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

IX.16 IX. SAURA-SIDDHĀNTA — SOLAR ECLIPSE 215 Moon’s, against the fact that it is only 13.37 times from the Śāstras, and what they give is equal to saying that there are 14.85 revolutions of the Moon in the year for the kakṣās vary directly as the periods of revolution, i.e. inversely as the number of cycles in a given period. We shall also see what havoc their wrong corrections play in the angular diameters following. [बिम्बमानम्] ‘(स्वरवसु) मुनीन्द्रविषया’ भानोः ‘खकृतर्तु[व]सुगुणाः’ शशिनः । तात्कालिकमानार्थं स्फुटकक्षाभ्यां पृथग्विभजेत् ॥ १६ ॥ Measure of the orbs 16. Divide 5,14,787 by the Sun’s kakṣā, and 38,640 by the Moon’s to get the respective angular diameters in minutes at the time. It is to be noted that the angular diameters (of the orbs of the Sun and Moon) are always given in minutes by our Śāstras. Thus, (a) The Sun’s angular diameter in minutes = 5,14,787/Sun’s kakṣā. (b) The Moon’s angular diameter in minutes = 38,640/Moon’s kakṣā. Example 11. To continue the problem of example 10, find the angular diameters of the Sun and Moon for the time given. (a) The Sun’s angular diameter = 5,14,787' ÷ 16,641 = 31'.0. (b) The Moon’s angular diameter = 38,640' ÷ 1171.2 = 33'.0. The derivation of the rules for the angular diameters is as explained below. The angle formed at the eye by the diameter of the orbs of the Sun and the Moon is their angular diameter and given in minutes. We all know from experience that the nearer the orbs, i.e. the lesser the radius vector (given in yojanas), the greater is the angle, and the farther away is the orb, i.e. the greater the radius vector, the lesser is the angle. Thus the angle and the radius vector are in inverse ratio, as also the kakṣā which is directly proportionate to the radius vector. So we have: Sine angle at the eye = 120 × diameter in yojanas ÷ the radius vector in yojanas. The angular diameter in minutes = 3438 × 120 × diameter in yojanas ÷ (radius vector in yojanas × 120.) Here, the author has reduced the diameter in yojanas by the same factor used in verse 15 to reduce the radius vector in yojanas to the kakṣā, and multiplying by 3438, as explained already, to convert the sine into minutes, he has given 5,14,787 for the Sun, and 38,640 for the Moon. The mean kakṣā of the Sun derived by us in the explanations is 16,042. Dividing 5,14,787 by 16,042, we have the Sun's mean angular diameter, 32'.1, and the Moon's is 38,640 ÷ 1200 = 32'.2. 16a. A.B1.2. खखवसुखमः; C.D. खवेसुखमुनीन्द्र; (D. मुनीन्दु) c. B2. तत्कालिक; B1.2. तत्कलिका b. B. खततर्तुः; A.B.C. om व; C. सुरगुणाः B2. Unnecessary gap after of शशिनः