Among the earliest philological research done on the Greco-Indian astral science was undertaken by the Dutch orientalist Henrik Kern, who was known mostly for his works in Buddhist and Austronesian studies. Kern studied Utpala’s commentaries of the Bṛhatsaṃhitā and Bṛhajjātaka in the late 19th century and most of the jyotiṣa entries from the Monier-Williams Sanskrit-English dictionary are based on Kern’s notes (not entirely reliable as Kern was only in his twenties then!) Subsequently, a number of important historical studies on the jātaka was published by P.V. Kane around the 1950s, followed by David Pingree from the 1960s onward. The Indian and Western scholars followed largely Kane and Pingree’s footsteps, with notably Indo-centric vs. Greco-centric bias. A much more balanced approach was undertaken by the Japanese scholars, most notably Yano Michio and his student Sugita Mizue, who jointly published an annotated Japanese translation of the Bṛhatsaṃhitā in 1995 . In addition, Sugita produced the e-texts of a number of key jyotiṣa work such as the Bṛhatsaṃhitā and the Bṛhajjātaka.
The next step of jātaka studies would be a comprehensive comparative study of the major Greco-Indian Jātakas, namely Sphujidhvaja’s Yavanajātaka, Mīnarāja’s Vṛddhayavanajātaka and Varāhamihira’s Bṛhajjātaka. At the moment, the e-texts of all the texts together with key passages and citations in Utpala’s commentaries have been prepared. For the past three years, Yano and myself have read and analyzed Utpala’s commentary on the Bṛhajjātaka (80% complete as of today). This summer at the World Sanskrit Conference, I will present my new edition of the Yavanajātaka. Today at a drinking party, Yano and myself have decided to begin our reading of the Vṛddhayavanajātaka once our reading of the Bṛhajjātaka is finished, probably some time before the end of the year.
The comparative study of the three jātakas will reveal most likely the historical relation of the three texts and to point us to the right direction in terms of what kind of Greek astrology it was supposedly based on. Since the origin and the earliest form of Greek astrology are rather sketchy, perhaps some important clues may be gleaned from the Sanskrit sources.