# Describe the main stages in the life cycle of a star similar in mass to our Sun, starting from a nebula and ending at its final stage. Include the names of each stage in your answer.

> Eduqas A-Level Physics — 4.3 Orbits and the wider universe · Describe · 5 marks

## Mark scheme (5 marks)

1. A nebula is a cloud of gas and dust that is pulled together by gravity / gravitational attraction causes the nebula to collapse
2. A protostar forms as the collapsing material heats up / temperature rises as matter compresses
3. The star becomes a main sequence star where hydrogen nuclei fuse to form helium (nuclear fusion)
4. When hydrogen runs out the star expands to become a red giant
5. The red giant eventually sheds its outer layers leaving behind a white dwarf as the final stage

## Key terms

- [nebula](https://www.gradenine.co.uk/glossary/nebula)

## Related

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Source: [GradeNine](https://www.gradenine.co.uk/q/describe-the-main-stages-in-the-317320cb) · Published by Druglandscape Ltd.