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Rahu-Ketu: Directory of Jyotisha Descriptions

Rahu-Ketu Main Page

/Mean Nodes/


/True Nodes/ (misnomer)

calculated positions


Rahu and Ketu

Q: Dear Mrs. Lama,

The nativity that you supplied seems to misplace my Rahu-Ketu within the navamsha.

Our family astrologer (until his decease) always claimed that I have Rahu in Singha in the first navamsha, and therefore, i would become a celebrity personality or a famous politician.

At first I was upset by this but on reflection I think your navamsha chart might be more accurate. It is hard to shift away from an old view. Still, here are the facts .

I am a 55 y.o. physician at a university research hospital, and my work on heart surgery outcomes has been professionally recognized. But I have never experienced big fame nor at this point do I crave it.

All these years my parents have been expecting me to show an interest in politics. Since there are other po liticians in my extended family, they often suggest me as a potential candidate. However, I much prefer my quiet life 10,000 miles away from those crazy loud political campaigns!

I just wanted you to know that I noticed the variance, and at first I was upset by the inaccuracy. However, now that I think about it, 55 years of life experience seems to be supporting Rahu in the 12th navamsha (as you say, the best place for research, and Singha heart). So, let's go forward with the reading. I am most interested to hear your views based on my " new" navamsha Rahu.

A: Namaste

Yes, this is apparently another example of the old dilemma caused by astrologers using the “true nodes” method to locate Rahu-Ketu, rather than using the statistically correct “mean nodes”.


BP Lama Jyotishavidya uses the arithmetic mean to determine the position of Rahu-Ketu.

“True nodes” is a misnomer, because Rahu-Ketu have no mass and Therefore, they have no absolute physical position.

They have a movement range, which is known only by the effect they have on other bodies (similar to tracking subatomic particles). That range has a statistically determinable center.

I'm delighted to know that you have found it scientifically interesting to consider a new placement due to its predictive ability to show an improved correspondence between upagraha geometry and real life.

Yes, Rahu-Simha in 12th navamsha would indicate a subtle passion for research into all-things-Simha, such as politics, heart, spine, and all bright hot reddish objects.

And yes, that same radiance-seeking Rahu in the 1st navamsha would naturally indicate a bright, attention seeking personality, naturally excellent for a politician or entertainer.

In the reading, those predictive indicators, Rahu-12 and Ketu-6, will be linked to their traditional outcomes within the Jyotishavidya.

A long-lasting marriage would also be expected by removing Ketu from navamsha-7 where it tends to distance the lifepartner. If marriage has been smooth and cooperative so far (by age 55) that is another confirmation of the nodes being in 6-12 navamsha rather than the much more fabulous 1-7.

Q: I am using the D-9 navamsha chart as a mystical life guide, and I find it unnerving that there is a discrepancy between your calculations for Rahu and Ketu in the navamsha, when compared to other charts that I have.

Isn't there just one TRUE position of Rahu in every varga? How can one calculation vary so much between software programs?

A: Namaste

In practice, the Rahu-Ketu positions identified by the statistical calculation of the arithmetic mean = "mean nodes" = are preferred.

It may be helpful to understand the terms " mean" and " true" in the astronomical context.

The label "true nodes" is a bit of a misnomer. Astronomically, true is a synonym for geometric location, while mean is a statistical result within a range. "True location" is astronomical shorthand for the postulated geometrical result obtained by seeking the pinpoint location of a no-mass object. This geometrical exercise can be done only in theory – not in practice..

Sadly, many "intuitive types" lack basic college math, and they attribute all sorts of wacky subjective personality values to the choice of mean vs. True.

It is not a value judgment! It is a mathematical method choice , and for a no-mass object like Rahu the better method is statistical.

The final choice of calculation method is an individual matter for the practitioner.

The ultimate proof of the validity of any calculation is whether it matches the historical life experiences. With modern software, it would be easy to compare and contrast both results (using mean and using true) against the biographical facts.

Q: What software do you use? Because some put Rahu in my 2nd house, which changes the whole interpretation as you have put Rahu in 3rd.

A: Namaste

At the moment Shri Jyoti Star, written by the estimable Andrew Foss, is the software of choice.

But the issue is not the software. The difference is in the astronomy.

The difference between claiming that your Rahu inhabits Simha 0: 2:44 versus claiming that your Rahu inhabits 29 ++ Karkata = the difference between using statistical calculations of Mean Nodes versus using geometrical calculations of True Nodes.

The important choice with setting the rashi of the nodes is whether the Jyotiṣika prefers to use the astronomical Mean nodes (more accurate) or the misleadingly named true nodes.

The preference = Mean Nodes.

