The Esstran sector resided within the Outer Rim Territories of the galaxy. Within this sector were included the planet Moraband and also the Thurra system, which itself held the planet Thule.
The first canon appearance of the Esstran sector was in the Star Wars: The Clone Wars episode "Sacrifice," which debuted on Netflix on March 7, 2014. This episode served as the thirteenth and concluding episode of the show's sixth season. The 2017 reference book Star Wars: Smuggler's Guide, authored by Daniel Wallace, provided the initial identification of the sector.
Within the Legends continuity, the Esstran sector made its debut in The Empire Strikes Back Monthly 149. Its first identification occurred in the Star Wars: The Essential Atlas Online Companion, which was published on StarWars.com.