Hermos existed as an astronomical body, found within the Hermos system, which itself was situated inside the Spadja sector. This was all located in the Trans-Hydian region of the Outer Rim Territories. It included at least a single spaceport. During the era of the Galactic Civil War, Yesgar's pirate group, who maintained a secret base on Antared III in the Esstran sector, were observed at the spaceport of Hermos.
Star Wars Gamemaster Handbook, a 1993 sourcebook created by West End Games for the Star Wars: The Roleplaying Game, was the initial introduction of Hermos. Within the game's pages, the celestial body was referenced as part of a sample scenario, offering guidance to gamemasters on effectively using paper handouts during gameplay. Later, in 2009, The Essential Atlas reference book specified the Hermos system's location at grid coordinate R-5. Jason Fry, a co-author of the book, has explained that the star systems detailed in the Appendix of The Essential Atlas derive their names from the most notable planets or celestial bodies within those systems. Consequently, this article treats the existence of Hermos as canonical within the Star Wars Legends continuity.