The Pleiades existed as a galactic locale. Within the Kalamith sector of the Outer Rim Territories, it housed the planet Endymion, which became the battleground for a skirmish. This conflict involved the Jedi and Sith during a widespread galactic conflict.
The mention of the Pleiades was brief, appearing in the 2010 publication Star Wars Art: Visions. Specifically, it was identified as the location of the planet Endymion in Skirmish on Endymion, an artwork by Michael Haynes. Haynes' website reveals his initial intention to portray the Pleiades as a constellation, a detail ultimately omitted from the book's final print. In actual astronomy, the Pleiades is a star cluster, specifically an open one, found within the constellation of Taurus. On June 12, 2015, the Star Wars: The Essential Atlas Companion was updated, introducing the Endymion system in the Kalamith sector of the Outer Rim, but the Pleiades was not referenced.