Rahu-Ketu which have no mass = an astronomical range of points, not a single point. The range exists in a small continuum that is sometimes called a wobble due to the curved pattern of the range. It is also said (by astronomers) that Earth's Moon wobbles when Moon traverses either Rahu-place or Ketu-place.

Considering that the object of assessment is a continuum and NOT a fixed location point, it makes much more sense to use a Mean point to establish mass-less Rahu's influence rather than an arbitrary True Point. True points only make sense for objects with mass.

Unfortunately, astrology beginners who lack a basic understanding of astronomy often select True nodes because it " sounds more accurate" .

As always in Jyotishavidya, the proof lies in the tangible life results.

  • If any of the previous Rahu bhukti caused the phenomena of bhava-2, such as a death in the immediate family, usually the death of a parent or a child, then that fact would support the argument for Rahu's correct bhava placement (not correct in the bhava-chalita, but correct in the radical D-1 or D-9).
  • If Rahu really was in bhava-2, then Rahu would be an empowered maraka there because Rahu's ruler would be [nīcha] Shani-Mesha-5 who owns 2 casts drishti upon 2 and occupies 12th-from-Chandra .

If the decease of a beloved parent or cherished child in fact occurred during Rahu-Rahu or Guru-Rahu, there would be further impetus to revise the calculations - probably by adjusting the birth time as well.

However, barring an abundance of contradictory evidence, ceteris paribus, the Mean positions generally provide a more accurate match to the biographical facts.


I am an advocate of True Nodes, as I prefer the true compared to the mean in everything, also symbolically.

Secondly, mean nodes not onlyfail toreflect the actual positions of the nodes, but they now always seem to go retrograde.

This shows how Vedic astrology has degenerated over time: one can not obtain information anymore if the nodes go direct and stationary in reality.



The choice between true-logical nodes versus mean-observed nodes is debated among astrologers of all traditions.

Generally among astronomically literate astrologers there is a preference for using statistical-mean nodes.

Poetic astrologers who lack astronomical literacy may express a preference for "true" nodes because they are unfamiliar with the geometrical-versus-statistical calculation options and they presume that true equals authentic. Unfortunately, true in this context is a synonym for logical, not a synonym for correct or for authentic.

The difference between mean and true is astronomical not astrological. It is not a discussion about symbolism, but rather about measurement.

Because upagraha such as Rahu-Ketu have no mass (and thus to materialistic science they do not exist except as calculated points) Rahu-Ketu do not follow predictable material trajectories in the same way as mass-bearing graha. In fact, there is no reliable way to " reflect the actual position of the nodes" at any specific moment.

Astronomically speaking, Rahu-Ketu are the product of interactions within the intersecting projected atmospheric fields of Surya, Chandra, and Terra. Rahu-Ketu's location is affected by solar flares, by movements of mass within Earth's interior, and by the frequent shifting of the metallic core of the Moon, inter alia.

Graha are living beings! They have moods and they sometimes behave oddly for their own internal reasons.

Here are the key distinctions in calculation method:

  • True nodes are logical objects calculated geometrically.

  • Mean nodes are measured objects calculated statistically.

True nodes are calculated geometrically by assuming that the relevant points of the terrestrial barycenter, the plane of the ecliptic, lunar orbit, and solar orbit are all perfectly regular.

But astronomers know that there are a number of push-pull variations in the relationships between Surya, Chandra, and Terra which belie the expectation of harmonious, predictable regularity in this logically aesthetic model.

In reality, Rahu-Ketu wander and twitch in response to sporadic changes in the force-fields of Surya, Chandra, and Terra. Rahu-Ketu location is never specifically pinpointed. Rather it is closely estimated based upon the predictable range of the wobble effect that Rahu-Ketu impose upon the movements of Chandra.

Astronomical data shows that there is always some variation in the trajectory of Rahu-Ketu, due to the behavioral fluctuations of the other parties. Despite the obvious appeal of an orderly logical triangulation, historical data demonstrate that Rahu-Ketu cannot reliably be presupposed to be exactly where they would be geometrically expected to be.

Because geometrically fixed true nodes cannot accommodate the documented range of movement caused by irregular interactions between Surya, Chandra, and Terra, true nodes (as pretty as they are) cannot represent an accurate identification of the position of Rahu-Ketu.

Mean Nodes * calculated by statistical mean * Preferred

An arithmetic mean is a calculated midpoint position within a statistical range. Using an arithmetic mean to estimate the position of wandering-twitching hypersensitive-responsive massless Rahu-Ketu is not a perfect solution, but the Mean-Midpoint method offers a more data-accurate option than the abstract logical-true method. Predictions based on calculations involving other upagraha that are used in Jyotishavidya, such as gulika and mandi, also benefit from the arithmetic-mean method.

Although there continues to be discussion and (in some circles) an ongoing search for better calculation methods to identify upagraha positions, most modern, astronomically competent astrologers choose to prefer statistical-mean nodes.

