Life Cycle of a Star like the Sun
Physics: Cambridge International GCSE Supplement, topic 6.2.3
Life Cycle of a Star like the Sun
Every star has a life cycle that depends on its size. All stars begin their life cycle in the same way as the Sun. Gravity pulls nebulae (more than 1 nebula) together to form a protostar. This protostar then becomes a main sequence star. If a star is about the same size as the Sun, a star’s lifecycle is like this:
Main sequence
- In a main sequence star, hydrogen nuclei are fused together to form helium.
- This releases energy as heat and light.
Red giant
- Eventually all the hydrogen fuel runs out.
- The star then cools and expands, becoming a red giant.
- The star then starts to fuse together helium nuclei to release energy.
White dwarf
- As the helium fuel runs out, the outward forces reduce in size and the star collapses inwards.
- This causes its temperature to increase.
- A white dwarf is formed, which is the hot core of the star.
- Around the white dwarf, a planetary nebula is left as the outer layers drift off.
Test yourself on Life Cycle of a Star like the Sun
Life Cycle of a Star like the Sun
Which of these is a part of a small star's life cycle?