This project investigates the earliest realistic star maps from the Tang and Song dynasties, such as the Cheonsang Yeolcha Bunyajido, the Dunhuang star map, and the Gezi Yuejin Tu. These maps preserve rare and valuable depictions of the medieval Chinese sky. Despite their significance for reconstructing constellation systems, studying historical observations, and interpreting ancient astronomical events, the dates of their creation, histories of revision and use, and connections with textual records remain unclear.
Adopting the perspective of constellation evolution, this study integrates methods from astronomical calculation, historical analysis, and digital reconstruction. It systematically cross-references Han–Tang star catalogs with coordinates extracted from the maps to clarify their data sources. By tracing changes in asterisms and comparing them with descriptions in historical texts, it establishes the relative chronology of the maps and, when possible, their compilation dates. Astronomical simulation software is employed to reconstruct period skies and replicate celestial events, such as planetary conjunctions, to identify the maps’ usage periods.
Beyond dating and source analysis, the project examines the technical foundations of ancient cartography, the transmission and transformation of constellation forms, and the cultural roles of these maps in their historical contexts. Framing them within a “data source–compilation–transmission–application” life-cycle model, the project offers a new approach to understanding medieval Chinese star maps and their place in East Asian histories of astronomy.