What is the significance of Rahu-Ketu in the Ashtakavarga system?
Ashtakavarga system
The principle of this system is as follows
Grahas transition in a sign.
Each sign is divided into 8 kakshas or parts.
Each Kaksha is 3 deg 45 min. For 8 kakshas the total is 30 degrees of a sign.
Each Kaksha is ruled by a Graha.
The sequence of Kakshas are Shani (Saturn), Guru (Jupiter), Kuja (Mars), Surya (Sun), Shukra (Venus), Budha (Mercury), Chandra (Moon) and Lagna. The sequence is mathematically based on the decreasing order of the time taken by the grahas, to transit a sign.
Rahu and Ketu move in retrograde motion and not taken for positive Mundane Predictions in Ashtakavarga.
Each house of a Graha and Houses gets benefitted or strength.
Ashtakavarga is done for each graha and also a cumulative Ashtakavarga called Sarva Ashtakavarga. The total sum of Sarva Ashtakavarga on all 12 bhavas is 337.
Rahu and Ketu do not have any kaksha in this system. More so the rashi is divided into 8 (Lagna + 7 Grahas), excluding Rahu Ketu. This proves that Rahu and Ketu Do NOT own any houses. And that is why no Bindus or Rekas is given for Rahu and Ketu.
In a way, Sage Parasara, had clearly stated that Rahu and Ketu do not have house ownership. There goes down another fallacy of modern day astrologers assuming House lordship and Oocha-Neecha for Rahu and Ketu.
Rahu Ketu is taken as one unit as it is an axis. Rahu and Ketu reflect the house lord’s significance , in which they are deposited.
One can use the Kaksha of this House lord for Ashtakavarga.
What is the Kaksha bindu value one may ask. It is just minus 1 (-one), in the deposited house and 0 in all other houses.
337 is the total without Rahu-Ketu, and with Rahu-Ketu it becomes 336, which is divisible by 12, to make it cyclic, as per astro-mathematical calculations.
Why minus, because, Rahu-Ketu always are in anti-clockwise to other Grahas. So be it. Tathaastu.
To start with
Use a good Astrological software to make your Sarva Ashtakavarga for your birth chart.
Mark the natal chart, starting from Lagna as 1 till the 12th house for Sarva and graha Ashtakavarga charts.
In the Sarva Ashtakavarga, note down the houses which has maximum and minimum bindus. Also in the graha Ashtakavarga charts.
The lowest bindu house indicates problems in the natal chart.
Weakest house is the one which has the lowest bindu and less than 25 bindus.
Medium houses are with equal to 25 till/equal to 28 bindus.
Strong house constitute greater than 28 bindus.
Strongest house has the highest bindus and greater than 28 bindus.
The highest bindu house makes that house significances strong.
Example : I have 36 in 11th house, which is house of profits. And in 12th house, which is 32. So good earning and good spending and with good savings of the left over.
Pros of Ashtakavarga
It is a quick way to assess a chart.
Gochara can be read, with the bindus of the house, graha transiting it.
Cons of Ashtakavarga
It cannot tell the event that will happen.
It cannot tell the time of the event based on the chart, namely using Vimshottari Dasha or any other.