Hidden bipolarity in red supergiant winds
  Many observations of late-type M stars show large near-spherical circumstellar envelopes, yet planetary nebulae and supernova remnants are frequently axisymmetric. We present VLBI and MERLIN observations of masers around the red supergiant S Per which show varying degrees of axisymmetry and a dynamically significant magnetic field. There is no evidence for rotation here or in most similar objects. We examine possible origins of the magnetic field. 
A.M.S. Richards (1), M.R.W. Masheder (2), H.J. van Langevelde (3),   R.J. Cohen (1), M.D. Gray (4), J.A. Yates (5), P.J. Dia...