K. Galsgaard (1), V. Archontis (2), F. Moreno-Insertis (3 and 4) and
  A. W. Hood (2) ((1) Niels Bohr Institute, Copenhagen, Denmark, (2) School of
  Mathematics and Statistics, University of St Andrews, UK, (3) Instituto de
  Astrofisica de Canarias (IAC), La Laguna, Spain, (4) Department of
  Astrophysics, Faculty of Physics, Universidad de La Laguna, Spain)