North Circumpolar Region from the Dunhuang Star Chart
This blog in our ancient map series deviates a bit from the representation of topography of planet Earth, to a remarkable charting of the heavens dating to circa 649-684 CE. Created in China during the Tang Dynasty, it is the earliest known manuscript atlas of the stars. While it is widely held that such charts were probably produced by earlier astronomers such as Claudius Ptolemy (Greek 83-161 CE) and Chen Zhuo (Chinese 220-280 CE), no physical charts or remains of such charts are known to exist.
The chart divides the night sky into segments with the final segment featuring the North Polar Region (pictured above), which was considered most important to Chinese astronomers. The final image of the chart is that of an archer, known as the Bowman. The caption alongside the archer’s image suggests that he is the Taoist deity of lightning, which would strike whenever he released his arrow.
The manuscript is a spectacular document in the history of astronomy, an exquisite star chart showing the entire night sky as visible from China. Hand drawn, the chart is on a thirteen foot long scroll made of fine Chinese paper. It was found amongst forty thousand other invaluable manuscripts addressing myriad subjects from religion, history, art and literature to medicine, mathematics and economics, and the stars of the night sky.
The manuscripts had been secreted in the caves of a Buddhist monastery positioned on the ancient Silk Road trade route, and were miraculously preserved due to the dry climate of the region. For reasons yet unknown, the caves were sealed in the eleventh century and stayed sealed until 1900 when a Taoist priest stumbled upon this treasure trove in one of the caves. The scroll containing the star chart was discovered by British-Hungarian archaeologist Aurel Stein in 1907 when he visited the caves. Stein subsequently took the star chart along with several thousand other manuscripts to the British Museum in London, from where it was transferred to the British Library.
The chart divides the night sky into segments containing thirteen maps with the final segment featuring the North Polar Region. It contains over thirteen hundred stars which are visible to the naked eye from the Chinese imperial observatory, along with an explanatory text, all recorded centuries before the telescope appeared. Over two hundred and fifty constellations are depicted and named. The stars are plotted according to a mathematically calculated projection system developed by the Chinese to accurately depict the night sky on a flat piece of paper. The system began to be developed in China before the first century CE, and is similar to the projection developed by Gerard Mercator in the sixteenth century CE.
Belt of Orion (left) and Pleiades and Hyades (right)
For China, astronomy was not a new topic of research in the seventh century CE. Evidence indicates that at least as early as 1300 BCE Chinese scholars and academics were studying the night sky. Oracle bones dating to this period have been found which feature names ascribed to stars. An early reliable record of a total solar eclipse was made by Chinese observers in 780 BC. Other reliable records exist which show that from the Warring States Period (4th century BCE) onward, detailed astronomical records were kept, including detailed catalogues of the stars.
The Bowman from the Dunhuang Star Chart