Ulugh Beg, Zīj-I jadīd-I sulṭānī (towards end of Jumādá II 938 [c. 25 January 1532])
MS 151
An early 15th-century Persian star catalogue that can hold its own with a late 20th-century catalogue produced by the Hipparcos satellite
A copy of Zīj-I jadīd-I sulṭānī ‘The New Tables of the Sultan’ by Ulugh Beg (1394-1449) in the Persian original is the main work in St John’s MS 151. The volume also contains an anonymous miscellany on birth charts (fols 132b-148a) and a collection of astronomical and calendric tables (fols 149a-180b). Ulugh Beg, sultan of the central-Asian Timurid Empire, is best remembered for his astronomical research conducted in Samarkand (today part of Uzbekistan) for over 30 years. His New Tables, completed in 1437, are a ‘register of 992 stars and their complete coordinates’ (Juhel, p. 49). This star catalogue was the first one ‘with positions based on new, independent measurements’ since the
Μαθηματικὴ Σύνταξις, better-known as Almagest, by Claudius Ptolemy (c. 100 CE-170 CE) (Verbunt & van Gent, p. 1). The measurements were taken in the observatory Ulugh Beg had built in Samarkand in the 1420s, which housed a vertical quadrant of 40m radius, the largest ever built (Juhel, p. 47). It took more than 200 years until Gian Domenico Cassini produced better observations between 1655 and 1669 (Juhel, p. 47). Moreover, a comparison with the measurements taken by the satellite Hipparcos in the late 20th century showed that only 0.1% of the star positions in Ulugh Beg’s New Tables are wrong by more than 150 arcminutes (one arcminute being 1/60 of one degree) and contains only 3 unidentified stars, which ‘[testifies] to the excellent quality’ of his star catalogue (Verbunt & van Gent, p. 1).
St John’s manuscript was used together with two Bodleian manuscripts by Thomas Hyde (1636-1703),
Laudian Professor of Arabic from 1691, in his partial edition of Ulugh Beg’s New Tables from 1665 (Savage-Smith, p. 23). Like all other Middle Eastern scientific manuscripts, MS 151 was donated to the College by Archbishop William Laud.
Further Resources
Full digitization available at Digital Bodleian
Descriptive catalogue records available at our Digital Library (scroll down to MS 151)