Tropical vs. Sidereal in Indian Astrology


I’ve done a number of Videos on this subject, so I will list these first:

Videos from 2017

Here is Part 1 of a live video presentation on the topic of Sidereal and Tropical Zodiacs in Vedic Astrology:

Here is Part 2 – which includes some very helpful animations.

Here is the first class of my 102 course on the 12 signs of the zodiac, where the zodiac itself is clearly explained, and the topic of sidereal and tropical is addressed.

Video from 2015

Here is an episode of my Q/A show that addressed the tropical basis for Elements, Modes and Rulers of the Signs:

Video from 2012

Here is the original video I made on the subject.


Here are the key texts involved in this subject:

Sūrya Siddhānta

Chapter 14, Text 7:

bhacakra-nābhau viṣuvad dvitiyam samasūtragam
ayana dvitayan caiva catasraḥ prathitāstutāḥ

The two solstices and two equinoxes are the thread upon which the core of the zodiac exists. 

Text 8:
tad atareṣu saṅkrānti dvitayam dvitayam punaḥ

Two borders are between each point.

Text 9:
bhānor marakara saṅkrānteḥ ṣaṇmāsā uttarāyaṇam
karkādestu tathavasyāt ṣaṇmāsā dakṣināyaṇam

It takes the Sun six months to reach the northern solstice after entering Capricorn; and six months to reach the southern solstice after entering Cancer.

Text 10
meṣādyo dvādaśaite māsāstair eva vatsaraḥ

The twelve divisions beginning from Aries are certainly the months which constitute a year.

Bhāgavata Purāṇa

Division 5, Chapter 21, Text 3:
sa eṣa udagayana-dakṣiṇāyana-vaiṣuvata-saṁjñābhir māndya-śaighrya-samānābhir gatibhir
The sun moves between the northern solstice, southern solstice, and equinotical points in a cardinal, fixed, and dual manner.

ārohaṇāvarohaṇa-samāna-sthāneṣu yathā-savanam abhipadyamāno
Its rise towards the northern solstice, its fall towards the southern solstice, and its crossing the middle point can be known by observing time.

makarādiṣu rāśiṣv aho-rātrāṇi dīrgha-hrasva-samānāni vidhatte.
The days and nights grow longer and shorter, revealing which of the signs – Capricorn, etc. – the Sun is in.

Text 4:
yadā meṣa-tulayor vartate tadāho-rātrāṇi samānāni bhavanti
When the Sun is in Aries and Libra, the days and nights are equal.

yadā vṛṣabhādiṣu pañcasu ca rāśiṣu carati
tadāhāny eva vardhante
hrasati ca māsi māsy ekaikā ghaṭikā rātriṣu.
When the Sun is in the five signs starting from Taurus, the days grow longer and nights which grow shorter, month by month.

Text 5:
yadā vṛścikādiṣu pañcasu vartate
tadāho-rātrāṇi viparyayāṇi bhavanti.
When the Sun is in the five signs starting from Scorpio, the days and nights change in the opposite way.

Bṛhat Parāśara Hora

Chapter 3, texts 2-5:

śṛṇu vipra pavakṣyāmi, bha-grahānāṁ paristhitim
Listen, scholar, I will explain the positions of the stars and planets.

ākāśe yāni dṛśyante, jyotir-bimbāny anekaśaḥ
In the sky we see many dots of light.

teṣu nakṣatra-saṁjñāni graha-saṁjñāni kānicit
Some of them are known as “stars” (nakṣatra), others as “planets” (graha).

tani nakṣatra-nāmāni sthira-sthānāni yāni vai
Those which stay fixed in their places are called “stars”.

gacchanto bhāni gṛhlanti, satataṁ ye tu te grahāḥ
But, those stars which always move, as if they had will and consciousness, are called “planets”.

Note: rāśī not mentioned. rāśī are not among the dots of light in the sky.

bha-cakrasya nagāśvy aṁśa, aśvinyādi-samāhvayāḥ
The celestial wheel has integral portions called āśvini and so on. It is like a wheel being turned by a horse.

