BREAKING NEWS
Epispiral

## Summary

The epispiral is a plane curve with polar equation

An epispiral with equation r(θ)=2sec(2θ)
${\displaystyle \ r=a\sec {n\theta }}$.

There are n sections if n is odd and 2n if n is even.

It is the polar or circle inversion of the rose curve.

In astronomy the epispiral is related to the equations that explain planets' orbits.