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Astronomy

Spectroscopy: Reading the Chemical Composition of Stars

Quick fact

The dark lines in a star's spectrum are like a barcode for elements – each chemical element produces its own unique pattern of lines, allowing astronomers to 'read' the star's composition from Earth.

Why this is interesting

Have you ever wondered how astronomers know a star is mostly hydrogen and helium when we can't visit a single one? The answer lies in the star's light itself, hidden in a rainbow.