The Vaultera Nebula was an emission nebula with a radius of eight light years. Its average composition was 79% hydrogen, 11% helium, 6% carbon, 3% oxygen, and 1% other substances. This nebula was located in the Alpha Quadrant.
The original Illyrian settlement was located in the Vaultera Nebula on the planet Illyria, which was in the Illyria system. In 2259, Number One asked the USS Enterprise computer to compile files on Illyrian genetic modification relating to disease control from this settlement. (SNW: "Ghosts of Illyria")
Captain Christopher Pike visited the nebula to seek the counsel of Neera Ketoul. The settlement's atmosphere couldn't be breathed by normal Humans as Captain Pike needed a breather unit while on the planet, The inhabitants of the planet could apparently breathe oxygen. (SNW: "The Broken Circle", "Ad Astra per Aspera")