Jean-Marc Bonnet-Bidaud is an astrophysicist in the Astrophysical Department of the French Atomic Energy Commission (C.E.A.), and specialises in high energy astrophysics and in the study of highly condensed stars in the Galaxy. He is also deeply interested in the history and popularisation of astronomy. He is currently the scientific adviser of the French astronomy magazine Ciel et Espace and has published numerous articles in different magazines and newspapers. He is mainly interested in the history of modern cosmology and in the roots of ancient astronomy in China and Africa.
Dr Fran?oise Praderie, an outstanding European astronomer, passed away on 28 January 2009, before this paper was published. Prior to that she was an Honorary Astronomer at the Paris Observatory. She was a former Vice-President of the Paris Observatory and former Editor of Astronomy and Astrophysics. She contributed to the creation of the trans-disciplinary European association Euroscience, where she served as its first Secretary General. Her main research interests are in stellar seismology, and she was the author of the book The Stars (which was co-authored with E. Schatzman).
Dr Susan Whitfield is Director of the International Dunhuang Project at the British Library and an historian and writer on China and the Silk Road. She is interested in cross-disciplinary research, combining history, archaeology, art history, the history of religions and science in her study of manuscripts and artefacts from the eastern Silk Road. She has published extensively, lectures worldwide and also has curated several exhibitions, including a display of historical star charts in the collections of the British Library.
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 representation 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. We conclude that precise mathematical methods were used to produce the Atlas. We also discuss the dating of the manuscript and its possible author, and we confirm the date +649-684 (early Tang Dynasty) as most probable based on the available evidence. This is at variance with a prior estimate of around +940. Finally, we present a brief comparison with later sky maps, both from China and Europe.
The Dunhuang star atlas is one of the most spectacular documents of the history of astronomy. It is a complete representation of the Chinese sky including numerous stars and asterisms depicted in a succession of maps covering the full sky (Figure 1). Apart its aesthetic appeal, the document found on the Silk Road is remarkable as it is the oldest star atlas known today from any civilization.
The Dunhuang star atlas is unique in the information it gives, which is discussed in more detail below: a) more than 1300 individual stars in the total sky are represented, as could be observed by eye from the Chinese imperial observatory; b) the sky is displayed as in the most modern charts with twelve hour-angle maps, plus a North polar region; c) the Chinese constellations are indicated with their names; d) the atlas is drawn in two inks on the finest paper and accompanied with complementary text; e) the document is shown to date from the early Tang period (618-907), while the oldest other star atlases in China date from the eleventh century.
The manuscript is very often quoted in encyclopaedic and popular publications as an illustration of Chinese astronomical knowledge. However, despite its crucial historical and scientific importance, we realized that no extensive description and analysis of the atlas existed in Western literature. Needham reproduced part of the manuscript and gave only a very short description (Needham, 1959, 264). Since then it has received only brief mentions in other studies (Sun Xiaochun and Kistemaker, 1997, 29; Deng Wenkuan and Liu Lexian, 2003, 76).
We decided to undertake a detailed study of the star atlas after the exhibition on the Silk Road organised in 2004 by the British Library where the document was shown and a preliminary analysis was given (Bonnet-Bidaud and Praderie, 2004). In the present paper, we shall first give a full review of the Chinese sources (sect. 2), then give a general description of the star atlas (sect. 3), examine the accuracy and the type of planar projection used and also present a method to give a date from astronomical arguments (sect. 4). We then discuss the date of the star atlas, compare the Dunhuang star atlas to other Chinese atlases and further comment on the status of these documents (sect. 5). In a monographic appendix, we also include the in-depth description of two representative sections of the document. This study was made possible by the use of high resolution digital copies of the star atlas made available to us by the International Dunhuang Project1. This first publication in Western language is aimed at making available basic information on this important document.
Figure 1: The complete Dunhuang Star Atlas, the last section of the Or.8210/S.3326 British Library manuscript, showing the twelve star maps (as seen above, from right to left), followed by the circumpolar map and ending with the drawing of a bowman in traditional clothes. The total dimensions are 2100 mm in length and 244 mm in width.
