The atmosphere refracts our earth, which is surrounded by the atmosphere. The transparent atmosphere contains carbon dioxide, oxygen, water molecules, clouds, fine dust and other substances, which actually contains very complex components. When the external light passes through the atmosphere or air at a certain distance, due to the fluctuation of density, humidity and temperature and the influence of air convection in the air, the light will be refracted or temporarily blocked, and the light can only pass intermittently, so the flashing visual effect appears.
Not only the starlight will be refracted, but also the light reflected by the stars in space will be refracted by the atmosphere. Many reflected light in our life will also refract and flicker when it passes through the atmosphere. For example, when we look at distant mountains on the horizon, city lights, tall buildings, fishing boats and islands on the sea level, we often see flickering images. At sunrise and sunset, the sun is bigger and different in color than when it rises. In fact, this is also a phenomenon of atmospheric refraction from different angles, which is almost the same as the refraction of starlight projected in the universe, except that the flicker on the horizon is ground flicker, and the starlight projected in the universe belongs to astronomical flicker.
The types of flicker are intermittent, flickering, and sometimes the light source is deformed. When the reflective light source is close to the horizon, it is easy to appear shaking images, which is related to the airflow movement and temperature change in the air. It is the movement of air that refracts or blocks the light, resulting in various flickering changes of light.