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Gallery 3

Star Fingerprints

Star fingerprints exhibit displaying the various emission lights

Each star emits and absorbs different wavelengths of light based on the type of elements within the star.

How it works

Look at the different spectrum tubes through the glasses. See how the wavelengths of light are separated as different colours.

Things to try or ask around the exhibit

  • Is the light the same colour at the beginning as it is at the end?
  • What colour is the light in the middle?

Background

When matter is energised it becomes more excited and eventually releases that energy as light. But the way it does so is unique to each element and molecule. Scientists use the absorption and emission of light from different materials to determine what they are made of. This can even be done with stars, giving each star its own unique light fingerprint. These light fingerprints are known as emission bands or spectral lines.

The most common spectral line observed is hydrogen. This appears in all stars and its unique emission bands are used to calibrate tests. Helium was discovered in the Sun using emission spectra, before helium was discovered on Earth.
As stars consume their fuel, they produce new heavier elements. Stars at the end of their lifespan contain a lot more oxygen and carbon. This can help astronomers understand not only the composition of a star but also its age and type.

Finding the science in your world

As each atom or molecule has a unique absorption and emission spectrum, emission and absorption lines are used in chemistry to determine the composition of materials. It can be used to determine if contaminants are present in samples to ensure purity or to detect elements in forensic crime investigations.