Henneberg surface

In differential geometry, the Henneberg surface is a non-orientable minimal surface[1] named after Lebrecht Henneberg.

It has parametric equation and can be expressed as an order-15 algebraic surface.

[2] It can be viewed as an immersion of a punctured projective plane.

[3] Up until 1981 it was the only known non-orientable minimal surface.

[4] The surface contains a semicubical parabola ("Neile's parabola") and can be derived from solving the corresponding Björling problem.