Note: nakṣatras are integral portions of the star field, and (as “a wheel turned by a horse”) they move together as a unit in relation to something about to be mentioned:

tad dvādaśā-vibhāgas tu, tūlya meṣādi-saṁjñakāḥ
But that same space can also be divided into twelve, known as Aries (meṣa) and so on.

Note: tu – but, this indicates that the rāśī are different than what was described before (nakṣatra). tūlya – similar / like, this indicates that they are similar but not identitcal. vibhāga differentiated division, this indicates that rāśī are distinct from the star field, unlike nakṣatra, which are aṁśa (integral, inseparable portions) of the star field.

Full Text of Original 2012 Video

The full text of this video is here: The 12 Signs of the Zodiac.

Diversion and Directness

This video addresses common reactions to my presentations

Written Reviews of Other Views

Comments on Andrew Foss:

Comments on P.V.N. Rao:

Comments on David Frawley


  • Sidereal vs. Tropical Debate, by Vaughn Paul Manley,
  • Sidereal vs. Tropical, by Cyber Witchcraft
  • For the Sidereal Zodiac, by Kenneth Bowser

I comment on all three in one post.

Back & Forth

To my knowledge there is only one substantial rebuttal of my paper so far. Here are my responses to that rebuttal [with links to the rebuttal itself, of course].

And sometimes, I just gotta vent!

Following Tradition

42 Comments Add yours

  1. Vidyasagar A says:

    So – does it mean we have to apply all the Principles and astrological rules on a chart by making the ayanamsa of Zero (sayana Ayanamsa) ? Is it enough or does the chart needs any more changes to make sure we follow Sidereal stars & Tropical zodiac that you just suggested ? Pls explain what else changes are required while using a software & different ayanamsa to construct a chart?



    1. Applying no ayanamsha to a modern calculation will give the correct signs/rashis, but incorrect stars/nakshatra. Applying ayanamsha such as Lahiri will give acceptable nakshatra, but incorrect rashi. Therefore both must be done: no adjustment made for the rashis, adjustment made for nakshatra.

      I’ve heard from others that Jagannath Hora now has an option to do this. I have not confirmed. I know that Kala has this option.

      The only other change you would want to do, is simplify all your criteria of interpretation and return to fundamentals like signs, houses, lords, vimshopak, and shadbala.


  2. Vic u supported a lot sidreal techniques in your yahoo posts. Now why there is a shift towards tropical zodiac. Unable to find this answer


    1. There is no such thing as a “sidereal technique” – sidereal is a definition of where the zodiac starts. It is a measurement, not a technique. I started off using sidereal zodiac measurements, because that is the culture in India. After practicing, exploring and researching in that system for several years, I realized what I have written in this article.


  3. Here is what you have written in one of your posting “If you do sidereal astrology, whole-sign is most effective for natal readings. even or uneven houses is effective for mundane (non-living) readings. If you do tropical astrology, whole sign is probably useless to you for most purposes.”


    1. When was that written?


  4. I first discovered the tropical zodiac thanks to Mr Ernst Wilhelm’s birth chart calculator. When I keyed in my info, my chart looked good, compared to my sidereal one : ) Anyway, I emailed him to understand why such a difference between my sidereal and tropical and he directed me to read his article on ayanamsa and listened to the audio. I had 2 readings with astrologers using the tropical zodiac and was convinced, it suited me. I then looked at charts of my friends and family, and realized how it suited them to.
    I recently came across a YouTube video on how we can use both zodiacs. The sidereal representing our higher self and the tropical representing the physical self on Earth. I pondered over it because I was of the opinion that by using the tropical zodiac, (since it uses the sidereal nakshatras and tropical sun) we would be reading both our higher and physical self.)
    I’ve been told that we can get a good amount of information if we were to study both charts and look at the overlapping details. I am still studying both my sidereal and tropical charts to see if this is true.

