Proceedings of the International Astronomical Union

Contributed Papers

Do young Suns undergo magnetic reversals?

Stephen C. Marsdena1, Sandra V. Jeffersa2, Jean-Francois Donatia3, Matthew W. Mengela4, Ian A. Waitea4 and Brad D. Cartera4

a1 Anglo-Australian Observatory, P.O. Box 296, Epping, NSW 1710, Australia email:

a2 Sterrekundig Instituut, Universiteit Utrecht, P.O. Box 80000, NL-3508 TA Utrecht, The Netherlands email:

a3 Laboratoire d'Astrophysique de Toulouse-Tarbes, Observatoire Midi-Pyrénées, 14 avenue Edouard Belin, F-31400 Toulouse, France email:

a4 Faculty of Sciences, University of Southern Queensland, Toowoomba 4350, Australia email:,,


A key part of the modern-day regenerative solar magnetic dynamo is the reversal of the Sun's global magnetic field every eleven years. However, recent theoretical models indicate that young-rapidly rotating Sun-like stars may not always undergo full magnetic reversals, but instead may sometimes undergo “attempted” reversals where the magnetic field declines in strength only to return with the same polarity. Using the technique of Zeeman Doppler imaging we have mapped the magnetic field topology of a small sample of young Sun-like stars at multiple epochs, and present tentative evidence of an “attempted” magnetic field reversal on one of our stars.


  • stars: late-type;
  • stars: imaging;
  • stars: magnetic fields