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

141
equation of centre pertaining to the planet which may be
taken to be equal to 2e as a first approximation where e is
the eccentricity of the elliptic orbit of the planet.
It may be further mentioned here that in Sūrya-
siddhānta, as well as elsewhere in this work, the circum-
ferences are given to vary continuously. This variability
curiously achieves ellipticity in the orbit as may be seen
as follows.
In the case of the Sun, the epicycle has a periphery
of 14° when m = 0 or 180° and of 13 ⅔° when m = 90° or
270 according to Sūryasiddhānta, where m is the Manda-
kendra or mean anomaly. At any arbitrary point, where
Fig. 10