Why is there Polaris, but not invivo, East Pole Star and West Pole Star?

Among the stars, Polaris is the most famous "star". This star at the tail of Ursa minor is close to the north celestial pole, which is not only striking, but also almost motionless in the sky. It is an important indicator in the night sky.

For thousands of years, people on the earth have relied on its starlight to navigate. Whether it is ancient navigation or modern outdoor activities, Polaris is an important indicator of people's positioning, helping people to identify their directions and not get lost. There is even a saying in English, "You are my North Star" (you are my North Star), which means that someone has played an important guiding role in his life and is deeply grateful.

Many people have this doubt-where there is North, there is South. Why have you only heard of Polaris and never heard of Invivo? In fact, there is indeed an "Antarctic constellation" in the south celestial pole, which was defined by the French astronomer Llakaj when he was working at the Cape of Good Hope in 1752.

From the position, the South Pole and Ursa minor occupy two celestial poles respectively, which is extremely glorious. Chen Yi, a dog belonging to Ursa minor, occupies an important position in the "North Star" and has unlimited scenery. So, is the curious "invivo" hidden in this South Pole?

Unfortunately, no. You don't have to be in a "polar position" to be a "North Star". We know that Gouchenyi in Ursa minor can become a Polaris because it meets two conditions: position and brightness. Polaris is a direction indicator in the sky, which is responsible for guiding people's direction. Only when the location is accurate and eye-catching, people can recognize it at a glance in the night sky and accurately identify the direction.

Unlike Ursa minor, Antarctica is a "low-key" constellation, and all its stars are dim. There is a "σ" star at the South Pole, and its distance from the South Pole is basically the same as that from the North Pole (Polaris), so it can be called "invivo" in position. The brightness of the Antarctic constellation σ is much worse than that of Polaris, which is only one twentieth of that of Polaris, so it is difficult for people to find it, let alone use it as a sign of positioning. In other words, from the current point of view, there is no star in Antarctica that can be used to undertake the mission of Invivo. However, a star from carina is expected to ascend the throne of Invivo in the future.