Inscribed on a roll of Chinese paper, the manuscript star atlas is surprisingly well preserved. The conditions in which the document was found are well known and leave no doubt about its antiquity. It was discovered by the British-nationalised but Hungarian-born archaeologist Aurel Stein in 1907 among the pile of at least 40,000 manuscripts (Hamilton, 1986) enclosed in the so-called Library Cave (Cave 17) in the Mogao ensemble, also known as the ‘Caves of the Thousand Buddhas’ near Dunhuang (Gansu). The Mogao caves are a set of several hundred Buddhist temples cut into a cliff and heavily decorated with statues and murals. The site was active from about +3602 to the end of the Mongol period. In about +1000, one cave was apparently sealed (Rong Xinjiang, 1999) to preserve a collection of precious manuscripts and some printed material including the world’s earliest dated complete printed book (Whitfield and Sims-Williams, 2004). The sealed cave was rediscovered by accident and re-opened only a few years before the arrival of Stein in 1907. He was therefore the first European visitor to see the hidden library.
These circumstances, together with the dry desert climate of Dunhuang, contributed to excellent conservation of the cave’s contents. Most of the Dunhuang documents are religious texts on Buddhism but there are some socio-economic documents and a few concern medicine, divination and astronomy (Kalinowski, 2003). The astronomical texts are all calendars or almanacs except for two star charts. One of them contains the representation of the whole sky as it could be observed from a latitude of ~ 34°N. This is now known as the Dunhuang star atlas. The other (probably only a fragment) represents incompletely the polar region but not the rest of the sky. This other chart (DB 76) is preserved in the Dunhuang City Museum in China.
After the visit of Stein and the subsequent visits of other foreigners such as Paul Pelliot, Otani Kozui and Sergei Oldenburg, as well as the clearing of the cave by the Chinese government, the manuscripts were dispersed to England, France, China, Russia and Japan.3 Stein’s collections were transferred to the British Museum, where the Dunhuang star atlas received the registration number Or.8210/S.3326 (S. for Stein, hereafter referred to as S.3326).4
S.3326 did not receive much attention at the time of its discovery. This manuscript, which is in two sections, was catalogued by Lionel Giles (Giles, 1957). He listed it under the classification
'divination' (cat. no. 6974) for the first section and described the second section as
'13 star-maps with explanatory text'. He did not estimate a date. His catalogue was published in 1957 but it had been ready for publication since 1947.5 Around the earlier date, Joseph Needham and Chen Shixiang studied the Stein collection of astronomy-related manuscripts for their volume on astronomy (Needham, 1959). In a footnote in the volume, Needham (1959: 264) claims to have been the one to recognize the worth of the star atlas:
'I discovered this extremely interesting map in conjunction with my friend Prof. Chhen Shih-Hsiang.' He is also probably responsible for the initial dating of this manuscript, quoted in most studies thereafter, as he continues:
'Its probable date makes it about contemporary with the maps in the Book of the Fixed Stars… (+903 to +986…)' and he puts the date at
'ca. +940' in his text and captions to the reproduced images (his Figs. 99 and 100).
Unfortunately, the Needham archives do not yield any further information about Needham’s visit to the British Museum to view the manuscripts, nor his research notes. The astronomy volume was published in 1959 but most of the work was carried out between 1949-56, when the manuscript for this volume was completed. It is probable therefore that the 'discovery' was in the early 1950s. By this time, Giles had completed work on his catalogue, although it was still unpublished, and could have directed Needham to the astronomy-related manuscripts.
Although we know that the sky was carefully observed for at least four millennia in China, India and Mesopotamia, what remains in written or graphical form of these observations is very patchy. China is noticeable, though, since astronomical chapters can be found in every of the official dynastic historical records starting in the second century BCE with the Historical Records (Shiji 史记)6 of Sima Qian (司马迁) (Chavannes, 1895), generally considered to be the first history of China. The astronomical chapters of the Shiji include stellar catalogues, which are copies of older, lost ones composed during the Warring States period (-476 to -221). They are known to result from different schools led by three astronomers of ancient times Shi Shen (石申), Gan De (甘德) and Wu Xian (巫咸) who composed reference books describing the stars and the different astrological predictions associated with them (Chavannes, 1895; Maspero, 1929). Though Sima Qian himself does not differentiate information from the three schools of astronomers, the three distinct catalogues were maintained through the Han period (-206-+220) and later combined by the astronomer Chen Zhuo 陈卓 (+220–280). The tradition of attributing each asterism (or Chinese constellation) to a different school survived because of the demands of astrological prediction.
