the beginning of the constellation we call Aries. So it appears that this was the time in history where the two ways of calculating the twelve signs overlapped and blurred.
Siderealists examine this clue one way, tropicalists another. Siderealists say that we wrongly took the names and qualities of the twelve constellations and ascribed them to the twelve mathematical divisions of the year. Tropicalists, on the other hand, say that we wrongly took the names and characteristics of the twelve mathematical divisions of the zodiac and ascribed them to stellar constellations.
Who is right?
Is the Twelvefold Sidereal Zodiac Original and Correct?
Those who feel that the sidereal starting point of the zodiac is original say that ancient peoples looked up at the stars in the sky, drew pictures up there by stringing together the patterns, and assigned mythology and meaning to the divisions created by those connections. They say that this mythologically informed “connect-the-dots” is the origin of astrology and of all the meaning of the twelve zodiac signs.
But I have two big questions:
- How can the imagery of the constellations be the source of all its meaning when they are just vague dots that don’t really look anything like the animals and creatures they are supposed to be? It is not reasonable to ask me to believe that the dots of light in the sky create the rich meaning of the twelve signs.
- If the stars themselves are the source of meaning for original zodiac, then the stars themselves should define the borders of the twelve areas of meaning. Why then is the sidereal zodiac not a division of some number of unequal signs?
Thus I do not find the siderealist’s argument compelling.
Is the Twelvefold Tropical Zodiac Original and Correct?
It is logical and reasonable that the clockwork interplay of Sun, Moon and the Earth is the origin of the borders and rich meanings of the twelve zodiac divisions. Symbols like rams and crabs and scorpions came later, devised as mnemonic and communicative aids for the rich meaning already extant in the divisions. Creatively tracing those pictures among the vague stars came much later, probably right around 2,000 years ago.
The zodiac has inherent meaning, and the symbolism is just an aid to express that meaning in an intuitive manner. Each zodiac sign derives meaning from four constituents:
- The planet who creates and tends it (“ruler”)
- The elemental material it is created from (“element”)
- The attitude it expresses itself with (“mode”)
- Its “natural order” in the zodiac.
The tropical system rationally explains all these. This is a serious mark of superiority over the sidereal system which asks us to believe that the meanings of the zodiac divisions arise from the imaginations of ancient star-gazers.
I will now attempt to express the rational tropical explanations for the four constituents of meaning in each sign.
Planetary Rulers Based on Relationship to the Sun
The planet which “rules” a sign is the active principle which transforms the latent energy of the primordial sign into something organized and meaningful – in just the same way as people go into wilderness and transform its resources into civilization. What logic determines which planet rules which sign? It is based on the relationship of the planets to the Sun.
The Sun and the Moon are the kings of the sky – they own the whole thing: i.e. their polyrhythmic interplay of 12:1 defines the zodiac as having twelve equal portions.
These two kings take possession of the two portions that appealed to them most, due to their elemental and modal affinity. The Sun takes the fifth portion, Leo; the Moon the fourth, Cancer. They then place the remaining ten divisions in the care of the five real planets.
Mercury is the closest to the Sun, so it gets the two divisions closest to the Sun and Moon: Gemini, which directly borders the Moon’s Cancer, and Virgo, which directly borders the Sun’s Leo. Venus is the next closest to the Sun, so gets the next closest zodiac divisions: Taurus (bordering Gemini) and Libra (bordering Virgo). The Earth is not an astrological planet, it is the foundation and stage of astrology, so the next closest planet to the Sun after Venus is Mars. Mars thus gets the next closest divisions: Aires (bordering Taurus) and Scorpio (bordering Libra). Then Jupiter gets Pisces (bordering Aries) and Sagittarius (bordering Scorpio). Finally Saturn, the furthest planet, gets the signs furthest away: Aquarius (bordering Pisces) and Capricorn (bordering Sagittarius).
The main source of meaning in the signs – the planetary ruler – is thus a Sun-based logic. This suggests that the Sun based starting point for the zodiac is the original twelvefold zodiac. The sun-based starting point is the vernal-equinox, which defines the tropical zodiac.
Elemental Nature Based on the Relationship of the Sun and Earth
If the ruling planet is the “person” who creates a culture and civilization out of wild raw materials, the elemental nature of the sign is the raw material itself. What logic decides what element exists in which sign? Logic based on the relation of the Sun to the Earth.
First we must consider the meaning of the Earth’s four cardinal directions, which is derived due to the Sun’s association with those directions.
