Neutron Stars Partially Dissected

mmol_6453 writes "An article at ScienceDaily details and explains observations that offer the first proof that what we consider neutron stars really are neutron superfluids. The original press release can be found here."

Comments

super fluids

[Anonymous Coward]

I would imagine at those super pressures found in a neutron star that our ways of defining states of matter would be of no relative importence. In the soup that is a neutron star, nuclear forces would dissasemble the parts of an atom. Now as we all know, there are 3 states of matter, solid, liquid, and gaseous, but a lot of people don't know about about a forth or even beyond. When one heats up a gas to super temperatures (like that found in a neutron star) the atoms will no longer be bound by their forces within them and neutrons will fly from protons in the nucleus, while the electrons would also start acting strangly. If we up the temp even more, the subatomic particles will start breaking down into their quarks and neutrinos. I am not sure what that state of matter is called, but that can happen in a neutron star. (just for fun, if you keep on heating the quarks and such, you would eventually rip a hole in space/time and I would really recomend leaving the room where you are doing this :)

Now my question is, this slush of various subatomic particles in the star: can you call it liquid? Another question is if you were to disect a neutron star, the subatomic particles would quickly reassemble themselves and you would be left with Hydrogen, wouldn't that leave you with almost no insite to a neutron? I could see how exciting this would be in an attempt to explain the seconds after the big bang, but just to explain superfluids?

bah..

forgot plasma

[wotevah]

As we all know, there are actually four states of matter: solid, liquid, gaseous and plasma.

Re:forgot plasma

[The Red Rooster]

There are actually several more:
solid
liquid
gas
plasma
AND
Bose-Einst ien Condensate
Quark somethingorother
superfluids

BEC's are ultra-cold bodies of matter where all atoms in the conglomerate 'march' to the same drum. In effect, each atom behaves not just exactly the same as all other atoms, but as if the whole she-bang were one single atom.

With the Quarks, inside super-hot, super-dense areas, quarks free themselves, something not normally allowed. The quarks end up shielding themselves from each other so that they cannot recombine quite as easily. IOW, you can actually cool the cloud down just a bit.

Superfluids are states not unlike BEC's wherein all sorts of strange things happen. Helium is the famous example. You can get superfluidic helium to flow uphill in the right conditions.

Re:Cool stuff

[Spock the Baptist]

Thought that I'd throw out a few links on the subject of quark stars. Here's a few useful, and informative links:

http://www.aip.org/enews/physnews/2002/split/585 -1 .html
http://itss.raytheon.com/cafe/qadir/q1401.h tml
http://slashdot.org/science/02/04/10/1840222. shtml ?tid=160
http://news.bbc.co.uk/1/hi/sci/tech/1922 574.stm
http://www.fi.uib.no/~nyiri/thesis.html

Please back up your assertions!

[Scott Carnahan]

yet within this small region may be over 10 solar masses of material.

Had you read the article, you would have seen that neutron stars are thought to contain the mass of about 1.4 suns. Barring certain speculative theories of exotic matter, no cold (i.e., not undergoing fusion) stellar configuration can have a mass greater than 5 suns. See, for example, Misner, Thorne, Wheeler, page 627.

The result is a gravitational field at the surface of a neutron star about 70 trillion times stronger than that on Earth.

Given that neutron stars have mass about 500,000 times that of the earth, and radius about 1/400 earth radius, one can use the Newtonian inverse-square law approximation to get a factor of about 80 billion, which is considerably less than your figure. Where did you get these numbers?

Its core consists mainly of densely-packed neutrons, with a sprinkling of protons and typically 3 times as many electrons as protons, in a liquid-like state known as neutronisticis.

Do you have a reference for this? Most models of neutron stars treat the core as a degenerate Fermi gas, and as another poster noted, your star seems to have a net negative charge. Where did the protons go? Also, this is the first time I've encountered the word "neutronisticis". A Google search turns up nothing but this very post.

As a neutron star cools and grows, strains develop in the crust so that it buckles, causing starquakes equal to 1000 on the richter scale.

Starquakes are thought to be possible, but if our time frame is more than a few seconds after formation, the cause is probably not due to thermal stresses. This is because the thermal contribution to pressure and density is negligible as long as the temperature of a neutron star is below the Fermi energy of matter at nuclear density (about 30MeV, or 3*10^11 K - see MTW page 599, referenced above), and neutrino radiation brings the temperature well below this level very rapidly.

The Richter scale is logarithmic, based at 105 Joules for a degree 0 quake (reference), and growing by a factor of 1000 for every two degrees. A quake registering 1000 would have to release 1.05*10^1502 Joules, which is much more than the mass-energy contained in the observable universe. Indeed, it is quite impossible for any stellar-scale phenomenon to register more than 40 on the Richter scale, simply because stars don't have enough mass to release that kind of energy.