A Tale of Two Zodiacs
By Antardwipa Dasa, (edited by ShyamasundaraDasa)
Over the course of 2012, a number of articles have been published regarding the tropical and sidereal definitions of the zodiac, and which of these is to be used for Vedic astrological purposes. These publications have mostly urged for a new approach to jyotish (Vedic astrology); although the authors generally claim that their presentations are actually the most traditional. One such article is, The 12 Signs of the Zodiac, by Vraja Kishor das. Some of the ideas presented therein are misleading, and therefore, for my own edification, and for the satisfaction of those who are knowledgeable, I would like to present the following to the esteemed readers.
For those not familiar with this ongoing discussion, the basic question under debate is, “Where does the circle of the zodiac begin? ” Or, framed in greater detail, “When constructing a horoscope, do we use the longitudes of planets as measured from the position of the sun when it is at the vernal equinox (tropical zodiac) or from a specified fixed star (sidereal zodiac)?”
This question has at times been hidden behind the inquiry as to whether the sidereal rasis (signs of the zodiac) match the constellations that exist as patterns of stars in the sky. Vraja Kishor presents the argument that there are thirteen constellations that make up the zodiac, and that they are of varying sizes; some larger than thirty degrees and some smaller. As such, these constellations do not match the twelve rasis of the sidereal zodiac. He concludes, therefore, that the zodiac signs (rasis) have nothing to do with the stars, and as a result:
“Once we realize that the zodiac signs have nothing to do with stars, we don’t really feel compelled to use the stars to define where they begin. In fact we feel quite compelled to use the point where the center of space is, where the equinox is, where the ecliptic crosses the equator.”
Although it is unclear what is meant by the term ‘center of space’, we shall ignore that and focus on his rejection of sidereal rasis. Vraja Kishor clearly believes that the rasis have nothing to do with the stars. This can be seen in another of his articles, Reconciliation of the Tropical and Sidereal Zodiacs, where he states:
“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!”
We must note, however, that the statements of the Jyotir Veda reveal this assertion to be false, and that there is in fact an authentic twelve-fold division of the stars. To prove this, we may begin by referring to the Surya-siddhanta 1.28. Vraja Kishor also quotes this verse, and correctly points out that it describes a rasi as being the geometrical division equal to one-twelfth of the circumference of a circle. Unfortunately, it appears that he has not fully grasped the significance of this.
All circles may be divided in this twelve-fold way, with the first thirty degree arc being known as Mesha, the second known as Vrishabha, and so on; covering the twelve familiar names of the rasis used in jyotish. This is the standard treatment given to arcs in traditional Indian geometry. Being applicable to all circles, it is nonsensical to claim that the circle of stars is not similarly composed of these same twelve rasis. Thus, it is irrelevant whether or not the visible constellations match the twelve sidereal rasis, because the sidereal zodiac is a circle, and therefore it naturally contains twelve divisions known as rasis.
More importantly though, this verse describing the layout of rasis on a circle comes immediately after a verse stating that planetary revolutions are to be counted from the end of Revati nakshatra. That the nakshatras are constellations of stars is undeniable and is accepted by all authors. Thus, in Surya-siddhanta 1.27, a specific point amongst the fixed stars is referenced as the point of zero degrees longitude, or the beginning of the circle of revolution, and then in the next verse, the divisions of that circle into twelve rasis is described. Considering the content and placement of these verses, it is unwise to conclude that the rasis have nothing to do with the sidereal zodiac, or that sidereal rasis are not presented in the Vedic texts.
To make this argument even more compelling, we may consider the Sanskrit terminology used. Surya-siddhanta 1.27 states:
“The planets’ revolutions are counted complete at the end of Revati nakshatra.”
Thus, a bhagana (planetary revolution) is counted as complete with respect to the end of a constellation of stars, Revati, which is also known as Paushna. After Revati comes Ashvini, and therefore, Ashviniis taken as the first nakshatra when considering the longitude of planets. Then in verse 1.28, it is said:
tat trimsata bhaved rasir bhagano dvadasaiva te
“Sixty seconds (vikala) make a minute (kala); sixty of these, a degree (bhaga); thirty of the latter is composed a sign (rasi); twelve of these are a revolution (bhagana).”
The term ‘bhagana‘ has been used in both of these verses. The circle of one revolution of a planet is known as a bhagana. After being described as beginning at the end of Revati nakshatra, it is then said to be composed of twelve rasis, each of which is thirty degrees. Thus, it is clear that these two verses, when taken together and understood correctly, indicate that the zodiac of twelve rasis, through which planetary movement is to be reckoned, has a beginning that is fixed in relation to the stars. Hence, it is clearly a sidereal zodiac composed of twelve rasis.
