Jyotihshastra: Astral and Mathematical Literature c4.s2.3

c4.s2.3

The earliest *siddhānta* that has come down to us is a Paitāmahasiddhānta²⁷ of the early fifth century. This is preserved because of its incorporation into the Viṣṇudharmottarapurāṇa²⁸ (2, 166–174), though it also (or at least the astronomical section, chapters 168–174) has been copied as an independent treatise.²⁹ Its position as the source of the Brāhmapakṣa is made evident by Brahmagupta’s dependence on it in composing the first ten chapters (Daśādhyāyī) of the BSS, and was explicitly recognized by Kamalākara (Siddhāntatattvaviveka 1, 62). Its chronological position is fixed by the fact that Sassanian astronomers in about 450 knew one of its characteristic parameters;³⁰ this makes it more than likely that Pitāmaha is the Svayambhū referred to by Āryabhaṭa (A Gola 50), whose Kalpa-system is a modification of the Brāhmapakṣa’s (he even accepts the Brāhma’s rotation of the *uccas* and *pātas* [A Daśagītikā 7 and Gola 2] despite the fact that in his system that is unnecessary), whose table of Sines (A Daśagītikā 10 and Gaṇitapāda 12) is derived from the Pait. (3, 12), and who copies various other formulae from the same source.