  We investigate the thermal emission from magnetic neutron star surfaces in
which the cohesive effects of the magnetic field have produced the condensation
of the atmosphere and the external layers. This may happen for sufficiently
cool atmospheres with moderately intense magnetic fields. The thermal emission
from an isothermal bare surface of a neutron star shows no remarkable spectral
features, but it is significantly depressed at energies below some threshold
energy. However, since the thermal conductivity is very different in the normal
and parallel directions to the magnetic field lines, the presence of the
magnetic field is expected to produce a highly anisotropic temperature
distribution, depending on the magnetic field geometry. In this case, the
observed flux of such an object looks very similar to a BB spectrum, but
depressed in a nearly constant factor at all energies. This results in a
systematic underestimation of the area of the emitter (and therefore its size)
by a factor 5-10 (2-3).
