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

362 the Moon with respect to the ecliptic where λ is the longi- tude of the Moon with respect to the nearer node and 270' or 4½° is taken to be the inclination of the lunar orbit to the ecliptic or what is the same, the maximum latitude of the Moon. Comm. The formula is evident and similar to that for calculating the declination of the Sun. Thus H sin β = (H sin λ × H sin 4½°) / R . But since β is small and also 4½°, we can take β = (H sin λ × 270') / R . The argument used by Bhāskara, however, is ‘ If by a H sin λ equal to R, we have the maximum latitude of 270', what shall we have for H sin λ?’ The result is as given. Note. The modern value for i the inclination of the lunar orbit to the ecliptic is given to vary between 4°-58' and 5°-18'. Verse 11. The definition of the magnitude of a lunar eclipse. Sthagita or the magnitude of an eclipse is defined as P+r+β where P and r are respectively the radii of the eclipsing and eclipsed bodies and β is the latitude of the Moon. If the Sthagita is greater than 2r, then the eclipse is total. [Diagram: Two intersecting circles representing the Moon (center M, radius r) and Earth's shadow (center C, radius P), along lines labeled "LUNAR ORBIT" and "ECLIPTIC"] Fig. 71