ब्राह्मस्फुटसिद्धान्त (ब्रह्मगुप्त - शून्य, कुट्टक, बीजगणित एवं सम्पूर्ण २१ अध्याय सान्वय सटीक)

310 BRAHMAGUPTA'S ASTRONOMY : ITS HIGHLIGHTS 42. Rule relating to the visibility-correction known as akṣa-dṛkkarma : BrSpSi. VI. 4. Also MBh. VI. 1-2; ŚiDVṛ. I. vii. 3 (ii); MSi. VII. 4; SiŚe. IX. 7. 43. Rule relating to the visibility correction known as ayanadṛkkarma : BrSpSi. VI. 3; X. 17. Slightly modified in MBh. VI. 2 (ii)-3; ŚiDVṛ. I. vii. 2-3 (i) · SiŚe. IX. 4-5; similar in MSi. VII. 2-3; more accurate in SiŚi. I. viii. 4-5. 44. Rule relating to the visibilily of moon : BrSpSi. VI. 6 ; X. 32. Also MBh; VI. 4-5 (i) PSi. V. 3 : ŚiDVṛ. I. vii. 5; SiŚe. IX. 8 (i). 13. 45. Rule for calculating the phase of the Moon : BrSpSi. VII. 11 (ii)-12. Also MBh. VI. 5 (ii)-7; ŚiDVṛ. I. ix. 12. 46. Rule for the determination of the Moon's true declination (i.e. the declination of the centre of the Moon's disc) : BrSpSi. VII. 5. Also MBh. VI. 8; ŚiDVṛ. 1. viii. 2: SiŚe. X. 7. (these are approximate rules; a more accurate rule occurs in SiŚi. I. vii. 3 and 13). 47. Graphical representation of the elevation of the lunar horns in the first quarter of the month at sunset : BrSpSi. VII. 7-10. Also MBh. VI. 13-17; ŚiDV. I. ix; SiŚi. I. ix. 48. Minimum distances of the planets from the Sun when they are visible : BrSpSi. vi 6 ; X. 32. Also MBh. VI. 44; ŚiDVṛ. I. vii. 5 (i); SiŚe. IX. 8 (i). 12. 49. Rule relating to the determination of the time and the common longitude of two planets when they are in conjunc- tion in longitude : BrSpSi. IX. 5-6. Also MBh. VI. 49-51; ŚiDVṛ. I. x. 7-9 (i); SiŚe. XI. 12-12. 50. Rule relating to the distance between two planets