विकिस्रोतः तः
Jump to navigation Jump to search
एतत् पृष्ठम् अपरिष्कृतम् अस्ति

40 above. Multiply that by the radius and divide the product by the 5.ghra aाःa which is obtained by formula (2) above. Then find the correspond ing arc, and add that to or subtract that from the true-mean longitude of the planet, according as the girakendra is less or greater than 180". The result thus obtained is the true longitude of the planet for true sumrise at the local place. Criterion for knowing whether a planet is stationary : 40. When (the longitude of ) a planet for today is equal to that for tomorrow, then is said to be the commencement or conclusion of the retrograde motion of that planet. A rule for finding the amounts of the retrograde and direct motions of a planet : 41. (Whatever is obtained on) subtracting the longitude (of a planet) for tomorrow from the longitude for today (when it is possible), is called the retrograde motion (of the planet for the day); and whatever results on performing the subtract ion reversely gives the direct motion (of the planet for the day). The commentator -Sarikaranarayapa interprets the text as follows:

  • When the longitude of a planet calculated for tomorrow is less than the

longitude for today, the motion (ofthe planet) is said to be retrograde; when it is the contrary, the motion is direct.”