Q: Why did you use mean nodes to calculate my charts, rather than true nodes? I don't like the sound of the word mean. Do you think I am a mean person? I would have preferred to use true nodes because I am always in search of truth. Why do astrologer say mean nodes or true nodes? Why not use nodes that is true adn correct?



  • " Mean Nodes" = using the method of arithmetic mean or midpoint within a statistical range to predict the location of Rahu-Ketu. It is not a character judgment!
  • " True Nodes" = geometrically logical triangulation of fixed points to predict the location of Rahu-Ketu. It is also not a character judgment!

Most modern, computer-using, astronomically literate Jyotiṣika prefer to use the statistical-mean method to calculate upagraha, as due to their irregular tendencies a logical-true model quickly becomes inaccurate.

However, Traditionalists who were trained by a guru-master using a memorization method of Jyotisha-learning without benefit of computerized rapid calculations (nor of critical thinking) may not be aware of the astronomical complexities of measuring the irregular trajectories of Rahu-Ketu.

Further, they may presume that the adjective "true" means accurate or correct or perfect -- whereas "true" in this context simply indicates geometrically logical.

But the movements of Rahu-Ketu are not fully logical. Their trajectories have certain illogical properties which are better accommodated by a statistical model (the arithmetic mean).

So although some are still using the logical-true method because it is geometrical and thus easier to calculate by hand than a statistical range midpoint (and it was the only known method in older times), the logical-true model does not consistently support observed data and thus the statistical-mean is a better way of matching the actual observed movements of Rahu-Ketu.


Respected Madam, Namashkar,

There is confusion in Rahu's Degree and Nakshatra in my chart. In India few softwares are stating 26:16 degree,while some are stating 27:15 degree, The problem is that due to small change in degree of Rahu, it's Nakshatra is changing moreover the divisional signs in Varga are changing ie. in case of 26:16 scorpio Navamsha and in 27:15 Dhanu Navamsha.

According many calculations are going wrong, I don't know how they are calculating, but this small error is making big difference in results.

Major error would be In dashamamsha -10 , where instead of 4 planets occupying the Kendra, will be only 2( Sat and Mars), Big concern for my Fame of National and International question.

How to confirm the exact Degree of Rahu on 7th Jan 1979. 21:07 pm Lucknow India.

A: /mean/ vs. /true/

Rahu: a Jyotisha calculation choice

Namaskaram, the astronomically correct degree for upagraha should be determined by the arithmetic mean position, which is a calculated midpoint within a statistical range = /Mean Rahu/

Conflict of Opinion within the Jyotisha Community of Practice

There is an interesting discussion involving several international Jyotiṣika on this page

  • Following even this brief discussion, one may observe that there is no consensus among Jyotiṣika, and that significant conflict on calculation points is acknowledged within the literary traditions of Jyotisha (North/South, guru/pandit, various editions of the Sanskrit/Tamil classics, etc.)

  • The Jyotiṣika who says "you have to use what works for you" is speaking from pragmatic experience. In practice, Pdt. Sanjay Rath is correct in this particular matter.

Rational vs. Intuitive components of Jyotisha Reading

Resolution through Intuition First

Congratulations: indeed this is a key distinction in practical application of Jyotishavidya.

Two separate types of knowledge are being processed during a Jyotisha analysis and prediction.

The reader gains much clarity by meditating upon the nativity first, before attempting to predict solely upon numerical calculations.

There are many intuitive forms of intelligence at work during a Jyotisha reading. It is not like physical science. The unit value of the numbers offers some guidance and the ratios between the numbers offer further guidance, but ultimately only two of three features will be salient for a given reading. It is intuitive pattern recognition rather than number values which will deliver the prioritizing choice for the Jyotiṣika.

Jyotishavidya is a whole brain knowledge base. That is, both left brain and right brain must be engaged and interacting constantly in order to make consistently accurate predictions. The pineal gland in the corpus callosum will hum slightly. As an elder teacher once described it " like the buzzing of a bumble bee in the cave of Brahma" .

Rational Analysis

The rational analysis is essentially an array search of a rather large table of mathematical items and their human-life descriptors. This table of correlations is huge. Computers automation helps these searches immensely.

Unfortunately a computer "dump" of all possible results of major and minor configuration items in a nativity is almost useless, because it is both too large to digest and it contains so much contradiction.

The more classical, traditional literature one consults, the more contradiction one discovers. How to make sense of this ocean of conflicting predictive information in the texts?

Intuitive Perception

The way to clear up the rational mess and to simplify one's search for meaningful predictive indicators is, to meditate briefly upon the nativity . In a meditative state the Jyotiṣika can receive guidance on central patterns to look for and how to frame the response to the client to that it is best pitched to their level of awareness.

