Classify a Star | The Schools' Observatory

Have you ever wondered why stars look different colours? What do these colours mean? How do we know what stars are made of? Explore these questions with our classify a star activity. Use Wien’s displacement law to work out the temperatures and classifications of some real stars!

By the end of this resource you will:

Have used Wien’s displacement law to calculate the temperature of a star
Used Wien’s displacement law on real stellar data
Analysed a stellar spectrum to find absorption lines

To complete this resource you will need:

The worksheet below
A calculator
A pen/pencil
A ruler

Files or Documents

Stellar_spectroscopy_worksheet_answers.pdf (411.69 KB)

Stellar_spectroscopy_worksheet.pdf (401.83 KB)

A photo of an open cluster of stars, several bright stars can be seen, mainly blue in colour, with some light being reflected from gas and dust close to the stars.

This work by NASA is licensed under Creative Commons Zero v1.0 Universal

Approx Duration

30 - 60 mins

Have a go!

Your challenge is to work out the temperature of a star using Wien’s displacement law using the worksheet above.

First, make sure you have a copy of the worksheet and a calculator to hand.
Follow the steps in the worksheet to find:
- The temperature of a blackbody
- The temperature of a real stellar spectrum
- Absorption lines in a stellar spectrum
Well done – you’ve classified a star!

If you liked this, why not try

Creating your own HR Diagram.

Testing your knowledge of the life cycle of a star.

Learning about what we can see on the Sun.

Have a go!

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