  Recent ALMA images of HL Tau show gaps in the dusty disk that may be caused
by planetary bodies. Given the young age of this system, if confirmed, this
finding would imply very short timescales for planet formation, probably in a
gravitationally unstable disk. To test this scenario, we searched for young
planets by means of direct imaging in the L'-band using the Large Binocular
Telescope Interferometer mid-infrared camera. At the location of two prominent
dips in the dust distribution at ~70AU (~0.5") from the central star we reach a
contrast level of ~7.5mag. We did not detect any point source at the location
of the rings. Using evolutionary models we derive upper limits of ~10-15MJup at
<=0.5-1Ma for the possible planets. With these sensitivity limits we should
have been able to detect companions sufficiently massive to open full gaps in
the disk. The structures detected at mm-wavelengths could be gaps in the
distributions of large grains on the disk midplane, caused by planets not
massive enough to fully open gaps. Future ALMA observations of the molecular
gas density profile and kinematics as well as higher contrast infrared
observations may be able to provide a definitive answer.
