Sigma Octanus system

Stats
121 Light Year from earth Southern Pole star as viewed from Earth

Summary
Sigma Octanus is a system of planets in FLEETCOM Sector Three with over 3 million people on Sigma Octanus IV. The Keyes Loop, The Battle of Sigma Octanus IV occurred here in 2552. Also Master Chief found one of the strange Forerunner artifacts in Côte d'Azur, on Sigma Octanus IV.

External Ref
Halo Maping Project