The universe is Cartesian : each star lies in a X:Y coordinateX and Y might be negative e.g. -19:-6around the star are planets orbiting and around planets orbit moons.so, -19:-6:41 is for a sun in X = -19, Y = -6, 4th orbit first moon.
You can use the navigation link in the main menu at any time, you will start at 0:0 of the universe in that case.
On planet view you can bookmark a location of interest for you, bookmarks help you to send fleets easier towards them, or guide through the universe faster.You can add a small note on every bookmark and you can manage all of them at your bookmarks page.