Furthermore, the term ‘bhagana‘ indicates that planetary longitudes are to be reckoned against the background of the stars. ‘Bhagana‘ literally means ‘the multitude of stars’, and thus it indicates the circle of the stars, or sidereal zodiac. That this very same term is used to describe a single revolution of each of the planets indicates that their movements are measured on this sidereal zodiac.
Aside from this, Vraja Kishor quotes other verses from the Surya-siddhanta to establish that a tropical definition of the rasis is given in that authentic text. Importantly, these other quotations do not nullify the explanation just given. Rather, it must be acknowledged that the Jyotir Veda describes both the nirayana cakra (sidereal zodiac) and the sayana cakra (tropical zodiac), and that each of these zodiacs is composed of twelve rasis. Thus, providing instances of a tropical definition does not discredit, nor override, the other statements that present and define the sidereal zodiac.
From the above, it is evident that simply knowing of the existence of the two zodiacs is not sufficient; one must also know how and when to use each appropriately. In this regard, we find in the Surya-siddhanta, 3.10, that the tropical zodiac is described as being used for the determination of kranti (declination), chaya (the shadow of the sundial) and caradala (length of time for signs to rise). Of course, other unspecified applications are also implied in this verse by the use of the word ‘adikam,’ which means ‘beginning with’ or ‘et cetera‘. Verses 3.46 − 49 describe some of these other calculations that are made with the help of the sayana cakra; in particular, the calculation of the lagna (ascendant) and madhyalagna (meridian).
What is important to note, is that planetary longitude is not listed amongst the items that are to be calculated using the tropical zodiac. Rather, Jyotir Veda presents the sidereal zodiac as the fixed basis of calculation, and all longitudes are naturally determined according to that measure. This is highlighted by the arrangement of chapters within the Surya-siddhanta: the first two chapters provide all calculations for determining the true longitude of the planets. It is only after such longitudes are calculated, that the topic of ayanamsa is presented in the third chapter. This calculation (the ayanamsa) is then used to calculate the tropical zodiac, which in turn is necessary for determination of the other elements mentioned above. Thus, ayanamsa plays no part in the calculation of planetary longitude, and because of this, it is logically impossible for the tropical zodiac to play any role in the calculation of such longitudes. Thus, the sidereal zodiac is the basis of longitude calculation and expression.
We may add that, by themselves, the terms ‘nirayana‘ and ‘sayana’ provide evidence that the longitudes of planets are to be measured against the sidereal zodiac. Before illustrating this, however, it should be noted that some speak of the use of the sayana longitude of the sun to calculate the lagna as some sort of evidence that the tropical zodiac is actually the only correct one. For example, Vraja Kishor states:
“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.”
We agree that one should consider the implications of this method for calculating the lagna, but not for the same reason as Vraja Kishor. Rather, by careful consideration of the terminology used, one will see that actually it is the sidereal longitudes of planets that are to be used in a horoscope, not the tropical.
It is clear from the astronomical texts that the lagna is to be calculated by using the sayana (tropical) longitude of the sun. There is no confusion about this. The lagna thus calculated is, however, properly called the “sayana lagna. ” This can be seen from the Bengali translation of Surya-siddhanta given by Srila Bhaktisiddhanta Sarasvati Thakura. In the translation to 3.47, which is the final verse in a series that describes the calculation of the lagna, he parenthetically includes the word ‘sayana‘ before ‘vlagna‘ to clarify what is being referred to.
So, by Surya-siddhanta we calculate the longitude of the sayana lagna. Considering that the term ‘sayana’ means ‘ with ayana’, it follows that the sayana lagna is equal to ‘lagna with ayanamsa‘ or ‘lagna plus ayanamsa‘. A natural consequence of this is that the longitude of the lagna (alone and without addition of anything) is equal to the sayana lagna minus the ayanamsa. [ie. lagna = (lagna + ayanamsa) – ayanamsa] Thus, the Sanskrit terminology actually makes it clear that the ayanamsa needs to be deducted so as to arrive at the lagna that is used along with the sidereal planetary longitudes that were calculated in the previous chapters.
These terminological subtleties are usually missed by the casual reader of sastra; partly due to the incorrect approach that they take and partly due to the esoteric presentation of the texts themselves. However, both of these causes for misunderstanding can be eradicated by studying under the guidance of a bona fide teacher. Indeed, this is the prescribed manner in which the sastra is to be approached. Thus, for those who neglect the teachings of previous authorities, the verses of the Vedic scriptures are impenetrable. For this reason, we must follow our revered preceptors in order to understand what is actually being given.
