In px from the center.
OptionallabelIts name along the radius, wrapped to the ring's depth; absent where it does not fit.
Its depth in the hierarchy: 0 for a top-level category.
The point a leaf is, by its index in the series; null for a category with points under it.
In degrees clockwise from 12 o'clock.
Its value: its point's, or the sum of the points under it.
A segment of a sunburst: one category of the hierarchy, or one point, as a ring sector.