Historical beliefs · Medieval Islamic world; al-Sufi of Isfahan, tenth century
Al-Sufi's Book of the Fixed Stars
In tenth-century Isfahan, the astronomer al-Sufi checked Ptolemy's star catalogue against the sky and wrote the Book of the Images of the Fixed Stars, with every constellation drawn twice.
The book
Al-Sufi rewrote Ptolemy's 48 constellations from his own observations, in Arabic.
Marika Sardar of the Metropolitan Museum describes al-Sufi (903–986) (opens in a new tab) as one of the most important of the astronomers who, between the ninth and eleventh centuries, criticised and improved Ptolemy's work. Supported by the Buyid ruler 'Adud al-Daula, to whom he dedicated it, he wrote the Book of the Images of the Fixed Stars in Arabic, based on new observations he made at Isfahan.
The book follows Ptolemy's Almagest (opens in a new tab), the Met explains, and covers the 48 constellations of the “fixed stars”, which medieval cosmology placed in the eighth of nine spheres around the Earth.
Sources for this section Marika Sardar, Astronomy and Astrology in the Medieval Islamic World, Heilbrunn Timeline of Art History, The Metropolitan Museum of Art (2011) (opens in a new tab); The Metropolitan Museum of Art, Kitab suwar al-kawakib al-thabita (Book of the Images of the Fixed Stars) of al-Sufi (13.160.10) (opens in a new tab)
Two views of each figure
Each constellation is drawn twice, as seen from Earth and as on a globe, so the two are mirror images.
In the copy at the Met, each constellation appears twice (opens in a new tab), in mirror image: once as seen from the Earth, looking up, and once as seen from outside the sky, as on a celestial globe.
The difference is real, not a mistake: a globe shows the sky as if from beyond it, so east and west swap. Ridpath (opens in a new tab) points out the same thing in a 1516 sketch of the Southern Cross, which shows the sky as on a celestial globe, a mirror image of the view from Earth.
Sources for this section The Metropolitan Museum of Art, Kitab suwar al-kawakib al-thabita (Book of the Images of the Fixed Stars) of al-Sufi (13.160.10) (opens in a new tab); Ian Ridpath, Star Tales: Crux (opens in a new tab)
The Met's copy
The illustrated manuscript at the Met was made some five centuries after al-Sufi wrote.
The Met's manuscript (opens in a new tab), in ink and gold on paper, is attributed to Iran in the late fifteenth century, about five hundred years after al-Sufi; it entered the museum in 1913.
The museum's essay places it among the many works in which scholars of the Islamic world (opens in a new tab) built on Greek, Iranian and Indian sources, and notes that this period also recorded Arab Bedouin knowledge of the fixed stars and the lunar mansions for the first time.
Sources for this section The Metropolitan Museum of Art, Kitab suwar al-kawakib al-thabita (Book of the Images of the Fixed Stars) of al-Sufi (13.160.10) (opens in a new tab); Marika Sardar, Astronomy and Astrology in the Medieval Islamic World, Heilbrunn Timeline of Art History, The Metropolitan Museum of Art (2011) (opens in a new tab)
In the sky today
Al-Sufi gave the first known description of the Andromeda Galaxy: a ‘nebulous smear’.
Ian Ridpath (opens in a new tab) notes that the first recorded mention of the Andromeda Galaxy is in al-Sufi's book, where it is called the nebulous smear.
It is still a smudge to the naked eye: the NASA Night Sky Network (opens in a new tab) describes it as a fuzzy patch, best from dark skies. The Andromeda guide shows where to look.
Sources for this section Ian Ridpath, Star Tales: Andromeda (opens in a new tab); Kat Troche (Astronomical Society of the Pacific), Catch Andromeda Rising!, NASA Night Sky Network (2024) (opens in a new tab)
Sources
Each story belongs to the people who tell it. This page reports one account from the sources below; it does not speak for everyone in a culture.
- History Marika Sardar, Astronomy and Astrology in the Medieval Islamic World, Heilbrunn Timeline of Art History, The Metropolitan Museum of Art (2011) (opens in a new tab) for al-Sufi, his patron, his observations and the wider context · checked 2 October 2026
- History The Metropolitan Museum of Art, Kitab suwar al-kawakib al-thabita (Book of the Images of the Fixed Stars) of al-Sufi (13.160.10) (opens in a new tab) for the book and the Met's copy · checked 2 October 2026
- History Ian Ridpath, Star Tales: Crux (opens in a new tab) for globe views as mirror images · checked 27 September 2026
- History Ian Ridpath, Star Tales: Andromeda (opens in a new tab) for the first record of the Andromeda Galaxy · checked 2 October 2026
- Astronomy Kat Troche (Astronomical Society of the Pacific), Catch Andromeda Rising!, NASA Night Sky Network (2024) (opens in a new tab) for seeing the galaxy · checked 27 September 2026
