Oth Sonin system
From Halopedia, the Halo wiki
The 0th Sonin System is the star that the Brute home world Doisac orbits, the third in distance from it, with two unknown planets orbiting it. This system is the Brute's homeworld and from 2554 it is the homeworld and capital of the Brute Alliance. The main planet, Doisac, is the capital planet but more planets (such as the moons of Doisac) in the system have been inhabited, with technological interventions. This system holds the main council and is therefore extremely significant to the Brutes.