    However, it seems that the info from tropical zodiac seems to be accurate as per the readings I’ve gotten and from how I’ve observed that my freinds were quick to jump and say that they prefer the reading from the tropical zodiac, even though I’ve helped them to read their sidereal charts before.

    Just wanted to share a constant contemplation on my mind these days “Sidereal or tropical or both?”


    1. Vraja Kishor says:

      Thank you for your comment.

      In my opinion the sidereal and tropical are used side by side, but for different things. The sidereal coordinates are used to measure stars (nakṣatra) and the tropical coordinates are used to measure signs (rāśi).


      1. So it is better to study both the sidereal zodiac charts and tropical zodiac charts to get a good amount of information instead of using either one?


        1. Vraja Kishor says:

          Use a hammer to hammer nails and a comb for combing hair. Don’t use a hammer on your head or a comb on nails. Use a thing for what it is meant for. The Sidereal (lit “stellar”) measurements are used for defining the positions of nakṣatras (lit. “stars”). The topical (lit, “sun’s relation to the equator”) measurements are used for definition the sections of the ecliptic (lit. “sun’s path”). So, use the tropical and sidereal systems together, but each one for the thing it is intended for. Not that you look at sidereal signs and houses and nakshatras and also look at tropical signs and houses and nakshatras. Look at sidereal nakshatras and tropical signs/houses.


          1. Great! Thank you : )


  5. Linda Purdy says:

    How do the Nakshatras coincide with the Tropical signs? Are they read through the tropical chart? It would be interesting to see the corresponding degrees. I am a novice, perhps you have already answered this, yet I am interested in this hybrid type of reading.


    1. Vraja Kishor says:

      There’s a naksatra every 13 and a third degrees. So all you need to know is the starting point and you can measure where the naksatra are in the sky. The starting point is 180 degrees opposite the main star of Citra nakshatra (Spica). Where this coincides with tropical space changes over the course of history because the stellar and equitorial/ tropical measurements of a “year” differ by 20 minutes per year. So, the stars drift through the 12 signs. The 12 signs are divisions of the sun’s path (‘ecliptic’) the stars also move against the ecliptic like the planets, but at a massively slower rate. About 5000 years ago, what we now consider the 3rd naksatra (Kṛttikā) was considered the 1st (in Ṛg and Atharva Veda, for example) because it aligned roughly with the beginning of the 1st division of the ecliptic, Aries. A little less than 2000 years ago what is commonly still thought of as the “1st” nakṣatra was Aśvinī, because it aligned with the 1st division of the ecliptic at the time. From that time things got confusing and astrologers/astronomers didn’t want to continue to update the position of the nakṣatras in reference to the position of the ecliptic divisions (rāśi). That’s why many people practicing Indian astrology still count Aśvinī as the 1st nakṣatra and even start the ecliptic divisions from the start of Aśvinī, creating a “sidereal zodiac.” However, the accurate fact is that currently the main star of Citrā (Spica) is 180 degrees opposite from just shy of 24 degrees Aries.

      Thus if we wanted to restart the ancient, accurate method of reviewing the status of ‘1st nakshatra’ we would make Pūrva-bhādrapadā, because that nakshatra is now the one roughly aligned with the start of the first division of the ecliptic.

      Anyway, its less confusing to start from 24 Aries, and measure 13 and a third degrees for each naksatra – that’s how you can know where each one currently is, plus or minus a handful of minutes of arc, since the start is still a little shy of 24 Aries in truth. So for example Aśvinī corresponds to 24 aries through 7:20 of Taurus. Bharanī from 7:20 Taurus to 20:40 Taurus. Kṛttika from 20:40 Taurus to 4 Gemini. Rohini from 4 Gemini to 17:20 Gemini, etc.

      This is the current correlation of nakṣatra to rāśi. In a century or two the drift would be significant enough that you would want to update the measurement.


      1. Linda Purdy says:

        Thanks so much for your quick response. much appreciated.


  6. Sai Teja says:

    I really appreciate your works on astrology. !


    1. Vraja Kishor says:

      Thank you very much!


