Gwynaura is one of the stars mentioned in the series that Sophie has memorized the position of.
Neverseen Hideout
The Neverseen name their hideouts after solo stars, which are stars that aren't in any constellations, or near any other stars (they shine pure white light), as revealed in Lodestar. One major Neverseen hideout was called Gwynaura, and was one of the first Sophie and her friends accessed.