[This is the Scheat of Tycho, the Palermo Catalogue, and modern lists generally, either from Al Sā'id the Upper Part of the Arm, or, as Hyde suggested, from the early Sa'd appearing in the subsequent three pairs of stars. Bayer had Seat Alpheras; Chilmead, Seat Alfaras; Riccioli, Scheat Alpheraz; and Schickard, Saidol-pharazi.]
Source: wiktionary