Journal of Astronomical History and Heritage, 12(1), 39-59 (2009). THE DUNHUANG CHINESE SKY: A COMPREHENSIVE STUDY OF THE OLDEST KNOWN STAR ATLAS Jean-Marc Bonnet-Bidaud Commissariat à l’Energie Atomique, Centre de Saclay, F-91191 Gif-sur-Yvette, France. E-mail:
[email protected] Françoise Praderie Observatoire de Paris, 61 Avenue de l’Observatoire, F-75014 Paris, France. and Susan Whitfield The British Library, 96 Euston Road, London NW1 2DB, UK. E-mail:
[email protected] Abstract: This paper presents an analysis of the star atlas included in the medieval Chinese manuscript Or.8210/S.3326 discovered in 1907 by the archaeologist Aurel Stein at the Silk Road town of Dunhuang and now housed in the British Library. Although partially studied by a few Chinese scholars, it has never been fully displayed and discussed in the Western world. This set of sky maps (12 hour-angle maps in quasi-cylindrical projection and a circumpolar map in azimuthal projection), displaying the full sky visible from the Northern Hemisphere, is up to now the 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 stellar content of each map (1,339 stars, 257 asterisms) and the texts associated with the maps. We establish the precision with which the maps were drawn (1.5-4° for the brightest stars) and examine the type of projections used.