I was working on my maths assignment about a question on stramfunctions. I worked out the streamfunction in axisymmetric spherical coords. I am asked to find the shape of the streamlines when the streamfunction is zero.

I equated the streamfunction to zero and I got r^(3) = a^(3) where a is simply a constant.

How do the streamlines look? I need to draw them on a graph. What kind of graph is it?