Darwin-de Sitter Spheroid

A Surface of Revolution of the form

$$r(\phi)=a[1-e\sin^2\phi-({\textstyle{3\over 8}}e^2+k)\sin^2(2\phi)],$$

where $k$ is a second-order correction to the figure of a rotating fluid.

See also Oblate Spheroid, Prolate Spheroid, Spheroid

References

Zharkov, V. N. and Trubitsyn, V. P. Physics of Planetary Interiors. Tucson, AZ: Pachart Publ. House, 1978.