At night, I saw a big red star in the southern sky. It's big and bright, and it's shining. What is that?

Hello, personally, I don't think what you see is a star. First of all, the celestial bodies you see with the naked eye can't tell red. Besides, the stars won't disappear in just five minutes. It should be similar to a Kongming Lantern or an airplane. This flicker may be caused by the flow of clouds in the atmosphere, or it may be a lamp on an airplane.

In this season, the brighter stars in the southern sky seen by the northern hemisphere are the "Winter Triangle", namely Sirius Canis, Nanhe San Canis and Betelgeuse of Orion. These three bright stars form an obvious triangle, and all the stars are above-1 visually, which is extremely obvious in the sky. Among them, the naked eye can see that Sirius has obvious flicker.