Since neutron stars are extremely rapidly rotating, would there be an interesting effect of the coriolis force on the surface?
$\begingroup$
$\endgroup$
1
-
$\begingroup$ It might matter more in the interior, since neutronium is often a superfluid (things are a bit complicated since there is an admixture of protons and electrons, and possibly a QCD core, each with their own superfluidity properties). Rotating superfluids get vortex lines holding the angular momentum. Now, if there is some flow of the fluid due to thermal instabilities or other things, the Coriolis effects are likely to really complicate the picture. $\endgroup$– Anders SandbergCommented May 5, 2022 at 23:36
Add a comment
|
1 Answer
$\begingroup$
$\endgroup$
2
The acceleration due to the Coriolis (pseudo)force is given by $-2 \left ( \mathbf{\Omega} \times \mathbf{v} \right )$. A rapidly rotating pulsar can spin at $40000$ RPM 1. However, gravity at a neutron star's surface is approximately $2 \times 10^{12}$ m.s$^{-2}$. Thus, for Coriolis force to become comparable with gravitational acceleration the formula suggests $v \sim 2 \times 10^8$ m.s$^{-1}$ is required (comparable with the speed of light). The Coriolis effect will become apparent at lower velocities, of course, though this hand-waving argument suggests it will be many orders of magnitude smaller than other forces present.
-
$\begingroup$ Aren't the gravitational force and the coriolis pseudoforce tangential? Why would it need to be that different? $\endgroup$ Commented May 6, 2022 at 17:14
-
$\begingroup$ @bananenheld As the formula for Coriolis acceleration implies, direction is determined by the velocity relative to axis of rotation. In general this will have a component tangential and a component normal to gravitational acceleration. $\endgroup$– FTTCommented May 7, 2022 at 23:25