Treatise on Astrology of the Kaiyuan Era

Treatise on Astrology of the Kaiyuan Era
Volume 105 of the Treatise on Astrology of the Kaiyuan Era, on calendars
Traditional Chinese	開元占經
Simplified Chinese	开元占经
Transcriptions Standard Mandarin Hanyu Pinyin Kāiyuán Zhānjīng

The Treatise on Astrology of the Kaiyuan Era is a Chinese astrology encyclopedia compiled by the lead editor Gautama Siddha and numerous scholars from 714 to 724 AD during the Kaiyuan era of Tang Dynasty. The compilation is attributed to the author by 729. Its full title is regarded as the Great Tang Treatise on Astrology of the Kaiyuan Era. It is also referred to as the Kaiyuan Star Observations.

The book is divided into 120 volumes and consisted of about 600,000 words. The compilation of writings was based on many previously written astrological and divination materials, and probably a similar classic known as the Yisizhan, compiled by Li Chunfeng approximately 645. It incorporated many fragments of other works, including the star catalogues of Shi Shen and Gan De, and contained a translated version of Navagraha calendar under the chapter of 104. The astronomical table of sines by the Indian mathematician and astronomer, Aryabhata, were also translated into the Kaiyuan Zhanjing.

The manuscript copies had started to fade away since the 10th century, but was over again received a special attention by scholar Cheng Mingshan in 1616 and was later included in the Siku Quanshu collections of the 18th century.