Can anyone explain the effects of Vargottama planets in the chart. I know that it strengthens the effects of the planet, but what is the significance and strength of the particular planets?
Vargottama means when a planet occupies the same rashi in the main chart and the 9th Divisional chart commonly known as the Navamsa.
Many people forget that these harmonics or Divisional charts are very important in analysis of any particular aspect of some1's life. However D9 is only one of them. It is very important. But so is D2, D3, D10, D12, D24 etc. Each of them are read as individual horoscopes but wearing shades of the D1 or main horo. Dont ask me to explain all these coz that is too long, you can find a lot of books and literature on these.
what is important is that once you start going higher up the harmonics (beyond D12) then the difference in lagnas of these charts can vary in as small as 2 mins difference in birth time. So one needs to be very very careful.
For example a person has an exalted venus in 10th house in basic horo...an astrolger might jump the gun and claim that venus dasha will be super for job/ profession. If however venus sits in virgo in 6th house in D10 or Dashamsa then its dasha will give very ordinary results related to job. etc etc
in a nutshell D9 or navamsha represents your other half or spouse.
for a layman--in general a vargottama planet is believed to gain extra power...