In this Brief Report we discuss an effect of accelerated mirrors which
has remained hitherto unnoticed: the formation of a field condensate
near its surface for massive fields. From the viewpoint of an observer
attached to the mirror, this effect is rather natural because a gravi
tational field is felt there. The novelty here is that since the effec
t is not observer dependent even inertial observers will detect the fo
rmation of this condensate. We further show that this localization is
in agreement with Bekenstein's entropy bound.