Superjättiläiset

Superjättiläiset are stars that have evolved beyond their main sequence phase and have expanded significantly in size. They are among the largest and most luminous stars in the universe. Their large size is a result of the depletion of hydrogen in their core, which leads to a series of nuclear fusion processes that generate more energy and cause the star's outer layers to expand.

The surface temperature of supergiant stars is generally lower than that of main sequence stars of the same mass, giving them a reddish or orange hue. This temperature, combined with their immense size, results in a very high luminosity. Supergiants can be hundreds or even thousands of times larger in diameter than our Sun, and their luminosity can be tens of thousands or even millions of times greater.

Supergiants are relatively short-lived stars due to their rapid consumption of fuel. They are destined to end their lives in spectacular supernova explosions. These explosions are crucial for the distribution of heavy elements, synthesized within the star, into the interstellar medium, which can then form new stars and planets. Examples of supergiant stars include Betelgeuse and Rigel in the constellation Orion.