Asymptotically euclidean manifolds and twister spinors

Based on the Berger-Simons holonomy classification, we characterize all Riemannian spin manifolds carrying a twister spinor with at least one zero. In particular, the dimension n of the manifold is either even or n = 7, Outside the set of zeros of the twister spinor the metric is conformal to either a flat metric or a Ricci flat and locally irreducible metric.