Scorpio, the Latin name of Scorpio, is one of the well-known twelve constellations. Its center is located at right ascension 16: 40 and declination -36, which is close to the center of the Milky Way. Scorpion's tail points to the southeast, between snake head, Sagittarius and Libra. Summer appears in the southern sky.
In ancient astronomy in China, the three stars on Scorpio are called Shang Xing, and the three stars on Orion's belt are called Laonian Xing. Scorpio and Orion are the most prominent constellations in summer and winter respectively. They just rise and fall, never meet, and can't appear in the sky at the same time. Therefore, Du Fu has a poem: "When friends meet, it is as difficult as the stars in the morning and evening."
The heart (main star) of Scorpio is the alpha star antares of Scorpio, which is the 15th bright star in the whole day. It is a red Supergiant star, which forms a visual binary system with a blue main sequence star. Its luminosity is 10900 times that of the sun, and its beautiful red color can be seen by naked eyes.
Antares, also known as fire in ancient China, is the heart of the Black Dragon for seven nights, which is used to determine the seasons. Legend has it that when China was in Zhuan Xu more than 4,000 years ago, he set up an official post of Huozheng, who was responsible for observing this star. The story about it should start with an idiom "July filariasis".
Legend has it that there was a country called Sui three thousand years ago, which was the birthplace of Zhou agricultural culture, in Bin County, Shaanxi Province. At that time, the calendar was not perfect, and the guidance of farming activities depended entirely on stargazing. Every year at the end of summer, a red star named "Fire" will appear in the sky due south. According to the observation experience, farmers know that summer is coming to an end, autumn is coming, and the busiest autumn harvest season of the year has arrived.
In a flash, it was a few days. At the same time in autumn and evening, the farmer looked at the southern sky again and found that the fire had moved westward and fell down compared with a few days ago. A few days later, it moved westward and fell even more. A month later, at the same time, looking at the southern sky, the fire had moved to the western horizon, trapped in the clouds and covered the mountains, out of sight. This process is called "fire in July". The fire here refers to the alpha star of Scorpio, not the fire in The Sun Burning Like Fire. Therefore, the first two sentences of July in Qi Feng are "filariasis in July, clothes in September". It should also be noted that the lunar calendar began to be used three thousand years ago. In modern times, if you want to observe, September in the solar calendar is the best time.
In addition to being a "red heart", Scorpio is also located near the center of the Milky Way, so the deep space objects inside it are also the targets of many enthusiasts. It is rich in deep space objects, such as open cluster M6 (butterfly cluster), M7 (Ptolemy cluster), globular cluster M4, M80 and the famous open cluster NGC 623 1. M7 is one of the most famous open clusters in the sky. It has many bright blue stars, and it can be seen at the tail of Scorpio with naked eyes at night. M7 is about 1000 light years away from us, and consists of about1000 stars, with an age of about 200 million years and a size of about 25 light years.
July is full of fire, September is full of clothes. Hold on to Scorpio's tail before it gets cold, and applaud for its successful conclusion this year.