- The Sun rises in the East. Thus the East is our source of light. It is therefore the direction of dharma – morality which illuminates the correct path and punishes those who willfully stray. The element of dharma and the east is fire, which both illuminates and punishes.
- The Sun sets in the West. Evening comes and we stop working and begin to relax and enjoy. The West is therefore the direction of kāma – enjoyment, pleasure and sensation. The element of kāma and the west is ever-fresh are unrestrained air.
- The Sun rises overhead to high noon in the South. During the bright daytime we work and earn our bread. Therefore it is the direction of artha – accumulation of prosperity and status. The element of artha and the South is practical, stable, and fertile earth.
- The Sun disappears in the midnight darkness of the North, which is therefore the direction of going deep within and withdrawing from common affairs. The North is thus the direction of mokṣa – self-realization. The element of mokṣa and the North is reflective, deep and contemplative water.
Next we must consider how the directions pertain to the signs. Tropical Aries is the vernal equinox, the “sunrise” of the year. It is therefore the East. Aries is similar to the first house, the location of the sunrise in the east, by the principle of “natural order.” So by that reckoning too Aries is east. The seventh house is the West, so is the seventh sign Libra. It is also the autumnal equinox, which is “sunset” of the year. The tenth house, high-noon, is the South, so is the tenth sign Capricorn. The fourth house is the North, so is the fourth sign Cancer.
- Since Aries is the East it is fire.
- Since Libra is the West it is air.
- Since Capricorn is the South it is earth.
- Since Cancer is the North it is water.
What about the rest of the signs?
Stand in the northern hemisphere and watch the Sun through the course of a day. At sunrise you must face east; at noon you face south; at sunset, west; and, if you could see the Sun below the earth at midnight you would be turned northward. Thus the Sun’s motion around the Earth proceeds in this order: east, south, west, north.
The elements of the zodiac proceed from Aries in the same order. Aries east, Taurus south, Gemini west, Cancer north, and so on. East (Aries) is fire. South (Taurus) is earth. West (Gemini) is air. North (Cancer) is water. Continue this pattern through all twelve divisions and you have a perfect map of the elements of the signs.
The twelvefold zodiac divisions derive their elemental meaning relative to the Sun’s interaction with the Earth. This is another strong point favoring the conclusion that a twelvefold zodiac anchored to a point defined by the Sun’s relationship to the Earth (the tropical zodiac anchored to the vernal equinox, for example) is the original zodiac, the origin of all the meaning therein.
Modal Nature Based on the Relationship of the Sun & Earth
There are three modes: Cardinal, Fixed, and Dual. What determines which signs are endowed with which modes? Logic, based upon the Sun’s relation to the Earth.
First let’s understand what the modes are.
- Cardinal commits to new direction.
- Fixed commits to staying on the course it already knows.
- Dual doesn’t commit, it tries to span divergent approaches.
Now, the logic of how the signs acquire the specific modes they have. There are four major milestones in the progress of the Sun’s relationship to the Earth.
- It crosses the equator heading north – the vernal equinox.
- It hits its most northerly point – the summer solstice.
- It crosses the equator heading south – the autumnal equinox.
- It hits its most southerly point – the winter solstice.
Aries begins at the vernal equinox. This is when the Sun commits to a new course (“cardinal”) of making the days longer than the nights. In Taurus, the second phase, it must remain fixed in this course. In Gemini, the third phase, it must do two things (“dual”): complete the current course and prepare to take a new one.
Cancer begins at the summer solstice, when the Sun commits to the new course of making days shorter. That is why Cancer is cardinal. The next sign Leo keeps the sun “fixed” on this course, and the next, Virgo has the “dual” role of finishing one course and getting ready for a new one.
Libra begins at the autumnal equinox. Now the Sun becomes “cardinal” again by committing to a new course: making the nights longer than the days. Thus Libra is cardinal. Scorpio keeps the Sun “fixed” on this course. Sagittarius prepares it to both (“dual”) complete the old course and begin a new one.
Capricorn begins at the winter solstice, where the Sun again becomes “cardinal” and commits to the new direction of making the nights shorter. After cardinal Capricorn, Aquarius keeps the course steady and “fixed,” and finally Pisces has the “dual” task of preparing to complete one direction and take up a new one.
Thus the twelve signs get their modal qualities as a result of tropical phenomena: the Sun’s relationship to the Earth.
Another source of meaning is the natural order of a sign. The logic here derives from the correlation of the first zodiac division with the first house, second with the second house, etc. Houses are phenomena derived from how the Sun travels through the sky over the course of a day – another tropical consideration.
Where do Things Really “Start”?
It all boils down to this: What is the “start”? What is the “beginning”?
