# What is the fastest spinning rotation of a Neutron star?

What is the fastest spinning rotation of a Neutron star? I have heard that Neutron stars have a specially fast spinning rotation. What is the fastest?

As it turns out, the fastest spinning neutron star found yet is a pulsar 18000 light years away in the constelation of Sagittarius which scientist catalogued as PSR J1748-2446ad. Pulsars are neutron stars that rotate, are highly magnetic and emit a strong perpendicular beam of electromagnetic radiation.

This pulsar's speed is such that:

At its equator it is spinning at approximately 24% of the speed of light, or over 70,000 km per second.

PSR J1748-2446ad rotates a little over 700 times a second, and scientists have this to say on the theoretical limits of the rotation speed of a pulsar (from here):

Current theories of neutron star structure and evolution predict that pulsars would break apart if they spun at a rate of ~1500 rotations per second or more, and that at a rate of above about 1000 rotations per second they would lose energy by gravitational radiation faster than the accretion process would speed them up.

The fastest celestial body we know so far is neutron star XTE J1739-285. It rotates 1122 times per second. Source: https://arxiv.org/abs/0712.4310?fbclid=IwAR2g9RYhybbBlxxzKOfquBa9C33H8mMwuZ_mHZbm1RbcsetrxO3vbvXq7gA

• Chakrabarty (2008) reports that the measurement of the sub-millisecond spin is marginal. Furthermore Drago et al. (2008) suggest that such an object would have to be a quark star or a hybrid quark-hadron star. – antispinwards Jan 28 at 20:51