This evolution is shown in the simulation. It illustrates the path of the star in the luminosity/temperature diagram (surface temperature, total luminosity).
Paris Observatory / ASM
A star like the sun burns its hydrogen in the center during the major part of its life. That's what happens now and what began 4 billion years ago.
In about 4-5 billion years, the Sun will rapidly evolve. No more hydrogen will be available. Its radius will increase and its temperature will decrease. Then it will explode and leave a very dense core which should form a white dwarf
As the nuclear reactions gradually change the different atoms, the structure of the star changes : the star evolves.
Depending on the mass of the star, the end of this evolution can be :
- Calm, the star gets colder slowly
- Explosive, some reactions can cause the partial or total destruction of the star (we then observe the novae or supernovae phenomena).
The more massive a star is, the more it evolves rapidly.
- A star like the Sun has a lifetime of about 10 billion years
- A star of 30 solar masses has a lifetime of only a few million years, whereas the less massive known stars (of about 0.1 solar masses) have lifetimes comparable to the age of the Universe (about 14 billion years).