From a Heavenly Arabic Poem to an Enigmatic Judeo-Arabic Astrolabe

Since the sole surviving astrolabe with engraving in Judaeo-Arabic came to light at an auction in 1988 the inscription on the rim has troubled researchers for it appeared to make little sense. We show here that the inscription is a corrupt version of a 10th-century poem compiled by the astronomer-mathematician-poet Abū Isfāq Ibrāhīm al-Sābi' for the ruler 'Adud al-Dawla when the scholar presented him with an astrolabe; this poem appeared in several manifestations between Baghdad and al-Andalus over the centuries, of which our astrolabe presents the most distorted version. There is also a problem with the plates, the latitudes underlying the markings often being at variance with what is stated on them. The difficulty of dating the astrolabe and assigning it to either of al-Andalus or the Maghrib is discussed.