Sophie had no idea what that thing was. But it had an arrow-like thingy. So she could guess, at least. She raised her hand. "Professor, is this to track stars or something? Like, this arrow moves around when the stars move! Or maybe planets..." she frowned a little while thinking. "Or when we want to find a specific star, it points towards it and shows us where it is!" Those were the only things that came to Sophie's mind for now.