The young, wide and very low mass visual binary Lambda Orionis 167

Aims. We look for wide, faint companions around members of the 5 Myr Lambda Orionis open cluster. Methods. We used optical, near-infrared, and Spitzer/IRAC photometry. Results. We report the discovery of a very wide very low mass visual binary, LOri167, formed by a brown dwarf and a planetary-mass candidate located at 5 arcsec, which seems to belong to the cluster. We derive T-eff of 2125 and 1750 K. If they are members, comparisons with theoretical models indicate masses of 17(-2)(+3) and 8(-1)(+5) M-jup, with a projected separation of 2000 AU. Conclusions. Such a binary system would be difficult to explain in most models, particularly those where substellar objects form in the disks surrounding higher mass stars.