Introduction of south vestibule

Sagittarius is one of the southern constellations. It was originally the largest constellation, but in the18th century it split into four independent constellations, namely, Vela, Carina, Tail and Compass. The bright star Laonian, second only to Sirius in brightness, is the brightest main star in Sagittarius. The four constellations, cauda, carina and compass, were originally four parts of the same constellation-Sagittarius australis. In ancient Greek mythology, they were collectively called the Southern Constellation, which is the largest constellation in the whole day. This constellation has more than 800 stars visible to the naked eye, which is almost one-eighth of the number of stars visible all day.