Divinations are delicate operations, both intellectually and socially. Whether they admit it or not, most people rely on divinatory predictions to set their life expectations and to make important life choices.

Their divinatory practice may be personal prayer, seated meditation, taking long walks in nature, reading holy books, or recording their dreams. Everyone seeks divine guidance in some way.

Many people seek guidance from astrologers. This is a heavy responsibility for practicing Jyotiṣika! Not only do we Jyotiṣika have the ego motive o make accurate real-world predictions (that is fun and very rewarding intellectually!) but we also have a spiritual motive o channel the greater good through our predictions. We all want to live in a better world. The Jyotiṣika who can help raise individual consciousness of pre-incarnation planning and encourage compassion for Self and others via good predictions, is helping the world to advance.

The Jyotisha must first establish a spiritual attunement , then proceed in a grounded mental state, with caution and respect, ideally remaining open to divine guidance during the reading or evaluation.

The practitioner will find that predictions are much improved by firstly entering a state of awareness of the native 's astral qualities and current needs.

Secondly one should engage the rational intelligence to begin a process of pattern recognition which can sort out the relevant factors from the less relevant background data.

The astral picture, obtained in meditation, is not produced by rational calculations. It is composed of light, color, texture, heat/cool, sound, and other sensual qualities. It is a bit like watching a dream-movie, or putting on a "virtual reality" headset. The astral picture gives the Jyotiṣika a psychic impression of the native which is then applied as a filter and guiding framework to emphasize dominant influences.

Combining Intuitive Guidance with Rational Calculations:

The Jyotisha whole-brain judgment process happens pretty quickly, and often the two components are so intermixed that they appear to be working simultaneously. But it is important to realize that the intuitive information was in place FIRST.

For example, your own nativity is very striking: Shani-yuti-Rahu in lagna in an extremely hostile rashi - the social identity is in chaos. This native does not easily find his place in society. It is the mark of either insanity(tantrik carryover from Rahu) or genius(breaking social taboos from a position of moral leadership) or both.

The astral impression is red and black, with flashing lights and loud noises of crashing but also wide smiles of intelligence and excitement. Clearly the native has chosen a lifetime practice of encountering and negotiating conflict. There is a famous French novel Germinal 1840-1902 Emile Zola. It tells about the violence and brilliance of social conflict in 1860's northern France. This book and its qualities comes to my mind, because of my own life path, when I meditate to estimate the intensity and scope of the nativity.

This is just a small, incomplete example of the astral picture which arises in meditation. It is offered for the purpose of establishing a practice skill.

Making accurate predictions using possibly inaccurate calculations :)

After the astral picture is detected, one is better positioned to negotiate calculation conflicts. Clearly Rahu is a major, major player in this nativity. Predictions related to Rahu Mahadasha are mission-critical for setting the native 's appropriate expectations of himself and his own performance.

And also, when a client shows a powerful Rahu, there is no doubt of one's tremendous hunger for intense experiences both 'easy' and 'difficult'. This native in particular MUST develop their own internal guidance system based on tantrik communication with Divine Intuition.

Making Choices in Jyotisha -- and Human Life in General

OK, that was a long lead-up to the concluding viewpoint regarding Mean versus True calculations for Rahu. If you have a doubt about which version of the Rahu calculations is correct for you and your path, there are four things to mention:

  1. Good for you! You have discovered an area of volatility and disagreement in Jyotisha tradition. This awareness that you now possess will prevent your becoming superstitious or relying unduly upon outside opinion

  2. The unique nature of your Rahu indicates profound tantrik capabilities . As you may know from studying traditional village shamans (or modern shamans such as macro-economists!) being a Shaman is a dangerous social position. It is easy to be run out of the village with burning torches. So you, above all people, MUST develop your internal guidance system, which means making the commitment to remain in a state of conscious ' background' awareness, even when you are actively engaged in the world. You have to check that inner radar screen constantly , to avoid getting into polarizing catalysis with Rahu-related disabilities such as impulsive marriages and illness from pollution (both spiritual and physical).

  3. In order to choose which of the Options for Rahu (Mean versus True) you will use , you will need to run the calculations both ways, and look at the two sets of results. Which set of results better matches your astral picture? In a meditative state there is no anxiety or rational mind-spinning. You can just look at the picture. Do this first. Then run both sets of calculations and see which one matches your INTUITION.

  4. This Rahu issue is important not only for your ability to use your Jyotisha charts as a reliable life guide, but also for your life practice in other areas of human choice-making behavior. I hope this situation can serve as a moment of life orientation, when one is forced to learn that intuition and logical reasoning should operate together as much as possible, but that intuition must come slightly first. Always honor your intuition. Intuition or the inner teaching is a channel for divine guidance.

Sincerely, Barbara Pijan Lama, Jyotishavidya


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