• Question: what coulours are stars?

    Asked by nazia1999 to Karen, Adam, Catherine, Leila, Nazim on 15 Mar 2012. This question was also asked by littlechatterbox.
    • Photo: Karen Masters

      Karen Masters answered on 15 Mar 2012:

      Stars are all different colours. The colour of a star just depends on how hot it is. So the hottest stars are very blue (or sometimes even white), and the coolest ones are red.

      Our eyes just see stars as white at night because they are not very sensitive to colour at low lighting levels (you see everything basically in shades of grey at night right – even though you know it has colour during the day). There’s a really near binary star system in the constellation of Cygnus the swan which I’ll try to show people during stargazing sessions (just with a basic telescope). If you look at it through the telescope you can see that the two different stars have different colours because they are close together.

      You might also just make out that Betelgeuse and Rigel (the two bright stars at the top right and bottom left of the constellation of Orion) have different colours. Betelgeuse is a red giant star, while Rigel is a blue supergiant.

    • Photo: Adam Stevens

      Adam Stevens answered on 16 Mar 2012:

      Karen or Nazim definitely better to answer this one!

    • Photo: Leila Battison

      Leila Battison answered on 19 Mar 2012:

      All the colours, probably! They vary depending on how old they are, how hot, and how big, but they give out so much energy that lots of wavelengths of light are represented, so the star is usually a variation on white, but some can be blue, or red, or even brown!

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