सिद्धान्तशिरोमणि: गणिताध्याय (भास्कराचार्य - ग्रहगणित, मध्यमाधिकार व स्पष्टाधिकार सटीक)
Siddhanta Shiromani Ganitadhyaya of Bhaskaracharya with Commentary
भास्कराचार्य द्वितीय द्वारा
पृष्ठ 382, कुल 573 में से
संदर्भ में पढ़ें362
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