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

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formulated by Hindu Astronomy agrees with its formula- tion in Modern Astronomy which enunciates elliptic motion; but it will be seen that the eccentric-circle theory also gives very approximately the same formula for the Equation of centre. There is just one point of difference, which does not matter. Whereas in Modern Astronomy the mean anomaly is reckoned from the perigee or perihelion as the case may be, it is reckoned in Hindu Astronomy from the apogee or aphelion. The difference is made up by prefixing the appropriate sign to the equation. The word Mandōccha stands for the apogee in the case of the Sun and the Moon and for the aphelion in the case of the other planets and the word Manda kendra stands for the mean anomaly in both the cases. In Hindu Astronomy the word ‘graha’ stands for not only the five planets Mercury to Saturn but also for the Sun and the Moon. Why that word is applied to the Sun and the Moon as well is, that both the Sun and the Moon also while moving among the stars along with the five other planets Mercury to Saturn, wield an influence on the residents of the Earth. The etymology of the word ‘graha’ is गृह्णातीति वा गृह्यते अनेनेति वा ग्रहः ie. ‘that which seizes upon the fates of the resi- dents of the Earth’, with this etymological significance only, even the lunar orbital nodes known as Rāhu and Kētu are also taken to be grahas in Hindu Astronomy. Hence translating the word graha as a planet and criticis- ing Hindu Astronomy for taking the Sun, Moon and the lunar orbital nodes also as such is not right. In other words the translation should be pronounced wrong. Uranus, Nep- tune and pluto were not mentioned in Hindu Astronomy. We shall now elucidate the eccentric and epicyclic theories of Hindu Astronomy, which will be seen to give identical position to the planets. How they came to be postulated will be also elucidated. Incidentally we deal with the ‘Bhagaṇōpapatti’ or the proof of the numbers of sideral revolutions of the various grahas enunciated in the