If you want to change the appearance of the Sun, press the key "C" to open the "commands" section and insert one of these commands: "increase sun size", "decrease sun size", "increase sun luminousity" or "decrease sun luminousity".
This is not supposed to be accurate; it is just a small demonstration of our solar system. I also added Planet X (a hypothetical planet about twenty times further than Neptune or so) if you have good sight.
