The Adega system, a star system located within the Auril sector of the Outer Rim Territories, held the planet of Ossus and was positioned at grid coordinate S-6 on the Standard Galactic Grid. It was the origin point for the Adegan crystal family. Among these was the mephite crystal, a scarce and radiant type of kyber crystal discovered in a limited number of locations both within and near the Adega system.
The initial canonically depicted appearance of the Adega system occurred in a Force vision featured in the 2015 movie Star Wars: Episode VII The Force Awakens. Its formal identification was first established in the roleplaying sourcebook Nexus of Power by Fantasy Flight Games. Within the Star Wars Legends timeline, the system's debut was in the first issue of Star Wars: Tales of the Jedi – The Freedon Nadd Uprising, a comic series. This issue was penned by Tom Veitch, with illustrations by Tony Akins, and released by Dark Horse Comics on August 2, 1994. Despite this comic issue marking its first physical appearance, the system received its initial mention in For a Thousand Generations, a set of endnotes authored by Tom Veitch and included at the conclusion of Dark Empire 4.