SN 1054 is a supernova that was first observed on 4 July 1054, and remained visible for around two years. The event was recorded in contemporary Chinese astronomy, and references to it are also found in a later (13th-century) Japanese document, and in a document from the Arab world. Furthermore, there are a number of proposed, but doubtful, references from European sources recorded in the 15th century, and perhaps a pictograph associated with the Ancestral Puebloan culture found near the Peñasco Blanco site in New Mexico.


A more likely explanation for the lack of widespread European reports of the A.D. 1054 event was offered by Zaleman⁷ and by Thomas⁸, who ascribe it to the Great Schism, which split Christianity into the Roman Catholic Church in the the West and the Orthodox Church in the East. The immediate events leading to the split occurred during 1054 July 16–24. Zaleman and Thomas suggest that church fathers would naturally have chosen to ignore the celestial event, rather than taking a chance on its misinterpretation as a portent. Political necessity rather than ideology (or failure of observation) is offered as the cause for the absense of such reports.

None of the above explanations is very satisfactory. Indeed, it is gratifying that a probable report of the A.D. 1054 event, by an observer in the Near East, recently came to light⁹. Ibn Buṭlān, a Christian physician from Bagdad, who lived in Cairo and then in Constantinople between A.D. 1052 and 1055 was reported (Fig. 1) in a book by Ibn Abī Uṣaybiᶜa (composed around A.D. 1242) to have written: "One of the well known epidemics of our time is that which occurred when the spectacular star (athari kawkab) appeared in Gemini in the year 446 H." (1054 April 12 – 1055 April 1). The internal details and consistency of the report identify the location of the star in Taurus (with the then-astrological sign of Gemini) during the early summer of A.D. 1054, in good agreement with the oriental reports*.