I don't know if there's an easier way to do this, but what I do when I see something strange in the skybox is to start selecting systems in the galaxy map around my position and checking how close it is to the detail in the skybox. I hone in the direction of the detail this way, trying to select a system matches the direction as well as possible until I find one that's as close to the same direction as possible, and then I just check in the galaxy map if there's something visible in that direction from my position.