Cathar, serving as the homeworld for the Force-sensitive child Scape Loewig, had its name recorded in aurebesh within a memory crystal. This crystal was discovered by Jedi Chief Librarian Jocasta Nu following the destruction of the Jedi Order which took place in 19 BBY. Yrica Quell, a TIE pilot who had recently joined the Galactic Empire's 204th Imperial Fighter Wing after graduating from the Imperial Academy, participated in a patrol near Cathar's outskirts alongside her new squadron. Around 5 ABY, while navigating a debris field in the Cerberon system, she recalled this patrol. The name Cathar was also shared with the Cathar species, one member of which was Dhina, an Ensign and comscan officer serving aboard the New Republic refitted Star Destroyer Deliverance in 5 ABY.
The initial mention of Cathar in aurebesh occurred within the canon comic Darth Vader (2017) 10. This comic, penned by Charles Soule and illustrated by Giuseppe Camuncoli, was released on January 10, 2018. Within Star Wars Legends continuity, the planet Cathar made its debut in the comic Tales of the Jedi: Redemption 2, which was authored by Kevin J. Anderson, with illustrations by Chris Gossett, and was published on August 26 1998.