This is nicely illustrated by Srila Bhaktisiddhanta Sarasvati Thakura’s translation of Surya-siddhanta 3.17 – 19. Therein, the process is described for calculating the corrected longitude of the sun from the shadow of the sundial. This is stated by our most esteemed translator as being the sayana longitude of the sun; which is natural as the size of the shadow on the sundial changes according to the sun’s movement on the tropical zodiac. While this is straightforward, the potential misunderstanding arises in the final verse of this section, where a further process is described for finding the mean longitude of the sun from his corrected longitude. In this verse (3.19), the corrected longitude of the sun is simply referred to with the pronoun ‘tat‘, meaning ‘that’. Thus, it may appear to be referring to the very same sayana corrected longitude that was used in the first half of the sloka. However, Srila Bhaktisiddhanta Sarasvati Thakura places the word ‘nirayana‘ in parentheses to show that the measure being referred to is the corrected longitude of the sun without the addition of the ayanamsa.
Thus, after dealing with sayana longitude, the Surya-siddhanta again reverts to the use of nirayana longitude in the same verse, without any definite specification of this use within the verse itself. Without the guidance of a learned teacher, this reversion is easily missed. Thus, we should conclude that when the Surya siddhanta is studied under the authority of one who actually knows the subject matter, then all such topics are easily understood by the student. In contrast to this, it is due to a lack of proper training that the present trend towards incorrect conjectures is manifesting amongst today’s astrologers.
Furthermore, within Vedic astrology, the sidereal zodiac is established as the fixed zodiac. Because it is considered fixed, it naturally follows that it is the basis upon which all measures of movement are considered. The tropical zodiac, on the other hand, is not fixed, and therefore, it is not the appropriate circle upon which to measure the longitude of planets. Srila Bhaktisiddhanta Sarasvati Thakura in his Bengali translation of the Surya-siddhanta, 3.11, confirms the movable nature of the tropical zodiac. Therein, he states in connection with the calculation and measurement of the ayanamsa:
“By the degrees of difference the circle of the sun’s declination has moved.”
Thus, he has described that it is the kranti-vritta (the circle of the sun’s declination) that moves. This kranti-vritta is the tropical zodiac. As such, the sidereal zodiac is fixed, and the tropical zodiac moves with respect to it. Being of changeable longitude itself, it is not appropriate to consider the tropical zodiac as the basis for measuring longitude. Therefore, it must be the sidereal zodiac alone that is employed as the circle of longitude for describing planetary movements and constructing horoscopes.
This fixed nature of the sidereal zodiac is also presented in the Srimad-Bhagavatam. For example, in 5.22.11, it is said:
“There are many stars located 200,000 yojanas [1,600,000 miles] above the moon. By the supreme will of the Supreme Personality of Godhead, they are fixed to the wheel of time, and thus they rotate with Mount Sumeru on their right, their motion being different from that of the sun. There are twenty-eight important stars, headed by Abhijit.”
Herein, the nakshatras are described as being fixed to the wheel of time. The reason for their fixity is also given; it is the will of the Supreme Personality of Godhead. Thus, it is established by the Lord that the sidereal zodiac is a fixed measure of the wheel of time. Being the sole fixed measure of this movement, it is a natural consequence that they remain the reference point to which all other movements are made.
Like the other planets, the sun moves with respect to this wheel of time, as can be seen from Srimad-Bhagavatam, 5.22.2:
yatha kulala-cakrena bhramata saha bhramatam tad-asrayanam pipilikadinam gatir anyaiva pradesantaresv apy upalabhyamanatvad evam naksatra-rasibhir upalaksitena kala-cakrena dhruvam merum ca pradaksinena paridhavata saha paridhavamananam tad-asrayanam suryadinam grahanam gatir anyaiva naksatrantare rasy-antare copalabhyamanatvat.
“Sri Sukadeva Gosvami clearly answered: When a potter’s wheel is moving and small ants located on that big wheel are moving with it, one can see that their motion is different from that of the wheel because they appear sometimes on one part of the wheel and sometimes on another. Similarly, the signs and constellations, with Sumeru and Dhruvaloka on their right, move with the wheel of time, and the antlike sun and other planets move with them. The sun and planets, however, are seen in different signs and constellations at different times. This indicates that their motion is different from that of the zodiac and the wheel of time itself.”
