The Sun in nearly all mystical traditions is the symbol of source energy, illumination and vitality. The higher self.
In The9SyStem, 9 is both the end and the beginning and the sun becomes the portal that constantly recycles light, life and consciousness.
The Sun gives us unity, births creation, transformation and guides us back to our original source self. This is why when you stand in sunlight you often feel recharged, renewed and remember who you are.