पञ्चसिद्धान्तिका (आचार्य वराहमिहिर - सूर्य, रोमक, पौलिश, वासिष्ठ एवं पितामह सिद्धान्त)

IX.4 IX. SAURA-SIDDHĀNTA — SOLAR ECLIPSE 199
Mean Moon
2. Multiply the Days by 9,00,000, deduct 6,70,217, and divide by
2,45,89,506. The approximate mean Moon in revolutions etc. is got.
3. Multiply the Days by 900, add 22,60,356, and divide by 29,08,789. The
approximate Moon's apogee in revolutions etc. is obtained.
4. Multiply the revolutions of mean Moon by 51, and divide by 3121. The
resulting seconds of arc are to be subtracted to get the exact mean Moon.
Multiply the revolutions of apogee by 10 and divide by 297. The resulting
seconds are to be added to get the exact apogee.
The following are the formulae:
(i) Mean Moon in revs. etc = (Days × 9,00,000 − 6,70,217) ÷ 2,45,89,506 − number of revolutions
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