Massive stars have shorter lifespans than average stars because their greater mass creates stronger gravitational forces that heat their cores to much higher temperatures. This increased core temperature accelerates the rate of nuclear fusion reactions, causing them to burn through their fuel much faster than smaller stars. Despite having more fuel overall, the rate at which they consume it is disproportionately high, leading to shorter lifetimes that typically range from a few million years compared to billions of years for average stars like the Sun.
Reason for Shorter Lifespan
- Massive stars have stronger gravity, compressing their cores significantly.
- This compression causes the core temperature to rise dramatically.
- Hotter cores mean faster nuclear fusion reactions, resulting in rapid fuel consumption.
- Because fuel runs out quickly, massive stars live fast and die young.
Contrast with Average Stars
- Average or smaller stars burn fuel at a slower rate due to lower core temperatures.
- They can sustain nuclear fusion for billions to trillions of years.
- Their slower fuel consumption leads to much longer lifespans.
Summary
In essence, the inverse relationship between star mass and lifespan is due to the nonlinear increase in fusion rate with temperature and mass, so massive stars have more fuel but they use it up at a far faster rate than smaller stars.
