sirius - colours

Fixed stars can be recognized by the fact that, unlike planets, they scintillate. This means that they change their color and brightness very quickly (more than 50 times per second). Our eyes hardly notice it because of the speed. But in a series of briefly exposed photos, Sirius shows changing colors. Scintillation comes about through the refraction and color breakdown of light due to density fluctuations in the atmosphere. With longer exposure and camera movement, colored traces appear.