The sun has approximately 7 to 8 billion years of life remaining.
Here's a more detailed explanation:
Astronomers estimate the lifespan of a star like our sun based on its mass and rate of fuel consumption (nuclear fusion). Currently, the sun is in its main sequence phase, fusing hydrogen into helium in its core. This is a very stable and long-lasting phase.
As the sun continues to burn hydrogen, it will eventually exhaust the supply in its core. This will cause the core to contract and heat up, while the outer layers of the sun will expand and cool. The sun will then become a red giant.
Sun's Future Stages
Here's a breakdown of the sun's future stages:
- Main Sequence (Current Stage): The sun is currently about 4.5 billion years old and has been in its main sequence phase for that duration. It will remain in this phase for another 5 billion years.
- Red Giant: After the hydrogen in the core is exhausted, the sun will expand into a red giant. This phase will last for about 2 billion years. During this phase, the sun will become much larger and brighter, engulfing Mercury, Venus, and possibly Earth.
- Helium Fusion: After the red giant phase, the sun will briefly fuse helium into carbon and oxygen in its core.
- Planetary Nebula: Eventually, the sun will run out of fuel entirely. It will then eject its outer layers into space, forming a planetary nebula.
- White Dwarf: What remains of the sun's core will cool and shrink, becoming a white dwarf. This white dwarf will slowly fade away over trillions of years.
Timeline Summary
| Stage | Approximate Duration (Years) |
|---|---|
| Main Sequence | ~5 billion |
| Red Giant | ~2 billion |
| Other Final Stages | ~1 billion |
Therefore, while the sun has about 5 billion years left in its main sequence, the overall time until it becomes a white dwarf is estimated to be around 7 to 8 billion years from now.
