# A star's surface temperature can be determined by studying the peak wavelength of radiation it emits. Describe how astronomers use the electromagnetic spectrum to determine the surface temperature of a star, and explain why stars of different temperatures appear to be different colours.

> Eduqas A-Level Physics — 1.6 Using radiation to investigate stars · Describe and Explain · 5 marks

## Mark scheme (5 marks)

1. Stars emit radiation across a range of wavelengths / emit a continuous spectrum of electromagnetic radiation
2. Each star has a peak wavelength / the wavelength at which most radiation is emitted
3. Higher surface temperature means the peak wavelength is shorter / shifted towards shorter wavelengths
4. Hotter stars appear blue/white because their peak wavelength is in the blue/ultraviolet part of the spectrum
5. Cooler stars appear red/orange because their peak wavelength is in the red/infrared part of the spectrum

## Key terms

- [peak wavelength](https://www.gradenine.co.uk/glossary/peak-wavelength)
- [electromagnetic spectrum](https://www.gradenine.co.uk/glossary/electromagnetic-spectrum)
- [surface temperature](https://www.gradenine.co.uk/glossary/surface-temperature)

## Related

- [Revision notes for Eduqas A-Level Physics](https://www.gradenine.co.uk/learn)
- [How to answer "Describe and Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-star-s-surface-temperature-can-be-a5d8deee) · Published by Druglandscape Ltd.