सिद्धान्तशिरोमणि: गणिताध्याय (भास्कराचार्य - ग्रहगणित, मध्यमाधिकार व स्पष्टाधिकार सटीक)

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Fig. 9
Eccentric circle theory.—Let E₁ be the earth's centre;
let M₁PA₁ be the circular orbit in which the planet (here
the Sun or the Moon) moves with a uniform motion. This
planet is termed the Madhyagraha or the mean planet.
Let M₂A₂P₂ be the actual orbit of the planet whose centre
E₂ is removed a little away from E₁. Since the centre E₂
is moved in a vertical direction away from E₁, every point
of the eccentric circle (E₂) will be vertically over the
corresponding point of the mean circle. Thus M₂ will be
the position of the actual planet where M₂ is vertically
above M₁ the mean planet. Join E₁M₂ to cut the mean
circle in P. Since A₂ is the position of the actual planet
farthest from E₁ the Earth's centre, the planet should have