Re:why not regular? somebody built it?? (Score 1)

so these types of structures aren't rare - and we have no explanation yet.

1 possibility; more detailed models of a star's magnetic field late in development will reveal spontaneous 'knotting' of field lines etc... Another possibility - engineered magnetic turbulence to make it easier for some extraterrestrial civilization to mine volatile materials (instead of being going in all directions the expelled plasma flows out the poles - how convenient)

didn't Dyson propose looking for the infrared signature of stars around which a shell had been built to capture their radiation output? Not found, maybe looking for the wrong type of structures.... dream on!