The Naked Scientists

The Naked Scientists Forum

Author Topic: Where have a neutron star's protons gone?  (Read 5795 times)

Offline DoctorBeaver

  • Naked Science Forum GOD!
  • *******
  • Posts: 12656
  • Thanked: 3 times
  • A stitch in time would have confused Einstein.
    • View Profile
Where have a neutron star's protons gone?
« on: 15/09/2008 13:15:27 »
Right, we have a nice big star which eventually goes SCHHHLLLOOOOOP and contracts. But although this star is big, it's not big enough to form a black hole. Instead, it forms a neutron star. So what has happened to its electrons & protons?

I assume the electrons have been kicked out in a burst of EM radiation - light, X-rays, etc - but what about the protons? Where do they go?


 

Offline RD

  • Neilep Level Member
  • ******
  • Posts: 8122
  • Thanked: 53 times
    • View Profile
Where have a neutron star's protons gone?
« Reply #1 on: 15/09/2008 15:19:32 »
Possibly the protons have been converted into neutrons by electron capture...

Quote
protons are known to transform into neutrons through the process of electron capture.
This process does not occur spontaneously but only when energy is supplied.
http://en.wikipedia.org/wiki/Proton
« Last Edit: 15/09/2008 15:23:07 by RD »
 

Offline DoctorBeaver

  • Naked Science Forum GOD!
  • *******
  • Posts: 12656
  • Thanked: 3 times
  • A stitch in time would have confused Einstein.
    • View Profile
Where have a neutron star's protons gone?
« Reply #2 on: 16/09/2008 10:15:28 »
Thank you, RD. I shall investigate that further.
 

lyner

  • Guest
Where have a neutron star's protons gone?
« Reply #3 on: 16/09/2008 13:14:42 »
Left to themselves, protons last much, much longer than neutrons, which decay into protons + electrons relatively quickly. Under the sorts of forces in a neutron star, things must just be very different.
 

Offline Soul Surfer

  • Neilep Level Member
  • ******
  • Posts: 3345
  • keep banging the rocks together
    • View Profile
    • ian kimber's web workspace
Where have a neutron star's protons gone?
« Reply #4 on: 26/09/2008 23:24:50 »
The pressure and density inside a neutron star is so great that in theory the protons and electrons have been squeezed together to form neutrons.  however this may not be the whole story because such an object may be considered to be a gravitationally bound nucleus formed out of a sea of quarks.  The electrons have definitely not gone because that would produce an object with a very strong net positive charge which would be very difficult to hold together even with gravity.
 

Offline DoctorBeaver

  • Naked Science Forum GOD!
  • *******
  • Posts: 12656
  • Thanked: 3 times
  • A stitch in time would have confused Einstein.
    • View Profile
Where have a neutron star's protons gone?
« Reply #5 on: 26/09/2008 23:41:55 »
Ian - would that not be the hypothesised quark star though?
 

Offline Soul Surfer

  • Neilep Level Member
  • ******
  • Posts: 3345
  • keep banging the rocks together
    • View Profile
    • ian kimber's web workspace
Where have a neutron star's protons gone?
« Reply #6 on: 27/09/2008 00:05:22 »
The original concept of the neutron star was created considerably before the quark model of baryons was established.  The actual structure of protons neutrons and quarks in conventional atomic nuclei is far from completely understood and shows interesting periodic structures. There is a sort of blending between protons neutrons and mesons that holds everything strongly together in spite of the strong electromagnetic positive charge.  To turn a proton and an electron into a neutron requires energy and the emission of a neutrino via the weak interaction.  It seems likely that this will happen because it is suggested that the spectacular blast of neutrinos is what blows away a large part of the mass in the supernova that forms the neutron star but the central pressure and temperature of such stars may be that the difference between a neutron star and a quark star is very small.
« Last Edit: 27/09/2008 00:07:18 by Soul Surfer »
 

Offline DoctorBeaver

  • Naked Science Forum GOD!
  • *******
  • Posts: 12656
  • Thanked: 3 times
  • A stitch in time would have confused Einstein.
    • View Profile
Where have a neutron star's protons gone?
« Reply #7 on: 27/09/2008 08:16:20 »
Ian - thank you for clarifying that.
 

The Naked Scientists Forum

Where have a neutron star's protons gone?
« Reply #7 on: 27/09/2008 08:16:20 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums