An Etymological Dictionary of Astronomy and Astrophysics

A large → asterism of four stars, approximately square in
shape, in the northern sky. Three of the stars, → → Markab, → Scheat, and → Algenib, belong to the constellation → Pegasus. The fourth, → Alpheratz, was lost to Pegasus when the constellation boundaries were formalised, and now lies just within the borders of → Andromeda.

Etymology (EN): → square; → Pegasus.

Etymology (PE): Chahârguš, → tetragon; → Pegasus.