The Pebble

The Pebble was a small round stone given to The Party by a fox spirit with instructions that "when [they] get to the Feywild, please give [The Pebble] to The Tall One". Indeed, when they went to the Feywild they did give it to The Tall One, and he placed it into the sky, where it became a star.
On returning to the Fadelands, Draven found that the new star was present on that plane as well, and was not listed on any of his star charts.