The sigma orientation is an H _∞ map

In an earlier paper, the authors constructed a natural map, called the sigma orientation, from the Thorn spectrum MU(6) to any elliptic spectrum. MU(6) is an H _∞ ring spectrum, and in this paper we show that if (E, C, t) is the elliptic spectrum associated to the universal deformation of a supersingular elliptic curve over a perfect field of characteristic p > 0, then the sigma orientation is a map of H _∞ ring spectra.