SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/astro-electron-degeneracy

What holds up a white dwarf against gravity?

Electron degeneracy pressure, not heat from fusion.

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  1. Ongoing hydrogen fusion
  2. Rotation
  3. Electron degeneracy pressure ✔

Why: White dwarfs have no fusion. Their electrons are packed so tightly they cannot be squeezed further, and that resistance, called degeneracy pressure, stops the collapse. It needs no heat to keep pushing.

Huh, didn't know that: A white dwarf cools slowly for billions of years toward a cold black dwarf.

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I lost an electron. You really have to keep an ion them.
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References

Answer: Electron degeneracy pressure. White dwarfs have no fusion. Their electrons are packed so tightly they cannot be squeezed further, and that resistance, called degeneracy pressure, stops the collapse. It needs no heat to keep pushing.

  1. Astronomy 2e, 23.1 The Death of Low-Mass Stars openstax.org/books/astronomy-2e/pages/23-1-the-death-of-low-mass-stars
    it is the degeneracy pressure of the electrons, and not of the nuclei, that halts the collapse of the core.
    Checked 2026-10-10.

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