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White dwarfs represent the final evolutionary stage of many medium-sized stars after they have exhausted their nuclear fuel. Following the collapse of the stellar core, the remaining material is comp_ _ _ _ _ _ into an extremely dense object no larger than Earth. Des_ _ _ _   their small size, white dwarfs retain enormous mass, resulting in grav_ _ _ _ _ _ _ _ _ forces strong enough to prevent further collapse. Unlike active stars, white dwarfs no lon_ _ _ generate energy through fusion; instead, they gradually cool as stored thermal energy is released into space. Over time, their brightness dim_ _ _ _ _ _ _ , making them increasingly difficult to detect. The study of white dwarfs therefore provides astronomers with valuable insight i _ _ _ stellar aging and the long-term evolution of galaxies.