The Norma Arm is a minor spiral arm of the Milky Way extending from and around its central hub region. The inner portion of the Arm is called the Norma Arm in narrow meaning. The outer end of it is identified either with the Cygnus Arm, that lies outside the Perseus Arm, or the Outer Arm, which is located further away from the center of the Galaxy than the Cygnus Arm. The Norma Arm begins 2.2 kpc from the Galactic Center, and extends outward to a radius of 15.5±2.8 kpc. It is named for the Norma constellation, through which the Arm as seen from Earth passes.