In the above diagram,
A = Starting Point, 0 degree Aries
P = Planet
S = Sun
E = Earth
Angle AEK = Manda Sphuta, heliocentric longitude, after manda samskara
Angle AES = Sheegroccha, mean Sun, mean longitude of Sol
Angle AEP = True geocentric longitude of planet
Angle KEP = The Sheegra Correction or sheegra phalam
The Anomaly of Conjunction = Sheegra Kendra = Angle AES – Angle AEK
x = Angle AES – Angle AEK
Sin ( x ) =
r sin (x)
_______________________
((R + r cos x)^2 + rsin x^2 ))^1/2
which is the Sheegra correction formula given by the Indian astronomers to calculate the geocentric position of the planet.