The Cygnus Arm or Outer Arm (labeled "+II") is one of four major spiral arms in the Milky Way galaxy, along with the Sagittarius Arm. The Outer Arm has a radius of 15.5 ± 2.8 kpc and lies outside the Perseus Arm. It is named after its proximity to the Cygnus constellation.
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Last updated: 05-21-2005 21:48:38