The answer is plain as day: Sunrise is the universal symbol of beginning.
Where is the sunrise? Its in the east. Therefore the east always represents beginnings. But, where is “east” in space? How do you define the four cardinal directions in reference to the sky? Well, it’s not that hard. The Sun moves north and south of the equator each year; its furthest northern point points to celestial north; its furthest southern points south.
Midway between moving from one extreme to the other, the Sun crosses exactly over the equator. We call it an “equinox” because this position of the Sun makes the days and nights exactly equal in length. It happens twice a year. While doing this northern and southern cycle and crossing over the equator, the Sun simultaneously revolves through the circle of the stars over the course of the year. So the Sun points in one celestial direction when it crosses the equator heading north, and the opposite celestial direction when it crosses heading south. The later points to celestial west, the former to celestial east.
We’ve come to call the former the “Vernal Equinox” because we associate it with spring. But regardless of the season, the Vernal Equinox marks celestial east, and therefore is the true, natural beginning for astrological and astronomical measurements: the celestial “starting line.”
The Tropical Zodiac is the Original Twelvefold Zodiac
Constellations themselves are not identical to the sidereal zodiac; and there is no logic in believing that vaguely connected dots of light in the sky are the original source of the rich meaning in the twelve divisions of the zodiac. On the contrary the Sun’s tropical interplay with the Earth is a complete, rational and logical origin for all the meanings and borders of the signs.
Therefore it seems beyond reasonable doubt that the original twelvefold zodiac is tropical. Our current measure of sidereal constellations bearing the same names and qualities must be the projections of the original tropical zodiac. If we rewind the precession of the equinoxes it appears that the projection we currently consider the sidereal signs was cast about 2,000 years ago.
What do the authoritative historical voices of astrology have to say about this? Do they describe the twelvefold zodiac as tropical or sidereal? I will, in keeping with my background and experience, examine Indian astrological authority.
Most highly regarded textbooks on Indian Astrology are entirely concerned with how to interpret the planets, not how to calculate their locations. India traditionally divides astrology into three branches: calculation, interpretation, and omen reading. The experts in one branch are not experts in another, since each branch is so vast. Thus, I will focus my attention on the historically authoritative books of Indian astrological calculation.
Sūrya Siddhānta & The Veda
The most authoritative Indian text on astrological / astronomical calculations is without a doubt the Sūrya Siddhānta, a title which declares the book to be “Perfect Conclusions of the Sun.”
The 13th text of the first chapter says that the twelve signs of the zodiac are determined by the months of the year, distinct from sidereal, civil, and lunar calculations given immediately preceding sentences. Thus Sūrya Siddhānta describes the twelvefold zodiac tropically.
Precession and Recognition of the Vernal Equinox
The 27th text says that all calculations of planetary positions should be made in reference to the sidereal nakṣatra, not the twelvefold tropical zodiac. These positions are later converted to tropical coordinates. I will elaborate on that later, but first there is something quite fascinating in this 27th text.
It states that planets complete their journey through the stars when they come to the end of the constellation Revatī, which aligns to the end of sidereal Pisces. Thus Sūrya Siddhanta says that the planets “begin” their movement at the beginning of the nakṣatra after Revatī: Aśviṇī, which aligns to the beginning of sidereal Aries. However, the oldest existing Indian astronomical texts (The Black Yajur Veda and the Atharva Veda) list Kṛttikā as the starting point, not Aśviṇi!
It makes good sense, because the vernal equinox was in Kṛttikā (which spans sidereal Aries and Taurus) when those older Veda were written. And by the time the current version of Sūrya Siddhānta was penned, the precession had moved the equinox into Aśviṇī. So, the Indian sages of old did consider the equinox to be the true start of the zodiac, and they made their declarations of which sidereal constellation was “first” based on the position of the vernal equinox at the time.
Sūrya Siddhānta itself tells us (in text 9) that it is periodically re-written and updated to keep in sync with various astronomical modulations, precessions, and irregularities. So it does not disturb ones loyalty to tradition to accept this explanation.
Mathematical, not Stellar, Divisions
The 28th text tells how to divide the zodiac circle into arc-measurements of seconds (vikalā), minutes (kalā), degrees (bhāga), and sign (rāśi). This confirms that the ancient Indian sages did not use actual constellations to measure the zodiac, but rather used mathematic divisions based on the 12:1 ratio of the Moon’s motion relative to the Sun.