Here, it is noteworthy that the rasis and nakshatras are described as moving with the wheel of time. As we saw above, it is the stars that are fixed to this wheel, and consequently moving with it. Therefore this verse indicates that the rasis and nakshatras are being defined in relation to the stars that are fixed to the wheel of time. Hence, in Srimad-Bhagavatam, a sidereal definition of the rasis is also given.
The sun, in his orbit, moves through these sidereal rasis in the course of a year. Thus, a year of the sun is being defined with respect to the fixed, sidereal zodiac. Additionally, this verse states that the motion of the planets is different from that of the zodiac. As such, the zodiac being referred to cannot be based on the orbit of any of the planets, including that of the sun. It must therefore be the zodiac that is made of the stars; the sidereal zodiac. Considering these points, it is again evident that the sidereal zodiac is the fixed reference point from which measures of movement are considered, and this is the conclusion presented within the Srimad-Bhagavatam.
Furthermore, in 5.22.5, we find the following:
“The sun-god, who is Narayana, or Visnu, the soul of all the worlds, is situated in outer space between the upper and lower portions of the universe. Passing through twelve months on the wheel of time, the sun comes in touch with twelve different signs of the zodiac and assumes twelve different names according to those signs. The aggregate of those twelve months is called a samvatsara, or an entire year. According to lunar calculations, two fortnights—one of the waxing moon and the other of the waning—form one month. That same period is one day and night for the planet Pitrloka. According to stellar calculations, a month equals two and one quarter constellations. When the sun travels for two months, a season passes, and therefore the seasonal changes are considered parts of the body of the year.”
Here it is stated that the sun god passes through twelve months on the wheel of time, and in so doing passes through the twelve rasis beginning with Mesha. It has already been established that the stars are fixed to the wheel of time, and hence the sidereal rasis are also fixed to the wheel of time. Therefore, the twelve divisions of the wheel that are being referred to in this verse must also be measured with respect to the stars. Consequently, the division of zodiac into twelve rasis that is being described is sidereal.
Furthermore, in this verse it is said, “According to stellar calculations, a month equals two and one quarter constellations.” The Sanskrit terminology for ‘two and a quarter constellations’ is ‘sapadarksa-dvayam‘ and many of the authorized commentators make notes regarding this. Srila Sridhara Svami, Srila Vijayadhvaja Tirtha, Srila Viraraghava Acarya, Srila Jiva Gosvami, Srila Visvanatha Cakravarti Öhakura and Srila Bhaktisiddhanta Sarasvati Thakura all state that with regards to solar measures, a month is the time taken for the sun to cover two and a quarter nakshatras. Thus, there is no doubt that solar time is measured with respect to the sun’s movement against the stars, and that the twelve rasis are also defined according to the same stars. Srimad Vijayadhvaja Tirtha is very explicit with regards to the rasis, and he states in his commentary:
“It should be understood that Mesha is Ashvini, Bharani and the first quarter of Krttika. The other rasis follow similarly.”
Thus we have shown that the Vedic scriptures describe a sidereal zodiac consisting of twelve rasis that remain aligned with the fixed stars, and that the calculation of solar time is based upon the sun’s movement through this fixed zodiac. Similarly, the movement of all other planets is calculated in the same way.
At this point, it should again be noted that the Srimad-Bhagavatam does provide descriptions of the tropical zodiac. There is however, no need for me to quote these as Vraja Kishor has done so nicely. But as mentioned above in relation to the Surya-siddhanta, evidence in favor of a tropical zodiac does not refute the evidence for the sidereal zodiac, as both the sidereal and tropical zodiacs are factual and are described in the Vedic literatures. The important point is using them for the correct purposes, and from the above statements of Srimad-Bhagavatam and Surya-siddhanta, it is clear that the sidereal zodiac is the correct basis for measuring planetary longitude.
As if the aforementioned were not enough, we may also quote from the writings of Varaha Mihira, who lived some fifteen hundred years ago. He wrote extensively on all areas of Vedic astronomy and astrology, and in his Brihaj-jataka, 1.4, he states:
“The signs of the zodiac, Mesha etc., are represented successively by the nine padas (quarters) of the several nakshatras commencing with Ashvini.”
Here, this great authority clearly states that the rasis are each composed of nine quarters of the nakshatras. This is equal to two and a quarter nakshatras, which is the same measure as sapadarksa-dvayam that was quoted above from Srimad-Bhagavatam. As previously stated, everyone accepts that the nakshatras are groups of stars. Thus, the rasis, as defined by Varaha Mihira, are divisions of the sidereal zodiac.