The most complete and detailed description of the Chinese sky, including positions, given by coordinates in Chinese degrees, is later found in the Astrological Treatise of the Kaiyuan Period (Kaiyuan Zhanjing 开元占经), a compilation attributed to the astronomer Qutan Xida (瞿坛悉达) in +729. Part of this information is also present in the astronomical chapters of the History of the Jin (Jinshu 晋书) and History of the Sui (Suishu 隋书), both probably written by the astronomer Li Chunfeng 李淳风 (+602–70) (Needham, 1959, 197, 201 ; Ho, 1966).
Chinese astronomy differs from the ecliptic-based Chaldeo-Greek tradition by its equatorial character, due to the central role of the polar star (Biot, 1862; de Saussure, 1930). The celestial region close to the equator is divided in 28 asterisms (group of stars), called xiu (宿), and often translated as 'mansions' or 'lunar lodges' (hereafter referred to as 'mansions'), which can be considered as an equatorial Chinese zodiac.7 A mansion is defined by an hourly interval corresponding to the meridian passage of two successive leading stars. The grouping of the stars in China is also totally different from the Greek tradition. Beside the equatorial region, the rest of the sky is divided in very numerous small asterisms (nearly three hundred), most associated with practical objects or persons of the Chinese empire, leading to astrological predictions. Lists of the Chinese constellations were maintained all through Chinese history and did not change much over time. They form the basis of the astronomical Chinese tradition (Ho, 1966; Sun and Kistemaker, 1997).
Based on different photographic reproductions, Chinese scholars, both historians and astronomers, have produced several papers in Chinese on S.3326 since the 1960s. Xi Zezong first published an article with complete images (1966). He probably used facsimile images of S.3326 taken from the microfilm. He emphasizes the progress represented for the first time by the representation of the sky charts not on a circular plan but in a way similar to the Mercator projection, several hundred years before Mercator. He notes that the column texts accompanying each hour-angle map are similar to the ones found in the chapter 64 of the Kaiyuan Zhanjing and provides more complete versions based on this text. He then describes the hour-angle maps and the circumpolar map, giving the number of stars by asterism, with asterisms being ordered according to the mansions. He counts 1,359 stars in total and compares it to the Chen Zhuo list giving 1,464 stars following a compilation of the catalogues of Shi Shen, Gan De and Wu Xian (Needham, 1959, 265).
Ma Shichang (1983) paid particular attention to the dating of S.3326. While Needham (1959) mentions, without any justification, a date of ca. +940, Ma Shichang analyzes three elements in the document: a) the style of writing, b) the clothing of the bowman whose drawing ends the manuscript, and c) the taboo characters in the text.8 He cites the taboo form of the character 民 (min) to infer that the manuscript was copied after the reign of Li Shimin (李世民), the personal name of the Taizong emperor (r. +626-49). He argues further that since the character 旦 (dan) occurs several times, the manuscript was written before the reign of the Ruizong emperor ( i.e. before +710), who had this character as his personal name, Li Dan (李旦). Starting with his reign, the character 旦 should have been replaced. Ma Shichang narrows the time gap further by using the type of clothes worn by the bowman (see also sect. 5.1), saying that this type was in use only since the time of Empress Wu Zetian (r.+690-705). Since the manuscript has no Empress Wu taboo characters, it had to be written after her reign, i.e. after +705. From this evidence he concludes that S.3326 was written in ~+705-710. His argument, however contains inconsistencies (see sect. 5.1).
Pan Nai (1989, 148) also produced a description of S.3326 with a valuable discussion on its date. , there is a possible reference to Li Chunfeng. He refutes the claim (Xia, 1982) that S.3326 was inspired by Songs of Pacing the Heavens (Bu Tian Ge (歩天歌) (Iannaccone, 2002; Zhou, 2004), a book in verses including some sky illustrations which is dated +590-600. Pan Nai supports the idea that there was an original star atlas prepared by Li Chunfeng from which S.3326 was copied. Considering the style of writing of the accompanying text, he proposes without any further argument that the copy may date from the tenth century, thus concurring with Needham (see also sect. 5.1).
Deng Wenkuan (1996: 58ff), in the context of a study of astronomical texts and calendars found in Dunhuang, reproduces the S.3326 star atlas with explanatory notes and punctuated versions of the text. In a more recent book (Deng, 2002), he dedicates a chapter to S.3326 and finds similarity with several other texts such as the astronomical chapters of the Jinshu, another text by Li Chunfeng (Yisi Zhan 乙巳占) and the Kaiyuan Zhanjing.菠菜网app 球探即时篮球比分 海南彩票下载 重庆彩票网app