The participants are two groups of famous bright stars in the sky. Shen refers to Sanjuku, one of the twenty-eight constellations in ancient China. It is roughly equivalent to Orion and is the most magnificent constellation in the sky on winter nights. The three bright stars aligned in the center are the three gems on Orion's belt. They were called the stars of the Altavian Star in ancient times and are located just on the celestial equator. In an era without clocks, it was a natural timepiece for long winter nights. The bright red star on Orion's left shoulder is Betelgeuse (Alpha Orion), and the bright blue star under his right knee is Betelgeuse (Beta Orion). They are both supergiants, and their true brightness is tens of thousands of times larger than the Sun.
"Shang" refers to the bright red star Antares in the starry sky on summer night, also known as "Fire". There is a slightly dimmer star on each side of it, collectively known as Antares. It is an important star for judging seasons and guiding farming in the Yin and Shang Dynasties. The Book of Songs "" Fire flows in July and clothes are given in September "means that the" fire "stars in the seventh month of the lunar calendar gradually" flow "to the west, and midsummer is about to end, and clothes for winter must be prepared before the ninth month of the lunar calendar. Antares belongs to the constellation Scorpius. The ancient Babylonians imagined Scorpius as a big scorpion in the sky, with a huge body and a curved poisonous hook.
Du Fu's famous saying,"If you don't meet each other in life, you move like participating in a business", which means that the Shang stars that appear in midsummer and the Shensu stars that appear in midwinter come one after another, and they never have the opportunity to meet each other. This is to express the emotion of the separation of relatives and friends during the "Anshi Rebellion".