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When a massive star's iron core collapses into a neutron star, about how big does it end up?

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  1. Less than about 20 km across
  2. About the size of Earth
  3. About the size of the Sun

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References

  1. Astronomy 2e, 23.2 Evolution of Massive Stars: An Explosive Finish openstax.org/books/astronomy-2e/pages/23-2-evolution-of-massive-stars-an-explosive-finish Checked 2026-10-10.

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