What is the primary factor that determines a star's life cycle?

The primary factor that determines a star's life cycle is its mass. The mass of a star influences its internal pressure and temperature, affecting how it undergoes nuclear fusion in its core. A more massive star has a higher gravitational pull, leading to greater pressure and temperature, which results in a faster rate of nuclear fusion. This acceleration leads to a shorter lifespan for massive stars compared to lower-mass stars, which fuse elements at a slower rate and can exist for billions of years.

Additionally, a star's mass determines the stages it will go through as it evolves, including whether it will become a red giant, a supernova, and what remains will be (such as a neutron star or black hole). These factors are intrinsic to the star's structure and function, making mass the crucial determinant in its life cycle.

In contrast, while a star's distance from Earth, its color, and its temperature provide information about the star and its immediate environment, they do not fundamentally influence the processes that dictate its lifespan and evolutionary path.