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From Western to Jyotish (aka Vedic)

I spent many years learning and practicing Western tropical astrology before I got the itch to branch out into the Indian system of astrology that is alternately called Vedic astrology (implying a relationship to the time long ago when the Vedas were scripted) or Jyotish (the science of light). More often than not, I tend to use the term Jyotish but every once in a while I might say Vedic astrology, for a change of pace. (By the way, the easy way to say “Jyotish” is “joe-tish”, you can skip the “y” sound.) In any case, you may be aware that Jyotish is an ancient system of astrology, and horoscopes are deeply integrated into Indian culture to this day.

After a couple of years of study, I got fairly comfortable with Jyotish. So that when I analyzed charts, I found myself starting with the Western chart and then using the Jyotish chart to complement my analysis with takes that were unique to the latter. The clincher for me in using this approach was that I could get a lot more out of the analysis by sticking to the most popular and widely used techniques in either, instead of using a single system and struggling to unearth deeper information by getting into increasingly arcane measurements that very often simply didn’t deliver reliable results.

The first step in learning Jyotish is to transform the Western into the Jyotish equivalent. Western astrology uses the tropical zodiac system, in which the vernal (spring) equinox always maps to the beginning of the sign Aries, every year. That is, the frame of reference is the seasonal cycle as experienced on Earth, as a part of the solar system. So the positions of the planets are tropical (symbolic), but not actual. For instance, a planet at 3 degrees of Leo in the tropical system would actually not be at that place in the sky – instead, it would be in the previous sign of Cancer.

Jyotish, on the other hand, uses the sidereal zodiac system in which the positions of planets and points are determined with reference to the fixed stars. Since the entire solar system is moving (albeit at a very slow rate), the positions of the planets are not the same as that in the tropical zodiac. A corrective factor, called the ayanamsa, is subtracted from the Western planetary positions to arrive at the equivalent sidereal positions.

The ayanamsa changes year to year. There are several ayanamsas that are used in practice including the Lahiri or Chitrapaksha ayanamsa, the Krishnamurthy ayanamsa, the Fagan/Bradley ayanamsa, Raman ayanamsa, etc. The Lahiri ayanamsa is arguably the most widely used, and I use it exclusively for all Jyotish charts.

Western chart to Jyotish

Let’s start with the western horoscope chart of the Dalai Lama:

Like I mentioned earlier, the ayanamsa varies year to year, by a few seconds of arc. At the time the Dalai Lama was born, the ayanamsa was roughly 22 degrees and 58 minutes. (The approximation here is shaving off the third-level seconds of arc.) The ayanamsa is subtracted from the position of each of the planets and points (angles and nodes) in the Western chart, and then placed in a chart with whole signs for the houses. This gives the following equivalent Jyotish chart for the Dalai Lama:

Notice that I have qualified this as the “South Indian Style” of chart drawing. There is an alternative style, the North Indian, which I will present shortly.

The first, and most obvious, difference between the Western chart and the Jyotish chart is that the latter is square shaped. To me, the difference in shapes is a metaphor for how the Western system and Jyotish are typically used in interpretation: the Western wheel suggests a psychological, subjective, “soft” approach, while the Jyotish square suggests an event-based, nuts and bolts, “hard” approach.

The second difference between the Western and Jyotish charts is that the planets and points are marked using text rather than symbols. Once again, this is suggestive of the humanistic, metaphorical approach of Western astrology contrasted with the relatively literal approach of Jyotish.

The third difference has to do with houses: they are whole-sign houses, and they are arranged in clockwise order unlike the Western anti-clockwise arrangement. Also, the first house (for the south Indian style) which corresponds to the sign containing the ascendant, is not always in the same place relative to the rest of the chart, unlike the Western chart where it always starts at the “9 o’clock” position. In the south Indian style chart, it is the signs that appear in fixed places: sidereal Pisces always appears at the top-left corner, followed by the rest of the signs in clockwise sequence. 

The ascendant in the Western chart is 9 Can 46. If you subtract the ayanamsa of 22 degrees and 58 minutes (applicable for the year of the Dalai Lama’s birth), you get 16 Gem 48. (Go back 23 degrees to get 16 Gem 46, then add back the extra 2 minutes we subtracted to get 16 Gem 48.) Take another example, say that of Venus. It is at 28 Leo 14 in the Western chart. Subtracting 22 degrees and 58 minutes gives 5 Leo 16. (This is an approximation since we haven’t used second of arc – throwing in that extra factor gives the chart position of 5 Leo 17.)

Since the ascendant position in the Dalai Lama’s Jyotish chart falls in Gemini, the whole-sign house system uses Gemini for the entire first house. The first house (and the ascendant itself) is called the lagna. Houses are numbered for convenience, since the same house in different charts will fall in different squares of the chart. You may notice the “Rah” in the 7th house of Sagittarius, and the “Ket” opposite it in the 1st house of Gemini. These are short for Rahu and Ketu, which are the Jyotish equivalents of the North Node and South Node, respectively.

In contrast, here is the North Indian style chart:

The North Indian chart holds the houses to fixed positions, so that the 1st house is always at the top. Starting there, houses are read clockwise. Since now it’s the signs that change positions, each sign is marked in its box. So reading this chart clockwise, the ascendant has Gemini, the second house has Cancer, etc.

I learn and practice Jyotish using the South Indian style chart, so I will be using this style exclusively in all Jyotish discussion going forward.

Traditional Jyotishis (astrologers who practice Jyotish) do not use the modern planets Uranus, Neptune, and Pluto. Also, they do not consider the Midheaven degree. However, since I use both the Western and Jyotish charts in my analysis, I tend to leave the outer planets in the chart but not the MC. (Although Jyotish texts do not offer any interpretative guidance for the modern–outer–planets.)

You must have noticed, of course, that due to the application of the ayanamsa, many planets will fall in the previous sign relative to their tropical positions. The Dalai Lama’s Sun, for instance, is now in sidereal Gemini, not Cancer. This is not cause for alarm because the Jyotish sidereal signs are not to be used in personality/character analysis using the tropical zodiac sign interpretations. That is, you should not apply the tropical Gemini characteristics to the sidereal Sun. The way these sidereal sign positions should be used will become clear as we cover more ground in Jyotish.

As you start learning Jyotish, the first thing for you to do is make your Jyotish chart. There are many apps out there that will do this for you. I haven’t tried any of them since I have written Lifespan to generate Jyotish charts, and so I have little in the way of a recommendation of a good app out there. There is however, an easier way, which is to use the chart generation feature at The horoscope page on this blog details how you can use the Extended Chart Selection feature to generate your Western chart. You can use the same feature, but with the following additions: in the Zodiac and Houses optional section, for House System choose “whole signs”, for Zodiac choose “Sidereal”, and for ayanamsha choose “Hindu/Lahiri”. The resulting chart will be circular but all the positions will now be sidereal, and you can redraw this in the South Indian style.

For example, here is the sidereal chart with the Lahiri ayanamsa with whole sign houses for a person born on June 1, 1995 at 1pm in San Francisco, CA:

You can tell this is not a tropical chart because the tropical Sun would be in Gemini on June 1, but here it’s in Taurus. On the chart page, below the chart you will see the actual ayanamsa offset that was used. In this case, the ayanamsa is reported to be Lahiri 23 degrees, 47 minutes, 35 seconds of arc. You can redraw this chart in the South Indian style, noting that the ascendant is in Leo, so the first house will be Leo.

In the next blog on Jyotish, I’ll get into some of the fundamental building blocks of interpretation.