Purple and white flying stars, also known as "flying on the nine planets", are a method to allocate the houses of the nine planets in the order of Luoshu and Jiugong, with the house on the mountain as the main one and the gossip position as the reference. It puts the three mountains under one hexagram (among the twenty-four mountains, every three mountains corresponds to one hexagram), puts the star of this mountain in the center of the palace, and observes the five elements of the hexagrams in the palace and other eight diagrams according to the flying method of Luoshu Jiugong, so as to judge whether they are good or bad.
In different time periods, the orientation and distribution of purple and white are also different.