premainsekvensen

Premainsekvensen, often referred to as the main sequence, is a continuous and distinct band of stars that stretches across the Hertzsprung-Russell diagram. Stars on the main sequence are in the longest and most stable phase of their stellar evolution, during which they are actively fusing hydrogen into helium in their cores. This process is the primary source of their energy. The position of a star on the main sequence is primarily determined by its mass. More massive stars are hotter, brighter, and bluer, and they are located at the upper left of the diagram. Less massive stars are cooler, dimmer, and redder, and they are found at the lower right. Our Sun is a main-sequence star, classified as a G-type main-sequence star. The duration a star spends on the main sequence is also dependent on its mass; massive stars burn through their hydrogen fuel much faster than less massive stars, leading to shorter main-sequence lifetimes. The majority of stars in the universe, including our Sun, are currently on the main sequence. Once a star exhausts the hydrogen in its core, it will leave the main sequence and evolve into other stages, such as a red giant or a white dwarf.