PanchaSiddhanta

The PanchaSiddhanta is an astronomical treatise attributed to Varahamihira, a scholar who lived in the 6th century CE. It is a compilation of five astronomical schools or siddhantas known to Indian astronomers at the time. The work itself is not extant in its original form, but its content is largely preserved through the commentaries and references made by later scholars, most notably Brahmagupta in his Brahma-sphuta-siddhanta and Bhaskara I.

The five siddhantas discussed in the PanchaSiddhanta are believed to be the Vasishtha, Romaka, Paulisa, Surya, and Paitamaha. Each of these schools had its own theories regarding planetary motion, solar and lunar eclipses, the calculation of time, and other astronomical phenomena. Varahamihira's contribution was to synthesize these diverse traditions, providing a comprehensive overview of the state of astronomical knowledge during his era.

The Romaka Siddhanta, for instance, showed strong Hellenistic influence, with its name likely derived from "Roman." The Paulisa Siddhanta is also thought to have foreign origins, possibly Persian or Greek. In contrast, the Vasishtha and Surya Siddhantas are considered more indigenous Indian traditions. The PanchaSiddhanta is therefore significant for illustrating the cross-cultural exchange in astronomical thought during ancient and medieval times. It offers valuable insights into the methodologies and parameters used by ancient Indian astronomers before the advent of more unified and mathematically sophisticated systems.