From Halopedia, the Halo wiki
Far Nomdagro was a small orange star in Forerunner space, located seven light-years from the ecumene's Capital. The star was orbited by the temperate planet Nomdagro where the Didact's and the Librarian's estate was once located. The planet was home to many Warrior-Servants; however, with the diminishing of their rate, many left the system upon joining the Builder rate, becoming Builder Security. Near the end of the Forerunner-Flood war, the system was conquered by the Flood. Far Nomdagro was located near a nebula home to many newborn stars. Around 98,445 BCE, when the Didact went into his first Cryptum, the light from a hundred-year-old supernova struck the nebula, illuminating it for several days.
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