Neutron star rotation

[bergyo]

How/why does a neutron star spin so fast and why doesn't it come apart?

 

[Helio]

Every star rotates. The cloud that a star forms from has some, even if small, motion before that portion of the cloud collapses into a star. Think of the ice skater analogy where she pulls her arms in to spin faster, which is a conservation of angular momentum law. But what if she spun slowly yet her arms were several trillion miles long and then she pulled them in, imagine how fast she would be spinning.

So, when a star goes into convulsions with the tiny but extremely dense neutron star result, then it would necessarily have to spin very fast.

But since the neutron star is both massive and small the gravity at its surface is enormous and very little can come lose from it.