ब्राह्मस्फुटसिद्धान्त (ब्रह्मगुप्त - शून्य, कुट्टक, बीजगणित एवं सम्पूर्ण २१ अध्याय सान्वय सटीक)

90 BRĀHMASPHUṬASIDDHĀNTA & KHAṆḌAKHĀDYAKA the nodes of the planets to be the same as in the Āryabhaṭīya. All these are the same as given by Brahmagupta in the Khaṇḍa- khādyaka. In the stanza 33 we have rules for finding the geocentric longitudes of planets which may be taken to be the same as in the Khaṇḍakhādyaka¹; compare these values with those in the Sūryasiddhānta of Varāhamihira in the Pañcasiddhāntikā, XVII. 6, but slight different from the Āryabhaṭīya.² The last stanza of the Mahābhāskarīya (35) gives the dimen- sions in yojanas of the orbits of planets ; these are the same as in the modern Sūryasiddhānta. Thus we find a great semblance in the constants as given by the Mahābhāskarīya of Bhāskara I, of the Sūryasiddhānta as given by the Pañcasiddhāntikā and understood by Varāhamihira, and also the constants as given by Brahmagupta in his treatises, specially the Khaṇḍakhādyaka. It must not be forgotten that the same Āryabhaṭa I who is the celeberated author of the Āryabhaṭīya is also the author of another treatise very often referred to as the Tantra. I shall quote Prabodha Chandra Sengupta in connection with these similarities, and the great influence of Āryabhaṭa on Indian Astronomy. He writes in his Introduction to the Khaṇḍakhādyaka as follows : We have shown that there is much resemblance in the constants between the Sūryasiddhānta of Varāha and the Khaṇḍakhādyaka and for the matter of that with the Tantrāntara of Āryabhaṭa I. In my papers “Ārya- bhaṭa and Āryabhaṭa's Lost Work”, I have establish- ed the fact that the Sūryasiddhānta as it existed before the time of Varāha, was made more accurate by him by borrowing the constants from Āryabhaṭa's ārdharātrika system. That there was a Sūryasiddhānta १. शीघ्रफलाद्धं मध्ये मन्दफलाद्धं च मन्दशीघ्रफले । सकले मध्ये स्पष्टः शीघ्रं मध्योनकं केन्द्रम् ॥ —KK. II. 18 २. मन्दोच्चाच्छीघ्रोच्चादर्धमृणधनं ग्रहेषु मन्द्येषु । मन्दोच्चात्स्फुट मध्याच्छीघ्रोच्चाच्च स्फुटा ज्ञेयाः ॥ शीघ्रोच्चादर्धोनं कर्तव्यमृणं धनं स्वमन्दोच्चे । स्फुटमध्यौ तु भृगुबुधौ सिद्धान्मन्दात्स्फुटौ भवतः ॥ —Arya. III. 23-24