  7. If the Tropical Rasis are considered accurate, Then why would not the Lunar Mansions or Nakshatras be which are based upon the 12 Tropical Zodiacal signs?
    Furthermore, there are over 25 different ayanamsa’s used for the calculations of the sidereal zodiac. No one can conclusively prove which ayanamsa is correct or accurate for calculating the constellations.

    What is known is that the sidereal zodiac was used in Babylonian times but not the ayanamsa used for the calculation. The Lahiri is simply a best guess with controversy behind this calculation

    Ernst Wilheim admits this too & it’s just a guessing game with the sidereal zodiac as degree’s & minutes are critical for accuracy as you yourself should know.


    1. Vraja Kishor says:

      Your comment is not clear.

      Nakṣatra are not based on the 12 tropical zodiac signs. Nakṣatra are the fixed stars themselves. The relationship between the 12 divisions of the ecliptic and the 27 groups of fixed stars drifts over time.

      The exact definition of the Nakṣatra by degree is a technical issue, basically they are in the general ecliptic projection of the visible stars. Hairsplitting astrology is doomed to failure anyway, as the human brain is insufficiently activated during kali-yuga to be able to accommodate such incredible inductive calculations.


  8. I personally always resonated with Tropical Rasis Only. Could never find answers using sidereal.


  9. Pr take a blind chart and predict by ur method ,it will be quiet clear & vivid which works ,ulimately we want results not debates on which one is right


    1. Vraja Kishor says:

      How will this solve anything? People have predicted accurately and immaculately using both systems. The approach needs to be more scientific and controlled than what you suggest.


  10. rathip5 says:

    From Ur article I understand that signs and nakshatra(stars) are independent of each other. But isn’t it the arrangement of stars(constellation) in night sky that creates shape from which signs derive their name. For eg., dhanu rashi is made of stars(constellation) which creates a shape like dhanushya(bow). If the stars are independent of signs then in time , the stars which now fall into vrishchika will move to Dhanu. It doesn’t appear rational then to say that even though the constellation forms a vrishchika(Scorpio) figure, it is Dhanu rashi.
    Awaiting Ur reply


    1. Vraja Kishor says:

      The symbolism of a sign is a result of the planet who rules it, the element it is made from, and the mode of its movement. Based on this, ancient astrologers named the signs with descriptive names, encapsulating the meaning of all that symbolism. The visuals (rams, bulls, etc). Are just the visual form of the name (Aries MEANS ram, Taurus MEANS bull, etc.). At a certain point in history, Europeans looked at the stars in the vicinity of the locations connected to the 12 signs and named them accordingly, connecting dots to form constellations matching the names. These dot-to-dot connections are very fanciful. A square box, for example, is supposed to look like a crab (Cancer). A straight line is supposed to look like a Ram (Aries), etc. Many other cultures draw many other pictures from the same stars. The stars themselves have no bearing or permanent correlation to the signs.


  11. galactus108 says:

    What do you think about the logic of exaltation of planets and their connection to nakshatra placement? For example Sun is exalted in first 10 degrees of Aries, traditionally falling in Ashvini nakshatra (Ketu). Now if we consider the tropical shifting and precession then the Sun at 0-10 deg Aries will be in Uttar Bhadrapada nakshatra (Saturn). I believe this has a connection with shifting of the ages and change in the earthly rhythms which could have a lot to do with the specific nakshatra in question..


    1. Vraja Kishor says:

      What about the other exaltation s?


  12. galactus108 says:

    I’m wondering about the relation of exaltation logic and their connection to nakshatras [Asvini 0.0 Aries] vs exaltation purely based on signs and the elemental nature of the sign. Moon debilitated in first 3 degrees of Scorpio, which falls in Vishaka nakshatra[Jupiter? Jupiter and Moon are inimical to each other] but exalted in first 3 degree of Taurus which is Krittika[Connected to Sun and Moon gets its light from the Sun] in sidereal terms. Do certain nakshatras exalt/debilitate or simply favor the planets placed in them and can these definitions change in time? Hypothetically if we start the Zodiac at 0 degree Uttar Bhadrapada(so as to sync the fixed stars to the tropical) then will the degree of exaltation change?


