पृष्ठम्:आर्यभटीयम्.djvu/36

xxxvi ARYABHATİYA f 11. Position of Ujjayini. Suryadeva endeavours to assign an astronomically significant latitude to Ujjain, viz., 24° N on the meridian of Lanka, which latter is taken, in Indian astronomy, to be a city located at the equator at 0 meridian. Thus, while explaining the passage उज्जयिनी लङ्कायाः तच्चतुरंशे समोत्तरतः । (A, Gola, 14) Suryadeva notes that the angular distance from Lanka to Meru at the north pole is 90° and that the angular distance of Ujjayini from Lanka would be 22 according to the above reading of the passage, with the expression taccaturanse. Now, 22 has no astronomical significance. He argues that Aryabhata should have mentioned Ujjayini only to indicate a place of maximum declination of the Sun, viz., 24°; otherwise, there was no purpose in mentioning Ujjayini at all. Hence, he argues, the correct reading of the expression should be paricadasarise; the intended measure of the latitude, viz., 24', would then be duly indicated, it being one-fifteenth of a complete circle of 360. 12. Motion of the Stars and the Planets contrasted Suryadeva specifies that the stars appear as if fixed on the zodiac and the zodiac, along with the stars, moves as a whole from east to west. The planets, however, are seen to move from one asterism to another to the east. This indicates the eastward motion of the planets. (Com. on Gitikā, 3, p. 14). 13. The nodes and apogees It is well known that the node and apogee of a planet are not material objects like the planet itself, the former being just the point where the planet, in its northward course, crosses the ecliptic and the latter the remotest point of the planet's orbit from the earth. However, these points keep on changing their positions, the said motion being capable of being counted in terms of revolutions during long periods of time. The point is well brought out by Suryadeva. Thus, after enumerating the number of revolutions of the nodes and apogees per yuga as depicted in A, i. 4, Suryadeva poses the