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

IX.18 IX. SAURA-SIDDHĀNTA — SOLAR ECLIPSE 217 18. The meridian point of the ecliptic (madhyalagnam) is got. Find its declina- tion, north or south. If north, find the difference between the declination and the latitude of the place. If south, add them. The sine of the result is called madhyajyā, i.e. sin zenith distance of the point. The madhyajyā is got thus: (i) Interval between noon and new moon = time of noon ~ time of new moon. (ii) The degrees of rise of the ecliptic, backward or forward from the Sun, using the corresponding ascensional differences of zero latitude, for the interval in (i) in the forenoon or afternoon respectively is to be found. (iii) (Longitude of) meridian ecliptic point = The Sun (or Moon) at new moon ∓ (ii), ( - for fore- noon, + for afternoon). (iv) The declination north or south of (iii) is to be found. (v) Sine zenith distance of m.e.p. in (iii) = sine (declination found in (iv) ± latitude), ( + if the declination is south, and the sine found is directed south, ~ if the declination is north, and the sine is directed north or south according as the declination or the latitude is greater.) Example 12. To continue example 10 using the times given there. (i) Interval between noon and new moon = nā. 20-40 - nā. 15-40 = 5 nā., afternoon. (ii) Given, Sun = Moon = rā. 2-0-0, at new moon. Forward counting is to be done (because after- noon) from the first point of Gemini where the Sun is. For successive 10° of rise, the times taken are, in vināḍis, 105.4, 107.6, 108.8, 108.8. For the interval, of 300 vināḍis = 105.4 + 107.6 + 87, there are 10° + 10° + 8° ( = 10° × 87 ÷ 108.8) = 28°. (iii) Adding, the meridian ecliptic point = rā. 2-0-0 + 28° = rā. 2-28-0. (iv) The declination of m.e.p. is 23° 58′N. (v) Sine zenith distance of m.e.p. = sine (23° 58′ - 10° 24′) = sine 13° 34′ = 28′ 9″, north (∵ declination is greater). It has been stated by us, above, in the context of the computation of the solar eclipse according to the Paulīśa, that in order to get the parallaxes in longitude and latitude, the nonagesimal and the sine and cosine of its zenith distance, (i.e. dṛgjyā and Śaṅku), are to be found. In the Saura, a diffe- rent method is given to get the sine of the zenith distance of the nonagesimal (z.d.n.) for which the m.e.p. and the sine of its zenith distance are necessary, and given here. It has been said that the m.e.p. is the point of intersection of the meridian (NZS in the fig.) and the ecliptic (OrO' in fig.) as M in fig. s is the position of the Sun at new moon, (occurring in the 17a. D. मध्याह्नलम्बित. B. लम्बितातीर्थे b. A. ०रनराश्युः; B1.2. ०रतराश्युः; B3. ०रसत्तराश्युः; 18b. B1.3. तस्माच्च C. ०निरक्षराश्यु; c. B1.3. विपुत D. ०रन्त[र]राश्यु. B. प्रीतिपाशाः d. A. या ज्याकृतिं सद्याभि०; B1.2. या ज्या सधाभि०; d. A.B. पक्षाधनकार्यः; A2. पक्षाधनकाकैर्यः B3. या ज्या सद्वाभि०;