What stage of the Stars life does nucleosynthesis occur?

Nucleosynthesis occurs during various stages of a star's life, primarily during the main sequence and later during the red giant phase. In the main sequence, hydrogen is fused into helium in the star's core. As stars evolve into red giants, they can undergo further nucleosynthesis processes, such as the fusion of helium into heavier elements like carbon and oxygen. In the final stages of massive stars, nucleosynthesis can lead to the formation of even heavier elements during supernova explosions.