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How can a neutronstar that only consists of neutrons

  1. Sep 12, 2006 #1
    Hi! Long time reader first time writer here.
    Just wondering, how can a neutronstar that only consists of neutrons be abel to generate an magnetic field and become an pulsar?
    If I hasn´t got it wrong a pulsar can work in different ways either its momenthum can be resposable for the light emitting or the star is an dipol and sends electrical chargde particles. How can a NEUTRONstar be an dipol?
    Thanx for every coming answer.
     
  2. jcsd
  3. Sep 13, 2006 #2

    Kurdt

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    A pulsar traps the magnetic field of its parent star as it collapses. All stars have some sort of magnetic field and if they collapse into a neutron star that field gets trapped and concentrated and the neutron star becomes essentially a massive and very powerful magnet. The neutrons have a magnetic dipole moment and in the process of collapse the stars original magnetic field aligns the dipole moments in the neutrons.
     
  4. Sep 15, 2006 #3
    :cool: I have also heard the neutrons will change to protons and back again, but I have not seen this clairified.

    The brightest flash ever observed, ignoring the sun, is from a magnetar, neutron star sgr1806, back in December of 2005. This was not in the visible range, however.
     
  5. Sep 18, 2006 #4

    Kurdt

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    A neutron free of the strong nuclear force naturally decays into a proton as a neutron is an unstable particle and a proton is as far as we know a stable particle. When a neutrondecays it does so by Beta decay which means it turns into a proton and also and electron and antineutrino. The everse process is also possible where a proton captures an electron and turns into a neutron and a neutrino.

    A neutron star is composed entirely of neutrons because the star it was formed from had a gravitational field so strong it forced the electrons into the nucleus of the atoms of material and turned all the protons into neutrons.
     
  6. Sep 18, 2006 #5
    Does this mean there is a constant process of neutron to proton to neutron occurring in a neutron star? If so, would that help explain the magnetic field, too?
     
  7. Sep 18, 2006 #6

    selfAdjoint

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    Well a neutron is well known to have a magnetic moment, in spite of having no (net) charge. This is now explained by its composition of charged quarks.
     
  8. Sep 19, 2006 #7

    Kurdt

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    Neutrons in a neutron star are bound by the strong nuclear force and are thus stable. The magnetic field is explained due to the fact that neutrons have a magnetic dipole moment as SelfAdjoint describes as being explained by a neutron's composition of charged quarks.
     
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