THE DUNHUANG CHINESE SKY: A COMPREHENSIVE STUDYOF THE OLDEST KNOWN STAR ATLAS

摘要

This paper presents an analysis of the star atlas included in the medieval Chinese manuscriptOr.8210/S.3326 discovered in 1907 by the archaeologist Aurel Stein at the Silk Road town of Dunhuang and nowhoused in the British Library. Although partially studied by a few Chinese scholars, it has never been fully displayedand discussed in the Western world. This set of sky maps (12 hour-angle maps in quasi-cylindrical projection and acircumpolar map in azimuthal projection), displaying the full sky visible from the Northern Hemisphere, is up to nowthe oldest complete preserved star atlas known from any civilisation. It is also the earliest known pictorial represent-ation of the quasi-totality of Chinese constellations. This paper describes the history of the physical object—a roll of thin paper drawn with ink. We analyse the stellarcontent of each map (1,339 stars, 257 asterisms) and the texts associated with the maps. We establish theprecision with which the maps were drawn (1.5-4° for the brightest stars) and examine the type of projections used.We conclude that precise mathematical methods were used to produce the Atlas. We also discuss the dating of themanuscript and its possible author, and we confirm the date +649-684 (early Tang Dynasty) as most probable basedon the available evidence. This is at variance with a prior estimate of around +940. Finally, we present a briefcomparison with later sky maps, both from China and Europe