Stars are "engines" of cosmic energy that produce light, ultraviolet rays, X-rays, and other forms of radiation. They are composed almost entirely of plasma.
Our observable universe hosts more than 100 billion galaxies, and each of them could have more than 100 billion stars.
Although the most well-known star, the Sun, exists alone, one in every three stars exists as part of a binary system composed of two stars orbiting each other. Stars in the sky can also appear in different colors because their temperatures are not the same.
Source: Chile Mobile Observatory - Marca Chile
