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