The spiral arm of our Galaxy that is about 5000 l.y. farther from the centre than the local Orion Arm in which the Sun lies, and roughly parallel to it. The Perseus Arm can be traced from the constellation of Cassiopeia via Perseus to Auriga, Gemini, and Monoceros, behind stars in our local arm. It contains the Double Cluster, the Crab Nebula, and the Rosette Nebula.
Subjects: Astronomy and Astrophysics.