Free Astronomy Magazine July-August 2014

STELLAR EVOLUTION 4 JULY-AUGUST 2014 There are neutron stars which magnetic field is so incredibly strong that they form a category of their own, the magnetars. The partly mysterious origin of these extraordinary objects has now been revealed, thanks to the discovery of an anoma- lous runaway star that thousands of years ago was paired with the progenitor of a magnetar discovered in the Wd1 cluster. Double stars of magnetar R endering of the magnetar J1647-45 inside the open cluster Wd1. Clearly shown are the force lines of the powerful mag- netic field. [ESO/L. Calçada]