Sigma Octanus system
From Halopedia, the Halo wiki
Summary
Sigma Octanus is a system of planets 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.
