Pay results fee

Sorry, you have not enough credits to pay results fee.

Calculate the shapes of neutron star cores

Launcher poly Australia
Status Vaulted: Jul 11, 2013 04:39


gravitation ; gravity star rotation neutron stars pulsars


Neutron stars and pulsars are believed largely made up of very densely-packed, spinning cores of neutrons. Calculations are wanted for the shapes of these spinning cores.

The default assumption is that such stars are spherical, but in view of the forces involved, this assumption is unlikely. Because of the mass concentration in these cores, gravitational forces are very high, but because of their rapid rates of spin, centrifugal (centripetal) forces are also very high.

In the attached sketch 'Neutron Core.jpeg', some possibilities are shown. Even in the relatively slowly-rotating Earth, this rotation is enough to swell it out at the equator into an oblate spheroid (B). The interplay of gravitation and centrifugal forces in star cores might lead to a bobbin shape (D), a spindle shape (E), a discoid (C), a torus, or a hollow rotating cylinder, or something else.

According to, a typical neutron star has a mass between about 1.4 and 3.2 solar masses (with a calculated radius of about 12 km if spherical), and rotation periods from about 1.4 ms to 30 seconds.

Shape calculations are wanted for this range of masses and rotation periods. Distorting effects of magnetic fields, relativistic influences, etc, may be noted but ignored in calculations.

Zomb Results

Results for this zomb have been placed in the vault.

You can access it for free.

Attached is a first-class evaluation by Darin Ragozzine of how the enormous densities and ultra-rapid rotation rates of NEUTRON STARS affect their shapes -- even at the known extremes of these values, calculations indicate that such stars distort from spherical only by swelling at their equators (oblate spheroids).

These results are placed, as is, in the Zombal Vault for public use and benefit. Some editorial changes and corrections, not affecting the results, may be applied later.

Poly, 2013 Jul 11

Comments for results

No comments yet.


Zombal does not in anyway guarantee the quality or correctness of the vaulted results. The results have been compiled by members on the site and have not been reviewed by a third party.

However, we encourage members to comment on vaulted work to improve its accuracy. If you're able to provide suggestions for improvement and to point out errors, you may be presented with the opportunity for paid follow-up work.