Here is a passage from Sandia's web site, explaining about their "z machine", an apparatus developed to study "z pinch" phenomena in plasmas:
Keep in mind this power output is generated in a fraction of a second, by an electric discharge through a conductor (hand-built matrix of wires). A sustained current would produce this effect in a sustained fashion. A star is the focus of a "z pinch" in a birkeland current, planets are formed by similar "z pinches", that's why they're all spherical, stars, planets, moons, because they all essentially slag from an electric arc, just like the spherical slag produced when an arc from an arc welder impinges on a surface. And the math is very solid on this, using the known properties and behaviors of electromagnetic forces, not appeals to "unobservable" stuff or imaginary processes that can't be reproduced in the lab.