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

386 of last contact has also the same formula where in each case β is the latitude at the moment of opposition. The path taken by the centre of the shadow is called 'ग्राहकमार्ग' ie. the path of the eclipsing body. The actual case when both C and M are both moving and when β is considered as a non-changing quantity is shown in fig. 74. In this Fig. 74 case, three positions are shown, (1) that at the first con- tact (2) that at opposition and (3) that at last contact, where C₁, M₁, C₂, M₂ and C₃, M₃ give the positions of the centre of the shadow and that of the Moon's disc respe- ctively, both the centres being shown as moving. Since the Moon moves faster than C and as such overtakes C, the path of M from M₁ M₃ which synchronizes with the path of C from C₁ to C₃, is shown to be longer. But, one may wonder, how C₁ N₁ and C₃ N₃ represent the Sparśa- Sthiti-Khanda and Mokṣa-Sthiti-Khanda respectively. The distance overtaken by M with respect to C from the point of first contact to the point of opposition is M₁ M₂ — C₁ C₂ = C₁ N₁. Hence we compute C₁ N₁ by the formula C₁ N₁² = (P+r)² — β². Similarly from the point of opposition to the point of last contact M overtakes C by the distance M₂ M₃ — C₂ C₃ = C₃ N₃ = √(P+r)² — β². Fig. 75 shows the situation when β changes as is the actuality. When the opposition takes place after the Moon crosses the node, then β₃ > β₂ > β₁, whereas if