What determines the life cycle of a star?

The life cycle of a star is primarily determined by its mass. A star's mass influences its core temperature and pressure, which directly affect nuclear fusion processes. Massive stars burn their nuclear fuel much faster than smaller stars, leading to different evolutionary paths. For instance, stars with greater than eight solar masses will undergo supernova explosions, while less massive stars may expand into red giants and ultimately shed their outer layers, forming planetary nebulae.

In contrast, factors such as distance from Earth, the presence of surrounding planets, or the amount of light emitted do not significantly influence how a star evolves over time. While these factors may play a role in observational astronomy—like how we perceive a star—it's the stellar mass that fundamentally dictates the stages of evolution from formation to extinction.