The Sector Solar, also called Sol Sector, is a sector of Imperial space within the Segmentum Solar. The Sector Solar is the very heart of the Imperium of Man and the oldest sector of space within its demesne. Terra, Luna, and Mars are all located in the Sector Solar, as was Cthonia, the ancient homeworld of both Horus and the Black Legion. The Sector Solar is guarded by Battlefleet Solar, the largest and most powerful Segmentum Battlefleet of the Imperial Navy.
- Sub-Sector Solar - The sub-sector of Sector Solar known to be home to the worlds of the Sol System.
- Codex: Imperialis (2nd Edition), pp. 8, 42