Zeta Doradus system
From Halopedia, the Halo wiki
The Zeta Doradus System is a planetary system near UNSC-controlled space. It contains many planets, almost all of which are ice worlds or gas giants, none of which are habitable. The one exception, however, is the planet Onyx.
The UNSC cruiser Pillar of Autumn was refit to serve near Zeta Doradus in 2550.
The The Battle of Onyx was fought here in 2552.
Doradus is an actual contstellation, though it does not possess a Zeta Doradus within it.
