The Scholia on Aratus constitute a body of ancient and Byzantine marginal commentaries on the astronomical poem Phaenomena by Aratus of Soli. They are not a single, unified work but rather a compilation of explanatory notes, ranging from brief glosses to extended passages, composed by multiple anonymous scholars from the Hellenistic period through the Byzantine era. These scholia serve to elucidate the poem's often difficult diction, its embedded mythological narratives, and its complex astronomical and meteorological concepts. Their content typically includes textual exegesis explaining archaic grammar and syntax, detailed astronomical commentary on constellations and celestial motions, mythological elucidation of the stories behind the stars, and source criticism identifying Aratus's primary models, such as the prose treatise of Eudoxus of Cnidus, while also noting discrepancies. The scholia survive exclusively within the medieval manuscript tradition of the Phaenomena itself, with a key source being the 9th-century Vatican Greek manuscript 1087. As a heterogeneous collection, their preservation is entirely dependent on the fortunes of the primary text's transmission. Critically edited in the modern era by scholars such as Ernst Maass, the scholia are a vital source for understanding the reception and scholarly treatment of Aratus's work. They provide significant insight into ancient exegetical methods and educational practices, are invaluable for the textual criticism of the Phaenomena, and help recover fragments of otherwise lost commentaries, including those by figures like Attalus of Rhodes.
