049.1 Heavy Element Formation
As soon as a carbon core forms, it begins to contract and heat up until the fusion of carbon to form Oxygen begins at its center.
An Oxygen core then forms and contracts and heats up in turn until it starts fusing to make Neon, and so on.
Each stage releases less energy than the last and proceeds faster. For a 20 solar mass star, life is very short indeed:
| Hydrogen burning | Lasts 10 million years. |
| Helium burning | Lasts 1 million years. |
| Carbon burning | Lasts 1000 years. |
| Oxygen burning | Lasts 1 year. |
| Silicon burning | Lasts 1 week. |
The final stage, when the iron core forms, lasts only a day.