  13. David Bay says:

    Just a thank you for addressing this important astrological issue. I am currently at the Sivananda Yoga Farm in Grass Valley, CA where they will hold their 17th Annual Vedic Astrology Conference from June 30 to July 4. I wish you were here to share your views. I hope to ask the panel of eight astrologers if any of them have a comment on this topic. I believe they are all sidereal astrologers but hope they are willing to discuss the matter. The more notable and published of the panel are, Andrew Foss Ph.D who developed the astrological software Shri Jyoti Star, William Levacy who has published several books and Komilla Sutton, from India, who has also published several books and is well known in the Hindu astrology community. If I hear something interesting I will share it. Thanks again for your continued support of “authentic” astrology.


    1. Vraja Kishor says:

      Good luck! 🙂


  14. galactus108 says:

    Do you think the Nakshatras relay their energy through the planets? You said that no planet ‘rules’ a nakshatra, but is it possible that a planet will bring something in a person’s life related to the nakshatra if it occupies it? Let’s say that if Venus in placed in Revati nakshatra, then how will Revati influence the person? During Mercury/Venus dasha?

    Also if we take exaltation based on degrees, then the Sun is exalted at 10 deg Aries, which falls in Uttara Bhadrapada instead of Ashvini as of now, so will the influence of Uttara Bhadrapada be felt through the Sun? Do you find anything reasonable with this line of thought or do you prefer to keep the tropical system restricted to planets alone and just check the sidereal dasha?


    1. Vraja Kishor says:

      Yes, I think Nakshatra represent effects only when planets are involved with them.

      I don’t think we should mix exaltation and dignity with nakshatra positions.


  15. galactus108 says:

    Is the tropical zodiac related to Bhuvar loka and nakshatra to Svarga Loka?


    1. Vraja Kishor says:

      Yes, this is EXACTLY correct.


  16. galactus108 says:

    I hadn’t gone through your earlier blog entries which have very interesting posts and answers to my questions, thanks for clarifying them anyways. I do appreciate your line of thought and logic – which can have important ramifications for the evolution of jyotish or rather jyotishis 😉


  17. Nerthus says:

    Hare Krishna Vraja Kishora!

    Having read through the all of the exchanges on Dandavats regarding tropical vs sidereal ayanamsa, allow me to compliment you on your ability to remain dispassionate and courteous. Your conduct was impressive and inspiring.

    Regardless of the negativity directed towards you in many of the comments, I assure you the conversation between your good self and H.G. Anterdweep Prabhu was very valuable and enlightening. The purpose of true conversation/debate is for all parties to develop a more nuanced understanding of the topic and to move together progressively towards the truth .

    Thanks to your sattvic devotional qualities, that was achieved.

    BG 10.32
    adhyātma-vidyā vidyānāṁ
    vādaḥ pravadatām aham

    From Surrender Unto Me:
    Vada is debate carried out fairly according to standard rules, without trying to force the establishment of a particular conclusion.

    Thanks again!


  18. Sagar M says:

    Now I understand why many techniques of Brihat Parashara Hora Shastra (like Sayandi Avasthas) do not make any sense using a sidereal zodiac. These are meant to be used on a tropical zodiac and hence make sense when a tropical zodiac is used!

    But I still could not figure out one thing – how do we interpret padas of Nakshatras when using a tropical zodiac?

    If sidereal zodiac is used, navamsas and nakshatra padas overlap perfectly and navamsas can be used to describe padas.

    My question is — can we still describe nakshatra padas in terms of 12 zodiacal signs even if were using a tropical zodiac? (For example, padas of Aswini being described as having Aries, Taurus, Gemini and Cancer nature, Bharani padas having Leo, Virgo, Libra and Scorpio nature, Krittika padas having nature of Sagittarius, Capricorn, Aquarius and Pisces and so on).


    1. Vic DiCara says:

      That is an intelligent question. I personally don’t see any need to use Nakṣatra Padas


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