The Emergence of “cyclic” tables in Indian Astronomy in the seventeenth century: Haridatta's Jagadbhusaṇa and its Islamic inspiration

Indian planetary tables can be classified into several distinct types with respect to their underlying mathematicbal structure. One of these, the so-called “cyclic” scheme was inspired by goal-year periods introduced via Islamic channels no later than the early seventeenth century. The first set of such cyclic planetary tables is the Jagadbhusaṇa of Haridatta, composed in Mewar, Rajasthan with an epoch of 31 March 1638. This substantial work, spreading over more than 100 folia in some manuscripts, computes the true longitudes of the planets in a manner similar to those in the Babylonian goal-year texts, Ptolemy, and al- Zarqali. We will consider the inspiration from these earlier sources and how they are incorporated into a distinctly Indian context, with respect to mathematical structure, astronomical foundation, and layout and arrangement of the data in the tabular format.