  We report on the discovery of a mid-infrared source at a projected distance
of only 1200 AU from the O9.5 V star sigma Orionis. The spatially resolved,
fan-shaped morphology and the presence of an ionization front, as well as
evidence in the spectrum for processed dust grains, all suggest that it is a
proto-planetary disk being dispersed by the intense ultraviolet radiation from
sigma Orionis. We compute the mass budget and the photo-evaporation timescale,
and discuss the possible nature of this remarkable object.
