What is the lifespan of a typical star like the Sun?

The lifespan of a typical star like the Sun is approximately 10 billion years. This duration reflects the time it takes for the star to undergo various stages of stellar evolution, starting from its formation through the main sequence phase, where it fuses hydrogen into helium, to its eventual transformation into a red giant and then a white dwarf.

Stars like the Sun spend around 90% of their lifespan, roughly 10 billion years, in the main sequence phase. During this time, they steadily fuse hydrogen in their cores, providing a stable energy output. Once the hydrogen is depleted, the star will evolve into a red giant as it starts fusing helium and undergoes further changes, leading ultimately to its shrinkage and cooling into a white dwarf.

The choice of approximately 1 billion years significantly underestimates the longevity of such stars, as they can exist for far longer periods. Regarding approximately 5 billion years, while this could account for part of the Sun’s life, it does not encompass the full extent of its expected lifetime. Likewise, while approximately 20 billion years exceeds the current understanding of stellar evolution for solar-type stars, which do not reach such extended lifetimes, the 10 billion years is a well-supported figure in astrophysics for