AL-S??F?, ABU’I-H?USAYN ‘ABD AL-RA?M?N IBN ‘UMAR AL-R?Z?

(b. Rayya, Persia, 903; d. 986)

astronomy.

Little is known of al-S?fi’s life and career. He seems to have been closely associated with members of the Buwayhid dynasty in Iran and Baghdad, especially Addu al-Dawala (d. 983); besides that of ’Adud al–Dawal, names of three other members of the dynasty occur in connection with some of al–s?fi’s writings. Occasionally he mentions a–mater–(Ust?dh) and “chief” (ra’?s) Abu’l-Fadl Muhammad ibn al-HUsayn, in whose company he visited D?nawar in 946/947 and Isfahan in 948/949. This person obviously is Ibn al-‘Am?d (d. 970), vizier of ‘Adud al Dawla’s father. Rukn al-Dawala, who had contributed a foreword to al-S?f?’s book on the astroble (which was dedicated to one of ’Adud al-Dawala’s sons, Sharaf al-Dawala).

Al-S?fi is most renowned for his observations and descriptions of the fixed stars. The result of his investigations in this field are presented in his Kit?b Stnrar al-kaw?kib al-th?bita (“Book on the Constellations of the Fixed Starts”), in which he gives a critical revision of Ptolemy’s star catalog, adding the differing or additional results of his own observations. The first such revision of Ptolemy’s finding, the work became a classic of Islamic astronomy for many centuries; it even found its way into medieval Western science, where al-S?f? became known as Azophi. In the “Book on the Constellations” the series of the forty-eight Ptolemaic constellations are dealt with according to the following scheme: first, there is general discussion of all the stars of each constellation, in which al-S?f? introduces his own criticism, mostly concerning positions, magnitudes, and colors; second, an identification of Arabic star names with the stars of the Ptolemaic stellar system contained in that constellation; third, two drawings of the constellation, as it seen in the sky and as it is seen on the celestial globe; and fourth, a table of the stars of the constellation, giving longitude, latitude, and magnitude for each star. The epcoh of the star table is the beginning of the year 1276 of Alexander (1 October 1964), adding a constant of 12°42’ to Ptolemy’s longitudes (adopting a precession of one degree sixty-six years, in accordance with the z?j al-Mumtahan, the Tabulae probatae, which were prepared in 829/830 by order of the caliph al-Ma‘m?n in order to improve certain parameters in the classical tradition). The magnitudes represent the results of al-S?f?’s own observations.

The scientific significance of this work lies in the valuable records of real star observations—in contrast with those of most other medieval astronomers, who merely repeated the Ptolemaic starcatalog, adding constant values to his longitudes. There is also another important aspect: the exact astronomical identification of the several hundred old Arabic star names, which had been registered and transmitted only in philogical works that completely omitted the exact astronomical consideration. Al-S?f? did his best to identify them astronomically, although he was not always successful. His identifications were adopted by most later Islamic writers on astronomy and even penetrated modern stellar terminology: from T. Hyde’s quotations form al-S?f? and his follower Ulugh Beg, G. Piazzi selected ninety-four star names and introduced them into common use through his praecipuarum stellarum inerrantium positiones . . . (1814).

Al-S?f? also wrote a rather long and detailed Kit?b al-‘amal bi‘l-asturl?b (“Book on the Use of the Astrolabe”), an “Introduction to the Science of Astrology” (extant only in manuscript), and a “Book on the Use of the Celestial Globe” (also unpublished). He seems to have constructed astronomical instruments as well, for a silver celestial globe of his manufacture is said to have been extant in Egypt around 1043.

A poem on the constellations, in the radjaz meter (“Urj?za f? suwar al-th?bita”), by Ab? ‘Al?ibn Abi’l-Husayn al-S?f? should be mentioned. He usually is referred to as Ibn al-S?f? the son of al-S?f?. There is, however, sufficient reason to assume that he could not have been a son of the subject of this article, for the person to whom the poem is dedicated was obviously a prince reigning in the middle of the twelfth century.