While this is clearly in support of the authenticity of the sidereal rasis, some may claim that by Varaha Mihira’s time, knowledge of the true nature of the rasis had already been lost. Indeed, Vraja Kishor has posited that some time in the last two millennia, astronomers in India forgot how and when to distinguish between the two zodiacs, and as a result of this ignorance, began to describe rasis according to the fixed stars. He has suggested that, due to the decline of knowledge in Kali-yuga, astronomers and astrologers in India “became locked into thinking that the tropical measurements and the stars were identical.”
However, this proposition is not supported by the writings of Varaha Mihira; an author of such repute that astronomers and astrologers have been studying his writings ever since he penned them. In his Brihat-samhita, 3.4, Varaha Mihira states:
“If the sun should change his course before reaching Makara, he will bring evil in the west and south; and if he should do so before reaching Kartaka, he will bring evil in the north and east.”
In this text, Varaha Mihira is describing the directional changes that occur at the solstices. These changes in the northward and southward movement of the sun are fixed in relation to the rasis of the tropical zodiac; as it is in relation to the solstices and the equinoxes that the tropical zodiac is defined. Therefore, the sun always turns north at the beginning of tropical Makara.
However, in this verse it is described that the change from southward movement to northward movement can occur before the sun reaches the beginning of Makara rasi. The Makara rasi being referred to must, therefore, be the sidereal rasi, as it cannot be the tropical counterpart. It is clear from this that Varaha Mihira correctly distinguished between the two zodiacs, and as such, his definition of the rasis as being sidereal was not a case of a lack of knowledge on his part.
Therefore, at a time when the sidereal and tropical zodiacs were closely aligned, this renowned author was describing rasis as being fixed according to the stars and that the tropical zodiac was moving with respect to them. This is the same conclusion that we have drawn from the Srimad-Bhagavatam and the Surya-siddhanta.
Finally, even though the ayanamsa was small, perhaps even zero, during Varaha Mihira’s life, it is clear from his writings that he was fully aware of both the sidereal and tropical zodiacs, and did not confuse one with the other. His ongoing fame has ensured that his writings have remained prominent till the present day; including his distinguishing between the sidereal and tropical zodiacs. Indeed, his works are still considered to be essential studies for anyone who is serious about learning the science of astrology. This is very significant evidence that Vraja Kishor’s ‘decline in knowledge’ theory is patently wrong.
In conclusion, it is foolhardy to claim that the Jyotir-veda does not use a sidereal zodiac that is divided into twelve rasis. Rather, we have shown that an authentic sidereal zodiac certainly existed in the Vedic astronomical and astrological tradition. Furthermore, we have seen that it is this zodiac that is the fixed basis upon which planetary movements are measured. Therefore, it is the sidereal zodiac, and not the tropical zodiac, that should be used for constructing a horoscope, as the longitudes of planets are properly measured only on the sidereal circle.
Having established all this, we are now in a position to respond to the following question posed by Vraja Kishor das:
“Beside force of habit, injured pride, the paralysis of shock, or fear of change – is there anything that would stop us all from embracing the unequivocal tropical definitions of the zodiac found in all the ancient and classical literature of the world?”
By the grace of guru and Krsna, we can confidently answer that the statements of sastra and the previous acaryas safely stop us from making such a grievous error.
About Antardwipa Prabhu (by Shyamasundara dasa)
He is a qualified Medical Doctor, and has a Masters degree in Education, he was principle in the ISKCON’s Australian gurukula.
Currently he teaches English, mathematics, and jyotish (astrology and astronomy) at the Bhaktivedanta Academy in Sridham Mayapura http://bhaktivedantaacademy.com/staff
He is also the Temple of the Vedic Planetarium’s consultant for Vedic Cosmology http://tovp.org/en/about-us/meet-the-team . He has studied both Puranic and Siddhantik astronomy in depth and is currently doing his Master’s degree in Astro-physics at James Cook University, Australia.
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Chatterjee, H. P., 1912. The Brihaj-jatakam of Varaha Mihira. The Panini Office: Allahabad
Iyer, N. C., 1884. Brihat Samhita of Varaha Mihira. South Indian Press: Madura
Krsnasankara Sastri, 1965. Srimad Bhagavata Mahapurana: Pancama Skandha. Ahmedabad
Shyamasundara Dasa, A Response to – The Argument for the Tropical Zodiac in Vedic Astrology, Part 1
Shyamasundara Dasa, A Response to – The Argument for the Tropical Zodiac in Vedic Astrology, Part 2
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Vraja Kishor Das, The 12 Signs of the Zodiac
Vraja Kishor Das, Reconciliation of the Tropical and Sidereal Zodiacs