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Astronomy

The Spectral Classification of Stars Using the Morgan-Keenan System

Quick fact

The Morgan-Keenan system classifies stars into seven main types (O, B, A, F, G, K, M) based on their spectra, with O stars being the hottest and M the coolest. The sequence is memorized by astronomy students with the phrase 'Oh, Be A Fine Girl/Guy, Kiss Me!'

Why this is interesting

Every star tells a story through its rainbow of light. But why do some stars blaze blue while others glow red, and what secrets hide in the dark lines of their spectra?

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The Spectral Classification of Stars Using the Morgan-Keenan System

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