A substellar-mass object in orbit at about 300 astronomical units (AU) from
the young low-mass star G196-3 was detected by direct imaging. Optical and
infrared photometry and low- and intermediate-resolution spectroscopy of the
faint companion, hereafter referred to as G196-3B, confirms its cool atmosphere
and allows its mass to be estimated at 25^{+15}_{-10} Jupiter masses. The
separation between both objects and their mass ratio suggest the fragmentation
of a collapsing cloud as the most likely origin for G196-3B, but alternatively
it could have originated from a proto-planetary disc which has been dissipated.
Whatever the formation process was, the young age of the primary star (about
100 Myr) demonstrates that substellar companions can form in short time scales.Comment: Published in Science (13 Nov). One color figur