The nature of the recent extreme outburst of the Herbig Be/FU Orionis binary Z Canis Majoris T. Szeifert, S. Hubrig, M. Schöller, O. Schütz, B. Stelzer and Z. Mikulášek A&A, 509 (2010) L7 Published online: 19 January 2010 DOI: 10.1051/0004-6361/200913704