# Astronomers analyse the light from distant stars to find out about their properties. Explain how the light from a star can be used to determine its temperature and its chemical composition.

> WJEC A-Level Physics (Wales) — 1.6 Using radiation to investigate stars · Explain · 5 marks

## Mark scheme (5 marks)

1. Stars emit a continuous spectrum (of light / electromagnetic radiation)
2. The peak wavelength / colour of the continuous spectrum indicates the temperature of the star
3. Hotter stars have a shorter peak wavelength / peak towards the blue end of the spectrum; cooler stars peak towards the red end
4. Dark absorption lines appear in the spectrum of starlight
5. Each element absorbs specific wavelengths, so the pattern of absorption lines identifies the elements / chemical composition present in the star's atmosphere

## Key terms

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

## Related

- [Revision notes for WJEC A-Level Physics (Wales)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/astronomers-analyse-the-light-from-distant-45741926) · Published by Druglandscape Ltd.