BIBLIOGRAPHY

I. Original Works. Al-S?f?s most widely known work is Kit?b suwar al-kaw?kib al-th?bita (“Book on the Constellations of the Fixed Stars”). The Arabic text was widely used and was quoted several times by T. Hyde in the commentary to his ed. of Ulugh Beg’s star catalog, Tabulae longitudinis et latitudinis stellarum fixarum exobservatione Ulugh Beighi (Oxford, 1665), 2nd ed. by G. Sharpe in Syntagma dissertationum (Oxford, 1767). L. Ideler drew many quotations from Hyde in his Untersuchungen über den Ursprung und die Bedentung der Sternnamen (Berlin, 1809). Al-S?f?’s intro. appears in French trans. by J.J.A. Caussin de Perceval in Notices et extraits des manuscrits, XII (Paris, 1831), 236 ff.: the entire book in French, with selected portions in Arabic and the drawings, was edited from two MSS by H. C. F. C. Schjellerup as Description des étoiles fixes par Ahd-al-rahman Al-Sûfi (St. Petersburg, 1874); the complete Arabic text was edited from five MSS and was augmented by the “urj?za” poem of Ibn al-S?f? at the Osmania Oriental Publications Bureau (Hyderabad, India, 1954), with intro. in English by H.J.J. Winter.

Nas?r al-D?n al-T?s? translated the book into Persian in 1250 but his translation has not been published. By order of Alfonso X of Castile, an adaptation of the work, in Castilian, was completed around the middle of the thirteenth century and was edited by Manuel Rico y Sinobas as Los libros del saber de astronomia, I (Madrid, 1863). There is a critical ed. of the star nomenclature in this Castilian version (and in a succeeding Italian trans.) by O. J. Tallgren as “Los nombres árabes de las estrellas y la transcripción alfonsina,” in Homenaje a R. Menéndez Pidal, II (Madrid, 1925), 633 ff., with “Correcciones y adiciones” in Revista de filología española, 12 (1925), 52 ff.

Traces of al-S?f?’s star catalog are also found in some Latin MSS, but there is no trans. of the complete text. See P. Kunitzsch, “S?f? Latinus,” in Zeitschrift der Deutschen Morgenländischen Gesellschaft, 115 (1965), 65 ff. Peter Apian sometimes quotes al-S?f? but detailed investigations are still requred in order to determine whether he quoted from the Arabic or from a translation.

For medieval Arabic criticism of al-S?f? (by al-B?r?n? and Ibn al-Sal?h), see P. Kunitzsch, ed., Ibn as-Sal?h, Zur Kriotik der Koordinatenüberlieferung im Sternkatalog des Almagest (Göttingen, 1975), 21, 109–111; and the places from p. 38 to 74 given in the name index s.v. as-S?f?

Al-S?f?’s other published work is kit?b al-’amal bi’lasturl?b (“Book on the Use of the Astrolabe”). The Arabic text, in 386 chapters, was edited from a Paris MS by the Osmania Oriental Publications Bureau (Hyderabad, India, 1962). An intro. in English, by E. S. Kennedy and M. Destombes, was printed separately (Hyderabad, India, 1967). For a geometrical treatise of al-S?f? see F. Sezgin, Geschichte des arabischen Schrifttums, V (Leiden, 1974), 309–310.

II. Secondary Literature. See C. Brockelmann, Geschichte der arabischen Litteratur, 2nd ed., I (Leiden, 1943), 253–254, and Supplement, I (Leiden, 1937), 398; and C. A. Storey, Persian Literature, II, pt. 1 (London, 1958), 41–42. For Ibn al-S?f? see Brockelmann, Supplement I 863, no. 4a. See also A,. Hauber, “Die Verbreitung des Astronomen S?f? in Islam, 8 (1918), 48 ff.; M Shermatov, “Ash-Shirazi’s comments on the star catalogue of as-Sufi,” in Uchenye zapiski Dushanbin. gos, pd, in-t., 81 (1971), 73–83 (in Russian); S. M. Stern, “Abd al-Rahm?n al-S?f? in Encyclopaedia of Islam, new ed., 1 (Leiden-London, 1960), 86–87; J. Upton, “A Manuscript of ’The Book of the Fixed Stars’ by ‘Abd Ar-Rahm?n As-S?f? in metropolitan Museum Studies, 4 (1933), 179–197; E. Wellesz, An Islamic Book of Constellations (Oxford, 1965); H.J.J. Winter, “Notes on Al-Kitab Suwar Al-Kawakib,” in Archives internationales d’histoire des sciences, 8 (1955), 126 ff. For critical remarks on al-S?f?s attitude and method in identifying the ancient Arabic star nomenclature, see P. Kunitzsch, untersuchungern zur Sternnomenkaltur der Araber (Wiesbaden, 1961), 10, 14 ff., 31; and also Arabische Sternnamen in Europa (Wiesbaden, 1959), 230–231. A sky map, including the Arabic stellar nomenclature according to al-S?f? was printed as Supplément to Le Mobacher (Algiers, Sept. 1881).

Paul Kunitzsch