Around 964, Al-Sufi published his
Kitab suwar al-kawakib (more commonly referred to by its English translation,
Book of the Fixed Stars). The stars were identified either with Arabic translations of Ptolemy’s Greek or with traditional Arabic names. What set Al-Sufi’s work apart from its predecessor, besides its Arabic text, was an improvement over the magnitude estimates of Hipparchus and Ptolemy.
Book of the Fixed Stars also included Al-Sufi’s highly artistic renderings of the constellations. He overlaid the star map of each constellation with a depiction of its mythological counterpart as seen from two perspectives — one from inside a celestial globe and the other from the outside. There is also a historical sidelight to Book of the Fixed Stars: It includes, in the notes and drawings of Andromeda, reference to “a little cloud,” the first recorded mention of the Andromeda Galaxy.
Book of the Fixed Stars was a standard reference for several centuries, bridging the gap between Greco-Roman times and the Renaissance of Western Europe. In the latter instance, Al-Sufi’s star names received a final tweak when Renaissance scholars “Latinized” them during a translation of
Almagest.
Book of the Fixed Stars was a significant resource for 15th- and 16th-century astronomers and remains so even today as evidence for the proper motion and brightness variations of bright stars over the past millennium.
When astronomers began naming the lunar craters being discovered via the newly invented telescope, they dubbed many with the names of celebrated astronomers of the past; Al-Sufi and his contemporaries were no exception. In the south central part of the Moon, you’ll find the crater Azophi (the Latinized form of Al-Sufi). Nearby are the craters Albategnius, Alfraganus, Alpetragius, Arzachel, and Thebit — all Latinized names of astronomers who applied their skills during the Golden Age of Islam.
Modern-day astronomers owe a debt of gratitude to Al-Sufi and others who worked during the age of Arabian astronomy. They kept alive the torch of scientific knowledge at a time when Western Europe was mired in the Dark Ages. In the process, they gave names to dozens of naked-eye stars. On a February evening, when we gaze skyward to mighty Orion with his 1st-magnitude stars Betelgeuse and Rigel and Belt stars Alnitak, Alnilam, and Mintaka, we truly are standing under an Arabian sky.
Questions, comments, or suggestions? Email me at
gchaple@hotmail.com. Next month: a league of our own. Clear skies!