Stars are classified by astronomers using the Morgan-Keenan spectral classification system, which groups stars by their temperature, color, and luminosity. The main sequence classes from hottest to coolest are O, B, A, F, G, K, and M - Remembered by the mnemonic 'Oh Be A Fine Girl, Kiss Me.' Our Sun is a G-type main-sequence star. O and B stars are hot, blue, and massive but short-lived. K and M stars are cooler red stars that are incredibly long-lived and abundant. Beyond main sequence, there are giant and supergiant classes. In this sortable quiz, you'll classify famous stars and star types into their correct stellar classification categories.
Unsorted items will count as wrong.