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Neutron star

  1. May 19, 2005 #1

    what mass does a neutron star hove and what is its life span?

    and any other information on the subject would not go un-apiretiated
  2. jcsd
  3. May 19, 2005 #2


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    Neutron stars typically have masses around 1.5 times the mass of the sun (~3 x 1030 kilograms). This is because there is a mass known as the "Chandrasekhar mass" beyond which electron degeneracy pressure (see this thread for a description of degeneracy pressure) cannot hold a star up from gravity. This mass is around 1.4 times the mass of the sun. Once it's passed, the electrons and protons undergo inverse beta decay and form neutrons. This leads to a star that is instead held up by neutron degeneracy pressure, called a neutron star. There is also a mass beyond which neutron degeneracy pressure will fail and the object will collapse to a black hole, but we don't know the exact value of this mass. From observations, we think it's less than 2 times the mass of the sun.

    As far as I know, there's no limit to how long they can live, but they will cool over time, radiating away their thermal energy. They're very dense and their sizes are typically around 10 kilometers.
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