Why do white dwarfs exist?
Show answer & explanation
Answer: Dead stars left after collapse
Dead stars left after collapse ✓ — Correct! White dwarfs are stellar remnants—cores left after low-mass stars (0.5-8 solar masses) exhaust fuel. Stars shed outer layers (planetary nebula), leaving core. No fusion occurs—just residual heat slowly radiating away over billions of years. Extremely dense: Earth-mass in Earth-size object! Electron degeneracy pressure prevents further collapse. Composed mainly of carbon/oxygen. Eventually cool to black dwarfs (theoretical)!
Baby stars forming from gas — Wrong. Baby stars are protostars. White dwarfs are stellar corpses—leftover cores from dead low-mass stars, no longer fusing.
Stars reflecting light brightly — Wrong. White dwarfs don't reflect—they glow from residual heat. They're extremely hot (~25,000K initially) but cool over billions of years.
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