Ayanāṁśa – Distance to the Equinox
Sūrya Sidhhānta then defines the difference between the sidereal and tropical zodiac anchors: ayanāmśa – a term that literally means “distance to the equinox.” It says that, after we calculate the positions of the planets in reference to sidereal phenomena, we must apply ayanāmśa to convert those to equinox-relative positions, the tropical zodiac!
It is rather shocking, because almost every Siderealist in or out of India thinks of the ayanāṁśa as the number which converts tropical to sidereal. But the Sūrya Siddhānta presents it for the exact opposite purpose: to convert sidereal coordinates to tropical! Thus, if we are supposed to read a sidereal zodiac, why would the Sūrya Siddhānta bother with ayanāṁśa at all!?
One argument that can be put forward is that we cannot know the ascendant without using the tropical zodiac. The ascendant is the location of the Earth’s eastern horizon. This has nothing to do with stars and everything to do with the Earth and the Sun’s rising over that point. Because the ascendant does not exist sidereally, even sidereal astrologers must use a tropical zodiac to calculate where the ascendant is. That is why Siderealists calculate first in tropical coordinates and then use ayanāṁśa to convert everything. But the Sūrya Siddhānta does not ratify this! It teaches us to make sidereal calculations first and then convert them to tropical. It never instructs us to apply ayanāṁśa in reverse: moving tropical to sidereal.
This brings up a fascinating point: The ascendant is by nature tropical, and is the very foundation of a natal horoscope. That the thing upon which the entire horoscope revolves is intrinsically tropical is surely a profound point for consideration.
The Yajur Veda has an appendix called “Jyotish” (the namesake of astrology in India). This treatise concerns itself entirely with how to calculate correct calendars for religious and cultural events. However, it does describe that the twelvefold division of the Sun’s paths corresponds directly to the months and seasons determined by the equinoxes and solstices.
The famous Bhāgavata Pūraṇa is revered mainly for its poetic beauty, philosophical completeness, and theological harmony. It is thought of as the full expansion of the Gāyatrī Mantra, Vyāsa’s own commentary on his Vedānta Sūtra, and the final Pūraṇa representing the full maturity of Indian thought. Right in the middle of the Bhāgavatam, in the 5th division, there is an elaborate astronomical description of the universe.
5.21.2-6 unambiguously defines the zodiac as tropical:
Outer space is measured by relation of heaven and earth. The Sun is the king of all the planets, in the center of everything, keeping everything together. It moves to the north, crosses the equator, and moves to the south. When it goes north of the equator days get longer. When it crosses the equator days and nights are equal. When it goes south of the equator days become shorter. On this basis the Sun moves through the twelve divisions called Capricorn and so forth.
The Sun is at Aries and Libra when the days and nights are equal. Passing through Taurus, etc. the days become longer and then decrease until again equal with the night. Passing through Scorpio, etc. the night becomes longer and then decrease to again become equal with the days.”
The True Sidereal Zodiac
There is a sidereal zodiac in Indian astrology, and probably in all ancient great astrological systems. Yet this sidereal zodiac is not twelve but twenty-eightfold!
The Sun and Moon, kings of the heavens, travel through space. During one complete journey of the Sun, the Moon makes twelve revolutions . Therefore, the Moon divides the Sun’s path into twelve sections. Conversely, while the Moon makes one complete journey through the heavens, the Sun makes twenty eight (in each moon cycle there are twenty eight sunrises, “days”). Therefore, the Sun divides the Moon’s path into twenty eight units.
Thus we have beautifully interwoven manners of dividing the zodiac. One has twelve and pertains to the path of the Sun. The other has twenty-eight and pertains to the path of the Moon. One of them is tropical by nature, the other sidereal!
I’ve already explored the logic, evidence and common sense decisively concluding that the Sun’s twelvefold zodiac is tropical. Now let’s explore the sense, logic and evidence in concluding that the Moon’s twenty-eightfold zodiac is sidereal.
The stars cannot be seen when the Sun is out, but we can almost always see the Moon against a backdrop of stars. Thus it appeals to common sense that the Moon’s movements be measured by its reference to stars.
No tropical phenomena account for the meaning ascribed to the 28 divisions of the sidereal lunar zodiac. The root cause of all meaning in the twenty-eight stars has no relationship to the earth (i.e. it is not tropical), and has everything to do with purely heavenly (sidereal) factors. The deities of the heavens reside in or empower each of the twenty-eight stars. The nature of the deity who empowers a star creates the full meaning of that star. It is that simple, and that mystical.
Evidence from Authority
Sūrya Siddhānta dedicates its second chapter to sidereal calculation of the twenty-eight stars of the lunar zodiac. The treatise says to convert planetary positions to tropical coordinates, but leaves the twenty-eight stars as they are.
