सिद्धान्तशिरोमणि: गणिताध्याय (भास्कराचार्य - ग्रहगणित, मध्यमाधिकार व स्पष्टाधिकार सटीक)

204 E minutes of arc. Then the equatorial rising time of E is (E × x) / 1800 asus because there are 1800' in a Rasi. We have to provide a correction in the planetary position including that of the Sun for this time. If the planet goes Y' during 21659 asus of a day, what arc is covered by the planet or the Sun in (E × x) / 1800 asus? The result is (E × x) / 1800 × y / 21659 minutes of arc. This correction is positive if the equation of centre of the Sun is positive, for, we want the planetary position for a latter time than Mean Sunrise, since the positive equation of centre advances the True Sun over the Mean. This correction will be appreciable only in the case of the Moon having a rapid motion. Verses 62, 63. The correction known as Udayāntara. The difference in minutes of arc in the longitude of the Sāyana mean Sun and the asus in his Right ascension, multiplied by the daily motion of the planet and divided by 21659 is the result to be added to or subtracted from the planet's longitude according as the asus in the Sun's Right ascension are greater or less than the minutes of arc of his longitude. This is what is called Udayāntara correction in the planetary position. Comm. (1) We have seen that the Bhujāntara is a correction in the mean planetary position due to the Equation of time in Eccentricity. (2) This Udayāntara is a correction in the same due to the Equation of time in obliquity. (3) Some have misconstrued that this Udayāntara correction is the Equation of time in the obliquity itself, whereas it is a correction to be effected in the planetary position due to the Equation of time due to obliquity.