The desk
Around 964, ʿAbd al-Raḥmān al-Ṣūfī completed The Book of the Fixed Stars. He worked at the Buyid court. Ptolemy’s forty-eight constellations provided the inherited framework, already in Arabic. Al-Sufi checked them against observation, corrected them, redrew them, and placed Arabic star knowledge beside the Greek catalogue.
Inherited
Ptolemy’s constellations, magnitudes, and coordinates, received through the Arabic Almagest. Al-Sufi keeps the Greek figures in view so a reader can see what the book received. He does not leave them untested.
Observed and named
The same lights as named among Arabic observers: ostriches, a mutilated hand, two fish across a body the Greeks called Andromeda. He draws many constellations twice, once as they appear on a globe and once as they appear in the sky, because those two pictures reverse left and right.
What he added
He corrected magnitudes where his eyes disagreed with Ptolemy. He noted a little cloud in Andromeda, later recognized as the Andromeda Galaxy. He recorded the Large Magellanic Cloud as seen from the south. Transmission was not passive copying.
THE WORD
How a name travels
Many star names now printed in Latin letters came through Arabic: Rigel from rijl, a foot; Aldebaran; Altair; Fomalhaut, fam al-ḥūt, mouth of the fish. Transmission is not invention. It is also not a single true name.
A physical star may carry a scientific designation, an IAU proper name, Bayer letters, Chinese asterism membership, Polynesian names. Each belongs to a language and a use. None erases the others.
THE FENCE
The manuscript is a primary document in libraries. This page is a story about it. We are looking at words about a book, not at the book.