The Śrīmad Bhāgavatam, two chapters after tropically defining the twelvefold zodiac, defines the twenty-eight stars of the lunar zodiac sidereally – in terms of their relationship to the North Star, milky way and other purely stellar objects.
Don’t the planetary rulers and their pairings with the rulers of the sidereal signs account for the meanings in the 28 stars?
There are no planetary rulers of the 28 stars. Planets are associated with different stars for the purpose of timing systems called nakṣatra-daśā. There are about a dozen such systems in authoritative texts. Each correlates the planets to the stars differently. Thus there is no permanent association of planets to the 28 stars, nor is it meant to define the meaning of the stars.
Can the meanings of the 28 stars be understood as an analog to the human lifecycle.
Where would you start? How will you define where the first phase is to begin? The first star 4,000 years ago was Kṛttikā. 2000 years ago it was Aśviṇī. Today it is Pūrvabhādra. If the meanings of the stars are derived by a progression relative to a beginning, then since the beginning point changes the meanings of the stars must be changed. I don’t think that’s very good.
The 28 stars as defined in India today are different in number and not uneven in size. You said this was a reason for discounting that the twelvefold zodiac should be sidereally based.
This argument simply proved that the sidereal zodiac was not “stellar” as is advertised. I think it is reasonable that the 28 stars would be evenly sized segments, since the stars are reference points within a domain affected by them. It is the domain, not the star, which is demarcated by the Moon’s motion and is therefore equal.
Regarding the number of stars, it may be that the “extra” star (abhijit) was dropped in the relatively recent attempt (2000 years or less) to make the sidereal stars fit neatly and cleanly into twelve sidereal signs. But I cannot say for certain now. My next topic of research may be the correct definition of the 28 stars.
Reconciliation of the Sidereal and Tropical Zodiacs
Doubtlessly the lunar zodiac is sidereal. That’s why we say it is composed of “stars” (literally, nakṣatra). It is now also beyond doubt that the solar zodiac is tropical. That’s why we say it is composed not of stars but of “signs” (literally, rāśi).
The ancients give us knowledge that our dank and small modern intuitive cognition still hobbles weakly to grasp the basic definitions of. We waste our effort arguing if tropical or sidereal is the correct definition of the zodiac. If we listen to the ancients carefully, we hear them tell us is that both co-exist in a unified truth.
The two zodiacs, the twenty-eight stars of the sidereal and the twelve divisions of the tropical, are two aspects of one reality – interwoven like yin and yang. The language of astrology cannot fully and clearly sound out by transposing one zodiac definition on another, or by trying to divorce them from their eternal marriage and discount one or the other. We must read both zodiacs simultaneously to hear the full communication from mother nature.
How? When any astrological chart based on an ascendant is cast, we have before us two strands of interwoven information, calling to mind the two strands of DNA: the tropical positions of planets in the twelve signs and houses, and their twenty-eightfold sidereal positions among the glittering stars of the heavens.
Now it is upon us to explore, uncover and become proficient with the correct methods and sciences for such interpretations. It will not be difficult, because our basic grammar will be far more clearly defined. In the near future I hope to publish several case studies. If your experience is anything like mine, you will find that all of the fundamental techniques preserved in the interpretive texts will shine forth much more clearly. You will, I think, comprehend the messages they declare to your inner ear with far greater ease and clarity.
May we be so blessed.
oṁ bhur bhuvaḥ svaḥ
There is bhu: the earth, with its sky of twelve houses.
There is svar: heaven, with its twenty-eight principle sidereal stars.
There is bhuvah: The uniting space linking them, with its twelve tropical divisions – The heavenly Sun, planets and stars shining upon and wandering across the Earth’s equator.
tat savitur vareṇyam, bharga devasya dhīmahī
The brilliant knowledge which will shine forth in the intuitive contemplation of an astrologer is the effulgence of this paradigm uniting heaven and earth: the twenty eight stars hosting the planets, tied to the earth via the twelve divisions of space and sky.
May we blessed with divine knowledge of such incomprehensible subjects. May such knowledge lead us only to divine love, the soul of true peace and joy.
 Thus from a modern archaeological point of view the sidereal zodiac is probably older, because it is much easier to measure the Moon’s movement against stars than to measure the Sun’s movement against mathematical locations related to an equinox. But where I feel the modern Siderealists are wrong is in assuming that this ancient and original “sidereal zodiac” is the same as the twelvefold zodiac of months. The ancient sidereal zodiac is quite different than the twelvefold tropical one.