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View Full Version : Fluidic properties of Neutron stars and Pulsars.



iniaes
2009-Dec-09, 05:26 PM
If I may I want to throw an other question in, are neutron stars and pulsars solid? ore are they still fluidic plasma? do they oblate?

korjik
2009-Dec-09, 07:17 PM
The concept of solid and fluid is a little off at densities like neutron stars. Technically, it is a solid crust, then it turns into a neutron fluid as the density goes up.

grant hutchison
2009-Dec-09, 07:34 PM
A neutron star's surface gravity is so high it has to spin very, very quickly in order to become oblate. But the millisecond pulsars are predicted to be strongly oblate, and IIRC the effect of this oblateness has been detected in binary pulsars, because it causes spin axis precession.

Edit: Here (http://www.bautforum.com/space-astronomy-questions-answers/80772-oblate-neutron-stars.html) is a thread about oblate neutron stars. If you skip past the bit early in the thread where I misplace a decimal point, you'll find some good references to the oblateness of fast pulsars.

Grant Hutchison

iniaes
2009-Dec-09, 07:39 PM
awesome stuff guys thanks for the replies :)

chornedsnorkack
2009-Dec-11, 04:23 PM
The concept of solid and fluid is a little off at densities like neutron stars. Technically, it is a solid crust, then it turns into a neutron fluid as the density goes up.

No, the concepts are still useful at any density. Solid has a nonzero shear strength (even though it is negligibly small compared to pressure) and it can transmit shear waves (at a speed which is slow compared to density wave speeds). And long range order (within single crystals).