Our Milky Way galaxy has tens of billions of stars and Sun is only one among those billions. We now know that our home Galaxy is a spiral galaxy and that we live about halfway out from the center. We talk about galactic longitude and galactic latitude. Here is a nice page to convert from the equatorial coordinate system to the galactic coordinate system. And in the universe of Star Trek, there is a somewhat similar way of charting our Milky Way galaxy. We do not yet have a very detailed map of our home galaxy. Artists have used data to render fairly detailed illustrations, showing the appearance of the spiral arms. There are a number of different interpretations of the basic data and the spiral arms are not always labeled the same way from one to another. Yet there are some overall features which we recognize: We identify three main parts of the galaxy: Disc Nucleus Halo