English: It's a standard image of Julia set of the rational function e2πitz2(z−4)/(1−4z) with t=.6151732... chosen so that the rotation number is (√5−1)/2, which possess a Herman ring.
Here is an example of a rational function which possesses a Herman ring
where such that the rotation number of ƒ on the
unit circle is .
The picture shown on the right is the Julia set of ƒ: the curves in the white annulus are the orbits of some points under the iterations of ƒ while the dashed line denotes the unit circle.
Herman ring of period 1 and rotation number the golden mean.
Compare with :
image of the same Julia set, with src code but worse quality
{{Information |Description={{en|1=It's a standard image of Julia set of a rational function which possess a Herman ring.}} |Source={{own}} |Author=Yangfei math |Date=2010-06-06 |Permission= |other_versions= }}