The evolution of Ap stars
  The many peculiarities of Ap stars (not only chemical ones, but also magnetic field and slow rotation) may vary during the main-sequence evolution of these stars. We review here briefly the evidences found in the last thirty years for such evolution, with an emphasis on the more recent research. The position in the HR diagram of low mass Ap stars with a significant surface magnetic field (as measured by us) is reviewed as well. 
P. North (1), J. Babel (2), D. Erspamer (3) ((1) Ecole Polytechnique   F\'ed\'erale de Lausanne (EPFL), Switzerland, (2) Neu...