There is a lot of confusion today about the proper use of divisional charts (Vargas). Both novice and senior astrologers alike are uncertain whether or not to use aspects, conjunctions, house placements amd/or lordships.
This confusion arises, in my opinion, due to the misconception that Vargas, like Rashi, are actual (physical) stand-alone charts. This notion, I believe, is completely false!
Certainly the sages tell us that the Vargas should be read in the same manner as Rashi. This is true in principle but so misunderstood in application.
Janma Kundali (Rashi or Natal Chart)
As we know, the birth chart (Janma Kundali) is a snapshot of the physical planets (navagrahas) at the moment of our birth. The sages tell us that, at the moment of birth, these divine planets recreate as a living entity whilst the signs of the zodiac manifest as the twelve bhavas (areas of life). This is a profound act of creation, reflected in the birth chart itself.
Just as we, essentially divine in essesnce, have a physical body so too do the physical planets (Sun through to Saturn). Both the physical attributes and the divine recreation of the grahas are present in Rashi.
Due to the physical nature of the grahas they cast their aspect on specific bhavas/grahas (as per Parasari principles). They also have lordship over certain houses and so forth. This is not the case with the divisional charts which, I believe, must be read in conjunction with natal chart...not as separate charts!
So what are the Vargas (Amsas)
Vargas are purely and simply divisions of the Rashis (Zodiac signs). They are not, nor were they ever intended to be, stand-alone charts with physical attributes similar to Rashi, There are no actual bhavas in these (so-called) charts. They simply represent certain divisions of natal chart, nothing more! To say that a planet owns a particular house in varga is an absolute furphy--erroneous concept!
If we look at the birth chart (below) of Bill Cosby (12 Jul 1937, 00:30 Philadelphia USA) we see the physical Sun in sign of Gemini occupying 4th house. This is the actual blueprint of the physical zodiac at the time of his birth. In this chart there is a mutual aspect between LagnaKaraka Sun and his nakshatra lord, lagnesh Jupiter (in 10th house of career).
Note also that these key planets exchange nakshatra lords.
In Dashamsha (Varga indicating career) Sun is placed in sign of Aquarius (owned by Saturn) whilst Jupiter is placed in sign of Virgo (ruled by Mercury). Now, please; can anyone tell me how these placements relate to the physical zodiac at the time of birth? There is no ephemeris in the world that will show these physical positions in divisional charts.
They are not, in my opinion, physical (stand-alone) charts at all and must be related back to the natal chart; as I hope the following examples will show.
The sages instruct us that we must be well versed in both Astrology and Astronomy; And (importantly) we're urged to use our own discretion (common-sense) when applying the dictums laid out in ancient texts.
How to interpret Vargas
Using the above chart as an example lets look at the death of Cosby's son (Ennis) on 16 Jan 1997. Cosby was running dasa of JU-ME-SA at the time
Dasa lord Jupiter, of course, is significator of children whilst bhukti lord Mercury occupies 5th house of children. Pratyantar lord Saturn, owning 8th from bhukti lord Mercury, occupies 8th from 5th lord Moon (dispositor of Mercury).
Looking now at the divisional chart of children (Saptamsha) we find pratyantar lord Saturn placed in sign of Scorpio which is ruled by Mars. In Rashi, Mars, inimically placed in 8th house, occupies 3rd from 5th lord Moon. As we know, 3rd signifies cause of death whilst Mars is significator for violence and weapons.
Ennis was shot dead while changing a flat tire on the side of the interstate 405 in Los Angeles.
In the below chart we find that Ennis was undergoing the dasa of VE-VE-RA-JU at the time of death. Its appropriate to consider the placement of these planets in Dreshkana which is a reflection of 3rd house. As well as governing siblings this house, 8th from 8th, is also connected with death...specifically the cause of our own death.
Note dasa lord Venus occupying Scorpio dreshkana. In natal chart Scorpio owns 12th house occupied by Mars himself. 12th, as we know, signifies loss, including loss of life, whilst Mars signifies violence, weapons and so forth.
Pratyantar lord Rahu occupies Pisces dreshkana which, to the best of my knowledge, represents the 22nd dreshkana (Jupiter)...see >here<
Note 22nd dreshkana is related to the 22nd dreshkana from lagna (usually 8th house from lagna in natal chart). Depending on the degree of natal lagna, 22nd dreshkana will fall on 1st, 2nd or 3rd dreshkanas of the 8th house (in the natal chart).
NB: These examples show how vargas are read in juxtaposition to natal chart. Members of jyotish-vidya discussion group will remember this being >discussed< some years ago.
If I am not mistaken, it was Sri Seshadri Iyer who popularised the use of divisionals as separate charts with his "New Techniques of Prediction". However, although I cannot say for certain just when this practice was first implemented, I can say with some certainty that the ancient rishis most certainly considered these divisions in conjunction with the natal chart and not as separate charts.
It's only from this premise that the dictums describing Navamsha aspects etc., can be clearly understood.
To calculate the divisions from natal chart we simply note the degree of the sign rising at the moment of birth (lagna) and the degree a planet occupies in a particular sign.
For navamsha, each sign consisting of 30 degrees is divided into 9 equal parts of 3:20 degrees. Then, depending upon the element of the sign, we calculate the positions as follows:-
Navamshas of planets in Fire signs (Aries,Leo,Sagittarius) are counted from Aries.
Navamshas of planets in Earth signs (Taurus,Virgo,Capricorn) are counted from Capricorn.
Navamshas of planets in Air signs (Gemini,Libra,Aquarius) are counted from Libra.
Navamshas of planets in Water signs (Cancer,Scorpio,Pisces) are counted from Cancer.